Porphyrin Arch-Tapes: Synthesis, Contorted Structures, and Full

Article pubs.acs.org/JACS

Porphyrin Arch-Tapes: Synthesis, Contorted Structures, and Full Conjugation Norihito Fukui,† Taeyeon Kim,‡ Dongho Kim,*,‡ and Atsuhiro Osuka*,† †

Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan Spectroscopy Laboratory for Functional π-electronic Systems and Department of Chemistry, Yonsei University, Seoul 03722, Korea

‡

S Supporting Information *

ABSTRACT: Porphyrin tapes possessing meso−meso β−β β−β triple direct linkages have been targets of extensive studies because of their fully conjugated characteristic πelectronic networks. In this paper, we report porphyrin archtapes that bear additional carbonyl group(s) or methylene group(s) inserted between one of the β−β linkage(s) of the porphyrin tapes. The carbonyl-inserted porphyrin arch-tapes were efficiently synthesized by double fusion reactions of β-toβ carbonyl-bridged porphyrin oligomers with DDQ and Sc(OTf)3, and were converted to the methylene-bridged porphyrin arch-tapes via Luche reduction with NaBH4 and CeCl3 followed by ionic hydrogenation with HBF4·OEt2 and BH3·NEt3. While the conventional porphyrin tapes display rigid and planar structures and low solubilities, these porphyrin arch-tapes show remarkably contorted structures, flexible conformations, and improved solubilities because of the presence of the incorporated seven-membered ring(s). Interestingly, the methyleneinserted arch-tapes exhibited conjugative electronic interactions that were comparable to those of porphyrin tapes probably owing to through-space interaction in the contorted conformations. The carbonyl-inserted arch-tapes displayed distinctly larger conjugative interactions owing to an active involvement of the carbonyl group(s) in the electronic conjugation. A similar trend was observed in the nonlinear optical properties, as evidenced by their two-photon absorption cross sections. Furthermore, as a benefit of the contorted structures, these porphyrin arch-tapes can catch C60 fullerene effectively. Naturally, the electron-rich methylene-bridged arch-tapes exhibited larger association constants than the electron-deficient carbonyl-bridged arch-tapes. Among these arch-tapes, a methylene-bridged syn-Ni(II) porphyrin trimer recorded the largest association constant of (1.5 ± 0.4) × 107 M−1 in toluene at 25 °C.

■

meso-substituents7 and/or axially coordinating groups8 are necessary for their manipulations. In recent years, curved π-conjugated molecules have attracted considerable interest because they exhibit characteristic properties such as flexible conformational change, high solubility, and effective binding of fullerenes, which are hard to observe in the conventional planar polycyclic aromatic hydrocarbons (PAHs).9 General synthetic strategy to cause molecular curvature is to incorporate five-membered rings in usual hexagonal arrays of PAH cores. Represented examples along this strategy are fullerene, corannulene 2,10 sumanene 3,11 and end-caps of carbon nanotubes (Scheme 1).12 As demonstrated in these examples, the incorporated five-membered ring caused a positive Gaussian curvature. Another strategy is to incorporate seven-membered rings into a hexagonal array, which is expected to induce a negative Gaussian curvature. Although the strategy of seven-membered ring incorporation has remained rare, elegant examples have been reported, including [7]circulene 4,13 curved hexabenzocoronene ana-

INTRODUCTION

Porphyrins having extended π-electronic networks are promising scaffolds to create a wide range of functional materials such as high performance organic conducting soft matters, nearinfrared dyes, and nonlinear optical materials.1 As the representative of such molecules, meso−meso β−β β−β triply linked porphyrin arrays 1, namely porphyrin tapes, have attracted considerable attention in light of the fully conjugated π-networks (Scheme 1).2 In the porphyrin tapes, the porphyrin segments are connected by triple linkages to form two fused six-membered rings, which causes fairly coplanar arrangements and full conjugation. The highly π-conjugated nature of the porphyrin tapes gives rise to various prominent attributes such as extremely red-shifted absorption bands, extraordinarily narrow HOMO−LUMO gaps,2 large two-photon absorption cross sections,3 multicharge storage capabilities,2 near-IR reverse saturable absorption,4 metal surface patterning,5 and high single-molecule conductances.6 While these attributes are quite promising, their rigidly held planar conformations entail serious poor solubility problems, owing to the severe aggregation. Therefore, in many case, introduction of bulky © 2017 American Chemical Society

Received: May 24, 2017 Published: June 16, 2017 9075

DOI: 10.1021/jacs.7b05332 J. Am. Chem. Soc. 2017, 139, 9075−9088

Article

Journal of the American Chemical Society Scheme 1. Structures of Porphyrin Tape 1, Corannulene 2, Sumanene 3, [7]Circulene 4, Curved Hexabenzocoronene Analogue 5, and Grossly Warped Nanographene 6

Scheme 2. Synthesis of Carbonyl-Inserted Porphyrin ArchTape Dimers 11a

logue 5,14 grossly warped nanographene 6,15 and so on (Scheme 1).16 These results encouraged us to envision the exploration of contorted porphyrin tapes by incorporation of a seven-membered ring in the bridging unit of porphyrin tapes. In this paper, we report the synthesis of porphyrin arch-tapes, in which a carbonyl or a methylene group(s) is inserted between one of the β-to-β direct linkages of porphyrin tapes. Due to the incorporated seven-membered ring(s), these porphyrin arch-tapes exhibited remarkably contorted structures and flexible conformations. As a benefit of these attributes, they displayed much improved solubility and effective C60-binding behaviors. Importantly, the conjugative electronic interactions of methylene-inserted arch-tapes were comparable to those of porphyrin tapes due to through-space interaction in the contorted conformations. Moreover, those of carbonyl-inserted arch-tapes became more effective owing to active involvement of the carbonyl group(s) in the electronic conjugation.

a DDQ = 2,3-dichloro-5,6-dicyano-p-benzoquinone, TFA = trifluoroacetic acid, Ar = 3,5-di-tert-butylphenyl.

and halogen-magnesium exchange reaction17 followed by addition of DMF. Unfortunately, these isomers were inseparable by silica-gel column chromatography. Therefore, the mixture was directly employed in a reaction with an in situ generated porphyrin-Grignard reagent, and the following oxidation with DDQ provided β-to-β carbonyl-bridged porphyrin trimers 14-syn and 14-anti in 45% and 44% yields, respectively. These isomers were separated by silica-gel column chromatography as pure coumpounds. Finally, oxidative fusion reactions of 14-syn and 14-anti with DDQ and Sc(OTf)3 gave carbonyl-inserted arch-tape trimers 15-syn and 15-anti in 75% and 49% yields, respectively. It is worth noting that, although we also attempted to synthesize the corresponding Zncomplexes of carbonyl-inserted arch-tape trimers, demetalation of precursors 14-syn and 14-anti did not proceed cleanly, giving a complicated mixture of partially demetalated products. Synthesis of Methylene-Inserted Porphyrin ArchTapes. We attempted reduction of the carbonyl-inserted porphyrin arch-tapes to the methylene-inserted arch-tapes (Scheme 4). While reduction of 11Ni with NaBH4 gave a complicated mixture, 11Ni was cleanly reduced by Luche reduction with NaBH4 and CeCl3 to give alcohol 16 almost quantitatively. The reduced dimer 16 was slightly unstable under aerobic conditions. Therefore, it was isolated quickly by recrystallization without silica-gel column chromatography. The subsequent ionic hydrogenation reaction21 of 16 with HBF4· OEt2 and BH3·NEt3 afforded methylene-inserted dimer 17 in 88% yield.22 Similarly, trimer 15-syn was reduced under the Luche reduction conditions to the corresponding alcohol almost quantitatively as a mixture of its stereoisomers, which were directly subjected to the ionic hydrogenation reaction to afford methylene-inserted trimer 18-syn in a two-step yield of

■

RESULTS AND DISCUSSION Synthesis of Carbonyl-Inserted Porphyrin Arch-Tapes. Carbonyl-inserted porphyrin arch-tape dimers 11Ni and 11Zn were synthesized as depicted in Scheme 2. A halogenmagnesium exchange reaction17 of β-iodoporphyrin 718 with iPrMgCl·LiCl followed by addition of β-formylporphyrin 817 afforded di(β-porphyrinyl)methanol 9. Because the alcohol 9 was unstable and gradually oxidized under ambient conditions, the crude mixture was directly oxidized with 2,3-dichloro-5,6dicyano-p-benzoquinone (DDQ) to provide the corresponding diporphyrinylketone 10Ni in a two-step yield of 95%. To our delight, an intramolecular oxidative double fusion reaction of 10Ni proceeded smoothly upon treatment with DDQ and Sc(OTf)3,2 giving the desired carbonyl-inserted arch-tape dimer 11Ni in 87% yield. Ni(II) porphyrin 10Ni was converted to Zn(II) porphyrin 10Zn by demetalation and the subsequent insertion of zinc, which was also oxidized with DDQ and Sc(OTf)3 to give carbonyl-inserted arch-tape dimer Zn(II)complex 11Zn in 86% yield. In the next step, we attempted to synthesize carbonylinserted arch-tape trimers 15-syn and 15-anti (Scheme 3). 5,15-Bis(3,5-di-tert-butylphenyl)porphyrinato nickel(II) 12 was transformed into β,β′-diformylporphyrin 13 as a mixture of the syn- and anti-isomers (13-syn and 13-anti)19 via sequential transformations of β-selective direct borylation,20 iodination,18 9076


Article

Journal of the American Chemical Society Scheme 3. Synthesis of Carbonyl-Inserted Porphyrin Arch-Tape Trimers 15-syn and 15-antia

a

A mixture of 13-syn and 13-anti (1.00:0.92). cod = 1,5-cyclooctadiene, dtbpy = 4,4′-di-tert-butyl-2,2′-bipyridyl, MTBE = methyl tert-butyl ether, NIS = N-iodosuccinimide, DMF = N,N-dimethylformamide, DDQ = 2,3-dichloro-5,6-dicyano-p-benzoquinone, Ar = 3,5-di-tert-butylphenyl.

crystal structural analyses (Figure 1, Figures S48−52). As shown in Figure 1a,b, carbonyl-inserted dimer 11Ni formed an arch-shaped contorted structure, in which both the porphyrin units took ruffled conformations. To quantify the degree of the curvature of 11Ni, we set a central angle θ of the arc formed by the π-conjugated surface as defined in Figure 1i (The detailed definition is described in SI, chapter 7). Accordingly, the θ value of 11Ni was evaluated to be 84°, which means that its πconjugated surface is contorted like a quadrant. On the other hand, methylene-inserted analogue 17 exhibited a more contorted structure with a θ value of 97°, in which the methylene group was more protruding from the π-surface than the carbonyl group of 11Ni (Figure 1c,d). The increased θ value of 17 will be attributed to the relatively longer C−C bond lengths between the methylene group and the neighboring βpositions (1.479(7) and 1.493(6) Å) than those of 11Ni (1.464(5) and 1.457(4) Å). Trimers 15-syn and 15-anti displayed more contorted semicircular structures with θ values of 175° and 138°, respectively (Figure 1e−h). To elucidate origins of the arch-shaped structures of 11Ni, 17, 15-syn, and 15-anti, density functional theory (DFT) calculations were conducted for their Ni(II)- and Zn(II)complexes along with meso−meso β−β β−β triply linked dimer 19 at the B3LYP/6-31G*(C,H,N,O) + LANL2DZ(Ni or Zn) level using Gaussian 09 package.23 The experimental and calculated θ values are summarized in Table 1. The observed θ values of 11Ni, 17, 15-syn, and 15-anti have been reasonably reproduced by the calculations with small differences (1−23°). These differences can be ascribed to packing forces in their solid states, because these compounds are conformationally flexible as described in studies on their arch-to-arch inversion behaviors (vide infra). In sharp contrast, the calculated θ value of porphyrin tape dimer 19 is 0°, indicating its perfect planarity. Therefore, the observed arch-shaped structures of 11Ni, 17, 15-

Scheme 4. Synthesis of Methylene-Inserted Arch-Tapes 11Ni, 15-syn, and 15-antia

a

Ar = 3,5-di-tert-butylphenyl.

29%. A similar transformation of 15-anti also furnished methylene-inserted trimer 18-anti in a two-step yield of 64%. X-ray Crystallography. Structures of 10Ni, 11Ni, 15-syn, 15-anti, and 17 have been unambiguously determined by X-ray 9077


Article

Journal of the American Chemical Society

Table 1. Experimental and Calculated θ Values of 11, 15-syn, 15-anti, 17, and 19 θ values 11 15-syn 15-anti 17 19

inner metal

exp

calcda

Ni Zn Ni Zn Ni Zn Ni Ni

84°  175°  138°  97° 

96° 58° 152° 83° 150° 97° 98° 0°

a DFT calculations were performed at the B3LYP/6-31G*(C,H,N,O) + LANL2DZ(Ni or Zn) level. tert-Butyl groups were replaced with hydrogen atoms to simplify the calculations.

and 15-anti along with that of porphyrin tape dimer 19 were measured by the following procedures. (1) A small amount of CH2Cl2 was added to the solids of each compound. (2) The resulting suspension was sonicated for 30 s and insoluble residue was removed by filtration. (3) The weight of the saturated solution (filtrate) was measured and then the weight of the solute was determined by isolation through recrystallization from CH2Cl2/MeOH. The solubilities S [g/100 g CH2Cl2] of 11Ni, 17, 15-syn, 15-anti, and 19 were determined to be 19.5, 15.9, 3.6, 3.8, and 2.5, respectively. The solubilities S of carbonyl-inserted and methylene-inserted arch-tape dimers 11Ni and 17 were eight and six times larger as compared with that of porphyrin tape dimer 19, respectively. Moreover, those of carbonyl-inserted arch-tape trimers 15-syn and 15-anti were larger than that of 19 although long porphyrin tapes containing more than three porphyrin units usually exhibit miserable solubilities.7,8 Indeed, although we attempted to synthesize porphyrin tape trimer 20Ni as a reference compound, our trials such as oxidative fusion of meso−meso linked trimer 21 and inner-metal exchange of the corresponding Zn(II)-complex 20Zn failed to give 20Ni, just producing an insoluble complicated mixture (Scheme 5). Therefore, we synthesized porphyrin tape trimer 22Ni which possessed bulky meso-substituents instead of 20Ni by an inner-metal exchange reaction of the corresponding Zn(II)-complex 22Zn.7a Optical Properties. The absorption spectra of carbonylinserted arch-tape dimer 11Ni, methylene-inserted arch-tape dimer 17, porphyrin tape dimer 19, and meso−meso β−β doubly linked dimer 232c in CH2Cl2 are shown in Figure 2. Doubly linked dimer 23 displayed a split Soret-band at 405 and 488 nm with a shoulder peak at 522 nm and Q-bands at 736 and 820 nm. Methylene-inserted dimer 17 exhibited a more split Soret-band at 404 and 555 nm, and red-shifted Q-bands at 762 and 846 nm, clearly indicating more effective electronic interaction between the porphyrin units as compared with that of 23. Dimeric porphyrin tape 19 showed a characteristically split Soret-band at 405 and 572 nm, and more red-shifted Qbands at 875 and 934 nm. Interestingly, carbonyl-inserted dimer 11Ni exhibited a split Soret-band at 412 and 575 nm and Q-bands at 843 and 960 nm, both of which are apparently more red-shifted than those of 19. DFT calculations of 11Ni, 17, 19, and 23 were performed at the B3LYP/6-31G*(C,H,N,O) + LANL2DZ(Ni) level using Gaussian 09 package (Figure 3). The calculated HOMO− LUMO gaps decrease in order of 23 > 17 > 19 > 11Ni in line with their optical HOMO−LUMO gaps. Our previous research

Figure 1. X-ray crystal structures of 11Ni, 17, 15-syn, and 15-anti. (a) Top view and (b) side view of 11Ni. (c) Top view and (d) side view of 17. (e) Top view and (f) side view of 15-syn. (g) Top view and (h) side view of 15-anti. Thermal ellipsoids are drawn at the 50% probability level for 11Ni, 17, and 15-anti, and 20% probability level for 15-syn. Solvent molecules, tert-butyl groups, and all hydrogen atoms are omitted for clarity (i) Definition of θ and structure of 19.

syn, and 15-anti can be clearly attributed to the embedded seven-membered rings. In addition, the optimized structures of the Zn(II)-complexes were relatively shallower with smaller θ values compared to those of Ni(II)-complexes (SI, Figure S65). It is widely known that Ni(II)-porphyrins can take a variety of nonplanar structures such as ruffled and saddle-like conformations owing to the relatively short N−Ni(II) distances.24 Therefore, such a conformational flexibility of the Ni(II)porphyrin cores should also play a key role to realize the highly contorted structures of 11Ni, 17, 15-syn, and 15-anti. Solubility. Curved π-compounds usually show increased solubilities due to suppressed intermolecular stacking interactions.9 “Practical” solubilities of arch-tapes 11Ni, 17, 15-syn, 9078


Article

Journal of the American Chemical Society Scheme 5. Structures of 20, 21, and 22a

a

Ar = 3,5-di-tert-butylphenyl.

Figure 3. (a) Energy diagrams of 11Ni, 17, 19, and 23. (b) Kohn− Sham orbital representations of the LUMOs (isovalue = 0.015). DFT calculations were performed at the B3LYP/6-31G*(C,H,N,O) + LANL2DZ(Ni) level. tert-Butyl groups were replaced with hydrogen atoms to simplify the calculations.

Figure 2. UV−vis−NIR absorption spectra of 11Ni (red), 17 (green), 19 (blue), and 23 (black) in CH2Cl2. λ = wavelength, ε = extinction coefficient.

These results suggest that the carbonyl group not only gives rise to the arch-shaped contortion, but also acts as a good πmediator to connect the β-positions. UV−vis−NIR absorption spectra of carbonyl-inserted trimers 15-syn and 15-anti, methylene-inserted trimers 18syn and 18-anti, and porphyrin tape trimer 22Ni are shown in Figure 4. Methylene-inserted arch-tape timers 18-syn and 18anti exhibited similar absorption spectra, namely a split Soretband at 405 and 589 nm and Q-bands at 954 and 1093 nm for 18-syn, and a split Soret-band at 402 and 590 nm and Q-bands at 958 and 1095 nm for 18-anti. Importantly, their optical HOMO−LUMO gaps are comparable to that of porphyrin tape trimer 22Ni, again suggesting effective through-space interactions caused by their contorted structures. Carbonyl-inserted arch-tape trimers 15-syn and 15-anti displayed more redshifted absorption spectra, namely a split Soret-band at 413 and 630 nm and Q-bands at 1085 and 1260 nm for 15-syn, and a split Soret-band at 411 and 617 nm and Q-bands at 1073 and 1254 nm for 15-anti, indicating effective conjugation mediated by the inserted carbonyl groups. The observed tendency of the optical HOMO−LUMO gaps is quite similar to that of the

on porphyrin tapes such as 19 revealed that bonding interactions between the β-positions significantly stabilized the LUMO levels.2d Indeed, the present calculations indicate that the HOMO−LUMO gaps mainly depend on degree of stabilization of the LUMOs. Namely, doubly linked dimer 23 exhibits the largest HOMO−LUMO gap, because it lacks one β-to-β linkage. In the case of methylene-inserted dimeric archtape 17, the two β-positions are formally deconjugated due to the presence of the methylene moiety, but the LUMO is considerably stabilized. It is worth noting that each porphyrin unit of 17 and 23 has similar distortion with mean plane deviations (MPDs)25 of 0.338 and 0.291 Å, respectively. Therefore, the conformational distortion will not attribute to the red-shifted absorption of 17.26 On the other hand, the Kohn−Sham orbital representation of the LUMO of 17 clearly indicates the presence of a through-space interaction,27 which is aided by its arch-shaped structure. Consequently, the HOMO− LUMO gap of 17 is close to that of dimeric tape 19. In the case of carbonyl-inserted dimer 11Ni, a π*-orbital of the inserted carbonyl group effectively mediates the β-to-β bonding interaction, resulting in the narrowest HOMO−LUMO gap. 9079


Article


were clearly smaller than that of meso−meso β−β doubly linked dimer 23 (1.56 eV), and comparable to that of dimeric porphyrin tape 19 (1.34 eV). These results again support the effective through-space interaction between the two adjacent βpositions separated by the bridging sp3-carbons. Carbonyl-inserted arch-tape trimers 15-syn and 15-anti showed nine reversible redox processes involving ten electrons, indicating their high multicharge storage abilities (Figure 6). Due to their effective π-conjugations, their electrochemical HOMO−LUMO gaps extremely decreased to be 0.87 and 0.85 eV, respectively. These values are clearly smaller than that of porphyrin tape trimer 22Ni (1.04 eV), supporting the enhanced conjugation by introduction of the carbonyl bridges. Methylene-inserted arch-tape trimers 18-syn and 18-anti displayed seven reversible redox processes with their ΔEHOMO−LUMO values of 1.04 and 0.98 eV, respectively. These electrochemical HOMO−LUMO gaps are close to that of 22Ni, again supporting the through-space interactions caused by their contorted structures. These electrochemical responses of trimers 15, 18, and 22Ni nicely accord with their observed UV−vis−NIR absorption spectra and theoretical calculations. Arch-to-Arch Inversion. The dynamics of curved compounds is of current interest. Corannulene exhibited rapid bowl-to-bowl inversion with a small activation barrier of 10.2 kcal/mol at −64 °C.29 On the other hand, sumanene showed a relatively higher energy barrier of 19.6 kcal/mol at 140 °C.11,30 Fortunately, methylene-inserted arch-tape dimer 17 possesses two distinguishable protons through the arch-to-arch inversion, which enabled us to determine the inversion barrier. Variable temperature 1H NMR spectra of 17 were recorded in toluened8 (Figure 5 and SI, Figure S78). A pair of doublets due to the methylene-bridge was clearly observed at −60 °C with an exchange constant Δν of 736 Hz. Upon increase of the temperature, they coalesced to show a singlet signal at 100 °C. Then, the coalescence temperature was found to be 30 °C, from which we calculated the arch-to-arch inversion barrier to be 13.3 kcal/mol at 30 °C.31 This value indicates that 17 can flexibly invert its structure at room temperature in solution. In a similar manner, the inversion barrier of methyleneinserted anti-trimer 18-anti was calculated to be 16.7 kcal/mol from its coalescence temperature of 110 °C and exchange constant of 551 Hz (SI, Figure S80). Interestingly, syn-trimer

Figure 4. UV−vis−NIR absorption spectra of 22Ni (blue), 18-syn (green, dashed), 18-anti (green, solid), 15-syn (red, dashed), and 15anti (red, solid) in CH2Cl2. λ = wavelength, ε = extinction coefficient.

corresponding dimers, which has been supported by the theoretical calculations (SI, Figure S54). Electrochemical Properties. Electrochemical properties of 10Ni, 11Ni, 15-syn, 15-anti, 16, 17, 18-syn, 18-anti, 19, and 22Ni were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) (SI, Figure S66−75). The obtained voltammograms along with the previously reported voltammogram of 2328 are summarized in Table 2. Di(β-porphyrinyl)ketone 10Ni displayed four slightly irreversible oxidation waves and two reversible reduction waves, giving the electrochemical HOMO−LUMO gap (ΔEHOMO−LUMO) of 2.16 eV. The low reversibility of the oxidation waves may be ascribed to electrochemical oxidative fusion. The corresponding fused product, carbonyl-inserted arch-tape dimer 11Ni, showed four reversible oxidation waves at 0.27, 0.61, 1.07, and 1.34 V, and two reversible reduction waves at −0.93 and −1.19 V with the remarkably decreased ΔEHOMO−LUMO value of 1.20 eV. Compared to the redox potentials of porphyrin tape dimer 19, those of 11Ni are positively shifted, which can be attributed to the electron-withdrawing carbonyl group. In addition, the ΔEHOMO−LUMO value of 11Ni is apparently smaller than that of 19 (1.34 eV) in accordance with their UV−vis−NIR absorption spectra and DFT calculations. Both hydroxymethylene- and methylene-inserted arch-tape dimers 16 and 17 showed four reversible oxidation waves and two reversible reduction waves with similar ΔEHOMO−LUMO values of 1.28 and 1.31 eV, respectively. These electrochemical HOMO−LUMO gaps

Table 2. Redox Potentials of 10Ni, 11Ni, 15-syn, 15-anti, 16, 17, 18-syn, 18-anti, 19, 22Ni, and 23a oxidation [V] 1/2

E 10Ni 11Ni 16 17 19 23d 15-syn 15-anti 18-syn 18-anti 22Ni

ox5

      1.31c 1.31c 1.19c 1.16c

1/2

E

ox4

1.27 1.34 1.38 1.23   1.04 1.07 0.86 0.97

E

1/2

ox3

1.08 1.07 1.11 1.00 1.02 0.95c 0.88 0.90 0.70 0.79 0.88

reduction [V] E

1/2

ox2

0.70 0.61 0.46 0.46 0.57 0.55 0.46 0.43 0.31 0.26 0.44

1/2

E

ox1

1/2

E

red1

−1.60 −0.93 −1.11 −1.16 −1.11 −1.33 −0.67 −0.67 −0.97 −0.94 −0.90

0.56 0.27 0.17 0.15 0.23 0.23 0.20 0.18 0.07 0.04 0.14

red2

E1/2red3

E1/2red4

ΔEHOMO−LUMOb

−1.83 −1.19 −1.39 −1.45 −1.38 −1.60 −0.83 −0.84 −1.17 −1.13 −1.12

      −1.54 −1.58 −1.86 −1.92 −1.90

      −1.91 −1.95

2.16 1.20 1.28 1.31 1.34 1.56 0.87 0.85 1.04 0.98 1.04

E

1/2

a

The redox potentials were measured by cyclic voltammetry in anhydrous CH2Cl2 with 0.1 M nBu4NPF6 as a supporting electrolyte, and Ag/AgNO3 as a reference electrode. Ferrocene/ferrocenium ion couple was used as an external reference. bElectrochemical HOMO−LUMO gap (E1/2ox1 − E1/2red1) cTwo-electron oxidation process. dRef 28. 9080


Article


band with a time constant of 2.3 ps, it can be assigned as vibrational cooling process occurring from the initially formed Franck−Condon state (A) to a vibrationally relaxed state (B) followed by electronic relaxation to the ground state with a time constant of 7.3 ps which is comparable to the previous studies on porphyrin tapes (4.5 ps).2d Previous reports on porphyrin tapes or hybrid tapes showed that as the number of constituent units increases, the electronic relaxation rate increases drastically due to energy gap law.34,35 Nonlinear Optical Properties. We conducted two-photon absorption (TPA) measurements for dimers 11Ni, 17, and 19, and trimers, 15-syn, 15-anti, 18-syn, 18-anti, and 22Ni by using the open aperture Z-scan method from 1900 to 2400 nm where contribution of one-photon absorption is negligible (SI, Figure S89 and S90). Measurements on 15-syn and 15-anti were limited by their one-photon absorption spectra extending to 1500 nm (our setup covers up to 1200 nm). Dimers of 11Ni, 17, and 19 exhibited the TPA cross sections of 560, 400, and 430 GM, respectively. This trend can be explained by conjugation effect. The carbonyl bridge of 11Ni seems to effectively help the π-conjugation in line with the one-photon absorption. Trimers of 18-syn, 18-anti, and 22Ni showed the TPA cross sections of 560, 610, and 460 GM, respectively, which are enhanced from those of the corresponding dimers because of the extended π-conjugation. Syn- or anti-position of two methylene bridges also affect TPA cross section value slightly although one-photon absorption feature implies their similar π-conjugation. Fullerene Binding. Recent supramolecular chemistry displayed that complexation of porphyrin tapes with fullerene C60 realized intriguing phenomena such as enhancement of the multicharge storage capabilities36 and C60-binding with unique cooperative effect.37,38 However, the flat structures of porphyrin tapes are inherently unsuitable to capture C60. Therefore, preparation of these porphyrin−C60 complexes required elaborate molecular designs like incorporation into a cyclic cage, peripheral introduction of directing groups, or attachment of C60-analogues by covalent bonds.36−38 Overcome of these problems will lead to wider uses of the porphyrin tapes and relative molecules in diverse applications. We examined complexation behaviors of porphyrin archtapes 11Ni, 17, 15-syn, 15-anti, 18-syn, and 18-anti with C60fullerene. Their complexation stoichiometries were confirmed to be 1:1 by the Job’s plots for all the compounds (SI, Figure S84). Addition of C60 to a dilute solution of 11Ni in toluene caused distinct spectral changes as shown in Figure 6a. Curve fitting of the [C60]total versus ΔAbs at 948 nm gave the association constant K of (1.03 ± 0.02) × 104 M−1. Relatively electron-rich methylene-inserted dimer 17 exhibited a slightly increased association constant K of (3.48 ± 0.12) × 104 M−1 (Figure 6b). On the other hand, planar triply linked porphyrin dimer 19 exhibited no distinguishable spectral change upon addition of C60 (SI, Figure S85). Furthermore, although some previous reports described that relatively electron-rich porphyrin Zn(II)-complexes exhibited larger association constants than those of Ni(II)-complexes,39 less curved Zn(II)-complex 11Zn displayed no spectral change (SI, Figure S86). From these results, we can estimate the association constants of 19 and 11Zn to be below 1 × 102 M−1. Therefore, C60-binding behaviors of 11Ni and 17 can be clearly ascribed to their contorted conformations. In the case of arch-tape trimers 15-anti, 15-syn, 18-anti, and 18-syn, the curve fittings provided their association constants to

Figure 5. Variable temperature 1H NMR spectra of 17 in toluene-d8 at (a) 100 °C, (b) 30 °C, and (c) −60 °C. *Solvent and impurities.

18-syn exhibited a significantly decreased inversion barrier of 11.6 kcal/mol, judged from its coalescence temperature of −10 °C and exchange constant of 558 Hz (SI, Figure S79). DFT calculations of 18-anti and 18-syn indicated that both of these trimers took contorted structures with similar θ values of 150° and 152°, respectively (SI, Figure S64). However, their central porphyrin units exhibited different conformations, namely a severely distorted saddle-like structure with MPD of 0.424 Å for the former, and a shallower ruffled conformation with a smaller MPD (0.360 Å) for the latter. Although the precise dynamics during the arch-to-arch inversions remain unclear, such an increased partial structural constraint in 18-anti will be responsible to its large arch-to-arch inversion barrier. As well as methylene-inserted arch-tapes 17, 18-syn, and 18anti, carbonyl-inserted dimer 11Ni and trimers 15-syn and 15anti also exhibited coalescences of the 1H NMR signals due to their meso-aryl groups at lower temperatures of −80, −60, and 0 °C, respectively (SI, Figure S81−83). Therefore, their archto-arch inversion barriers can be estimated to be smaller than those of the corresponding methylene-inserted analogues, although the exact values are difficult to be determined. These results indicate that both carbonyl- and methyleneinserted porphyrin arch-tapes can flexibly change their conformations in solution at room temperature, even though planar porphyrin tapes own rigid π-conjugated surfaces. Excited-State Dynamics. We carried out femtosecond transient absorption (fs-TA) measurement to investigate the excited-state dynamics of 11Zn (other samples having Ni were not measured because Ni complexes undergo a very rapid decay through metal (d,d) state).32 TA spectra until 100 ps are shown in SI, Figure S88a. Evolution-associated spectra (EAS) and time trace of population ratio were obtained using Glotaran program.33 A rapid spectral change was observed and quantitatively analyzed by EAS and time trace of population ratio as shown in SI, Figure S88b and S88c. Two decay components of 2.3 and 7.3 ps were obtained. Seen from the rapid spectral evolution and blue-shifted induced absorption 9081


Article


porphyrin arch-tapes are comparable and distinctly larger as compared with those of the porphyrin tapes, respectively, as evidenced by their UV−vis−NIR absorption spectra, TPA cross sections, redox properties, and DFT calculations. The former can be ascribed to effective through-space interaction in the contorted conformations, and the latter can be attributed to active involvement of the carbonyl group(s) in the electronic conjugation. As a benefit of the contorted structures, the porphyrin arch-tapes bound C60 with large association constants. Among them, methylene-inserted syn-trimer 18-syn displayed the largest association constant of (1.5 ± 0.4) × 107 M−1 with C60 in toluene at 25 °C. These favorable attributes of the porphyrin arch-tapes may allow for creation of novel functional materials based on curved and effectively conjugated π-systems.

■

EXPERIMENTAL SECTION

Instrumentation and Materials. 1H NMR (600 MHz) and 13C NMR (151 MHz) spectra were taken on a JEOL ECA-600 spectrometer. Chemical shifts were reported as delta scale in ppm relative to CHCl3 (δ = 7.26), CHDCl2 (δ = 5.32), C6D5CHD2 (δ = 2.08), and 1,2-dichlro-3,4,6-trideuteriobenzene (δ = 6.93) for 1H NMR, and to CDCl3 (δ = 77.16) for 13C NMR. UV−vis−NIR absorption spectra were recorded on a Shimadzu UV-3600 spectrometer. High-resolution APCI-TOF mass and ESI-TOF mass spectra were taken on a Bruker micrOTOF. MALDI-TOF mass spectra were taken on a Shimadzu AXIMA-CFRplus. Redox potentials were measured by cyclic voltammetry method on an ALS model 660 electrochemical analyzer. X-ray data were taken at −180 °C with a Rigaku XtaLAB P200 diffractometer by using graphite monochromated Cu Kα radiation (λ = 1.54187 Å). The structures were solved by using direct methods (SIR-97,44 SHELX-97,45 or SHELXT46 programs). Structure refinements were carried out by using SHELXL2014/7 program.47 CCDC numbers 1551993 (10Ni), 1551994 (11Ni), 1551997 (17), 1551995 (15-syn), and 1551992 (15-anti) contain supplementary crystallographic data for this paper. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif. Preparative separations were performed by silica gel column chromatography (Wako gel C-200, C-300, and C-400). THF was purified by passing through a neutral alumina column under N2. Toluene and dry CH2Cl2 were distilled from CaH2. DMF as a reagent for formylation was purchased from Wako as a degassed grade. Methyl tert-butyl ether (MTBE) and mesitylene were dried over activated molecular sieves 4A under N2. A solution of iPrMgCl·LiCl in THF was prepared by according to the literature.48 Unless otherwise noted, materials obtained from commercial suppliers were used without further purification. The two-photon absorption (TPA) spectrum was measured in the NIR region by using the open-aperture Z-scan method with 130 fs pulses from an optical parametric amplifier (Light Conversion, TOPAS) operating at a repetition rate of 1 kHz generated from a Ti:sapphire regenerative amplifier system (Spectra-Physics, Hurricane). After passing through a 10 cm focal length lens, the laser beam was focused and passed through a 1 mm quartz cell. Since the position of the sample cell could be controlled along the laser beam direction (z axis) by using the motorcontrolled delay stage, the local power density within the sample cell could be easily controlled under constant laser intensity. The transmitted laser beam from the sample cell was then detected by the same photodiode as used for reference monitoring. The on-axis peak intensity of the incident pulses at the focal point, I0, ranged from 40−60 GWcm−2. For a Gaussian beam profile, the nonlinear absorption coefficient was obtained by curve fitting of the observed open-aperture traces T(z) with eq 1 in which α0 is the linear absorption coefficient, l the sample length, and z0 the diffraction length of the incident beam.

Figure 6. (a) UV−vis−NIR absorption spectral changes during titration of 11Ni with C60 at 25 °C in toluene ([11Ni]total = 1.8 × 10−5 M, [C60]total = 0−4.6 × 10−4 M). Inset: plot of ΔAbs at 948 nm versus [C60]total. (b) UV−vis−NIR absorption spectral changes during titration of 17 with C60 at 25 °C in toluene ([17]total = 1.7 × 10−5 M, [C60]total = 0−5.4 × 10−4 M). Inset: plot of ΔAbs at 845 nm versus [C60]total.

be (1.32 ± 0.02) × 105 M−1, (1.14 ± 0.05) × 106 M−1, (4.0 ± 0.6) × 106 M−1, and (1.5 ± 0.4) × 107 M−1, respectively (Figure 7). These values are apparently larger than those of dimers 11Ni and 17, which can be attributed to their extended π-conjugated surfaces. Moreover, their association constants are distinctly larger than those of other curved π-systems40−42 such as corannulenes41 and triquinacenes,42 and comparable to or even larger than those of cyclic porphyrin oligomers which were designed for the purpose of fullerene-capturing.39,43 Perhaps, as well as their contorted structures, their high flexibilities represented by their arch-to-arch inversion behaviors will also play an important role to take an appropriate conformation for C 60 -binding, resulting in their large association constants.

■

CONCLUSIONS Oxidative fusion reactions of β-to-β carbonyl-bridged porphyrin dimer 10Ni and trimers 14 furnished the corresponding carbonyl-inserted porphyrin arch-tape dimer 11Ni and trimers 15, respectively. The subsequent Luche reduction with NaBH4 and CeCl3 followed by ionic hydrogenation with HBF4·OEt2 and BH3·NEt3 afforded methylene-inserted porphyrin arch-tape dimer 17 and trimers 18. While conventional porphyrin tapes took on rigid and planar structures, these porphyrin arch-tapes exhibited remarkably contorted structures and high conformational flexibility. Consequently, they settled an intrinsic problem of the conventional porphyrin tapes, namely the extremely poor solubility. Importantly, the conjugative electronic interactions of the methylene- and carbonyl-inserted 9082


Article


Figure 7. (a) UV−vis−NIR absorption spectral changes during titration of 15-anti with C60 at 25 °C in toluene ([15-anti]total = 9.5 × 10−6 M, [C60]total = 0−2.8 × 10−4 M). Inset: plot of ΔAbs at 1243 nm versus [C60]total. (b) UV−vis−NIR absorption spectral changes during titration of 15syn with C60 at 25 °C in toluene ([15-syn]total = 1.8 × 10−6 M, [C60]total = 0−5.5 × 10−5 M). Inset: plot of ΔAbs at 1251 nm versus [C60]total. (c) UV−vis−NIR absorption spectral changes during titration of 18-anti with C60 at 25 °C in toluene ([18-anti]total = 2.3 × 10−6 M, [C60]total = 0−5.9 × 10−5 M). Inset: plot of ΔAbs at 1097 nm versus [C60]total. (d) UV−vis−NIR absorption spectral changes during titration of 18-syn with C60 at 25 °C in toluene ([18-syn]total = 1.3 × 10−6 M, [C60]total = 0−7.5 × 10−5 M). Inset: plot of ΔAbs at 1094 nm versus [C60]total.

T (z) = 1 −

Bis(β-Ni(II)-porphyrinyl)ketone 10Ni. A flask containing 2iodoporphyrin 718 (159 mg, 0.15 mmol) was purged with N2, and then charged with dry THF (3.0 mL). After the solution was cooled to −40 °C, iPrMgCl·LiCl (0.82 M solution in THF, 0.18 mL, 0.15 mmol) was slowly added over 3 min. Then, the reaction mixture was stirred at −40 °C for 1 h. 2-Formyl-5,10,15-tris(3,5-di-tertbutylphenyl)porphyrin Ni(II)-complex 817 (96 mg, 0.10 mmol) was added to the crude mixture in a dropwise manner. After being stirred at −40 °C for 3 min and at room temperature for 1 h, the reaction mixture was quenched with a sufficient amount of NH4Cl solution, and extracted with CH2Cl2. The combined organic extracts were washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was dissolved in CH2Cl2 (10 mL), to which DDQ (159 mg, 0.7 mmol) was added, and the resulting mixture was stirred at room temperature for 1 h. Then, the mixture was passed through a small plug of alumina with CH2Cl2 eluent. After removal of the solvent in vacuo, the residue was separated by silica gel chromatography by eluting with CH2Cl2/n-hexane (2:5). Recrystallization from CH2Cl2/MeOH gave 10Ni (179 mg, 0.095 mmol, 95%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 10.67 (s, 2H, meso), 9.35 (s, 2H, β), 9.10 (d, J = 4.6 Hz, 2H, β), 8.92−8.87 (m, 6H, β), 8.80 (d, J = 4.6 Hz, 2H, β), 8.75 (d, J = 4.6 Hz, 2H, β), 7.95 (d, J = 1.4 Hz, 4H, Ar), 7.94 (d, J = 1.4 Hz, 4H, Ar), 7.79 (t, J = 1.4 Hz, 2H, Ar), 7.77 (t, J = 1.4 Hz, 2H, Ar), 7.72 (d, J = 1.4 Hz, 4H, Ar), 7.36 (t, J = 1.4 Hz, 2H, Ar), 1.55 (s, 36H, tert-butyl), 1.53 (s, 36H, tert-butyl), and 1.06 (s, 36H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 191.02, 149.29, 149.21, 148.94, 144.29, 143.90, 143.57, 143.25, 143.07, 141.90, 141.08, 140.00, 139.85, 139.30, 137.84, 133.81, 133.32, 133.22, 133.14, 132.89, 132.43, 128.91, 128.84, 122.46, 121.40 (overlap of four signals), 120.89, 119.80, 35.18 (overlap), 34.72, 31.86 (overlap), and 31.43 ppm; APCI-TOF-MS m/z = 1886.9980. Calcd for

βI0(1 − e−a0l) 2

2α0[1 + (z /z 0)]

(1)

After the nonlinear absorption coefficient was obtained, the TPA cross-section σ2 of one solute molecule (in units of GM, for which 1 GM = 10−50 cm4 s photon−1 molecule−1) was determined by using eq 2 in which NA is the Avogadro constant, d is the concentration of the compound in solution, h is the Planck constant, and ν is the frequency of the incident laser beam. β=

10−3σ 2NAd hv

(2)

To obtain the time-resolved transient absorption difference signal (ΔA) at a specific time, the pump pulses were chopped at 500 Hz and absorption spectra intensities were saved alternately with or without pump pulse. Typically, 2000 pulses excite the samples to obtain the fsTA spectra at each delay time. The polarization angle between pump and probe beam was set at the magic angle (54.7°) using a Glan-laser polarizer with a half-wave retarder in order to prevent polarizationdependent signals. Cross-correlation fwhm in pump−probe experiments was less than 200 fs and chirp of WLC probe pulses was measured to be 800 fs in the 400−800 nm region. To minimize chirp, all reflection optics in the probe beam path and a quartz cell of 2 mm path length were used. After fs-TA experiments, the absorption spectra of all compounds were carefully examined to detect if there were artifacts due to degradation and photo-oxidation of samples. The three-dimensional data sets of ΔA versus time and wavelength were subjected to singular value decomposition and global fitting to obtain the kinetic time constants and their associated spectra using Surface Xplorer software (Ultrafast Systems).49 9083


Article

Journal of the American Chemical Society C125H142N858Ni2O: 1887.0019 [M]−; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 412 (2.40 × 105), 535 (3.56 × 104), and 580 (3.15 × 104) nm. Carbonyl-Inserted Arch-Tape Dimer Ni(II)-Complex 11Ni. A flask containing 10Ni (189 mg, 0.10 mmol), DDQ (114 mg, 0.50 mmol), and Sc(OTf)3 (246 mg, 0.50 mmol) was purged with N2, and then charged with dry toluene (40 mL). The resulting mixture was stirred at 60 °C for 2 h. The reaction was quenched by addition of a saturated aqueous NaHCO3 solution. The organic phase was separated and washed with water and brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane (1:2). Recrystallization from CH2Cl2/MeOH gave 11Ni (164 mg, 87 μmol, 87%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 9.11 (s, 2H, β), 8.19 (d, J = 4.6 Hz, 2H, β), 8.17 (d, J = 4.6 Hz, 2H, β), 8.15 (d, J = 4.6 Hz, 2H, β), 8.13 (d, J = 4.6 Hz, 2H, β), 7.96 (s, 2H, β), 7.80−7.70 (m, 18H, Ar), 1.57 (br-s, 72H, tert-butyl), and 1.51 (s, 36H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 182.76, 149.72, 149.60, 149.55, 146.52, 146.30, 145.74, 145.17, 144.99, 144.69, 142.76, 140.05, 139.69, 138.67, 138.54, 138.36, 138.28, 132.33, 131.86, 131.63, 131.53, 127.93 (overlap), 127.79, 127.03, 126.64, 125.53, 125.09, 122.04, 121.74, 121.64, 112.54, 35.16, 35.13 (overlap), 31.84 (overlap), and 31.77 ppm; APCI-TOF-MS m/z = 1882.9561. Calcd for C125H138N858Ni2O: 1882.9706 [M]−; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 412 (1.16 × 105), 575 (8.42 × 104), 843 (1.82 × 104), and 960 (4.76 × 104) nm. Bis(β-Zn(II)-porphyrinyl)ketone 10Zn. Conc. H2SO4 (0.5 mL) was added slowly to a mixture of 10Ni (18.9 mg, 10 μmol) and TFA (1.0 mL) at 0 °C. The reaction mixture was stirred at 0 °C under air for 2.5 h, and then poured into water. After neutralization with an aqueous Na2CO3 solution at 0 °C, the product was extracted with CH2Cl2, and the organic extract was washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the reaction mixture was diluted with CH2Cl2 and filtered through a small plug of silica gel with copious washings (CH2Cl2). After removal of the solvent in vacuo, the residue was dissolved in CH2Cl2 (2.0 mL). After addition of an excess amount of Zn(OAc)2·2H2O (28 mg, 0.13 mmol) in MeOH (0.5 mL), the mixture was stirred for 1 h at room temperature in air. The residue was passed through a small plug of silica gel with copious washings (CH2Cl2). After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane (1:1). Recrystallization of the separated solids from CH2Cl2/MeCN gave 10Zn (14.1 mg, 7.4 μmol, 74%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 10.98 (s, 2H, meso), 9.74 (s, 2H, β), 9.13 (d, J = 4.6 Hz, 2H, β), 9.07−9.04 (m, 4H, β), 9.03− 9.00 (m, 4H, β), 8.97 (d, J = 4.6 Hz, 2H, β), 8.11 (d, J = 1.9 Hz, 4H, Ar), 8.09 (d, J = 1.9 Hz, 4H, Ar), 7.96 (d, J = 1.9 Hz, 4H, Ar), 7.81 (t, J = 1.9 Hz, 2H, Ar), 7.80 (t, J = 1.9 Hz, 2H, Ar), 7.35 (t, J = 1.9 Hz, 2H, Ar), 1.54 (s, 36H, tert-butyl), 1.53 (s, 36H, tert-butyl), and 1.01 (s, 36H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 193.86, 152.13, 151.88, 151.36, 151.03, 150.61 (overlap), 148.90, 148.82, 148.56, 147.60, 146.66, 143.09, 141.90, 141.62, 141.27, 138.49, 133.36 (overlap), 133.11, 132.94, 132.78, 132.44, 129.86 (overlap), 129.75, 124.42, 123.29, 122.02, 121.13, 121.08, 120.88, 106.96, 35.24 (overlap), 34.73, 31.95 (overlap), and 31.43 ppm; APCI-TOF-MS m/z = 1898.9774. Calcd for C125H142N864Zn2O: 1898.9895 [M]−; UV−vis (CH2Cl2 + 1% of pyridine) λmax (ε [M−1 cm−1]) = 429 (3.11 × 105), 455 (3.19 × 105), 569 (3.60 × 104), and 615 (2.29 × 104) nm. Carbonyl-Inserted Arch-Tape Dimer Zn(II)-Complex 11Zn. A flask containing β-to-β carbonyl-inserted Zn(II)-porphyrin dimer 10Zn (38.1 mg, 20 μmol), DDQ (23 mg, 0.10 mmol), and Sc(OTf)3 (49 mg, 0.1 mmol) was purged with N2, and then charged with dry toluene (8.0 mL). The mixture was stirred at 60 °C for 3 h. The reaction was quenched by addition of a saturated aqueous NaHCO3 solution. The organic phase was separated and washed with water and brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane/pyridine (9:11:0.12). Recrystallization from CH2Cl2/MeCN gave 11Zn (32.9 mg, 17.3 μmol, 86%).

H NMR (600 MHz, CDCl3, 25 °C) δ = 8.46 (s, 2H, β), 8.08−8.03 (m, 6H, β), 7.95 (d, J = 4.6 Hz, 2H, β), 7.88 (s, 2H, β), 7.77 (d, J = 1.3 Hz, 4H, Ar), 7.75 (d, J = 1.3 Hz, 4H, Ar), 7.73 (d, J = 1.3 Hz, 4H, Ar), 7.70 (t, J = 1.3 Hz, 2H, Ar), 7.69 (t, J = 1.3 Hz, 2H, Ar), 7.65 (t, J = 1.3 Hz, 2H, Ar), 1.49 (s, 36H, tert-butyl), 1.48 (s, 36H, tert-butyl), and 1.45 (s, 36H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 192.12, 154.04, 153.91, 153.76, 153.45, 153.07, 152.12, 151.17, 149.37, 149.02, 148.87, 147.70, 140.72, 140.65, 140.13, 137.64, 137.23, 134.50, 132.42, 132.34, 132.03, 131.83, 129.95, 129.22, 128.86, 128.26, 127.92, 126.51, 126.25, 121.72, 121.28, 121.23, 120.28, 35.13 (overlap), 35.10, 31.86 (overlap), and 31.79 ppm; APCI-TOF-MS m/z = 1894.9485. Calcd for C125H138N864Zn2O: 1894.9582 [M]−; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 413 (1.47 × 105), 475 (6.65 × 104), 562 (1.43 × 105), and 1051 (4.12 × 104) nm. β,β′-Diformylporphyrins 13-syn and 13-anti. A flask containing 5,15-bis(3,5-di-tert-butylphenyl)porphyrin Ni(II)-complex 12 (744 mg, 1.0 mmol), bis(pinacolato)dibron (B2pin2, 406 mg, 1.6 mmol), [Ir(cod)OMe]2 (33.2 mg, 50 μmol), and 4,4′-di-tert-butyl-2,2′bipyridyl (dtbpy, 26.8 mg, 0.10 mmol) was purged with N2, and then charged with dry mesitylene (5 mL) and dry MTBE (15 mL). The mixture was stirred at 70 °C for 17 h. After removal of the solvent in vacuo, the residue was passed through a short silica gel column eluting with CH2Cl2. The solvent was removed in vacuo. A flask containing the residue, CuI (572 mg, 3.0 mmol), and Niodosuccinimide (NIS, 675 mg, 3.0 mmol) was charged with DMF (50 mL) and toluene (25 mL). The mixture was stirred at 80 °C for 3 h in air. Then, red precipitates appeared, and the supernatant was removed by filtration. The precipitate was washed with NH4Cl aq., H2O, Na2S2O3 aq., H2O, and MeOH, and dried in vacuo. A flask containing the obtained red crystals was purged with N2, and then charged with dry THF (35 mL). After the solution was cooled to −40 °C, iPrMgCl·LiCl (0.80 M solution in THF, 3.9 mL, 4.9 mmol) was slowly added over 6 min. Then, the reaction mixture was stirred at −40 °C for 1 h. Dry DMF (0.35 mL, 4.5 mmol) was added to the crude mixture dropwise, and the mixture was stirred at −40 °C for 10 min. After being stirred for 1 h at room temperature, the reaction mixture was quenched with a sufficient amount of aqueous NH4Cl solution, extracted with CH2Cl2, washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/nhexane (1:1). Recrystallization from CH2Cl2/MeOH gave a mixture of 13-syn and 13-anti (1.00:0.92, 264 mg, 0.33 mmol, 33%). β-to-β Carbonyl-Bridged Porphyrin Trimers 14-syn and 14anti. A flask containing β-iodoporphyrin 7 (317 mg, 0.30 mmol) was purged with N2, and then charged with dry THF (12 mL). After the solution was cooled to −40 °C, iPrMgCl·LiCl (0.82 M solution in THF, 0.44 mL, 0.36 mmol) was slowly added over 3 min. Then, the reaction mixture was stirred at −40 °C for 1 h. A solution of a mixture of 13-syn and 13-anti (1.00:0.92, 80 mg, 0.10 mmol) in THF (0.9 mL) was added to the crude mixture dropwise, and the mixture was stirred at −40 °C for 30 min. After being stirred for 1 h at room temperature, the reaction mixture was quenched with a sufficient amount of NH4Cl solution, extracted with CH2Cl2, washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was dissolved in CH2Cl2 (15 mL). After the subsequent addition of DDQ (340 mg, 1.5 mmol), the mixture was stirred at room temperature for 3 h. Then, the mixture was passed through a small plug of alumina with copious washings (CH2Cl2). After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane (1:3). Recrystallizations from CH2Cl2/MeOH gave 14-syn (63.5 mg, 24 μmol, 45%) and 14-anti (56.7 mg, 21 μmol, 44%). 14-syn: 1H NMR (600 MHz, CDCl3, 25 °C) δ = 10.64 (s, 2H, meso), 10.63 (s, 2H, meso), 9.28 (s, 2H, β), 9.23 (s, 2H, β), 9.08 (d, J = 5.0 Hz, 2H, β), 9.05 (d, J = 5.0 Hz, 2H, β), 8.89 (d, J = 5.0 Hz, 2H, β), 8.84 (d, J = 5.0 Hz, 2H, β), 8.84−8.80 (m, 4H, β), 8.73 (d, J = 5.0 Hz, 2H, β), 8.66 (d, J = 5.0 Hz, 2H, β), 7.91 (d, J = 1.9 Hz, 2H, Ar), 7.88 (d, J = 1.9 Hz, 4H, Ar), 7.86 (d, J = 1.9 Hz, 4H, Ar), 7.77 (t, J = 1.9 Hz, 1H, Ar), 7.74 (t, J = 1.9 Hz, 2H, Ar), 7.72 (t, J = 1.9 Hz, 2H, Ar), 7.64 (d, J = 1.9 Hz, 4H, Ar), 7.50 (d, J = 1.9 Hz, 2H, Ar), 7.30 (t, J = 1

9084


Article

Journal of the American Chemical Society 1.9 Hz, 2H, Ar), 6.94 (t, J = 1.9 Hz, 1H, Ar), 1.52 (s, 18H, tert-butyl), 1.49 (s, 36H, tert-butyl), 1.47 (s, 36H, tert-butyl), 0.99 (s, 36H, tertbutyl), and 0.55 (s, 18H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 190.90, 149.52, 149.31, 149.22, 148.98, 148.94, 145.65, 144.33, 144.02, 143.93, 143.58, 143.27, 143.07, 142.04, 141.91, 141.52, 140.99, 139.93, 139.79, 139.71, 139.47, 139.26, 139.19, 138.45, 138.39, 137.80, 134.47, 133.83, 133.77, 133.36, 133.27, 133.20, 132.94, 132.44, 129.14, 128.98, 128.90 (overlap), 128.82, 124.64, 122.45, 121.64, 121.53, 121.41 (overlap), 121.37, 120.92, 119.81, 119.59, 105.95, 105.23, 35.23, 35.18 (overlap), 34.72, 34.33, 31.87, 31.85, 31.42, 31.03, and 29.88 ppm; MALDI-TOF-MS m/z = 2655.28. Calcd for C174H192N1258Ni3O2: 2655.33 [M]+; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 436 (2.96 × 105), 537 (4.84 × 104), and 580 (4.04 × 104) nm. 14-anti: 1H NMR (600 MHz, CDCl3, 25 °C) δ = 10.70 (s, 2H, meso), 10.63 (s, 2H, meso), 9.38 (s, 2H, β), 9.35 (s, 2H, β), 9.09−9.05 (m, 4H, β), 8.87 (d, J = 5.0 Hz, 2H, β), 8.86−8.84 (m, 4H, β), 8.79 (d, J = 5.0 Hz, 2H, β), 8.76 (d, J = 5.0 Hz, 2H, β), 8.71 (d, J = 5.0 Hz, 2H, β), 7.90 (d, J = 1.8 Hz, 4H, Ar), 7.89 (d, J = 1.8 Hz, 4H, Ar), 7.75 (t, J = 1.8 Hz, 2H, Ar), 7.74 (t, J = 1.8 Hz, 2H, Ar), 7.70 (br-s, 8H, Ar), 7.36 (br-s, 4H, Ar), 1.51 (s, 36H, tert-butyl), 1.49 (s, 36H, tert-butyl), 1.05 (s, 36H, tert-butyl), and 1.04 (s, 36H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 190.98, 149.30, 149.21, 149.13, 149.09, 144.44, 144.35 (overlap), 144.24, 143.96, 143.55, 143.29, 143.06, 142.63, 141.54, 141.34, 140.99, 140.61, 139.92, 139.77, 139.27, 139.19, 138.96, 138.03, 137.88, 134.01, 133.79 (overlap), 133.35, 133.30, 133.21, 132.94, 132.45, 128.98 (overlap), 128.89, 128.82, 122.48, 121.92, 121.55, 121.41 (overlap), 121.36, 120.93, 119.82, 106.16, 105.25, 35.17 (overlap), 34.73 (overlap), 31.85 (overlap), and 31.42 (overlap) ppm; MALDI-TOF-MS m/z = 2655.42. Calcd for C174H192N1258Ni3O2: 2655.33 [M]+; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 425 (3.17 × 105), 439 (3.19 × 105), 534 (4.14 × 104), and 591 (5.51 × 104) nm. Carbonyl-Inserted Arch-Tape Syn-trimer Ni(II)-Complex 15syn. A flask containing 14-syn (10.6 mg, 4.0 μmol), DDQ (13.6 mg, 60 μmol), and Sc(OTf)3 (29.5 mg, 60 μmol) was purged with N2, and then charged with dry toluene (1.5 mL). The mixture was stirred at 60 °C for 5 h. The reaction was quenched by addition of a saturated aqueous NaHCO3 solution. The organic phase was separated and washed with water and brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane (3:7). Recrystallization from CH2Cl2/MeOH gave 15-syn (8.2 mg, 3.1 μmol, 75%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 8.83 (s, 2H, β), 8.48 (s, 2H, β), 7.96−7.92 (m, 4H, β), 7.91 (d, J = 4.6 Hz, 2H, β), 7.86 (d, J = 4.6 Hz, 2H, β), 7.65 (s, 2H, β), 7.64−7.48 (m, 22H, Ar), 7.42 (br-s, 2H, Ar), 7.29 (s, 2H, β), 1.47 (s, 18H, tert-butyl), 1.42 (s, 36H, tertbutyl), 1.40 (br-s, 54H, tert-butyl), and 1.38 (s, 36H, tert-butyl) ppm; 13 C NMR (151 MHz, CDCl3, 25 °C) δ = 180.78, 149.82, 149.74, 149.54 (overlap), 148.43, 147.89, 146.76, 146.37, 145.99, 145.62, 145.38, 144.64, 143.61, 142.80, 141.86, 140.23, 139.95, 138.04, 137.94 (overlap), 137.63, 137.02, 136.99, 134.34, 133.59, 132.64, 131.90, 131.72, 131.65, 129.66, 127.71, 127.55, 127.51, 127.45, 127.10, 126.89, 126.23 (overlap), 125.01, 122.76, 122.09, 122.00, 121.79, 121.71, 119.56, 111.06, 35.10, 35.06 (overlap), 31.79, 31.76 (overlap), 31.73, and 31.68 ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); MALDI-TOF-MS m/z = 2647.43. Calcd for C174H184N1258Ni3O2: 2647.27 [M]+; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 413 (1.17 × 105), 488 (8.32 × 104), 545 (8.79 × 104), 630 (9.70 × 104), 1085 (3.24 × 104), and 1260 (1.13 × 105) nm. Carbonyl-Inserted Arch-Tape Anti-trimer Ni(II)-Complex 15anti. A flask containing 14-anti (16.0 mg, 6.0 μmol), DDQ (20.4 mg, 90 μmol), and Sc(OTf)3 (44.3 mg, 90 μmol) was purged with N2, and then charged with dry toluene (2.3 mL). The mixture was stirred at 60 °C for 5 h. The reaction was quenched by addition of a saturated aqueous NaHCO3 solution. The organic phase was separated and washed with water and brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was separated by silica gel

chromatography eluting with CH2Cl2/n-hexane (3:5). Recrystallization from CH2Cl2/MeOH gave 15-anti (7.8 mg, 2.9 μmol, 49%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 8.85 (s, 2H, β), 8.41 (s, 2H, β), 7.94 (d, J = 5.0 Hz, 2H, β), 7.92 (d, J = 5.0 Hz, 2H, β), 7.90− 7.88 (m, 4H, β), 7.66 (s, 2H, β), 7.63 (t, J = 1.9 Hz, 2H, Ar), 7.62 (t, J = 1.9 Hz, 2H, Ar), 7.60 (t, J = 1.9 Hz, 2H, Ar), 7.57 (t, J = 1.9 Hz, 2H, Ar), 7.28 (s, 2H, β), 1.43 (s, 36H, tert-butyl), 1.39 (s, 36H, tert-butyl), and 1.36 (s, 36H, tert-butyl) ppm (Signals due to aryl groups at the meso-positions are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); 1H NMR (600 MHz, CDCl3, 60 °C) δ = 8.84 (s, 2H, β), 8.40 (s, 2H, β), 7.93 (d, J = 5.0 Hz, 2H, β), 7.91 (d, J = 5.0 Hz, 2H, β), 7.89 (d, J = 5.0 Hz, 2H, β), 7.87 (d, J = 5.0 Hz, 2H, β), 7.69 (s, 2H, β), 7.65 (t, J = 1.9 Hz, 2H, Ar), 7.64 (t, J = 1.9 Hz, 2H, Ar), 7.62 (t, J = 1.9 Hz, 2H, Ar), 7.60 (t, J = 1.9 Hz, 2H, Ar), 7.60−7.45 (m, 16H, Ar), 7.31 (s, 2H, β), 1.45 (s, 36H, tert-butyl), 1.43 (br-s, 36H, tert-butyl), 1.41 (s, 36H, tert-butyl), and 1.38 (s, 36H, tertbutyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 181.85, 149.84, 149.74, 149.57, 149.54, 149.02, 146.79, 146.38, 145.83, 145.39, 145.27, 144.49, 143.87, 143.74, 142.58, 140.05, 139.79, 138.80, 138.31, 138.03, 137.89, 137.41, 137.09, 136.67, 135.38 132.46, 132.11, 131.62 (overlap), 131.54, 127.68, 127.51, 127.31, 126.29, 125.84, 124.62, 122.43, 122.09, 121.78, 119.71, 111.12, 35.10, 35.06 (overlap), 31.77, 31.73 (overlap), and 31.68 ppm; MALDI-TOF-MS m/z = 2647.23. Calcd for C174H184N1258Ni3O2: 2647.27 [M]+; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 411 (1.21 × 105), 466 (8.46 × 104), 617 (1.40 × 105), 1073 (2.87 × 104), and 1254 (1.37 × 105) nm. Hydroxymethylene-Inserted Arch-Tape Dimer Ni(II)-Complex 16. A solution of CeCl3 (246 mg, 1.0 mmol) in MeOH (5.0 mL) was added to a solution of 11Ni (94.2 mg, 50 μmol) in CH2Cl2 (20 mL) at −80 °C. Then, NaBH4 (18.9 mg. 0.50 mmol) was added to the reaction mixture. The crude mixture was stirred at −80 °C for 1 h. The reaction was quenched by addition of a saturated aqueous NH4Cl solution. The organic phase was separated and washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, recrystallization from CH2Cl2/MeOH gave 16 (91.7 mg, 48.6 μmol, 97%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 8.41 (br-s, 2H, β), 8.20− 8.16 (m, 4H, β), 8.12 (d, J = 5.1 Hz, 2H, β), 8.08−8.84 (m, 4H, β), 7.70−7.65 (m, 4H, Ar), 7.60 (t, J = 1.9 Hz, 2H, Ar), 1.47 (br-s, 72H, tert-butyl), and 1.39 (s, 36H, tert-butyl) ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); 1H NMR (600 MHz, toluene-d8, 100 °C) δ = 8.44 (s, 2H, β), 8.25 (s, 2H, β), 8.23 (d, J = 5.0 Hz, 2H, β), 8.16−8.10 (m, 6H, β), 7.90 (br-s, 4H, Ar), 7.84−7.78 (m, 6H, Ar), 7.76−7.72 (m, 6H, Ar), 7.68 (t, J = 1.8 Hz, 2H, Ar), 7.27 (br-s, 1H, CHOH), 1.47 (br-s, 36H, tert-butyl), 1.41 (s, 36H, tert-butyl), and 1.31 (s, 36H, tert-butyl) ppm; 13 C NMR (151 MHz, CDCl3, 25 °C) δ = 149.42 (overlap), 145.60, 145.16, 144.97, 144.54, 144.33, 143.57, 140.45, 139.13, 138.93, 138.89, 138.19, 137.98, 132.04, 131.37, 131.22, 130.99, 128.68, 128.36, 128.06, 125.80, 124.91, 124.28, 123.75, 121.55, 121.49, 121.39, 112.14, 100.05, 35.17, 35.16, 35.10, 31.82 (overlap), and 31.76 ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); ESI-TOF-MS m/z = 1867.9742. Calcd for C125H139N858Ni2: 1867.9824 [M−OH]+; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 405 (1.18 × 105), 557 (9.75 × 104), and 863 (5.86 × 104) nm. Methylene-Inserted Arch-Tape Dimer Ni(II)-Complex 17. A flask containing hydroxymethylene-inserted arch-tape dimer Ni(II)complex 16 (37.8 mg, 20 μmol) was purged with N2, and then charged with dry CH2Cl2 (5.0 mL). Tetrafluoroboric acid diethyl ether complex (30 μL, 0.22 mmol) was introduced dropwise to the solution, and the solution was stirred for 10 min at room temperature. Then, borane triethylamine complex (0.10 mL, 0.68 mmol) was added to the solution. The mixture was stirred for 10 min at room temperature. The reaction was quenched by NaHCO3 aq. The organic phase was separated and washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane (1:9). Recrystallization from CH2Cl2/MeOH gave 17 (33.0 mg, 17.6 μmol, 88%). 9085


Article

Journal of the American Chemical Society H NMR (600 MHz, CDCl3, 25 °C) δ = 8.29 (s, 2H, β), 8.28−8.24 (m, 4H, β), 8.23−8.19 (m, 4H, β), 8.13 (d, J = 5.0 Hz, 2H, β), 7.73 (br-s, 4H, Ar), 7.64 (t, J = 1.8 Hz, 2H, Ar), 1.51 (br-s, 72H, tert-butyl), and 1.43 (br-s, 36H, tert-butyl) ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); 1 H NMR (600 MHz, toluene-d8, 105 °C) δ = 8.34 (s, 2H, β), 8.26 (d, J = 5.7 Hz, 2H, β), 8.19−8.14 (m, 8H, β), 7.89 (br-s, 4H, Ar), 7.85 (brs, 4H, Ar), 7.82 (t, J = 1.8 Hz, 2H, Ar), 7.78−7.75 (m, 4H, Ar), 7.69 (t, J = 1.8 Hz, 2H, Ar), 5.31 (br-s, 2H, CH2), 1.48 (s, 36H, tert-butyl), 1.43 (s, 36H, tert-butyl), and 1.32 (s, 36H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 149.34, 145.58, 145.41, 144.67, 144.01, 143.81, 143.31, 140.43, 139.34, 139.02 (overlap), 137.84, 134.38, 132.09, 131.36, 131.07, 130.83, 128.67, 128.54, 128.37, 128.13, 125.38, 124.69, 123.75, 122.75, 121.48, 121.35, 121.31, 112.33, 35.17, 35.15, 35.08, 31.84 (overlap), and 31.76 ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); APCI-TOF-MS m/z = 1868.9714. Calcd for C125H140N858Ni2: 1868.9913 [M]−; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 404 (1.15 × 105), 555 (9.65 × 104), 762 (2.23 × 104), and 846 (6.61 × 104) nm. Methylene-Inserted Arch-Tape Syn-trimer Ni(II)-Complex 18-syn. A solution of CeCl3 (49.3 mg, 0.20 mmol) in MeOH (0.5 mL) was added to a solution of 15-syn (13.3 mg, 5.0 μmol) in CH2Cl2 (2.0 mL) at −80 °C. Then, NaBH4 (3.8 mg. 0.10 mmol) was added to the reaction mixture. The crude mixture was stirred at −80 °C for 1 h. The reaction was quenched by addition of a saturated aqueous NH4Cl solution. The organic phase was separated and washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, recrystallization from CH2Cl2/MeOH gave gray solids. A flask containing the gray solids was purged with N2, and then charged with dry CH2Cl2 (2.0 mL). Tetrafluoroboric acid diethyl ether complex (2 drops, ca. 20 μL, ca. 0.15 mmol) was introduced dropwise to the solution, and the solution was stirred for 10 min at room temperature. Then, borane triethylamine complex (1 drop, ca. 10 μL, ca. 75 μmol) was added to the solution. The mixture was stirred for 10 min at room temperature. The reaction was quenched by NaHCO3 aq. The organic phase was separated and washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane (1:7). Recrystallization from CH2Cl2/MeOH gave 18-syn (3.8 mg, 1.4 μmol, 29%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 8.14−8.10 (m, 4H, β), 8.10−8.06 (m, 4H, β), 8.03 (s, 2H, β), 7.99 (d, J = 4.6 Hz, 2H, β), 7.78 (s, 2H, β), 7.77 (s, 2H, β), 7.72 (br-s, 2H, Ar), 7.65 (br-s, 4H, Ar), 7.63 (br-s, 4H, Ar), 7.56 (br-s, 4H, Ar), 5.30 (br-s, 4H, CH2), 1.53 (brs, 18H, tert-butyl), 1.43 (br-s, 18H, tert-butyl), 1.43 (br-s, 72H, tertbutyl), and 1.36 (br-s, 36H, tert-butyl) ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); 1H NMR (600 MHz, toluene-d8, 60 °C) δ = 8.23−8.18 (m, 4H, β), 8.12 (br-s, 4H, β), 8.10 (d, J = 5.0 Hz, 2H, β), 8.06 (s, 2H, β), 7.93 (s, 2H, β), 7.90 (t, J = 1.8 Hz, 1H, Ar-p), 7.85 (s, 2H, β), 7.81 (brs, 8H, Ar-o), 7.78 (t, J = 1.8 Hz, 2H, Ar-p), 7.77 (br-s, 2H, Ar-o), 7.76− 7.73 (m, 5H, Ar-o + Ar-p), 7.72 (br-s, 4H, Ar-o), 7.66 (t, J = 1.8 Hz, 2H, Ar-p), 4.89 (s, 4H, CH2), 1.57 (br-s, 18H, tert-butyl), 1.46 (br-s, 18H, tert-butyl), 1.43−1.38 (m, 72H, tert-butyl), and 1.27 (br-s, 36H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 149.55, 149.35 (overlap), 149.26, 145.84 (overlap), 145.65, 145.08, 144.91, 144.73, 144.29, 144.03, 143.78, 143.02, 141.89, 140.73, 139.14, 138.94 (overlap), 138.68, 138.26, 135.17, 134.28, 134.01, 132.22, 131.40, 131.01, 130.66, 129.54, 128.45, 127.94 (overlap), 127.29, 127.00, 125.21, 124.98, 124.21, 124.08, 122.94, 121.61, 121.47, 121.34, 117.58, 111.19, 35.19, 35.10, 35.04 (overlap), 31.87, 31.80, 31.78, and 31.71 ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); MALDI-TOF-MS m/z = 2619.44. Calcd for C174H188N1258Ni3: 2619.31 [M]+; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 405 (1.12 × 105), 501 (9.82 × 104), 589 (7.93 × 104), 954 (3.71 × 104), and 1093 (1.04 × 105) nm. Methylene-Inserted Arch-Tape Anti-trimer Ni(II)-Complex 18-anti. A solution of CeCl3 (49.3 mg, 0.20 mmol) in MeOH (0.5 mL) was added to a solution of 15-anti (13.3 mg, 5.0 μmol) in

CH2Cl2 (2.0 mL) at −80 °C. Then, NaBH4 (3.8 mg. 0.10 mmol) was added to the reaction mixture. The crude mixture was stirred at −80 °C for 1 h. The reaction was quenched by addition of a saturated aqueous NH4Cl solution. The organic phase was separated and washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, recrystallization from CH2Cl2/MeOH gave gray solids. A flask containing the gray solids was purged with N2, and then charged with dry CH2Cl2 (2.0 mL). Tetrafluoroboric acid diethyl ether complex (2 drops, ca. 20 μL, ca. 0.15 mmol) was introduced dropwise to the solution, and the solution was stirred for 10 min at room temperature. Then, borane triethylamine complex (1 drop, ca. 10 μL, ca. 75 μmol) was added to the solution. The mixture was stirred for 10 min at room temperature. The reaction was quenched by NaHCO3 aq. The organic phase was separated and washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane (1:5). Recrystallization from CH2Cl2/MeOH gave 18-anti (8.4 mg, 3.2 μmol, 64%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 8.17 (d, J = 5.0 Hz, 2H, β), 8.16−8.11 (m, 4H, β), 8.06 (d, J = 5.0 Hz, 2H, β), 7.99 (d, J = 5.0 Hz, 2H, β), 7.94 (s, 2H, β), 7.81 (s, 2H, β), 7.69 (t, J = 1.8 Hz, 2H, Ar), 7.68 (t, J = 1.8 Hz, 2H, Ar), 7.63 (t, J = 1.8 Hz, 2H, Ar), 7.60 (s, 2H, β), 7.57 (t, J = 1.8 Hz, 2H, Ar), 5.74 (d, J = 17 Hz, 2H, CH2), 4.90 (d, J = 17 Hz, 2H, CH2), 1.59 (br-s, 36H, tert-butyl), 1.43 (br-s, 72H, tertbutyl), and 1.37 (br-s, 36H, tert-butyl) ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); 1H NMR (600 MHz, 1,2-dichlorobenzene-d4, 150 °C) δ = 8.15 (s, 2H, β), 8.13 (d, J = 5.4 Hz, 2H, β), 8.10 (s, 2H, β), 8.07 (d, J = 5.4 Hz, 2H, β), 8.06−8.02 (m, 4H, β), 7.85−7.70 (m, 22H, β + Ar), 7.68−7.64 (m, 6H, Ar), 5.18 (br-s, 4H, CH2), 1.53 (s, 36H, tert-butyl), 1.50 (s, 36H, tert-butyl), 1.42 (s, 36H, tert-butyl), and 1.32 (s, 36H, tert-butyl) ppm; 13C NMR (151 MHz, CDCl3, 25 °C) δ = 149.60, 149.38 (overlap), 148.46, 146.93, 146.21, 145.85, 145.36, 144.94, 144.77, 144.16, 143.78, 142.68, 142.47, 141.03, 139.34, 138.98, 138.70, 137.81, 135.43, 134.24, 132.74, 132.14, 131.29, 131.09, 130.74, 128.77 (overlap), 128.54, 127.98, 127.74, 127.23, 125.55, 125.21, 124.22, 123.16, 123.09, 121.69, 121.45, 121.36 (overlap), 117.56, 112.01, 35.21 (overlap), 35.11, 35.07, 31.89 (overlap), 31.78, and 31.73 ppm (Some signals are too broad to analyze because of arch-to-arch inversion of the porphyrin skeleton.); MALDI-TOF-MS m/z = 2619.18. Calcd for C174H188N1258Ni3: 2619.31 [M]+; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 402 (1.21 × 105), 496 (8.72 × 104), 590 (1.14 × 105), 706 (2.91 × 104), 958 (3.71 × 104), and 1095 (1.31 × 105) nm. Porphyrin Tape Trimer Ni(II)-Complex 22Ni. Methanesulfonic acid (0.10 mL) was added slowly to a mixture of porphyrin tape trimer Zn(II)-complex 22Zn7a (17.1 mg, 3.3 μmol) and CH2Cl2 (10 mL) at 0 °C under N2. The reaction mixture was stirred at 0 °C for 10 min, and then poured into water. After neutralization with an aqueous Na2CO3 solution at 0 °C, the product was extracted with CH2Cl2, and the organic extract was washed with brine, and dried over anhydrous Na2SO4. After removal of the solvent in vacuo, the reaction mixture was purified by silica gel chromatography eluting with CH2Cl2/nhexane (1:3). After removal of the solvent in vacuo, the residue was dissolved in dry mesitylene (3.0 mL). After addition of nickel(II) acetylacetonate (4.8 mg, 16 μmol), the mixture was stirred for 12 h at 150 °C under N2. After cooling to room temperature, the residue was passed through a small plug of silica gel with copious washings (CH2Cl2). After removal of the solvent in vacuo, the residue was separated by silica gel chromatography eluting with CH2Cl2/n-hexane (1:3). Recrystallization of the separated solids from CH2Cl2/MeOH gave 22Ni (1.2 mg, 0.23 μmol, 7%). 1 H NMR (600 MHz, CDCl3, 25 °C) δ = 8.33 (s, 2H, meso), 8.08 (d, J = 4.6 Hz, 4H, β), 8.05 (d, J = 4.6 Hz, 4H, β), 7.72 (s, 4H, β), 7.18− 7.15 (m, 6H, Ar′), 7.13 (s, 4H, Ar′), 7.00 (d, J = 1.8 Hz, 4H, Ar′), 6.98 (d, J = 1.8 Hz, 8H, Ar′), 6.95 (t, J = 1.8 Hz, 4H, Ar′), 6.84 (d, J = 1.8 Hz, 8H, Ar′), 6.82 (s, 8H, Ar′), 6.62 (s, 4H, β), 6.60 (d, J = 1.8 Hz, 16H, Ar′), 6.59 (s, 8H, Ar′), 1.28 (s, 36H, tert-butyl), 1.27 (s, 72H, tert-butyl), 1.12 (s, 72H, tert-butyl), and 1.02 (s, 144H, tert-butyl)

1

9086


Article

Journal of the American Chemical Society ppm; The 13C NMR spectrum of 22Ni was not available due to its low solubility; MALDI-TOF-MS m/z = 5219.02. Calcd for C348H408N1258Ni260NiO18: 5218.94 [M]+; UV−vis (CH2Cl2) λmax (ε [M−1 cm−1]) = 404 (1.74 × 105), 673 (2.86 × 105), 1046 (8.22 × 104), and 1135 (7.20 × 104) nm. Crystal Data for 10Ni. C125H142N8Ni2O·4.5(C2H4Cl2), triclinic, space group: P1̅ (No. 2), a = 15.6525(17) Å, b = 20.125(3) Å, c = 21.372(2) Å, α = 89.650(17)°, β = 69.675(16)°, γ = 89.297(2)°, V = 6312.7(14) Å3, ρcalced = 1.223 g·cm−3, Z = 2, Completeness = 0.961, R1 = 0.0600 [I > 2.0σ (l)], Rw = 0.1776 (all data), GOF = 1.073, solvent system: C2H4Cl2/MeOH, CCDC number: 1551993. Crystal Data for 11Ni. C125H138N8Ni2O·4.5(C6H5CH3), triclinic, space group: P1̅ (No. 2), a = 14.5661(19) Å, b = 19.936(2) Å, c = 23.022(4) Å, α = 82.722(10)°, β = 86.975(9)°, γ = 85.150(7)°, V = 6601.8(16) Å3, ρcalced = 1.155 g·cm−3, Z = 2, Completeness = 0.961, R1 = 0.0604 [I > 2.0σ (l)], Rw = 0.1758 (all data), GOF = 1.023, solvent system: toluene/MeOH, CCDC number: 1551994. Crystal Data for 15-syn. C174H184N12Ni3O2, triclinic, space group: P1̅ (No. 2), a = 20.499(8) Å, b = 22.937(7) Å, c = 23.325(10) Å, α = 74.83(2)°, β = 83.70(4)°, γ = 80.25(5)°, V = 10307(7) Å3, Z = 2, Completeness = 0.954, R1 = 0.0994 [I > 2.0σ (l)], Rw = 0.2898 (all data), GOF = 1.060, solvent system: C6H5Cl/iPrOH, CCDC number: 1551995. Contributions to scattering arising from presence of the disordered solvents in the crystal were removed by use of SQUEEZE program in PLATON software package.50 Crystal Data for 15-anti. C174H184N12Ni3O2·3(C6H5Cl) ·0.5(C6H14), monoclinic, space group: C2/c (No. 15), a = 42.985(12) Å, b = 11.933(3) Å, c = 41.613(12) Å, β = 112.041(8)°, V = 19785(9) Å3, ρcalced = 1.633 g·cm−3, Z = 4, Completeness = 0.975, R1 = 0.0967 [I > 2.0σ (l)], Rw = 0.3083 (all data), GOF = 1.090, solvent system: C6H5Cl/MeOH/hexane, CCDC number: 1551992. Crystal Data for 17. C125H140N8Ni2·3.5(C6H5Cl), triclinic, space group: P1̅ (No. 2), a = 17.6424(7) Å, b = 18.2854(5) Å, c = 20.0755(6) Å, α = 87.344(2)°, β = 88.846(3)°, γ = 81.075(3)°, V = 6390.5(4) Å3, ρcalced = 1.178 g·cm−3, Z = 2, Completeness = 0.967, R1 = 0.0815 [I > 2.0σ (l)], Rw = 0.2493 (all data), GOF = 1.039, solvent system: C6H5Cl/EtOH, CCDC number: 1551997.

■

JSPS Fellowship for Young Scientists. This work at Yonsei University was supported by the Global Research Laboratory Program (2013K1A1A2A02050183) funded by the Ministry of Science, ICT & Future, Korea (D.K.). We thank Prof. Dr. H. Maeda, Dr. Y. Haketa, and Dr. Y. Bando at Ritsumeikan University for MALDI-TOF MS measurement, and Prof. Dr. K. Maruoka and Mr. Y. Aota at Kyoto University for IR measurement.

■

(1) (a) Anderson, H. L. Chem. Commun. 1999, 2323. (b) Vicente, M. G. H.; Jaquinod, L.; Smith, K. M. Chem. Commun. 1999, 1771. (c) Reimers, J. R.; Hush, N. S.; Crossley, M. J. J. Porphyrins Phthalocyanines 2002, 6, 795. (d) Fox, S.; Boyle, R. W. Tetrahedron 2006, 62, 10039. (e) Aratani, N.; Kim, D.; Osuka, A. Chem. - Asian J. 2009, 4, 1172. (f) Jiao, C.; Wu, J. Synlett 2012, 23, 171. (g) Lewtak, J. P.; Gryko, D. T. Chem. Commun. 2012, 48, 10069. (h) Pereira, A. M. V. M; Richeter, S.; Jeandon, C.; Gisselbrecht, J.-P.; Wytko, J.; Ruppert, R. J. Porphyrins Phthalocyanines 2012, 16 (16), 464. (i) Mori, H.; Tanaka, T.; Osuka, A. J. Mater. Chem. C 2013, 1, 2500. (j) Grzybowski, M.; Skonieczny, K.; Butenschön, H.; Gryko, D. T. Angew. Chem., Int. Ed. 2013, 52, 9900. (k) Tanaka, T.; Osuka, A. Chem. Soc. Rev. 2015, 44, 943. (2) (a) Tsuda, A.; Furuta, H.; Osuka, A. Angew. Chem., Int. Ed. 2000, 39, 2549. (b) Tsuda, A.; Osuka, A. Science 2001, 293, 79. (c) Tsuda, A.; Furuta, H.; Osuka, A. J. Am. Chem. Soc. 2001, 123, 10304. (d) Cho, H. S.; Jeong, D. H.; Cho, S.; Kim, D.; Matsuzaki, Y.; Tanaka, K.; Tsuda, A.; Osuka, A. J. Am. Chem. Soc. 2002, 124, 14642. (e) Kim, D.; Osuka, A. Acc. Chem. Res. 2004, 37, 735. (3) Ahn, T. K.; Kim, K. S.; Kim, D. Y.; Noh, S. B.; Aratani, N.; Ikeda, C.; Osuka, A.; Kim, D. J. Am. Chem. Soc. 2006, 128, 170. (4) McEwan, K. J.; Fleitz, P. A.; Rogers, J. E.; Slagle, J. E.; McLean, D. G.; Akdas, H.; Katterle, M.; Blake, I. M.; Anderson, H. L. Adv. Mater. 2004, 16, 1933. (5) Bonifazi, D.; Spillmann, H.; Kiebele, A.; de Wild, M.; Seiler, P.; Cheng, F.; Güntherodt, H.-J.; Jung, T.; Diederich, F. Angew. Chem., Int. Ed. 2004, 43, 4759. (6) Sedghi, G.; Esdaile, L. J.; Anderson, H. L.; Martin, S.; Bethell, D.; Higgins, S. J.; Nichols, R. J. Adv. Mater. 2012, 24, 653. (7) (a) Ikeda, T.; Tsuda, A.; Aratani, N.; Osuka, A. Chem. Lett. 2006, 35, 946. (b) Ikeda, T.; Lintuluoto, J. M.; Aratani, N.; Yoon, Z. S.; Kim, D.; Osuka, A. Eur. J. Org. Chem. 2006, 2006, 3193. (c) Ikeda, T.; Aratani, N.; Osuka, A. Chem. - Asian J. 2009, 4, 1248. (d) Tanaka, T.; Lee, B. S.; Aratani, N.; Yoon, M.-C.; Kim, D.; Osuka, A. Chem. - Eur. J. 2011, 17, 14400. (8) Ikeue, T.; Aratani, N.; Osuka, A. Isr. J. Chem. 2005, 45, 293. (9) (a) Kawase, T.; Kurata, H. Chem. Rev. 2006, 106, 5250. (b) Scott, L. T. Angew. Chem., Int. Ed. 2004, 43, 4994. (c) Wu, Y.-T.; Siegel, J. S. Chem. Rev. 2006, 106, 4843. (d) Miao, Q. Chem. Rec. 2015, 15, 1156. (e) Segawa, Y.; Yagi, A.; Matsui, K.; Itami, K. Angew. Chem., Int. Ed. 2016, 55, 5136. (10) Barth, W. E.; Lawton, R. G. J. Am. Chem. Soc. 1966, 88, 380. (11) Sakurai, H.; Daiko, T.; Hirao, T. Science 2003, 301, 1878. (12) Scott, L. T.; Jackson, E. A.; Zhang, Q.; Steinberg, B. D.; Bancu, M.; Li, B. J. Am. Chem. Soc. 2012, 134, 107. (13) (a) Yamamoto, K. Pure Appl. Chem. 1993, 65, 157. (b) Yamamoto, K.; Harada, T.; Nakazaki, M. J. Am. Chem. Soc. 1983, 105, 7171. (c) Yamamoto, K.; Harada, T.; Okamoto, Y.; Chikamatsu, H.; Nakazaki, M.; Kai, Y.; Nakao, T.; Tanaka, M.; Harada, S.; Kasai, N. J. Am. Chem. Soc. 1988, 110, 3578. (d) Yamamoto, K.; Saitho, Y.; Iwaki, D.; Ooka, T. Angew. Chem., Int. Ed. Engl. 1991, 30, 1173. (e) Yamamoto, K.; Sonobe, H.; Matsubara, H.; Sato, M.; Okamoto, S.; Kitaura, K. Angew. Chem., Int. Ed. Engl. 1996, 35, 69. (f) Gu, X.; Li, H.; Shan, B.; Liu, Z.; Miao, Q. Org. Lett. 2017, 19, 2246. (14) (a) Luo, J.; Xu, X.; Mao, R.; Miao, Q. J. Am. Chem. Soc. 2012, 134, 13796. (b) Cheung, K. Y.; Xu, X.; Miao, Q. J. Am. Chem. Soc. 2015, 137, 3910.

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/jacs.7b05332. Spectroscopic data, crystallographic data, DFT calculations, and cyclic voltammogram (PDF) Crystal data for 10Ni (CIF) Crystal data for 11Ni (CIF) Crystal data for 15-anti (CIF) Crystal data for 15-syn (CIF) Crystal data for a complex of 15-syn with fullerene (CIF) Crystal data for 17 (CIF)

■

REFERENCES

AUTHOR INFORMATION

Corresponding Authors

*[email protected] *[email protected] ORCID

Dongho Kim: 0000-0001-8668-2644 Atsuhiro Osuka: 0000-0001-8697-8488 Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS The work at Kyoto University was supported by Grants-in-Aid from JSPS (Nos.: 25220802 (Scientific Research (S)), 16K13952 (Exploratory Research)). N.F. acknowledges a 9087


Article


(36) Bonifazi, D.; Scholl, M.; Song, F.; Echegoyen, L.; Accorsi, G.; Armaroli, N.; Diederich, F. Angew. Chem., Int. Ed. 2003, 42, 4966. (37) (a) Sato, H.; Tashiro, K.; Shinmori, H.; Osuka, A.; Murata, Y.; Komatsu, K.; Aida, T. J. Am. Chem. Soc. 2005, 127, 13086. (b) Sato, H.; Tashiro, K.; Shinmori, H.; Osuka, A.; Aida, T. Chem. Commun. 2005, 2324. (38) Moreira, L.; Calbo, J.; Aragó, J.; Illescas, B. M.; Nierengarten, I.; Delavaux-Nicot, B.; Ortí, E.; Martín, N.; Nierengarten, J.-F. J. Am. Chem. Soc. 2016, 138, 15359. (39) Reviews: (a) Tashiro, K.; Aida, T. Chem. Soc. Rev. 2007, 36, 189. (b) García-Simón, C.; Costas, M.; Ribas, X. Chem. Soc. Rev. 2016, 45, 40. (40) Reviews: (a) Pérez, E. M.; Martín, N. Chem. Soc. Rev. 2008, 37, 1512. (b) Canevet, D.; Pérez, E. M.; Martín, N. Angew. Chem., Int. Ed. 2011, 50, 9248. (41) (a) Mizyed, S.; Georghiou, P. E.; Bancu, M.; Cuadra, B.; Rai, A. K.; Cheng, P.; Scott, L. T. J. Am. Chem. Soc. 2001, 123, 12770. (b) Georghiou, P. E.; Tran, A. H.; Mizyed, S.; Bancu, M.; Scott, L. T. J. Org. Chem. 2005, 70, 6158. (c) Sygula, A.; Fronczek, F. R.; Sygula, R.; Rabideau, P. W.; Olmstead, M. M. J. Am. Chem. Soc. 2007, 129, 3842. (d) Yanney, M.; Fronczek, F. R.; Sygula, A. Angew. Chem., Int. Ed. 2015, 54, 11153. (e) Kuragama, P. L. A.; Fronczek, F. R.; Sygula, A. Org. Lett. 2015, 17, 5292. (f) Yokoi, H.; Hiraoka, Y.; Hiroto, S.; Sakamaki, D.; Seki, S.; Shinokubo, H. Nat. Commun. 2015, 6, 8215. (42) (a) Georghiou, P. E.; Dawe, L. N.; Tran, H.-A.; Strübe, J.; Neumann, B.; Stammler, H.-G.; Kuck, D. J. Org. Chem. 2008, 73, 9040. (b) Bredenkötter, B.; Henne, S.; Volkmer, D. Chem. - Eur. J. 2007, 13, 9931. (43) Selected examples: (a) Tashiro, K.; Aida, T.; Zheng, J.-Y.; Kinbara, K.; Saigo, K.; Sakamoto, S.; Yamaguchi, K. J. Am. Chem. Soc. 1999, 121, 9477. (b) Zheng, J.-Y.; Tashiro, K.; Hirabayashi, Y.; Kinbara, K.; Saigo, K.; Aida, T.; Sakamoto, S.; Yamaguchi, K. Angew. Chem., Int. Ed. 2001, 40, 1858. (c) Gil-Ramírez, G.; Karlen, S. D.; Shundo, A.; Porfyrakis, K.; Ito, Y.; Briggs, G. A. D.; Morton, J. J. L.; Anderson, H. L. Org. Lett. 2010, 12, 3544. (d) Song, J.; Aratani, N.; Shinokubo, H.; Osuka, A. J. Am. Chem. Soc. 2010, 132, 16356. (e) Yoshida, K.; Osuka, A. Chem. - Eur. J. 2016, 22, 9396. (44) Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G.; Giacovazzo, C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Spagna, R. J. Appl. Crystallogr. 1999, 32, 115. (45) Sheldrick, G. M. Acta Crystallogr., Sect. A: Found. Crystallogr. 2008, A64, 112. (46) Sheldrick, G. M. Acta Crystallogr., Sect. A: Found. Adv. 2015, A71, 3. (47) (a) Sheldrick, G. M.; Schneider, T. R. Methods Enzymol. 1997, 277, 319. (b) Sheldrick, G. M. Acta Crystallogr., Sect. C: Struct. Chem. 2015, 71, 3. (48) Krasovskiy, A.; Knochel, P. Angew. Chem., Int. Ed. 2004, 43, 3333. (49) Malinowski, E. R. Factor Analysis in Chemistry, 2nd ed.; John Wiley & Sons: New York, 1991. (50) Spek, A. L. Acta Crystallogr., Sect. C: Struct. Chem. 2015, 71, 9.

(15) (a) Kawasumi, K.; Zhang, Q.; Segawa, Y.; Scott, L. T.; Itami, K. Nat. Chem. 2013, 5, 739. (b) Kato, K.; Segawa, Y.; Scott, L. T.; Itami, K. Chem. - Asian J. 2015, 10, 1635. (16) (a) Mughal, E. U.; Kuck, D. Chem. Commun. 2012, 48, 8880. (b) Pradhan, A.; Dechambenoit, P.; Bock, H.; Durola, F. J. Org. Chem. 2013, 78, 2266. (c) Ż yła, M.; Gońka, E.; Chmielewski, P. J.; Cybińska, J.; Stępień, M. Chem. Sci. 2016, 7, 286. (d) Márquez, I. R.; Fuentes, N.; Cruz, C. M.; Puente-Muñoz, V.; Satorrios, L.; Marcos, M. L.; Choquesillo-Lazarte, D.; Biel, B.; Crovetto, L.; Gómez-Bengoa, E.; González, M. T.; Martin, R.; Cuerva, J. M.; Campaña, A. G. Chem. Sci. 2017, 8, 1068. (17) Fujimoto, K.; Yorimitsu, H.; Osuka, A. Eur. J. Org. Chem. 2014, 2014, 4327. (18) Fujimoto, K.; Yorimitsu, H.; Osuka, A. Org. Lett. 2014, 16, 972. (19) Characterizations of 13-syn and 13-anti are described in SI, chapter 4. (20) Hata, H.; Shinokubo, H.; Osuka, A. J. Am. Chem. Soc. 2005, 127, 8264. (21) Kato, K.; Kim, W.; Kim, D.; Yorimitsu, H.; Osuka, A. Chem. Eur. J. 2016, 22, 7041. (22) Upon the peer review of the manuscript, one reviewer gave us a fruitful suggestion that the use of other nucleophiles instead of hydride would open a new chemistry. Although we have never attempted these transformations, it will be a nice approach to synthesize novel functional molecules. For example, addition of a linker that has two nucleophilic sites may provide a covalently linked arch-tape dimer. (23) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A., Jr.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, J. M.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, O.; Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian 09, Revision E.01; Gaussian, Inc.: Wallingford, CT, 2009. (24) The Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard, R., Eds.; Academic Press: USA, 2000; Vol. 3. (25) The MPDs are defined by the 25 core atoms consisting of mesocarbons, four pyrrole units, and central nickel atom. (26) Distorted porphyrins generally show red-shifted absorption. The Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard, R., Eds.; Academic Press: USA, 2000; Vol. 1. (27) (a) Hoffmann, R.; Imamura, A.; Hehre, W. J. J. Am. Chem. Soc. 1968, 90, 1499. (b) Heilbronner, E.; Schmelzer, A. Helv. Chim. Acta 1975, 58, 936. (28) Fukui, N.; Yorimitsu, H.; Osuka, A. Chem. - Eur. J. 2016, 22, 18476. (29) (a) Scott, L. T.; Hashemi, M. M.; Bratcher, M. S. J. Am. Chem. Soc. 1992, 114, 1920. (b) Seiders, T. J.; Baldridge, K. K.; Grube, G. H.; Siegel, J. S. J. Am. Chem. Soc. 2001, 123, 517. (30) (a) Amaya, T.; Sakane, H.; Muneishi, T.; Hirao, T. Chem. Commun. 2008, 765. (b) Shrestha, B. B.; Karanjit, S.; Higashibayashi, S.; Sakurai, H. Pure Appl. Chem. 2014, 86, 747. (31) Gasparro, F. P.; Kolodny, N. H. J. Chem. Educ. 1977, 54, 258. (32) Drain, C. M.; Kirmaier, C.; Medforth, C. J.; Nurco, D. J.; Smith, K. M.; Holten, D. J. Phys. Chem. 1996, 100, 11984. (33) Snellenburg, J. J.; Laptenok, S. P.; Seger, R.; Mullen, K. M.; van Stokkum, I. H. M. J. Stat. Softw. 2012, 49, 1. (34) Siebrand, W.; Williams, D. F. J. Chem. Phys. 1968, 49, 1860. (35) Lee, S.; Mori, H.; Lee, T.; Lim, M.; Osuka, A.; Kim, D. Phys. Chem. Chem. Phys. 2016, 18, 3244. 9088


Porphyrin Arch-Tapes: Synthesis, Contorted Structures, and Full

Recommend Documents