Single-Crystal-to-Single-Crystal Transformation of Di

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Single-Crystal-to-Single-Crystal Transformation of Di(isopropylammonium) (Z,Z)-Muconate into the (E,E)-Muconate during One-Way Photoisomerization in the Solid State Natsuko Nishizawa, Junya Nakamura, and Akikazu Matsumoto* Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan

bS Supporting Information ABSTRACT: The solid-state EZ photoisomerization of di(isopropylammonium) (Z,Z)-muconate (ZZ-1a) into the corresponding EE isomer (EE-1a) via a single-crystal-to-single-crystal reaction process was investigated. The molecular motion based on a bicycle-pedal model was directly observed during the photoisomerization in the crystals by an X-ray single crystal structure analysis. The photoirradiation of ZZ-1a provided EE-1a in a quantitative yield via a one-way isomerization mechanism, being different from the solution products in the photostationary state. The isomerization reactivity was discussed for the ammonium and ester derivatives of muconic acid.

’ INTRODUCTION The EZ photoisomerization of olefins, azo compounds, and polyenes in constrained media is explained by the volume-conserving reaction mechanism using the bicycle-pedal1 (BP) and hulatwist2 (HT) models. The BP model accounts for the two-bond photoisomerization of dienes, photochromism, and conformational changes in the crystals.3 9 The HT model is applied to various reactions including the isomerization of olefins and polyenes with bulky substituents in confined media, such as a viscous fluid, rigid matrix, organic glass, and organic crystals.10,11 Both the BP and HT models include less molecular motion during the reaction, while the conventional one-bond flip (one-bond twist) motion requires a large space for a change in the position of the substituents bound to a double bond. Several types of solidstate photoreactions of muconic derivatives as conjugated 1,3diene compounds, including topochemical polymerization,12,13 [2 + 2] cyclodimerization,14,15 and EZ isomerization16 have been reported. The reactions proceed via a topochemical mechanism under crystal lattice control, depending on the molecular packing structure in the crystals. Not only the ester derivatives17 but also the amide18 and ammonium19 23 derivatives of the mono- and dicarboxylic acid 1,3-diene compounds produce a highly controlled photoreaction product. Some ammonium carboxylate compounds have great potential as the supramolecular synthon to construct robust hydrogen bonded networks in the crystals24 27 and are often used for the crystal engineering research of chiral recognition28 and regio-, stereo-, and enantioselective photoreactions29 33 in the solid state because of their advantageous features,34 38 such as easy preparation, high crystallinity, large number of possible combinations, predictable hydrogen bond structures, finely tunable crystal structures, and so on. r 2011 American Chemical Society

Recently, we determined the topochemical photoisomerization process of dibenzyl (Z,Z)-muconate (ZZ-2a) in the solid state by monitoring the change in the crystal structure using an in situ X-ray single crystal structure analysis.39,40 The ammonium salts of the muconic acid imply the diverse network structures of strong and weak hydrogen bonds on the basis of intermolecular interactions, such as NH/O and CH/π interactions.23 Intermolecular hydrogen bonds often restrict the molecular motions during the isomerization in the crystals,41 but the fast EZ isomerizations of several ammonium muconates were actually reported.16 In this paper, we report the solid-state photoisomerization of di(isopropylammonium) (Z,Z)-muconate (ZZ-1a) to di(isopropylammonium) (E,E)-muconate (EE-1a) (Scheme 1) via a single-crystal-to-single-crystal isomerization process according to a bicycle pedal model mechanism. The feature of the solidstate photoisomerization of the ammonium muconates as well as the ester derivatives is also discussed (Figure 1).

’ EXPERIMENTAL SECTION General Methods. NMR, IR, and UV visible spectra were recorded using Bruker AV300, Jasco FT/IR-430, and Shimadzu UV-160 spectrometers, respectively, at room temperature. The single-crystal X-ray diffraction data were collected using a Rigaku RAXIS RAPID imaging plate diffractometer with Mo KR radiation (λ = 0.71073 Å) monochromated by graphite. The crystal structures were solved by a direct method using SIR92 and refined by the full-matrix least-squares method on F2 with anisotropic displacement parameters for the non-hydrogen atoms Received: February 7, 2011 Revised: June 21, 2011 Published: June 28, 2011 3442

dx.doi.org/10.1021/cg200184c | Cryst. Growth Des. 2011, 11, 3442–3447

Crystal Growth & Design

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Scheme 1. Photoisomerization of Di(isopropylammonium) (Z,Z)-Muconate (ZZ-1a) to Di(isopropylammonium) (E,E)Muconate (EE-1a) in the Solid State

Figure 1. Chemical structure of ammonium and ester derivatives of (Z,Z)-muconic acid.

using SHELXL-97. The powder X-ray diffraction profiles were recorded using a Rigaku RINT-2100 with monochromated Cu KR radiation (λ = 1.54184 Å, 40 kV, 40 mA, scan speed 2.0°/min) equipped with a high-resolution parallel-beam optics system consisting of a PSA100U parallel slip analyzer and a graded 2960C1 multiplayer. Materials. The (Z,Z)- and (E,E)-muconic acids were purchased from Aldrich Co., Ltd., and used as received. The esters were prepared by the reaction of the muconic acids according to a previously reported procedure.17,40 The single crystals were obtained during the evaporation of the chloroform or ethanol solutions at room temperature. Photoreaction. The photoreaction was carried out using an ultrahigh pressure mercury Moritex MUV-250U-L lamp (500 W; 254, 313, 365, 405, 436 nm and others) and an IRA-25S infrared absorption filter after the sample was ground to a powder. The UV light was irradiated directly to the solid samples or as the dispersions of the powder crystals in n-hexane or a mixture of water and methanol (4/1 volume ratio) with stirring using a quartz cell under argon atmosphere. The photoreaction of the single crystals was carried out using the same irradiation apparatus and a UV-D36B band path filter (Asahi Techno Glass Co.) to irradiate light in the wavelength range of 300 400 nm and supplied for the X-ray structure analysis. The crystal was exposed to light for which it has a low absorption to obtain a homogeneous product throughout the bulk of the crystal and achieve a single-crystal-to-single-crystal reaction.42 After the

Figure 2. Molecular packing structures for (a) ZZ-1a and (b) EE-1a viewed down along the crystallographic b- and a-axes in the crystals and (c) a repeating unit for 1D ladder hydrogen bond. photoirradiation, the conversion of the isomer was determined by NMR spectroscopy.

’ RESULTS AND DISCUSSION Figure 2 shows the molecular packing and the hydrogen bond network structure for the ZZ-1a and EE-1a crystals. The cell parameters are shown in Table 1. The crystals ZZ-1a and EE-1a have similar lattice lengths, angles, molecular packing structures, and crystal symmetry. Both crystals imply a similar onedimensional (1D) ladder hydrogen bond structure, which is built up of a repeating 10-membered ring consisting of four hydrogen, one carbon, three oxygen, and two nitrogen atoms along the b-axis with a 21 helical structure (Figure 2c and Table 2).21,28 The 1D ladder hydrogen bond structures were maintained, and the geometry of the muconate changed from ZZ to EE during the isomerization. During the initial stage of the photoisomerization in the crystals, a disordered structure was observed around the muconate moiety. The ORTEP drawings for the crystals of ZZ1a before and after the photoirradiation are shown in Figure 3. The disordered structure observed after the photoirradiation was revealed to consist of both the ZZ-1a and EE-1a molecules. The conversion of ZZ-1a to EE-1a was estimated to be 17% from the 3443

dx.doi.org/10.1021/cg200184c |Cryst. Growth Des. 2011, 11, 3442–3447


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Table 1. Selected Cell Parameters for the Crystals of ZZ-1a and EE-1a ZZ-1a after 5-h ZZ-1a formula formula weight

photoirradiation

EE-1a

C12H24N2O4 C12H24N2O4 260.33 260.33

C12H24N2O4 260.33

crystal system

P21/n

P21/c

P21/n

a, Å

6.5119(4)

6.4631(17)

6.5022(14)

b, Å

5.8624(8)

5.9109(19)

5.8929(16)

c, Å

20.426(5)

20.402(8)

20.534(6)

β, deg

93.904(8)

97.10(3)

94.839(10)

V, Å3

778.0(3)

773.4(4)

784.0(3)

Z Fcalc, g/cm3

2 1.111

2 1.118

2 1.103

unique reflections

1767

1781

1708

no. observed (I > 2σ(I)) 1259

1250

977

R1,

0.038

0.095

0.050

wR2

0.095

0.090

0.129

GOF

1.096

0.926

0.915

temp, K

123

123

123

Figure 3. ORTEP drawings of ZZ-1a (a) as the initial molecular structure and (b) after 5 h photoirradiation. The structure in (b) is separated into ZZ-1a and EE-1a with a site occupancy factor of 17% for EE-1a. The thermal ellipsoids are plotted at the 50% probability level.

Table 2. Hydrogen Bond Length and Angle for the Crystals ZZ-1a and EE-1a crystal

hydrogen bond

ZZ-1a

N1 H1 3 3 3 O1 N1 H2 3 3 3 O2 N2 H3 3 3 3 O1 N1 H1 3 3 3 O1

EE-1a

N1 H2 3 3 3 O2 N2 H3 3 3 3 O1

H3 3 3A (Å)

D3 3 3A (Å)

D H 3 3 3 A angle (deg)

1.879

2.803

171.25

1.811

2.785

170.15

1.705

2.723

171.59

1.901

2.805

172.43

1.857

2.752

167.50

1.848

2.740

165.91

site occupancy factor of the product in the crystal after a 5 h photoisomerization. As already described in the introduction, the BP43 and HT44,45 models have been used for the interpretation of the EZ isomerization mechanism of olefin and diene compounds in constrained media. The isomerization of ZZ-1a to EE-1a occurs according to the BP model as clearly elucidated by the results in Figure 3. This conclusion agrees well with the previous results for the isomerization of the benzyl muconate (ZZ-2a).39,40 A small expansion of the cell size was observed because of the coexistence of the starting ZZ-1a molecules and product EE-1a molecules in the crystal during the photoisomerization. As summarized in Table 1, the crystal density of ZZ-1a after photoirradiation (F = 1.103 g/cm3) was lower than that before the irradiation (1.111 g/cm3) and that for EE-1a (1.118 g/cm3). An increase in the crystal volume during a reaction is often observed during solidstate reactions, for example, the topochemical polymerization of the muconate derivatives. Previously, we examined a continuous change in the crystal structure and the strain accumulated in the crystals during the shrinking and expanding polymerizations.46 When the change in the X-ray diffraction profiles of the muconates was investigated by continuous X-ray radiation, some lattice lengths temporarily increased during an initial stage of the polymerization. The lattice lengths then gradually decreased and approached the values for the single crystals of the corresponding polymer.

Figure 4. Change in X-ray diffraction profile of ZZ-1a during photoirradiation in the crystalline state. The conversion of ZZ-1a to EE-1a was determined by NMR spectroscopy.

The isomerization of the molecule ZZ-1a to EE-1a can occur with the maintenance of the single crystals during the initial stage of the reaction, but a longer photoirradiation leads to the collapse of the single crystals to produce polycrystals. Figure 4 shows the change in the powder X-ray diffraction patterns during the photoisomerization of ZZ-1a under UV irradiation in the solid state. The conversion of ZZ-1a to EE-1a was determined by NMR spectroscopy. A change in the powder X-ray diffraction profile revealed that the solid-state reaction process via a heterogeneous reaction mechanism47 accompanied the crystal phase separation and the crystal phase transition from a substrate crystal structure to a product crystal structure during the photoisomerization. Previously, we investigated the polymerization of the di(4-alkoxybenzyl) (E,E)- and (Z,Z)-muconates monitored by in situ single-crystal and powder X-ray diffraction experiments to discuss the effect of crystal phase separation on a reaction mechanism. It was demonstrated that all diffraction lines continuously shifted from a position for the monomer to that for the polymer without broadening of the line in the powder X-ray 3444



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Figure 5. Time conversion plots for the one-way photoisomerization of (Z,Z)-muconic derivatives to the corresponding EE isomers during UV irradiation at room temperature. (O) ZZ-1a, (0) ZZ-1d, (9) ZZ-2a (R form) (ref 40), and (b) ZZ-2a (β form) (ref 40). The powder crystals were irradiated by an ultrahigh pressure mercury lamp. The conversion was determined by NMR spectroscopy.

diffraction profile observed during the polymerizations of the (E,E)-ester. On the other hand, the diffraction lines of the (Z,Z)derivative showed a discontinuous change under the same radiation conditions. The profiles of the diffraction from the (Z,Z) crystals consisted of the lines due to the monomer and the polymer accompanied by crystal phase separation. Topochemical polymerization includes two kinds of polymerization mechanisms as the extreme cases;42 one is the homogeneous reaction mechanism, as was seen in the polymerization of the (E,E)-muconate. In this model, the polymerization occurs at random positions of the crystals and forms a solid solution. No phase separation is observed at the intermediate stage of the reaction. Another is the heterogeneous reaction mechanism, being observed for the (Z,Z)-muconate. The reaction starts preferentially near specific defect sites and accompanies the nucleation of a product phase. The product forms a new domain in the substrate crystals in the process of the reaction, and consequently, phase separation is observed at the intermediate stage. In this study, ZZ-1a undergoes the isomerization to EE-1a with the maintenance of the single crystals during the initial stage of the reaction (below 20% conversion), and a phase separation between the substrate and the product domains occurs via a heterogeneous reaction mechanism, leading to the polycrystals at a higher conversion. The solid-state reactivity of a substrate depends on circumstances in the solid in addition to its intrinsic molecular reactivity. The desired product is often obtained only at a low conversion because of a change in the state of the medium from crystalline to amorphous. In contrast, the photoisomerization of ZZ-1a occurred via a crystal-to-crystal reaction process to allow quantitative conversion to EE-1a during a 20 h irradiation, as shown in a time conversion relationship for the isomerization of several (Z,Z)-muconic derivatives to the corresponding EE isomers in Figure 5. In general, olefins usually undergo EZ-isomerization in the singlet excited state during direct photoirradiation, and the triplet state isomerization often occurs in the presence of any photosensitizer.48 While olefins usually undergo an EZ mutual (two-way) isomerization in the singlet as well as in the triplet state, it has been reported that several olefins substituted by bulky alkyl groups undergo a one-way EZ isomerization because of the lowering of the triplet state energy.49,50 For the EZ-photoisomerization of the muconate derivatives, we have confirmed that they

Figure 6. Change in the isomer composition during the UV irradiation of (a) ZZ-1a, (b) EE-1a, (c) ZZ-2a, and (d) EE-2a in methanol-d4 at room temperature. (O) ZZ-isomer, (Δ) EZ-isomer, (0) EE-isomer. Substrate concentration, 5 wt %. No accurate isomer composition was determined for the isomerization of the ester derivative (c and d) after a 50 h photoirradiation because of the formation of other products including dimers.

undergo one-way isomerization in the solid state. In a solution, the isomer composition reaches a ratio in the photostationary state (EE ∼ 50%, EZ ∼ 50% and ZZ < 2%) that is independent of the starting geometry of the muconates (Figure 6). Thus, the isomerization behavior of the muconates significantly depends on the reaction medium, that is, in the crystals or solutions. It is also noted that dimers and other oligomers were competitively produced for the reaction of the ester derivatives during photoirradiation for a long time, while no dimer formation was detected in the reaction of the ammonium derivative under the conditions at the same substrate concentration. This may be due to repulsion between the muconate anion in a solution. No dimer formation was observed during the reaction of ZZ-1a and ZZ-2a during photoirradiation in the solid state. The distance between the double bonds of the adjacent molecules is far from that appropriate for the dimer formation.14 The solid-state isomerization reactivity of ZZ-1a and the other ammonium derivatives was similar or greater than those for the ester derivatives (Figure 5 and Table 3). It should be noted that the rate of the solid-state photochemical reactions significantly depends on many factors, such as the size and shape of the solid samples. In the UV vis diffusion reflection absorption spectra of ZZ-1a and ZZ-2a in the solid state, both derivatives have similar maximum absorption wavelengths, independent of the ZZ and EE structures; λmax = 259 nm (λmax = 257 nm in methanol) for ZZ-1a, λmax = 259 nm (λmax = 257 nm in methanol) for EE-1a, λmax = 265 nm for ZZ-2a and λmax = 266 nm for EE-2a. This suggests a similar excitation structure upon photoirradiation and a similar subsequent photochemical process for the isomerization. The photoisomerization of ZZ-1a and ZZ-2a was carried out in the dispersion of their powder crystals in n-hexane and a water/methanol mixture (4/1 volume ratio) as the nonsolvents, respectively, to carry out the reactions under the more efficient 3445



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Table 3. Photoisomerization of the Ammonium and Ester Derivatives of Muconic Acid with Various Alkyl Substituents derivative ZZ-1a

substituent R CH(CH3)2

time (h)

conv (%)

8

69

0.2a 2a

55a 98a

ZZ-1b

C2H5

8

14

ZZ-1c

(CH2)2CH3

8

35

ZZ-1d

(CH2)3CH3

8

95

ZZ-1e

(CH2)6CH3

8

84

ZZ-1f

(CH2)7CH3

8

27

ZZ-1 g

(CH2)8CH3

8

22

ZZ-1 h ZZ-2a

C6H11 (cyclohexyl) CH2C6H5 (R form)

8 20

10 86

0.2b

47b

b

2

89b

ZZ-2a

CH2C6H5 (β form)

20

54

ZZ-2b

CH3

24

3

ZZ-2c

(CH2)9CH3

24

26

ZZ-2d

C6H11 (cyclohexyl)

24

17

a

Dispersed in n-hexane. b Dispersed in a mixture of water and methanol (4/1 volume ratio).

photoirradiation conditions. As a result, both isomerization reactions rapidly proceeded and the EE products were produced in a high yield within a short time during the photoirradiation. The ZZ-1a crystals showed a higher reactivity than the ZZ-2a crystals. At the present time, however, we cannot conclude the effect of the alkyl substituent on the isomerization reactivity in the solid state because the isomerization behavior sensitively changes according to the crystal structures such as polymorphs.17,40

’ CONCLUSION It has been demonstrated that the isomerization from the ZZ to the EE form of the ammonium muconate occurs according to a BP model with minimum movement of the atoms in the solid state based on the results of the X-ray single-crystal structure analysis of a single-crystal-to-single-crystal reaction process. The intermolecular hydrogen bond network was found to be maintained during the isomerization, and the one-way EZ isomerization proceeded with a 100% yield in the solid state, similar to the isomerization of the muconic esters. ’ ASSOCIATED CONTENT

bS

Supporting Information. CIF for ZZ-1a, ZZ-1a (after photoirradiation), and EE-1a. This material is available free of charge via the Internet at http://pubs.acs.org.

’ AUTHOR INFORMATION Corresponding Author

*E-mail: [email protected].

’ ACKNOWLEDGMENT A part of this work was supported by Grants-in-Aids from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.

’ REFERENCES (1) Warshel, A. Nature 1976, 260, 679–683. (2) Liu, R. S. H. Acc. Chem. Res. 2001, 34, 555–562. (3) Saltiel, J.; Krishna, T. S. R.; Clark, R. J. J. Phys. Chem. A 2006, 110, 1694–1697. (4) Saltiel, J.; Krishna, T. S. R.; Turek, A. M.; Clark, R. J. Chem. Commun. 2006, 1506–1508. (5) Saltiel, J.; Krishna, T. S. R.; Laohhasurayotin, S.; Fort, K.; Clark, R. J. J. Phys. Chem. A 2008, 112, 199–209. (6) Saltiel, J.; Bremer, M. A.; Laohhasurayotin, S.; Krishna, T. S. R. Angew. Chem., Int. Ed. 2008, 47, 1237–1240. (7) Saltiel, J.; Krishna, T. S. R.; Laohhasurayotin, K.; Ren, Y.; Phipps, K.; Davis, P. H.; Yee, W. A. J. Phys. Chem. A 2011, 115, 2120–2129. (8) Harada, J.; Ogawa, K. Chem. Soc. Rev. 2009, 38, 2244–2252. (9) Sokolov, A. N.; Swenson, D. C.; MacGillivray, L. R. Proc. Nat. Acad. Sci. U.S.A. 2008, 105, 1794–1797. (10) Liu, R. S. H. Photochem. Photobiol. 2002, 76, 580–583. (11) Yang, L.-Y.; Liu, R. S. H.; Boarman, K. J.; Wendt, N. L.; Liu, J. J. Am. Chem. Soc. 2005, 127, 2404–2405. (12) Matsumoto, A.; Matsumura, T.; Aoki, S. J. Chem. Soc., Chem. Commun. 1994, 1389–1390. (13) Matsumoto, A. Top. Curr. Chem. 2005, 254, 263–305. (14) Mori, Y.; Matsumoto, A. Cryst. Growth Des. 2007, 7, 377–385. (15) Atkinson, M. B. J.; Halasz, I.; Bucar, D.-K.; Dinnebier, R. E.; Mariappan, S. V. S.; Sokolov, A. N.; MacGillivray, L. R. Chem. Commun. 2011, 47, 236–238. (16) Odani, T.; Matsumoto, A.; Sada, K.; Miyata, M. Chem. Commun. 2001, 2004–2005. (17) Matsumoto, A.; Tanaka, T.; Tsubouchi, T.; Tashiro, K.; Saragai, S.; Nakamoto, S. J. Am. Chem. Soc. 2002, 124, 8891–8902. (18) Mori, Y.; Chiba, T.; Odani, T.; Matsumoto, A. Cryst. Growth Des. 2007, 7, 1356–1364. (19) Matsumoto, A.; Odani, T.; Chikada, M.; Sada, K.; Miyata, M. J. Am. Chem. Soc. 1999, 121, 11122–11129. (20) Matsumoto, A.; Odani, T.; Aoki, S. Polym. J. 1998, 30, 358–360. (21) Matsumoto, A.; Nagahama, S.; Odani, T. J. Am. Chem. Soc. 2000, 122, 9109–9119. (22) Nagahama, S.; Matsumoto, A. J. Am. Chem. Soc. 2001, 123, 12176–12181. (23) Nagahama, S.; Inoue, K.; Sada, K.; Miyata, M.; Matsumoto, A. Cryst. Growth Des. 2003, 3, 247–256. (24) Aaker€oy, C. B.; Nieuwenhuyzen, M. J. Am. Chem. Soc. 1994, 116, 10983–10991. (25) Russell, V. A.; Etter, M. C.; Ward, M. D. J. Am. Chem. Soc. 1994, 116, 1941–1952. (26) Biradha, K.; Dennis, D.; MacKinnon, V. A.; Zaworotko, M. J. J. Am. Chem. Soc. 1998, 120, 11894–11903. (27) Sada, K.; Shiomi, N.; Miyata, M. J. Am. Chem. Soc. 1998, 120, 10543–10544. (28) Kinbara, K.; Hashimoto, Y.; Sukegawa, M.; Nohira, H.; Saigo, K. J. Am. Chem. Soc. 1996, 118, 3441–3449. (29) Ito, Y.; Borecka, B.; Trotter, J.; Scheffer, J. R. Tetrahedron Lett. 1995, 36, 6083–6086. (30) Cheung, E.; Netherton, M. R.; Scheffer, J. R.; Trotter, J. J. Am. Chem. Soc. 1999, 121, 2919–2920. (31) Cheung, E.; Kang, T.; Netherton, M. R.; Scheffer, J. R.; Trotter, J. J. Am. Chem. Soc. 2000, 122, 11753–11754. (32) Scheffer, J. R.; Wang, K.-Y. Synthesis 2001, 1253–1257. (33) Turowska-Tryk, H.; Bakowicz, J.; Scheffer, J. R.; Xia, W. Cryst. Eng. Commun. 2006, 8, 616–621. (34) Zimmerman, H. E.; Alabugin, I. V. A.; Smolenskaya, N. Tetrahedron 2000, 56, 6821–6831. (35) MacNicol, D. D.; Toda, F.; Bishop, R., Eds.; Comprehensive Supramolecular Chemistry; Pergamon: Oxford, 1996; Vol. 6. (36) Ramamurthy, V., ed.; Photochemistry in Organized & Constrained Media; VCH: New York, 1991. 3446



ARTICLE

(37) Ramamurthy, V.; Chanze, K. S., Eds.; Organic Molecular Photochemistry; Marcel Dekker: New York, 1999. (38) Toda, F., Ed.; Organic Solid State Reaction. In Topics in Current Chemistry; Springer: New York, 2005; Vol. 254. (39) Furukawa, D.; Kobatake, S.; Matsumoto, A. Chem. Commun. 2008, 55–57. (40) Nishizawa, N.; Furukawa, D.; Kobatake, S.; Matsumoto, A. Cryst. Growth Des. 2010, 10, 3203–3210. (41) Kinbara, K.; Kai, A.; Maekawa, Y.; Hashimoto, Y.; Naruse, S.; Hasegawa, M.; Saigo, K. J. Chem. Soc., Perkin Trans. 2 1996, 247–253. (42) Enkelmann, V.; Wegner, G.; Novak, K.; Wagener, K. B. J. Am. Chem. Soc. 1993, 115, 10390–10391. (43) Saltiel, J.; Krishna, T. S. R.; Turek, A. M. J. Am. Chem. Soc. 2005, 127, 6938–6939. (44) Yang, L.-Y.; Liu, R. S. H.; Wendt, N. L.; Liu, J. J. Am. Chem. Soc. 2005, 127, 9378–9379. (45) Zhao, Y.-P.; Yang, L.-Y.; Simmons, C. J.; Liu, R. S. H. Chem.— Asian J. 2009, 4, 754–760. (46) Matsumoto, A.; Furukawa, D.; Mori, Y.; Tanaka, T.; Oka, K. Cryst. Growth Des. 2007, 7, 1078–1085. (47) Furukawa, D.; Matsumoto, A. Macromolecules 2007, 40, 6048–6056. (48) Turro, N. J.; Ramamurthy, V.; Sciano, J. C., Eds.; Modern Molecular Photochemistry of Organic Molecules; University Science: Sausalito, CA, 2010. (49) Arai, T. Organic Molecular Photochemistry; Ramamurthy, V., Chanze, K. S., Eds.; Marcel Dekker: New York, 1999; pp 131 167. (50) Arai, T.; Tokumaru, K. Chem. Rev. 1993, 93, 23–39.

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Single-Crystal-to-Single-Crystal Transformation of Di

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