Article pubs.acs.org/Organometallics
Synthetic and Structural Studies on Linear and Macrocyclic Pd- and Pt-Bridged Butterfly Fe/S Cluster Complexes Li-Cheng Song,*,†,‡ Long-Duo Zhang,† Bei-Bei Liu,† Shu-Da Ding,† Hao Chen,† Xiu-Fang Xu,*,† and Gui-Lan Fan† †
Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry and ‡Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China S Supporting Information *
ABSTRACT: Three types of (diphosphine)Pd- or Pt-bridged butterfly Fe/S cluster complexes have been prepared by a simple and convenient one-pot synthetic method. The first type of such complexes involves the linear (diphosphine)Pd- or Pt-bridged double-butterfly Fe/S clusters [(μ-RS)(μ-SCS)Fe2(CO)6]2[M(diphosphine)] (1−12; M = Pd and Pt; R = Et, t-Bu, Ph, and pMeC6H4; diphosphine = dppe, dppv, and dppf), which were prepared by sequential reactions of monoanions [(μ-RS)(μ-CO)Fe2(CO)6]− (formed in situ from Fe3(CO)12, RSH, and Et3N) with excess CS2, followed by treatment of the resulting monoanions [(μRS)(μ-SCS)Fe2(CO)6]− with (diphosphine)MCl2. The second type of complexes involves the macrocyclic (diphosphine)M-bridged double-butterfly Fe/S clusters [μ-S(CH 2 ) 4 S-μ][(μ-SCS)Fe2(CO)6]2[M(diphosphine)] (13−16; M = Pd and Pt; diphosphine = dppe and dppv), which were prepared by sequential reactions of dianion [{μ-S(CH2)4S-μ}{(μ-CO)Fe2(CO)6}2]2− (generated in situ from Fe3(CO)12, dithiol HS(CH2)4SH, and Et3N) with excess CS2, followed by treatment of the resultant dianion [{μS(CH2)4S-μ}{(μ-SCS)Fe2(CO)6}2]2− with (diphosphine)MCl2. In contrast, when dithiol HS(CH2)4SH was replaced by HS(CH2)3SH (a dithiol with a shorter carbon chain), the aforementioned sequential reactions afforded the third type of macrocyclic complexes which involves the (diphosphine)M-bridged quadruple-butterfly Fe/S clusters [{μ-S(CH2)3S-μ}{(μ-S CS)Fe2(CO)6}2]2[M(diphosphine)]2 (17−20; M = Pd and Pt; diphosphine = dppe and dppv). While the two possible pathways are suggested for production of the two types of novel macrocyclic Fe/S clusters 13−20, respectively, all new complexes 1−20 have been characterized by elemental analysis, spectroscopy, and, for some of them particularly, DFT calculations and X-ray crystallography.
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INTRODUCTION The butterfly Fe/S cluster complexes have received great attention in recent years, largely due to their unique structures and varied chemical reactivities,1−11 and particularly their close relationship with [FeFe]-hydrogenases.12−20 In 2010, we reported a simple and convenient one-pot synthetic method,21 by which three types of (diphosphine)Ni-bridged butterfly Fe/ S complexes were prepared by sequential reactions of the in situ generated one-μ-CO-containing monoanions [(μ-RS)(μ-CO)Fe2(CO)6]− (A)9,22 and two-μ-CO-containing dianions [{μS(CH2)nS-μ}{(μ-CO)Fe2(CO)6}2]2− (B, n = 4; C, n = 3)10,23 with carbon disulfide and various diphosphine-chelated nickel dichlorides. While the first type of such complexes involves a linear (diphosphine)Ni-bridged double-butterfly Fe/S cluster, the second and third types of such complexes involve macrocyclic (diphosphine)Ni-bridged double-butterfly or quadruple-butterfly Fe/S cluster, respectively (Scheme 1). To show the generality of this one-pot synthetic method and to prepare the hitherto unknown Pd and Pt analogues of the previously reported three types of the (diphosphine)Ni-bridged © XXXX American Chemical Society
butterfly Fe/S complexes, we carried out the sequential reactions of one-μ-CO-containing monoanions A (formed in situ from Fe3(CO)12, RSH, and Et3N)9,22 and two-μ-COcontaining dianions B and C (generated in situ from Fe3(CO)12, dithiol HS(CH2)4SH or HS(CH2)3SH, and Et3N)10,23 with carbon disulfide and various diphosphinechelated Pd or Pt dichlorides. As a result, the expected three types of the (diphosphine)Pd- or Pt-bridged butterfly Fe/S complexes were produced. This implies that this one-pot synthetic method is potentially generalizable for preparation of the other transition metal-bridged linear and macrocyclic butterfly Fe/S cluster complexes. Herein, we report the synthetic procedures and structural characterization of these novel linear and macrocyclic (diphosphine)Pd- or Pt-bridged butterfly Fe/S complexes. In addition, the possible pathways for production of the two types of macrocyclic Fe/S cluster complexes are also described. Received: February 16, 2017
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DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
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Organometallics Scheme 1. Previously Reported (Diphosphine)Ni-Bridged Butterfly Fe/S Cluster Complexes21
Scheme 2. Synthetic Route to Linear Double-Butterfly Complexes 1−12
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RESULTS AND DISCUSSION Synthesis and Structural Characterization of Linear Pd or Pt-Bridged Double-Butterfly Fe/S Clusters [(μRS)(μ-SCS)Fe2(CO)6]2[M(dppe)] (1, M = Pd, R = Ph; 2, Pd, Et; 3, Pt, p-MeC6H4; 4, Pt, t-Bu), [(μ-RS)(μ-S CS)Fe2(CO)6]2[M(dppv)] (5, M = Pd, R = Ph; 6, Pd, t-Bu; 7, Pt, p-MeC6H4; 8, Pt, t-Bu), and [(μ-RS)(μ-SCS)Fe2(CO)6]2[M(dppf)] (9, M = Pd, R = Ph; 10, Pd, Et; 11, Pt, p-MeC6H4; 12, Pt, t-Bu). The linear (diphosphine)Pd- or Pt-bridged complexes that contain two butterfly [Fe2SCS] cluster cores, namely, 1−12, were found to be prepared by sequential reactions of the [Et3NH]+ salts of one-μ-COcontaining monoanions [(μ-RS)(μ-CO)Fe 2 (CO)6 ]− (A, formed in situ from Fe3(CO)12, Et3N, and RSH)9,22 with excess CS2, followed by treatment of the resulting [Et3NH]+ salts of one-μ-CS2-containing monoanions [(μ-RS)(μ-S CS)Fe2(CO)6]− (A′)24,25 with diphosphine dppe-, dppv-, or dppf-chelated palladium and platinum dichlorides, respectively (Scheme 2). Linear Pd- or Pt-bridged Fe/S complexes 1−12 are air-stable red solids and have been characterized by elemental analysis, infrared (IR) spectrophotometry, and various NMR spectroscopic techniques. For example, the IR spectra of 1−12 showed three strong absorption bands in the range of 2061−1975 cm−1 for their terminal carbonyls and one medium absorption band in the range of 1000−988 cm−1 for their μ-CS groups, which are very close to those corresponding to their Ni analogues,21 respectively. The 1H NMR spectra of 3, 7, and 11 showed a singlet at ca. 2.25 ppm for the methyl groups of their p-MeC6H4 groups, while those of 4, 6, 8, and 12 displayed a singlet at ca. 1.42 ppm for the t-Bu groups bound to their bridged S atoms. In addition, the 31P{1H} NMR spectra of 1−8 with organic diphosphine dppe or dppv ligand exhibited two singlets in the range of 39−61 ppm attributed to their diphosphine P atoms, whereas those of 9−12 with organometallic diphosphine dppf ligand displayed one or two singlets in the region of 12−25 ppm for thier diphosphine P atoms. The 13C{1H} NMR spectra of 1−12 displayed a singlet at 308−315 ppm for the 13C atoms in their μ-CS groups. To further confirm the molecular structures of representative linear double-butterfly complexes 1 and 3 and to obtain the corresponding geometric parameters, the X-ray crystal diffraction analyses for complexes 1 and 3 were obtained.
While Figures 1 and 2 show their molecular structures, Table 1 gives their selected bond lengths and angles. As shown in Figure 1, complex 1 indeed consists of two single-butterfly cluster cores Fe1Fe2S3C13S2 and Fe3Fe4S6C20S5, which are combined together by the dppe-chelated Pd1 atom through Pd1−S1 and Pd1−S4 bonds. All 12 CO’s bound to iron atoms are terminal, and the two phenyl groups are attached to S3 and S6 atoms via an equatorial type of bonds, C14−S3 (nonbonded angle ∠C14−S3···S2 = 164.6°) and C21−S6 (nonbonded angle ∠C21−S6···S5 = 171.7°).4,26 Thiocarbonyls C13S2 (1.691 Å) and C20S5 (1.684 Å) in complex 1, similar to its Ni analogues21 and the other μ-CS2-containing butterfly Fe/S complexes,27 are coordinated to Fe1 and Fe3 by σ-bonds (Fe1−C13 = 1.966 Å, Fe3−C20 = 1.965 Å) and to Fe2 and Fe4 through donation of the lone electron pair from S2 or S5 (Fe2−S2 = 2.302 Å, Fe4−S5 = 2.314 Å). As can be seen in Figure 2, complex 3 is almost isostructural with complex 1. For example, complex 3 also comprises two single-butterfly cluster cores (Fe1Fe2S1C20S2 and Fe3Fe4S6C47S5), which are connected together by the dppe-chelated Pt1 atom via Pt1− S3 and Pt1−S4 bonds. In addition, its p-MeC6H4 groups are bound to the bridged S1 and S6 atoms by equatorial type of bonds, C13−S1 (nonbonded angle ∠C13−S1···S2 = 161.2°) and C48−S6 (nonbonded angle ∠C48−S6···S5 = 162.8°).4,26 Synthesis and Structural Characterization of Macrocyclic Pd or Pt-Bridged Double-Butterfly Fe/S Clusters [μ-S(CH2)4S-μ][(μ-SCS)Fe2(CO)6]2[M(dppe)] (13, M = Pd; 14, Pt) and [μ-S(CH2)4S-μ][(μ-SCS)Fe2(CO)6]2[M(dppv)] (15, M = Pd; 16, Pt). The macrocyclic (diphosphine)Pd- or Pt-bridged complexes containing two butterfly [Fe2SCS] cluster cores, namely, 13−16, could be prepared by sequential B
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
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Organometallics
Figure 1. Molecular structure of 1 with 30% probability level ellipsoids. All hydrogen atoms have been omitted for clarity.
the two μ-CS groups bridged between their two Fe atoms.21 In addition, while the 31P{1H} NMR spectra of 13−16 exhibited one or two singlets in the range of 40−61 ppm for the two P atoms in their diphosphine ligands, the 13C{1H} NMR spectra of 13−16 displayed a singlet at 312−316 ppm for the 13C atoms in their μ-CS groups. To further know the molecular and electronic structures of the representative macrocycles of Pd- and Pt-bridged complexes 13 and 14, the DFT calculations on 13 and 14 were carried out. All of the calculations were performed with Gaussian 09 software package.28 The geometry optimizations for 13 and 14 were performed in gas phase with the B3LYP functional.29−33 The Stuttgart/Dresden effective core potential (SDD)34 was used for iron, palladium, and platinum atoms, whereas the 6-31G(d) basis set was employed for other atoms. In addition, the frequency calculations were performed at 298.15 K to verify that the two macrocycles were the local minima. The DFT-optimized molecular structures of 13 and 14 are depicted in Figure 3, while Table 2 lists their calculated bond lengths and angles. As can be seen in Figure 3, complexes 13 and 14 contain two single-butterfly cluster moieties Fe1Fe2S5C1S3 and Fe3Fe4S6C2S4 linked together by a butylene chain (via C3−S5 and C4−S6 bonds) and a dppe-chelated palladium or platinum moiety (via Pd1−S1 and Pd1−S2 or Pt1−S1 and Pt1−S2), respectively. The calculated Fe1−Fe2 (2.617 Å) and Fe3−Fe4 (2.618 Å) bond lengths for 13 and 14 are very close to the corresponding bond lengths of their Ni analogues.21 The butylene group is attached to S5/S6 atoms via an axial type of bonds C3−S5 (nonbonded angles: ∠C3−S5··· S3 = 77.9° and ∠C4−S6···S4 = 77.2° for 13; ∠C3−S5···S3 = 77.8° and ∠C4−S6···S4 = 77.2° for 14) in order to reduce the ring strains in such a type of microcycles. In addition, the geometric configurations of the Pd and Pt atoms in 13 and 14 are nearly square-planar, and the bond lengths around Pd1 and Pt1 atoms are very close to the corresponding bond lengths for other Pd/Pt compounds.35,36
Figure 2. Molecular structure of 3 with 30% probability level ellipsoids. All hydrogen atoms have been omitted for clarity.
reactions of the [Et3NH]+ salt of two-μ-CO-containing dianion [{μ-S(CH2)4S-μ}{(μ-CO)Fe2(CO)6}2]2− (B, generated in situ from Fe3(CO)12, dithiol HS(CH2)4SH, and Et3N)23 with excess CS2, followed by treatment of the resultant [Et3NH]+ salt of two-μ-CS2-containing dianion [{μ-S(CH2)4S-μ}{(μ-SCS)Fe2(CO)6}2]2− (B′)23 with diphosphine dppe- or dppvchelated PdCl2 and PtCl2, respectively (Scheme 3). Macrocyclic Pd- or Pt-bridged Fe/S complexes 13−16 are also air-stable red solids and have been characterized by elemental analysis and various spectroscopic methods. For instance, the IR spectra of macrocycles 13−16, similar to those of linear complexes 1−12, showed three absorption bands in the range of 2053−1975 cm−1 for their terminal CO’s and one medium absorption band in the region of 999−989 cm−1 for C
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
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Organometallics Table 1. Selected Bond Lengths (Å) and Angles (deg) for 1 and 3 Complex 1 Pd(1)−P(1) Pd(1)−P(2) Pd(1)−S(1) Pd(1)−S(4) P(1)−Pd(1)−S(1) P(1)−Pd(1)−S(4) P(1)−Pd(1)−P(2) S(1)−Pd(1)−S(4)
2.2683(10) 2.2655(9) 2.3761(9) 2.3591(10) 94.69(3) 175.91(3) 86.24(4) 89.39(3)
Pt(1)−P(1) Pt(1)−P(2) Pt(1)−S(3) Pt(1)−S(4) P(1)−Pt(1)−S(4) P(1)−Pt(1)−S(3) P(1)−Pt(1)−P(2) S(3)−Pt(1)−S(4)
2.2599(12) 2.2629(11) 2.3713(11) 2.3684(11) 93.08(4) 172.13(4) 85.98(4) 87.13(4)
Fe(1)−S(3) S(2)−C(13) Fe(2)−S(2) Fe(1)−Fe(2) S(2)−Fe(2)−Fe(1) Fe(2)−S(3)−Fe(1) Fe(2)−Fe(1)−C(13) S(3)−Fe(1)−Fe(2)
2.2560(11) 1.691(4) 2.3023(11) 2.6350(8) 74.57(3) 71.40(4) 79.56(11) 54.36(3)
Fe(1)−S(1) Fe(2)−S(1) Fe(1)−S(2) Fe(1)−Fe(2) S(1)−Fe(2)−C(20) S(1)−Fe(1)−S(2) S(1)−Fe(1)−Fe(2) S(2)−Fe(1)−Fe(2)
2.2501(13) 2.2598(14) 2.3039(13) 2.6121(10) 83.74(12) 82.70(5) 54.78(4) 76.00(4)
Complex 3
Scheme 3. Synthetic Route to Macrocyclic Double-Butterfly Complexes 13−16
Table 2. Selected Bond Lengths (Å) and Angles (deg) for 13 and 14 Pd(1)−P(1) Pd(1)−P(2) Pd(1)−S(1) Pd(1)−S(2) P(1)−Pd(1)−P(2) S(1)−Pd(1)−S(2) P(1)−Pd(1)−S(1) P(2)−Pd(1)−S(2) Pt(1)−P(1) Pt(1)−P(2) Pt(1)−S(1) Pt(1)−S(2) P(1)−Pt(1)−P(2) S(1)−Pt(1)−S(2) P(1)−Pt(1)−S(1) P(2)−Pt(1)−S(2)
Complex 2.357 2.351 2.418 2.410 86.26 91.65 93.00 89.13 Complex 2.335 2.331 2.430 2.424 86.73 91.01 92.87 89.40
13 Fe(1)−S(3) Fe(2)−C(1) Fe(1)−Fe(2) Fe(3)−Fe(4) S(5)−Fe(1)−Fe(2) S(5)−Fe(2)−Fe(1) S(6)−Fe(3)−Fe(4) S(6)−Fe(4)−Fe(3) 14 Fe(1)−S(3) Fe(2)−C(1) Fe(1)−Fe(2) Fe(3)−Fe(4) S(5)−Fe(1)−Fe(2) S(5)−Fe(2)−Fe(1) S(6)−Fe(3)−Fe(4) S(6)−Fe(4)−Fe(3)
2.365 2.006 2.617 2.618 55.78 55.35 55.61 55.50 2.365 2.005 2.617 2.618 55.81 55.31 55.63 55.47
The frontier molecular orbitals of 13 and 14 obtained by DFT calculations are shown in Figure 4. It can be seen that the highest occupied molecular orbital (HOMO) of 13 is located
Figure 3. Optimized structures of 13 and 14. D
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
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Scheme 4. Synthetic Route to Macrocyclic QuadrupleButterfly Complexes 17−20
Figure 4. Frontier molecular orbitals of 13 and 14 based on DFT {B3LYP/SDD-6-31G(d)} calculations.
Now, the questions are how were [2 + 2] type macrocycles 17−20 produced from dianion C′, and how were [1 + 1] type macrocycles 13−16 generated from dianion B′? In order to answer the two questions, two corresponding possible pathways are proposed (Scheme 5). As shown in Scheme 5, [1 + 1] type macrocycles 13−16 are produced first via the intermolecular nucleophilic attack of the one negatively charged S atom in dianion B′ at Pd or Pt atom in (diphosphine)MCl2 to give intermediate m1 and then the intramolecular nucleophilic attack of another negatively charged S atom in m1 at its Pd or Pt atom accompanied by ring-closure. However, in contrast to intermediate m1, intermediate m2 (generated similarly by the intermolecular nucleophilic attack of dianion C′ at Pd or Pt atom of (diphosphine)MCl2) does not easily undergo the intramolecular ring-closure to give the corresponding [1 + 1] type macrocycles (presumably due to their high strain caused by the shorter carbon chain in m2), so [2 + 2] type macrocycles 17−20 are finally produced by doubly intermolecular nucleophilic attacks of the two negatively charged S atoms in two molecules of m2 at their two Pd or Pt atoms, respectively. It is apparent that the proposed pathways shown in Scheme 5 are based on the nucleophilic reactivities of dianions B′/C′, and the two pathways shown in Scheme 5 are very similar to the pathways previously suggested for formation of the two types of macrocyclic Ni analogues.21 Novel [2 + 2] type macrocycles 17−20 (as air-stable red solids) have been fully characterized by elemental analysis and various spectroscopic methods. Similar to those of linear complexes 1−12 and [1 + 1] type macrocycles 13−16, the IR spectra of 17−20 displayed three strong absorption bands in the range of 2054−1977 cm−1 for their terminal CO’s and one medium absorption band in the region of 999−987 cm−1 for their μ-CS groups.21 The 13C{1H} NMR spectra of 17−20 showed one singlet at 314−317 ppm for the 13C atoms in their
on the two Fe2SCS2 single-butterfly cluster moieties. This HOMO is mainly characterized by a large Fe−Fe bond density and is also contributed to by the 3p orbital of S atoms. In addition, the lowest unoccupied molecular orbital (LUMO) is located on the PdP2S2 moieties consisting of a Pd center and the ligated P and S atoms. This LUMO is mainly characterized by the d orbital of the Pd atom and the 3p orbital of the ligated P and S atoms around the Pd center. Similarly, the HOMO of 14 is also located on the two Fe2SCS2 moieties, and its LUMO is located on the PtP2S2 moieties. It is well-known that the energy gap between HOMO and LUMO is a characteristic quantity for the electronic structure of a given molecule. This quantity is related to the chemical reactivity of a molecule. The high reactivity of a molecule may be at least partially attributed to its small energy gap, and the large energy gap may lead to low reactivity.37,38 It follows that the very close energy gaps for 13 (3.02 eV) and 14 (3.42 eV) shown in Figure 4 imply that the chemical reactivity (or stability) of Pd-bridged macrocycle 13 is very close to that of its Pt analogue 14. Synthesis and Structural Characterization of Macrocyclic Pd or Pt-Bridged Quadruple-Butterfly Fe/S Clusters [{μ-S(CH2)3S-μ}{(μ-SCS)Fe2(CO)6}2]2[M(dppe)]2 (17, M = Pd; 18, Pt) and [{μ-S(CH2)3S-μ}{(μ-SCS)Fe2(CO)6}2]2[M(dppv)]2 (19, M = Pd; 20, Pt). The macrocyclic (diphosphine)Pd- or Pt-bridged complexes containing four butterfly [Fe2SCS] cluster cores, namely, 17−20, were found to be prepared by sequential reactions of the [Et3NH]+ salt of two-μ-CO-containing dianion [{μ-S(CH2)3Sμ}{(μ-CO)Fe 2 (CO) 6 } 2 ] 2− (C, generated in situ from Fe3(CO)12, dithiol HS(CH2)3SH, and Et3N)21 with excess CS2 and subsequent treatment of the resulting [Et3NH]+ salt of the two-μ-CS2-containing dianion [{μ-S(CH2)3S-μ}{(μ-S CS)Fe2(CO)6}2]2− (C′)24 with dppe- or dppv-chelated PdCl2 or PtCl2, respectively (Scheme 4). E
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
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Scheme 5. Two Possible Pathways for Production of the Double-Butterfly Macrocycles 13−16 and Quadruple-Butterfly Macrocycles 17−20
Figure 5. Whole molecular structure of 17 with 30% probability level ellipsoids. All hydrogen atoms have been omitted for clarity.
μ-CS groups, whereas their 31P{1H} NMR spectra exhibited one singlet in the range of 38−60 ppm for their diphosphine P atoms. Fortunately, complex 17 as a representative [2 + 2] type macrocycle was further confirmed by X-ray crystallography. The whole molecular structure of 17 is depicted in Figure 5, whereas Figure 6 shows its skeleton structure. In addition, selected bond lengths and angles are given in Table 3. As can be seen in Figures 5 and 6, complex 17 contains four singlebutterfly Fe/S clusters Fe1Fe2S9C43S8, Fe3Fe4S4C70S5, Fe5Fe6S3C86S2, and Fe7Fe8S10C27S12, which are linked by two propylene chains (via S3/S4 and S9/S10 atoms) and two dppe-chelated Pd1 and Pd2 atoms (via S6/S7 and S1/S11 atoms) to give a 32-membered metallacycle. It is noteworthy that the two propylene groups in 17 are attached to S3/S4 and
S9/S10 all by an equatorial type of bonds4,26 (nonbonded angles: ∠C79−S3···S2 = 162.5°, ∠C77−S4···S5 = 160.3°, ∠C36−S9···S8 = 161.9°, and ∠C34−S10···S12 = 161.2°). In addition, the eight Fe atoms of 17 all adopt a slightly distorted square-pyramidal geometry with the average Fe−Fe bond length of 2.628 Å,21 whereas its two Pd atoms have a slightly distorted square-planar geometry with the average Pd−S bond length of 2.381 Å and Pd−P bond length of 2.276 Å.35,36
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SUMMARY AND CONCLUSIONS We have synthesized and characterized the three types of new (diphosphine)Pd- or Pt-bridged butterfly Fe/S cluster complexes, 1−20. The first type of such complexes, 1−12, are linear double-butterfly clusters, which can be prepared by sequential F
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
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Figure 6. Skeleton structure of 17 with 30% probability level ellipsoids.
Table 3. Selected Bond Lengths (Å) and Angles (deg) for 17 Pd(1)−P(11) Pd(1)−P(14) Pd(1)−S(6) Pd(1)−S(7) S(6)−Pd(1)−S(7) P(11)−Pd(1)−P(14) S(7)−Pd(1)−P(11) Fe(2)−S(8)−C(43)
2.2703(13) 2.2832(14) 2.3919(13) 2.3748(14) 87.03(5) 85.48(5) 91.34(5) 93.71(19)
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reactions involving as the final step reaction of monoanions A′ with (diphosphine)MCl2 (M = Pd and Pt). The second type of such complexes, 13−16, and third type of such complexes, 17− 20, are the two- or four-butterfly Fe/S cluster core-containing macrocycles, which can be produced by sequential reactions involving as the final step reactions of dianions B′ and C′ with (diphosphine)MCl2 (M = Pd and Pt), respectively. Based on the well-known nucleophilic reactivities of monoanions B′ and C′, the two possible pathways for production of [1 + 1] and [2 + 2] type macrocycles 13−20 are proposed, respectively. Apparently, the formation of [2 + 2] type macrocycles 17−20 by intermolecular nucleophilic attack between the two molecules of the propylene (a shorter chain than butylene present in monoanion m1)-bridged monoanion m2 is in order to avoid formation of [1 + 1] type high-strain-containing macrocycles by intramolecular nucleophilic attack of propylenebridged monoanion m2. While structures of the three types of complexes 1−20 have been characterized by elemental analysis and various spectroscopic methods, those of the second type, complexes 13 and 14, have been further characterized by DFT calculations, and those of the first and third types, complexes 1, 3, and 17, were confirmed by X-ray crystallography. The successful synthesis of the three types of Pd- or Pt-bridged complexes 1−20 and the corresponding Ni analogues24 may allow one to expect that such a type of one-pot synthetic method, which involves unique μ-CS2-containing diiron carbonyl monoanions A′ as well as dianions B′ and C′ as the novel thiolate-type ligands, might be able to synthesize the other transition-metal-bridged butterfly Fe/S clusters and thus be able to promote development of the transition metal cluster chemistry.
Fe(1)−S(9) Fe(2)−S(9) Fe(2)−S(8) Fe(1)−Fe(2) Fe(1)−Fe(2)−S(8) Fe(2)−Fe(1)−C(43) S(8)−Fe(2)−S(9) C(43)−S(8)−Fe(2)
2.089(5) 2.347(3) 2.2900(15) 2.6310(16) 76.04(5) 77.44(19) 82.89(8) 93.71(19)
EXPERIMENTAL SECTION
General Comments. All reactions were carried out using standard Schlenk and vacuum-line techniques under an atmosphere of nitrogen. Tetrahedrofuran (THF) was purified by distillation from sodium/ benzophenone ketyl. RSH (R = Et, t-Bu, Ph, and p-MeC6H4), HS(CH 2 ) n SH (n = 3 and 4), and (dppe)PdCl 2 (dppe = Ph2PCH2CH2PPh2) were available commercially and used as received. Fe3(CO)12,39 (dppv)PdCl2(dppv = Ph2PCHCHPPh2),40 (dppf)PdCl2 (dppf = Ph2PC5H4FeC5H4PPh2),41 (dppe)PtCl2,42 (dppv)PtCl2,43 and (dppf)PtCl244 were prepared according to literature procedures. Preparative thin-layer chromatography (TLC) was carried out on glass plates (26 × 20 × 0.25 cm) coated with silica gel H (10− 40 μm). IR spectra were recorded on a Bio-Rad FTS 135 infrared spectrophotometer. 1H, 13C{1H}, and 31P{1H} NMR spectra were obtained on a Bruker Avance 400 NMR spectrometer. Elemental analyses were performed on an Elementar Vario EL analyzer. Melting points were determined on a SGW X-4 microscopic melting point apparatus and were uncorrected. Preparation of [(μ-PhS)(μ-SCS)Fe2(CO)6]2[Pd(dppe)] (1). A 100 mL three-necked flask equipped with a magnetic stir-bar, a rubber septum, and a nitrogen inlet tube was charged with PhSH (0.110 mL, 1.0 mmol), Fe3(CO)12 (0.504 g, 1.0 mmol), Et3N (0.140 mL, 1.0 mmol), and THF (15 mL). The mixture was stirred at room temperature for 0.5 h to give a brown-red solution containing monoanion [(μ-PhS)(μ-CO)Fe2(CO)6]−. The solution was cooled to −40 °C, and then CS2 (0.120 mL, 2.0 mmol) was added. The new mixture containing monoanion [(μ-PhS)(μ-SCS)Fe2(CO)6]− was allowed to warm up to room temperature and stirred at this temperature for 0.5 h. After Pd(dppe)Cl2 (0.287 g, 0.5 mmol) was added, the new mixture was stirred for 2 h. Solvent was removed at reduced pressure, and the residue was subjected to TLC separation using CH2Cl2/petroleum ether (v/v = 1:2) as eluent. From the main red band, complex 1 (0.337 g, 47%) was obtained as a red solid, mp 112−113 °C. Anal. Calcd for C52H34Fe4O12PdP2S6: C, 43.53; H, 2.39. Found: C, 43.29; H, 2.54. IR (KBr disk): νCO 2056 (vs), 2018 (vs), G
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
Article
Organometallics 1979 (vs); νCS 992 (m) cm−1. 1H NMR (400 MHz, CDCl3): 2.30− 2.39 (m, 4H, CH2CH2), 7.15−7.50 (m, 30H, 6C6H5) ppm. 13C{1H} NMR (100 MHz, DMSO-d6): 26.8 (s, CH2CH2), 126.9−142.9 (m, C6H5), 207.6, 209.1, 211.6 (3s, CO), 311.5 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 50.7 (s), 51.0 (s) ppm. Preparation of [(μ-EtS)(μ-SCS)Fe2(CO)6]2[Pd(dppe)] (2). The same procedure as that for 1 was followed, but EtSH (0.074 mL,1.0 mmol) was used instead of PhSH. From the main red band, complex 2 (0.348 g, 52%) was obtained as a red solid, mp 94−95 °C. Anal. Calcd for C44H34Fe4O12PdP2S6: C, 39.47; H, 2.56. Found: C, 39.56; H, 2.81. IR (KBr disk): νCO 2052 (vs), 2014 (vs), 1976 (vs); νCS 988 (s) cm−1. 1H NMR (400 MHz, DMSO-d6): 1.39 (t, J = 7.2 Hz, 6H, 2CH2CH3), 2.40−2.69 (m, 8H, 2CH2CH3, CH2CH2), 7.45−7.65 (m, 20H, 4C6H5) ppm. 13C{1H} NMR (100 MHz, DMSO-d6): 18.1 (s, CH3), 26.8, (s, CH2CH2), 34.9 (s, CH2CH3), 127.7−132.6 (m, C6H5), 208.0, 210.2, 211.4 (3s, CO), 310.8 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 50.1 (s), 50.6 (s) ppm. Preparation of [(μ-p-MeC6H4S)(μ-SCS)Fe2(CO)6]2[Pt(dppe)] (3). The same procedure as that for 1 was followed, but p-MeC6H4SH (0.124 g, 1.0 mmol) and (dppe)PtCl2 (0.332 g, 0.5 mmol) were used instead of PhSH and (dppe)PdCl2, respectively. From the main red band, complex 3 (0.287 g, 37%) was obtained as a red solid, mp 75− 77 °C. Anal. Calcd for C54H38Fe4O12PtP2S6: C, 41.80; H, 2.47. Found: C, 41.95; H, 2.54. IR (KBr disk): νCO 2056 (s), 2018 (vs), 1979 (vs); νCS 993 (m) cm−1. 1H NMR (400 MHz, acetone-d6): 2.25 (s, 6H, 2CH3), 2.59−2.68 (m, 4H, CH2CH2), 7.01−7.31 (m, 8H, 2C6H4), 7.52−7.70 (m, 20H, 4C6H5) ppm. 13C{1H} NMR (100 MHz, CDCl3): 21.4 (s, CH3), 27.9, 28.3 (2s, CH2CH2), 129.1−140.7 (m, C6H5, C6H4), 208.3, 210.2, 211.9 (3s, CO), 313.7 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 39.3 (s), 39.7 (s) ppm. Preparation of [(μ-t-BuS)(μ-SCS)Fe2(CO)6]2[Pt(dppe)] (4). The same procedure as that for 1 was followed, but t-BuSH (0.112 mL,1.0 mmol) and (dppe)PtCl2 (0.332 g, 0.5 mmol) were used instead of PhSH and (dppe)PdCl2, respectively. From the main red band, complex 4 (0.326 g, 44%) was obtained as a red solid, mp 69− 71 °C. Anal. Calcd for C48H42Fe4O12PtP2S6: C, 38.86; H, 2.85. Found: C, 38.91; H, 2.64. IR (KBr disk): νCO 2051 (s), 2014 (vs), 1975 (vs); νCS 993 (m) cm−1. 1H NMR (400 MHz, CDCl3): 1.44 (s, 18H, 6CH3), 2.15−2.24 (m, 4H, CH2CH2), 7.34−7.68 (m, 20H, 4C6H5) ppm. 13C{1H} NMR (100 MHz, CDCl3): 27.8, 29.4 (2s, CH2CH2), 34.5 (s, CH3), 49.8 (s, C(CH3)3), 127.0−134.0 (m, C6H5), 208.4, 211.7, 211.9, 212.3 (4s, CO), 313.8 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 39.1 (s), 39.3 (s) ppm. Preparation of [(μ-PhS)(μ-SCS)Fe2(CO)6]2[Pd(dppv)] (5). The same procedure as that for 1 was followed, but (dppv)PdCl2 (0.286 g, 0.5 mmol) was utilized in place of (dppe)PdCl2. From the main red band, complex 5 (0.351 g, 49%) was obtained as a red solid, mp 125−127 °C. Anal. Calcd for C52H32Fe4O12PdP2S6: C, 43.59; H, 2.25. Found: C, 43.55; H, 2.31. IR (KBr disk): νCO 2056 (s), 2018 (vs), 1979 (vs); νCS 991 (m) cm−1. 1H NMR (400 MHz, DMSOd6): 7.19−7.65 (m, 30H, 6C6H5), 7.84−8.04 (m, 2H, CHCH) ppm. 13 C{1H} NMR (100 MHz, DMSO-d6): 127.5−133.3 (m, C6H5), 143.4−146.4 (m, CHCH), 208.2, 209.7, 212.2 (3s, CO), 314.0 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 60.5 (s), 60.9 (s) ppm. Preparation of [(μ-t-BuS)(μ-SCS)Fe2(CO)6]2[Pd(dppv)] (6). The same procedure was followed as for 1, but t-BuSH (0.112 mL, 1.0 mmol) and (dppv)PdCl2 (0.286 g, 0.5 mmol) were employed in place of PhSH and (dppe)PdCl2, respectively. From the main red band, complex 6 (0.348 g, 50%) was obtained as a red solid, mp 99−100 °C. Anal. Calcd for C48H40Fe4O12PdP2S6: C, 41.39; H, 2.89. Found: C, 41.24; H, 3.09. IR (KBr disk): νCO 2050 (vs), 2014 (vs), 1975 (vs); νCS 990 (m) cm−1. 1H NMR (400 MHz, DMSO-d6): 1.40 (s, 18H, 6CH3), 7.39−7.69 (m, 20H, 4C6H5), 7.75−7.97 (m, 2H, CHCH) ppm. 13C{1H} NMR (100 MHz, DMSO-d6): 34.1, 34.3 (2s, CH3), 50.1 (s, C(CH3)3), 129.7−133.3 (m, C6H5), 145.7−146.4 (m, CH CH), 208.6, 208.9, 212.0 (3s, CO), 314.1 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 59.9 (s), 60.1 (s) ppm. Preparation of [(μ- p-MeC6H4S)(μ-SCS)Fe2(CO)6]2[Pt(dppv)] (7). The same procedure as that for 1 was followed, but p-MeC6H4SH
(0.124 g, 1.0 mmol) and (dppv)PtCl2 (0.331 g, 0.5 mmol) was utilized in place of PhSH and (dppe)PdCl2. From the main red band, complex 7 (0.225 g, 29%) was obtained as a red solid, mp 79−81 °C. Anal. Calcd for C54H36Fe4O12PtP2S6: C, 41.85; H, 2.34. Found: C, 42.01; H, 2.42. IR (KBr disk): νCO 2056 (s), 2018 (vs), 1978 (vs); νCS 993 (m) cm−1. 1H NMR (400 MHz, CDCl3): 2.26 (s, 6H, 2CH3), 6.96− 7.49 (m, 30H, CHCH, 4C6H5, 2C6H4) ppm. 13C{1H} NMR (100 MHz, CDCl3): 21.0 (2s, CH3), 128.8−140.4 (m, C6H5, C6H4), 145.1− 145.8 (m, CHCH), 208.0, 209.9, 211.7, 212.1 (4s, CO), 314.8 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 48.8 (s), 49.3 (s) ppm. Preparation of [(μ-t-BuS)(μ-SCS)Fe2(CO)6]2[Pt(dppv)] (8). The same procedure as that for 1 was followed, but t-BuSH (0.112 mL, 1.0 mmol) and (dppv)PtCl2 (0.331 g, 0.5 mmol) were utilized in place of PhSH and (dppe)PdCl2, respectively. From the main red band, complex 8 (0.296 g, 40%) was obtained as a red solid, mp 72− 74 °C. Anal. Calcd for C48H40Fe4O12PtP2S6: C, 38.91; H, 2.72. Found: C, 38.75; H, 2.86. IR (KBr disk): νCO 2051 (s), 2014 (vs), 1975 (vs); νCS 993 (m) cm−1. 1H NMR (400 MHz, CDCl3): 1.43 (s, 18H, 6CH3), 6.88−7.09 (m, 2H, CHCH), 7.47−7.57 (m, 20H, 4C6H5) ppm. 13C{1H} NMR (100 MHz, CDCl3): 34.3 (s, CH3), 49.9 (s, C(CH3)3), 129.4−132.1 (m, C6H5), 145.1, 145.8 (2s, CHCH), 208.3, 211.7 (2s, CO), 315.1 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 48.6 (s), 48.8 (s) ppm. Preparation of [(μ-PhS)(μ-SCS)Fe2(CO)6]2[Pd(dppf)] (9). The same procedure as that for 1 was followed, but (dppf)PdCl2 (0.365 g, 0.5 mmol) was employed instead of (dppe)PdCl2. From the main red band, complex 9 (0.278 g, 35%) was obtained as a red solid, mp 143 °C (dec). Anal. Calcd for C60H38Fe5O12PdP2S6: C, 45.30; H, 2.41. Found: C, 45.50; H, 2.60. IR (KBr disk): νCO 2056 (s), 2018 (vs), 1980 (vs); νCS 999 (m) cm−1. 1H NMR (400 MHz, DMSOd6): 4.18−4.58 (m, 8H, 2C5H4), 7.20−7.64 (m, 30H, 6C6H5) ppm. 13 C{1H} NMR (100 MHz, DMSO-d6): 71.6, 74.1, 75.9 (3s, C5H4), 127.0−142.8 (m, C6H5), 207.2, 209.1, 211.3 (3s, CO), 308.2 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 24.2 (s) ppm. Preparation of [(μ-EtS)(μ-SCS)Fe2(CO)6]2[Pd(dppf)] (10). The same procedure as that for 1 was followed, but EtSH (0.074 mL, 1.0 mmol) and (dppf)PdCl2 (0.365 g, 0.5 mmol) were used in place of PhSH and (dppe)PdCl2, respectively. From the main red band, complex 10 (0.314 g, 42%) was obtained as a red solid, mp 137 °C (dec). Anal. Calcd for C52H38Fe5O12PdP2S6: C, 41.78; H, 2.56. Found: C, 41.58; H, 2.47. IR (KBr disk): νCO 2052 (vs), 2015 (vs), 1976 (vs); νCS 993 (m) cm−1. 1H NMR (400 MHz, d6-DMSO): 1.37−1.41 (m, 6H, 2CH3), 2.36−2.70 (m, 4H, 2CH2), 4.15−4.19, 4.56 (m, s, 8H, 2C5H4), 7.47−7.65 (m, 20H, 4C6H5) ppm. 13C{1H} NMR (100 MHz, d6-DMSO): 18.8 (s, CH3), 35.5 (s, CH2), 74.5, 74.6, 76.3 (3s, C5H4), 129.0−134.2 (m, C6H5), 210.8, 211.7, 211.8 (3s, CO), 308.5 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 23.8 (s), 24.5 (s) ppm. Preparation of [(μ-p-MeC6H4S)(μ-SCS)Fe2(CO)6]2[Pt(dppf)] (11). The same procedure as that for 1 was followed, but pMeC6H4SH (0.124 g, 1.0 mmol) and (dppf)PtCl2 (0.410 g, 0.5 mmol) were employed in place of PhSH and (dppe)PdCl2, respectively. From the main red band, complex 11 (0.196 g, 23%) was obtained as a red solid, mp 118 °C (dec). Anal. Calcd for C62H42Fe5O12PtP2S6: C, 43.61; H, 2.48. Found: C, 43.65; H, 2.27. IR (KBr disk): νCO 2061 (s), 2019 (vs), 1980 (vs); νCS 1000 (m) cm−1. 1H NMR (400 MHz, CDCl3): 2.25 (s, 6H, 2CH3), 4.32 (br.s, 8H, 2C5H4), 6.96−7.46 (m, 28H, 4C6H5, 2C6H4) ppm. 13C{1H} NMR (100 MHz, CDCl3): 21.2 (s, CH3), 72.7−76.1 (m, C5H4), 128.6−140.7 (m, C6H5, C6H4), 207.7, 209.9, 211.3 (3s, CO), 309.1 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 12.8 (s) ppm. Preparation of [(μ-t-BuS)(μ-SCS)Fe2(CO)6]2[Pt(dppf)] (12). The same procedure as that for 1 was followed, but t-BuSH (0.112 mL, 1.0 mmol) and (dppf)PtCl2 (0.410 g, 0.5 mmol) were used in place of PhSH and (dppe)PdCl2, respectively. From the main red band, complex 12 (0.246 g, 30%) was obtained as a red solid, mp 122 °C (dec). Anal. Calcd for C56H46Fe5O12PtP2S6: C, 41.02; H, 2.83. Found: C, 40.89; H, 2.92. IR (KBr disk): νCO 2056 (vs), 2016 (vs), H
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
Article
Organometallics 1976 (vs); νCS 1000 (m) cm−1. 1H NMR (400 MHz, CDCl3): 1.44 (s, 18H, 6CH3), 4.31 (s, 8H, 2C5H4), 7.50 (br.s, 20H, 4C6H5) ppm. 13 C{1H} NMR (100 MHz, CDCl3): 34.5 (s CH3), 49.7 (s, C(CH3)3), 72.9−76.0 (m, C5H4), 128.3−134.5 (m, C6H5), 208.1, 212.0, 212.1 (3s, CO), 310.2 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 13.3 (s) ppm. Preparation of [μ-S(CH2)4S-μ][(μ-SCS)Fe2(CO)6]2[Pd(dppe)] (13). The flask described above was charged with HS(CH2)4SH (0.062 mL, 0.5 mmol), Fe3(CO)12 (0.504 g, 1.0 mmol), Et3N (0.140 mL, 1.0 mmol), and THF (15 mL). The mixture was stirred at room temperature for 0.5 h to give a brown-red solution containing dianion [{μ-S(CH2)4S-μ}{(μ-CO)Fe2(CO)6}2]2−. The solution was cooled to −40 °C, and then CS2 (0.120 mL, 2.0 mmol) was added. The new mixture containing dianion [{μ-S(CH 2 ) 4 S-μ}{(μ-SCS)Fe2(CO)6}2]2− was allowed to warm up to room temperature and stirred at this temperature for 0.5 h. After Pd(dppe)Cl2 (0.287 g, 0.5 mmol) was added, the new mixture was stirred for additional 12 h. Solvent was removed at reduced pressure, and the residue was subjected to TLC using CH2Cl2/petroleum ether (v/v = 1:1) as eluent. From the main red band, complex 13 (0.071 g, 11%) was obtained as a red solid, mp 121−122 °C. Anal. Calcd for C44H32Fe4O12PdP2S6: C, 39.53; H, 2.41. Found: C, 39.52; H, 2.54. IR (KBr disk): νCO 2052 (s), 2014 (s), 1975 (vs); νCS 990 (s) cm−1. 1H NMR (400 MHz, CDCl3): 2.08−2.63 (m, 12H, PCH2CH2P, SCH2CH2CH2CH2S), 7.26−7.65 (m, 20H, 4C6H5) ppm. 13C{1H} NMR (100 MHz, CDCl3): 27.4, 29.8 (2s, PCH2CH2P), 32.3, 41.0 (2s, SCH2CH2CH2CH2S), 129.3−133.9 (m, C6H5), 208.2, 210.3, 212.0, 212.5 (4s, CO), 313.8 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 51.3 (s) ppm. Preparation of [μ-S(CH2)4S-μ][(μ-SCS)Fe2(CO)6]2[Pt(dppe)] (14). The same procedure as that for 13 was followed, but Pt(dppe)Cl2 (0.332 g, 0.5 mmol) was used instead of Pd(dppe)Cl2 (note that after Pt(dppe)Cl2 was added the new mixture was stirred for 24 h). From the main red band, complex 14 (0.069 g, 10%) was obtained as a red solid, mp 110 °C (dec). Anal. Calcd for C44H32Fe4O12PtP2S6: C, 37.07; H, 2.26. Found: C, 37.12; H, 2.46. IR (KBr disk): νCO 2052 (s), 2016 (vs), 1976 (vs); νCS 999 (m) cm−1. 1H NMR (400 MHz, CDCl3): 2.03−2.68 (m, 12H, PCH2CH2P, SCH2CH2CH2CH2S), 7.29−7.68 (m, 20H, 4C6H5) ppm. 13C{1H} NMR (100 MHz, CDCl3): 28.4, 29.7 (2s, PCH2CH2P), 32.1, 40.7 (2s, SCH2CH2CH2CH2S), 126.8−133.7 (m, C6H5), 208.0, 210.6, 211.6, 212.1 (4s, CO), 312.7 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 40.4 (s), 40.7 (s) ppm. Preparation of [μ-S(CH2)4S-μ][(μ-SCS)Fe2(CO)6]2[Pd(dppv)] (15). The same procedure as that for 13 was followed, but (dppv)PdCl2 (0.286 g, 0.5 mmol) was used instead of Pd(dppe)Cl2. From the main red band, complex 15 (0.073 g, 11%) was obtained as a red solid, mp 118−119 °C. Anal. Calcd for C44H30Fe4O12PdP2S6: C, 39.59; H, 2.27. Found: C, 39.73; H, 2.42. IR (KBr disk): νCO 2052 (s), 2014 (s), 1976 (vs); νCS 989 (s) cm−1. 1H NMR (400 MHz, CDCl3): 2.02−2.84 (m, 8H, CH2CH2CH2CH2), 7.00−7.53 (m, 22H, CHCH, 4C6H5) ppm. 13C{1H} NMR (100 MHz, CDCl3): 32.3, 40.9 (2s, CH2), 129.6−133.7 (m, C6H5), 144.9−145.7 (m, CHCH), 208.1, 210.3, 211.8, 213.0 (4s, CO), 315.5 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 60.5, 60.7 (2s) ppm. Preparation of [μ-S(CH2)4S-μ][(μ-SCS)Fe2(CO)6]2[Pt(dppv)] (16). The same procedure as that for 13 was followed, but Pt(dppv)Cl2 (0.331 g, 0.5 mmol) was used instead of Pd(dppe)Cl2 (note that after Pt(dppv)Cl2 was added the new mixture was stirred for 24 h). From the main red band, complex 16 (0.088 g, 12%) was obtained as a red solid, mp 104 °C (dec). Anal. Calcd for C44H30Fe4O12PtP2S6: C, 37.12; H, 2.12. Found: C, 37.09; H, 2.22. IR (KBr disk): νCO 2053 (s), 2016 (vs), 1976 (vs); νCS 991 (m) cm −1 . 1 H NMR (400 MHz, CDCl 3 ): 1.89−2.64 (m, 8H, CH2CH2CH2CH2), 6.96−7.46 (m, 22H, CHCH, 4C6H5) ppm. 13 C{1H} NMR (100 MHz, CDCl3): 32.6, 40.7 (2s, CH2), 126.8−133.5 (m, C6H5), 145.2−145.8 (m, CHCH), 208.0−212.6 (m, CO), 314.3 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 48.7 (s) ppm.
Preparation of [{μ-S(CH2)3S-μ}{(μ-SCS)Fe2(CO)6}2] 2[Pd(dppe)]2 (17). The flask described above was charged with HS(CH2)3SH (0.050 mL, 0.5 mmol), Fe3(CO)12 (0.504 g, 1.0 mmol), Et3N (0.140 mL, 1.0 mmol), and THF (15 mL). The mixture was stirred at room temperature for 0.5 h to give a brown-red solution containing dianion [{μ-S(CH2)3S-μ}{(μ-CO)Fe2(CO)6}2]2−. After the solution was cooled to −40 °C, CS2 (0.120 mL, 2.0 mmol) was added. The new mixture containing dianion [{μ-S(CH2)3S-μ}{(μSCS)Fe2(CO)6}2]2− was allowed to warm up to room temperature and stirred at this temperature for 0.5 h. After (dppe)PdCl2 (0.287 g, 0.5 mmol) was added, the new mixture was stirred for additional 12 h. Solvent was removed at reduced pressure, and then the residue was subjected to TLC using CH2Cl2/petroleum ether (v/v = 1:1) as eluent. From the main red band, complex 17 (0.077 g, 12%) was obtained as a red solid, mp 118−119 °C. Anal. Calcd for C86H60Fe8O24Pd2P4S12: C, 39.04; H, 2.29. Found: C, 39.22; H, 2.41. IR (KBr disk): νCO 2052 (vs), 2013 (vs), 1978 (vs); νCS 987 (m) cm−1 . 1H NMR (400 MHz, CD2Cl2): 2.11−2.66 (m, 20H, 2PCH2CH2P, 2SCH2CH2CH2S), 7.24−7.54 (m, 40H, 8C6H5) ppm. 13 C{1H} NMR (100 MHz, CD2Cl2): 27.0 (s, PCH2CH2P), 36.6 (s, SCH2CH2CH2S), 41.3 (s, SCH2CH2CH2S), 128.3−133.5 (m, C6H5), 208.1, 210.4, 211.7, 212.5 (4s, CO), 314.7 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 49.9 (s) ppm. Preparation of [{μ-S(CH 2) 3S-μ}{(μ-SCS)Fe2(CO) 6} 2] 2[Pt(dppe)]2 (18). The same procedure as that for 17 was followed, but (dppe)PtCl2 (0.332 g, 0.5 mmol) was used in place of (dppe)PdCl2 (note that after Pt(dppe)Cl2 was added the new mixture was stirred for 24 h). From the main red band, complex 18 (0.073 g, 10%) was obtained as a red solid, mp 105 °C (dec). Anal. Calcd for C86H60Fe8O24Pt2P4S12: C, 36.59; H, 2.14. Found: C, 36.80; H, 2.35. IR (KBr disk): νCO 2053 (vs), 2014 (vs), 1977 (vs); νCS 999 (m) cm −1 . 1 H NMR (400 MHz, CDCl 3 ): 1.88−2.69 (m, 20H, 2PCH2CH2P, 2SCH2CH2CH2S), 7.28−7.66 (m, 40H, 8C6H5) ppm. 13 C{1H} NMR (100 MHz, CDCl3): 29.7 (s, PCH2CH2P), 36.2 (s, SCH2CH2CH2S), 41.3 (s, SCH2CH2CH2S), 128.9−133.9 (m, C6H5), 207.9, 210.6, 211.6, 212.1 (4s, CO), 314.8 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 38.1 (s) ppm. Preparation of [{μ-S(CH2)3S-μ}{(μ-SCS)Fe2(CO)6}2] 2[Pd(dppv)]2 (19). The same procedure as that for 17 was followed, but (dppv)PdCl2 (0.286 g, 0.5 mmol) was used instead of (dppe)PdCl2. From the main red band, complex 19 (0.061 g, 9%) was obtained as a red solid, mp 122−124 °C. Anal. Calcd for C86H56Fe8O24Pd2P4S12: C, 39.10; H, 2.14. Found: C, 39.00; H, 2.27. IR (KBr disk): νCO 2053 (s), 2014 (vs), 1978 (vs); νCS 987 (m) cm−1. 1H NMR (400 MHz, CD2Cl2): 2.19−2.37 (m, 4H, 2SCH2CH2CH2S), 2.65−2.76 (m, 8H, 2SCH2CH2CH2S), 7.12−7.61 (m, 44H, 2CHCH, 8C6H5) ppm. 13 C{1H} NMR (100 MHz, CD2Cl2): 36.8 (s, SCH2CH2CH2S), 41.5 (s, SCH2CH2CH2S), 129.6−133.5 (s, C6H5), 145.1−145.9 (m, CH CH), 208.4, 210.7, 211.8, 213.0 (4s, CO), 316.7 (s, CS) ppm. 31 1 P{ H} NMR (162 MHz, CDCl3, 85% H3PO4): 59.8 (s) ppm. Preparation of [{μ-S(CH 2) 3S-μ}{(μ-SCS)Fe2(CO) 6} 2] 2[Pt(dppv)]2 (20). The same procedure as that for 17 was followed, but (dppv)PtCl2 (0.331 g, 0.5 mmol) was used in place of (dppe)PdCl2 (note that after Pt(dppv)Cl2 was added the new mixture was stirred for 24 h). From the main red band, complex 20 (0.066 g, 9%) was obtained as a red solid, mp 112 °C (dec). Anal. Calcd for C86H56Fe8O24Pt2P4S12: C, 36.64; H, 2.00. Found: C, 36.57; H, 2.14. IR (KBr disk): νCO 2054 (s), 2015 (vs), 1977 (vs); νCS 999 (m) cm −1 . 1 H NMR (400 MHz, CDCl 3 ): 2.00−2.80 (m, 12H, 2CH2CH2CH2), 6.89−7.55 (m, 44H, 2CHCH, 8C6H5) ppm. 13 C{1H} NMR (100 MHz, CDCl3): 36.3 (s, SCH2CH2CH2S), 41.4 (s, SCH2CH2CH2S), 126.9−133.6 (m, C6H5), 145.3−145.9 (m, CH CH), 208.0−212.7 (m, CO), 316.6 (s, CS) ppm. 31P{1H} NMR (162 MHz, CDCl3, 85% H3PO4): 47.9 (s) ppm. X-ray Structure Determinations of 1, 3, and 17. While single crystals of 1 and 3 suitable for X-ray diffraction analysis were grown by slow diffusion of hexane into their CH2Cl2 solutions at −35 °C and −5 °C, respectively, those of 17 suitable for X-ray diffraction analysis were grown by slow diffusion of diethyl ether into its CH2Cl2 solution at −35 °C. A single crystal of 1 or 3 was mounted on a Rigaku MM-007 I
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
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Organometallics Table 4. Crystal Data and Structure Refinements Details for 1, 3, and 17 mol formula mol wt cryst syst space group a (Å) b (Å) c (Å) α (deg) β (deg) γ (deg) V (Å3) Z Dc (g·cm−3) abs coeff (mm−1) F(000) index ranges no. of reflns no. of indep reflns 2θmax (deg) R Rw GOF largest diff peak, hole (e Å−3)
1
3
17
C52H34Fe4O12P2PdS6 1434.89 monoclinic C2/c 35.363(3) 14.7490(13) 27.309(2) 90 124.423(2) 90 11749.3(18) 8 1.622 1.589 5744 −46 ≤ h ≤ 44 −19 ≤ k ≤ 19 −35 ≤ l ≤ 35 53730 14038 55.88 0.0535 0.1004 1.135 0.520/−0.805
C54H38Fe4O12P2PtS6 1551.63 monoclinic P21/n 14.633(4) 23.032(5) 22.401(5) 90 108.993(5) 90 7139(3) 4 1.444 3.015 3064 −17 ≤ h ≤ 17 −27 ≤ k ≤ 27 −26 ≤ l ≤ 22 59960 12579 50.02 0.0361 0.0952 1.049 1.763/−1.259
C86H60Fe8O24P4Pd2S12 2645.54 monoclinic P21/c 15.3709(3) 34.0985(7) 25.7071(5) 90 100.151(2) 90 13262.8(5) 4 1.325 1.402 5280 −19 ≤ h ≤ 18 −42 ≤ k ≤ 40 −32 ≤ l ≤ 31 68285 27078 52.74 0.0659 0.1794 1.100 2.627/−3.007
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(rotating anode) diffractometer equipped with a Saturn 724 CCD, and data were collected using a confocal monochromator with Mo Kα radiation (λ = 0.71075 or λ = 0.71073 Å) in the ω scanning mode at 113 K. A single crystal of 17 was mounted on a SuperNova diffractometer equipped with an Eos, and data were collected using a confocal monochromator with Mo Kα radiation (λ = 0.7107 Å) in the ω scanning mode at 99.9 K. Data collection, reduction, and absorption correction were performed by CRYSTALCLEAR program.45 The structures were solved by direct methods using the SHELXS-97 program46 and refined by full-matrix least-squares techniques (SHELXL-97)47 on F2. Hydrogen atoms were located by using the geometric method. Details of crystal data, data collections, and structure refinements are summarized in Table 4.
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ACKNOWLEDGMENTS We are grateful to the Ministry of Science and Technology of China (973 program 2014CB845604) and the National Natural Science Foundation of China (21472095, 21421001) for financial support.
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(1) For reviews, see for example (a) Markó, L.; Markó-Monostory, B. In The Organic Chemistry of Iron; von Gustor, E. A. K., Grevels, F. W., Fischler, I., Eds.; Academic Press: New York, 1981; Vol. 2, p. 283. (b) Song, L.-C. Trends Organomet. Chem. 1999, 3, 1−20. (c) Song, L.C. Acc. Chem. Res. 2005, 38, 21−28. (d) Song, L.-C. Sci. China, Ser. B: Chem. 2009, 52, 1−14. (e) Li, Y.; Rauchfuss, T. B. Chem. Rev. 2016, 116, 7043−7077. (2) Nametkin, N. S.; Tyurin, V. D.; Kukina, M. A. J. Organomet. Chem. 1978, 149, 355−370. (3) Seyferth, D.; Song, L.-C.; Henderson, R. S. J. Am. Chem. Soc. 1981, 103, 5103−5107. (4) Seyferth, D.; Henderson, R. S.; Song, L.-C. Organometallics 1982, 1, 125−133. (5) Winter, A.; Zsolnai, L.; Huttner, G. Z. Naturforsch., B: J. Chem. Sci. 1982, 37, 1430−1436. (6) Bose, K. S.; Sinn, E.; Averill, B. A. Organometallics 1984, 3, 1126− 1128. (7) Kovacs, J. A.; Bashkin, J. K.; Holm, R. H. J. Am. Chem. Soc. 1985, 107, 1784−1786. (8) Mathur, P.; Ghosh, S.; Sarkar, A.; Satyanarayana, C. V. V; Puranik, V. G. Organometallics 1997, 16, 4392−4398. (9) Seyferth, D.; Womack, G. B.; Dewan, J. C. Organometallics 1985, 4, 398−400. (10) Song, L.-C.; Fan, H.-T.; Hu, Q.-M. J. Am. Chem. Soc. 2002, 124, 4566−4567. (11) Song, L.-C.; Tan, H.; Zhu, A.-G.; Hu, Y.-Y.; Chen, H. Organometallics 2015, 34, 1730−1741. (12) For reviews, see for example (a) Simmons, T. R.; Berggren, G.; Bacchi, M.; Fontecave, M.; Artero, V. Coord. Chem. Rev. 2014, 270−
ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.organomet.7b00117. IR and NMR spectra of the representative complexes 2, 8, 11, 13, and 20 (PDF) Crystal data, atomic coordinates, and thermal parameters, and bond lengths and angles for 1, 3, and 17 (CIF) Cartesian coordinates of 13 and 14 (XYZ)
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REFERENCES
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[email protected]. ORCID
Li-Cheng Song: 0000-0003-0964-8869 Notes
The authors declare no competing financial interest. J
DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
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DOI: 10.1021/acs.organomet.7b00117 Organometallics XXXX, XXX, XXX−XXX
