Guohua Pan

A novel pentanuclear CoS raft cluster compound consisting of fused Co3(μ3-S) units: X-ray crystal structure of Co5(CO)2S3(SC5H4N)7

Abstract The reaction of Na[Co(CO)4] with Pys—(2-mercapto-pyridine) in THF at room temperature gave a dark crystalline product [Co5(CO)2(μ3-S)3(SC5H4N)7] (1). The crystal structure of 1 determined by single crystal X-ray diffraction, revealed a pentanuclear metallic core, Co5(μ3-S)3(μ-S), which can be described as a skeleton comprising three incomplete cubane-like structural units, two SCo3S3 and a SCo3S3C, in an inversion arrangement sharing two rhombic CoS3Co faces or, in other words, as a raft-type structure consisting of fused Co3(μ-S) units. The geometry around each Co atom is a distorted octahedron and the octahedra are divided into four types according to the different coordination environments. The three CoCo bond distances of 2.72–2.80 A indicate weak metal metal interactions. The formal dation states of the five cobalt atoms are one CoI and four CoIII. The formation of 1 is discussed and the cyclic voltammetry of 1 has been measured. Interestingly, 1 contains three inorganic μ3-S atoms notwithstanding the absence of inorganic S2-source in the synthetic reaction system, implying a process related to desulfurization of 2-mercaptopyridine in the preparative reaction.

Synthesis and structural characterization of Mo2(μ-SC6H4–Cl-p)2(μ-dppm)(CO)6 and [(dppm)(CO)2Mo(μ-SC6H4–Cl-p)2Mo(O)]2(μ-SC6H4–Cl-p)2(μ-O) and electrochemical property of Mo2(μ-SC6H4–Cl-p)2(μ-dppm)(CO)6

Abstract Dimolybdenum(I) compound Mo2(μ-SC6H4–Cl-p)2(μ-dppm)(CO)6 (1), (dppm=(C6H5)2PCH2P(C6H5)2), and a trace unexpected mixed-valence tetranuclear molybdenum compound [(dppm)(CO)2Mo(μ-SC6H4–Cl-p)2Mo(O)]2(μ-SC6H4–Cl-p)2(μ-O) (2) were obtained from the reaction of Mo2(μ-SC6H4–Cl-p)2(CO)8 with dppm in CH2Cl2. The crystal structures of the two compounds have been determined by X-ray diffraction studies. 1: monoclinic, P2(1)/n, a=13.1082(3), b=23.9584(4), c=14.8510(2) A, β=105.865(1)°, V=4486.32(14) A3, Z=4, 9859 unique data, R1=0.0805, wR2=0.1076. 2·CH2Cl2: monoclinic, C2/c, a=22.0955(13), b=19.1563(11), c=25.1981(14) A, β=112.243(1)°, V=9871.9(1) A3, Z=4, 7053 unique data, R1=0.0450, wR2=0.1222. The cyclic voltammetry (CV) measurement for 1 showed a reversible two-electron transfer in a single step.

New dinuclear molbydenum(0)-SR compound containing a “butterfly” type MoS2Mo core: synthesis, structure and cyclic voltammetry of DI-(o-methylphenthiolato)dimolybdenum(0) cotacarbonyl dianion, Mo2(o-CH3C6H4S)2(CO)8]2−

Abstract Reaction of molybdenum hexacarbonyl with o -methyl-thiophenolate in MeCN afforded a new dinuclear Mo 0 SR compound, [Et 4 N] 2 [Mo 2 ( o CH 3 C 6 H 4 S) 2 (CO) 8 ] ( 1 ). Compound 1 ·MeCN was characterized by single-crystal X-ray structure determination and its electrochemical behaviour was measured by cyclic by voltammetry. The anion of 1 contains a “butterfly” type bimetallic MoS 2 Mo core with an MoMo distance of 3.942(3) A, MoS of 2.622 A, SMoS of 77.3° and MoSMo of 97.54°, and exhibits very different electrochemical behaviour from its analogues, [Mo 2 (0-OHC 6 H 4  S ) 2 (CO) 8 ] 2− ( 4 ) with a core which consists of a non-planar MoS 2 Mo unit and a bridging carbonyl. Considering 1–4 together, the synthesis, influence of steric hindrance of ligands on MoS 2 Mo core configuration and thus on the electrochemical behaviour were discussed.

Crystal structure of tetraethylammonium bis(tetracarbonylmolybdenum)-tetrathiotungstate, [Et4N]2[(OC)4MoS2WS2Mo(CO)4] and synthesis, infrared spectra, 95 Mo NMR spectra and cyclic voltammetry of new linear trinuclear Mo(W)–S carbonyl clusters containing mixed-valence metal atoms [(OC)4MS2M′SM(CO)4]2− (M, M′=Mo or W)

Four trinuclear molybdenum(tungsten)-sulfur carbonyl cluster compounds, [Et 4 N] 2 [(OC) 4 Mo-S 2 MoS 2 Mo(CO) 4 ] (1), [Et 4 N] 2 [(OC) 4 WS 2 WS 2 W(CO) 4 ] (2), [Et 4 N] 2 [(OC) 4 MoS 2 WS 2 Mo(CO) 4 ] (3), [Et 4 N] 2 [(OC) 4 WS 2 MoS 2 W(CO) 4 ] (4) have been prepared by both reaction of [M(CO) 4 (S 2 CNEt 2 )] − with M′S 4 2 − in MeOH and reaction of MeCN solution of M(CO) 6 with M′S 4 2 − in MeOH (M=Mo, W; M′=Mo, W). These complexes has been characterized by routine elemental analysis and spectroscopy and the structures of 1 and 3 have been determined by X-ray crystallography. The structure study reveals that the anion of 3 contains a heteronuclear Mo–W–S trimetallic core, [MoS 2 WS 2 Mo] 2 −, consisting of two perpendicular rhombic MoS 2 W units sharing a tungsten atom. The Mo–W bond distances are 3.028(2) and 3.031(2) A and the Mo–W–Mo angle is 176.04(5)°. The average bond lengths of W–S and Mo–S are 2.21 and 2.54 A, respectively. The X-ray, structure, IR, CV (cyclic voltammetry) and 95 Mo NMR studies on these four cluster complexes indicated that these cluster complexes possess wide separated oxidation states of metal atoms and exhibit the charge transfer, M L →M H S 4 (M L represents a low-valance metal atom and M H a high valence metal atom), between the two different valence metallic centers in the cluster complexes. It has been found that the charge transfer, M L →M H S 4 , in the complexes are: 1>4, 3>2, 1>3, 4>2, 1>2 and 3∼4 implying the electron-donation ability of low-valence metal atoms in the complexes is Mo 0 >W 0 and the electron-accepted ability of the high valence metal atoms in the complexes is Mo VI >W VI .

A mixed tribridging dimolybdenum(I) compound, bis(μ-benzenethiolato-S:S)hexacarbonyl-μ-iodo-dimolybdenum(I)(Mo—Mo)

In the structure of the complex anion of the title compound, (C 16 H 36 N)[Mo 2 I(C 6 H 5 S) 2 (CO) 6 ], two Mo atoms are linked by three bridging ligands (one I and two benzenethiolate), forming an Mo 2 I(C 6 H 5 S) 2 core. The Mo 2 S 2 unit, with a mean Mo-S distance of 2.475(2) A and a mean Mo-S-Mo angle of 71.21(4)°, is approximately planar. Relative to this Mo2S2 unit, the two benzene rings are in a syn configuration. The Mo-I distances are 2.9460 (6) and 2.9599 (6) A, the Mo-Mo distance is 2.8824 (7) A and the Mo-I-Mo angle is 58.43 (2)°.

A dimolybdenum(I) carbonyl compound with thiolate and carboxylate bridges: tetrabutylammonium bis(μ-benzenethiolato-S:S)hexacarbonyl-μ-pivalate-O:O'-dimolybdenum(Mo—Mo)

In the anion of the title compound, (C 16 H 36 N)[Mo 2 -(C 5 H 9 O 2 )(C 6 H 5 S) 2 (CO) 6 ], each Mo atom and three terminal carbonyl groups form a fac-Mo(CO) 3 fragment, and two Mo atoms and two benzenethiolate bridging ligands form a planar Mo2S2 unit, with the two phenyl rings in an anti configuration. The pivalate acts as a conventional μ,η 2 -ligand bridge to two Mo atoms, to form an approximately planar five-membered ring. The two [MoOS 2 (CO) 3 ] octahedra share a common S-S edge.

A Hetero-Tribridged Dinuclear Molybdenum Compound [Bu4N][Mo2(CO)6(p-Cl-C6H4 S)2Br]

The title compound, tetra-n-butylammonium μ-bromo-bis(μ-p-chlorobenzenethiolato)bis(tricarbonylmolybdenum)(Mo-Mo), (C 16 H 36 N)[Mo 2 Br(C 6 H 4 ClS) 2 (CO) 6 ], contains a Bu 4 N + cation and an [Mo 2 (CO) 6 (p-Cl-C 6 H 4 S) 2 Br] - anion. The structure of the anion can be viewed as a cofacial bi-octahedral dimer, in which two fac-Mo(CO) 3 fragments are bridged by two p-Cl-C 6 H 4 S - groups and one Br- ligand. The mean Mo-Br distance is 2.765 (2) A and the Mo-Br-Mo angle is 62.68 (4)°.

A New Dinuclear Molybdenum Compound, (Bu4 N)[Mo2(CO)6(SPh)2(CH2CCH3COO)]

The crystal structure of the title compound, tetrabutylammonium bis(μ-benzenethiolato-S:S)-μ-methacrylato-O:O′-bis(tricarbonylmolybdenum)(Mo—Mo), (C16H36N)[Mo2(C4H5O2)(C6H5S)2(CO)6], shows that it contains a Bu4N+ cation and a dinuclear anion with three bridging ligands, i.e. [Mo2(CO)6(SPh)2(CH2CCH3COO)]−; the α-methacrylate group acts as a bidentate bridging ligand and coordinates two Mo atoms to form a five-membered ring. The Mo—Mo bond distance is 2.9115 (5) A and the O—C—O angle is 125.8 (4)°.