Lingjie He

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, structure and possible formation pathway of a novel cobalt carbonyl compound with new type BO bond, Co(CO)3(PPh3)2BEt3, and mixed metal CoFeS cluster with possible nonlinear optical property, [Et4N][CoFe2(CO)8S(PPh3)]

Reaction of Co(CNS) 2 with Fe 2 S 2 (CO) 6 , LiBEt 3 H and PPh 3 in THFMeCN resulting in a novel cobalt carbonyl complex, Co(CO) 3 (PPh 3 ) 2 BEt 3 ( 1 ) and mixed-metal CoFeS cluster compound, [Et 4 N][Fe 2 Co(CO) 8 S(PPh 3 )] ( 2 ). The structures of 1 and 2 were determined from X-ray three dimension data. Structure studies reveal that 1 is a new cobalt carbonyl complex containing a novel BO bond of 1.601(5) A in which the oxygen atom is from metal carbonyl and the B atom is from BEt 3 and 2 contained a triangular pyramid mixed-metal CoFeS core [CoFe 2 S] − with CoS of 2.189, FeS of 2.208, CoFe of 2.56 and FeFe of 2.58 A. Theoretical calculation on 1 and 2 shows that BO bonding energy of complex 1 is lower than that of normal covalent bonding and 2 possesses a calculated nonlinear optical first molecular hyperpolarizability component of 28.5×10 −30 esu. The possible formation pathway of 1 and 2 was discussed.

A new molybdenum-tungsten-sulphur cluster complex family, [{(OC)4M}xM′S4]2− (M = Mo or W, M′ = Mo or W; x = 1,2). Synthesis, structure and properties of a new trinuclear mixed-valence MoS cluster, [Et4N]2[(OC)4MoS2MoS2Mo(CO)4]

Abstract The reaction of molybdenum(0) dithiocarbamato carbonyl complexes, [Et 4 N][Mo(CO) 4 (S 2 CNEt 2 ] with tetraethyl ammonium tetrathiomolybdate in MeOH affords a trinuclear mixed-valence MoS complex, [Et 4 N] 2 [(OC) 4 MoS 2 MoS 2 Mo(CO) 4 ] ( 1 ) in high yield. The structure of 1 was studied by X-ray crystallography. The structure of the anion of 1 comprises two octahedra around low-valence molybdenum atoms and a tetrahedron with the high-valence molybdenum atom in the centre sharing two edges which are the line between the bridging sulphur atoms. Thus, 1 contains a trimetallic MoS 2 MoS 2 Mo core with two Mo 2 S 2 planes sharing a molybdenum atom perpendicularly. The MoMo bond distances are 2.9979(6) and 3.0003(6) A; the MoMoMo angle is 174.46(2)° and MoS bond lengths are 2.22 and 2.53 A 95 Mo NMR measurements show that the three molybdenum atoms in 1 are in two oxidation states. The cyclic voltammetry studies on 1 and the dinuclear complex, [(OC) 4 MoS 2 MoS 2 ] 2− , reveal the existence of two different redox metal centres in 1 . The electron delocalization between the three mixed-valence molybdenum atoms is discussed by comparing them with the dinuclear molybdenum member of this cluster family.

Mixed metal pentanuclear clusters [MFe4S4(CO)12]z− (M=V, Mn and Cr; z=0, 2) and X-ray crystal structures of [VFe4S4(CO)12] and [MnFe4S4(CO)12]2−

Abstract Reaction of VCL 3 , MnCl 2 and CrCl 3 +Zn with [Fe 2 S 2 (CO) 6 ] 2− , from reduction of [Fe 2 S 2 (CO) 6 ] by LiEt 3 BH, resulting in pentanuclear mixed metal clusters [VFe 4 S 4 (CO) 12 ] ( 1 ), [Et 4 N] 2 [MnFe 4 S 4 (CO) 12 ] ( 2 ) and [Et 4 N] 2 [CrFe 4 S 4 (CO) 12 ] ( 3 ), respectively. Complexes 1 , 2 and 3 have been characterized by elemental analysis, spectroscopy and the crystal structures of 1 and 2 have been determined by X-ray crystallography. The structures of 1 and 2 contain a penta-nuclear M–Fe–S core, [Fe 2 S 2 MS 2 Fe 2 ] z − (M=V, z =0 ( 1 ) and M=Mn, z =2 ( 2 )), consisting of two [Fe 2 S 2 ]-units chelating to a metal atom. The two [Fe 2 S 2 ] units are in ‘butterfly’ type configuration like the one in [Fe 2 S 2 (CO) 6 ] 2− . In 1 there are four V–Fe bonds of 2.822–2.865 A, but in 2 there were no Mn–Fe bonds found. V–S distances are 2.205–2.210 A and Mn–S bond lengths are 2.358–2.380 A. The novel structural configuration, IR spectra and synthesis were discussed.

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.

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 .