The formation and molecular structure of the Di-μ-oxo-di[di(benzenethiolato)-oxomolybdate(v)] dianion

Abstract

The orange-red complexes (R4N)2 [Mo2O4(SPh)4] (R = Me, Et), (Et4N)2 [Mo2O4(SCH2CH2- CH2S)2] and (Et4N)2 [Mo2O4{SCH2(CHOH)2CH2S}2] have been synthesized. Crystalline (Me4N)2 [Mo2O4(SPh)4], space group P1, contains two [(μ-O)2(OMo(SPh)2)2]2- complexes in each of which two approximately square-pyramidal (Ob)2Mo(Ot)(SPh)2 coordination spheres (b, bridging; t, terminal) share an Ob--Ob edge with cis-bent stereochemistry. Important average dimensions are Mo-Mo 2.61, Mo-S 2.45, Mo-Ot 1.68, Mo-Ob 1.94 Ǻ, Mo 0.71 Ǻ above the (Ob)2S2 basal plane. There occur two different orientations of S-C vectors, relative to the Mo-Mo vector, associated with two clearly distinct classes of S-Mo-S angles, 81.9�0.5 and 73.8�0.4°. The latter abnormally small angle, concomitant with an interligand S--S distance of 2.94 Ǻ, occurs only in the conformation where S--S σ-orbital overlap is possible, and suggests the existence of some interligand bonding. Crystal data: a 12.376, b 14.513, c 11.307 Ǻ, α 104.00, β 99.55, γ 71.32°, cell contents 2xMo2S4O4N2C32H44, 3207 reflections, R 0.033.

Transition metal complexes containing the 1,2-dicarba-closo-dodecaborane-1,2-dithiolate ligand: crystal structures of [4-MeC5H4NMe]2[Pd(S2C2B10H10)I2], [NEt3H][Mo(η5-C5H5)(NO)(S2C2B10H10)I], [NBu4][Re(O)(S2C2B10H10)2] and [4-MeC5H4NMe]2[{Mo(O)(μ-O)(S2C2B10H10)}2]

“…The Mo᎐S, Mo᎐O (bridging) and Mo᎐O (terminal) lengths are 2.424(1) (mean of two values), 1.938(5) (mean of two values) and 1.673(4) Å, respectively. In the di-µ-oxo-bis[di(benzenethiolato)oxomolybdate()] dianion, 22 which is based on the same central atomic configuration, mean bond lengths are Mo᎐S 2.447 Å, Mo᎐O (bridging) 1.937 Å and Mo᎐O (terminal) 1.677 Å, with a 27Њ angle between the basal planes of the molybdenum co-ordinating square pyramids, very similar to the situation in our structure (4).…”

The Mononuclear Molybdenum Enzymes

“…(It is known that aldehyde oxidoreductase, xanthine oxidase, and related enzymes operate in a quite low oxidation−reduction regime.) Such a role for the pterin cofactor in modulating the molybdenum reduction potential has in fact been anticipated on the basis of the structures of relatively simple inorganic complexes of molybdenum such as L 2 MoO 2 (LSC(CH 3 ) 2 CH 2 NH(CH 3 )) and [Mo 2 O 4 (SC 6 H 5 ) 4 ] 2- …”

{2,12-Dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene}nitritonitronickel(II) hemihydrate

“…This shows the greater trans effect of a/z-MoS bond relative to a/z-MoO bond, as already mentioned by Mennemann & Mattes (1979). The mean Mo-S L bond length is significantly longer (0.04 to 0.08 A) than in other Mo v complexes with uni-and bidentate S donor ligands (Newton, McDonald, Yamanouchi & Enemark, 1979;Dance, Wedd& Boyd, 1978). dts is obviously a rather poor ligand towards Mo v.…”