Halogenation at a Dimolybdenum(V) and Ditungsten(V) Sulfur Bridge: Metallosulfenyl Halides M2(.mu.-SX) and [M2(.mu.-SX3)]n. Charge-Transfer Interactions

Abstract

The reactions of halogens at anionic, radical, and neutral bridge sulfur sites within M2S2 cores of various [M2-(NAr)2(S2P(0Et)2)2(«-S)2(M-02CMe)] compounds (M = Mo, W) produced covalent halosulfide ligands. Complexes containing the W2(m-SX) unit were obtained for X = Cl, Br, and I; trihalide polymers of [M2(m-SX3)]" units were obtained for M = W or Mo and X = Br or I. These latter compounds engaged in depolymerization equilibria in solution. The derivative containing the structural unit [Mo2(«-Sl3)]" undergoes photolysis in fluorescent light to I2 and a disulfide of the type M02S-SM02. Crystallography of the W2(ti-SBr) product clearly revealed the discrete bromosulfide bridge ligand, µ-SBr. Crystallography of the [Mo2(m-SI3)]" product revealed SX3S3ligands which interconnected the Mo2 structural units into one-dimensional polymer chains. Simple charge transfer interactions between metallosulfur sites of various derivatives and iodine were also observed.

Activation of Ligand Reactivity: Thiolate C−S and Dithiophosphate Ester C−O Heterolyses within a Dimolybdenum(V) System

“…The solution NMR spectra showed isomers corresponding to inversion of the pyramidal thiolate−sulfur bridges. As previously documented for RS{Mo 2 }S 2 and related derivatives, − , these are freely fluxional invertomers; they are labeled distal ( d ) or proximal ( p ) depending on the thiolate orientation with respect to the tolylimido rings. For MeS{Mo 2 }SMe + , the dominant solution isomer contains both thiolate groups in distal orientation (distal−distal, d - d ); this isomer is portrayed in the prior structural illustrations for 3 .…”

“…Subsequent studies showed that the remaining sulfide bridge site in 2 was incompletely passivated and there remained some electron density for further reaction. This was made evident by the sulfide's ability to act as a charge transfer donor to elemental halogen and by the sulfide's vulnerability to oxygenation to give μ-SO and photosensitive μ-SO 2 dimers …”

Sulfur Site Iodine Adduct of a Nickel Thiolate Complex

“…While there are numerous examples of I 2 adducts of organic sulfides, R 2 S···I 2 , ,, and thiones, R 2 CS···I 2 , and a few cases of coordination complex inorganic sulfides using a bridging sulfide as the I 2 binding site, two adducts appear to be most pertinent as analogues of Ni-1* ·I 2 . The structure of the [14]aneS 4 ·I 2 tetrathiacrown ether adduct, vide supra, is appropriate for comparison because of its lack of intermolecular interactions.…”

Trapping of a Thiolate→Dibromine Charge‐Transfer Adduct by a Macrocyclic Dinickel Complex and Its Conversion into an Arenesulfenyl Bromide Derivative

“…Only a dinuclear tungsten complex with a bridging bromosulfido ligand has been described. [16] The mean NiÀS Br bond length (2.667(2) ) is much longer than the Ni À S thiolate bond length (2.439(2) ) indicative of a greatly decreased electrondonating ability of the sulfenyl bromide.…”