Mono-oxo Bis(dithiolene) Mo(IV)/W(IV) Complexes as Building Blocks for Sulfide Bridged Bi- and Tri-Nuclear Complexes

Tungsten Ligand-Based Sulfur-Atom-Transfer Catalysts: Synthesis, Characterization, Sustained Anaerobic Catalysis, and Mode of Aerial Deactivation

The synthesis, properties, X-ray structures, and catalytic sulfur-atom-transfer (SAT) reactions of W₂(μ-S)(μ-S₂)(dtc)₂(dped)₂ [1; dtc = S₂CNR₂^-, where R = Me, Et, iBu, and Bn; dped = S₂C₂Ph₂^2-] and W₂(μ-S)₂(dtc)₂(dped)₂ (2) are reported. These complexes represent the oxidized (1) and reduced (2) forms of anaerobic SAT catalysts operating through the bidirectional, ligand-based half-reaction (μ-S)(μ-S₂) ↔ (μ-S)₂ + S⁰. The catalysts are deactivated in air through the formation of catalytically inactive oxo complexes, (dtc)WO(μ-S)(μ-dped)W(dtc)(dped) (3), prompting us to recommend that group 6 SAT activity be assessed under strictly anaerobic conditions.

Hydrosulfide complexes of the transition elements: diverse roles in bioinorganic, cluster, coordination, and organometallic chemistry

Molecules containing transition metal hydrosulfide linkages are diverse, spanning a variety of elements, coordination environments, and redox states, and carrying out multiple roles across several fields of chemistry.

Synthesis, structure and theoretical investigation into a homoleptic tris(dithiolene) tungsten

A new homoleptic dithiolene tungsten complex, tris-{1,2-bis(3,5-dimethoxyphenyl)-1,2-ethylenodithiolene-S,S'}tungsten, was successfully synthesized via a reaction of the thiophosphate ester and sodium tungstate. The thiophosphate ester was prepared from 3,5-dimethoxybenzaldehyde via benzoin condensation to produce the intermediate 1,2-bis-(3,5-dimethoxyphenyl)-2-hydroxy-ethanone compound, followed by a reaction of the intermediate with phosphorus pentasulfide. FTIR, UV-Vis spectroscopy, 1H NMR and 13C NMR and elemental analysis confirmed the product as tris{1,2-bis-(3,5-dimethoxyphenyl)-1,2-ethylenodithiolene-S,S'}tungsten with the molecular formula of C54H54O12S6W. Crystals of the product adopted a monoclinic system with space group of P2(1)/n, where a=12.756(2) Å, b=21.560(3) Å, c=24.980(4) Å and β=103.998(3)°. Three thioester ligands were attached to the tungsten as bidentate chelates to form a distorted octahedral geometry. Density functional theory calculations were performed to investigate the molecular properties in a generalized-gradient approximation framework system using Perdew-Burke-Ernzerhof functions and a double numeric plus polarization basis set. The HOMO was concentrated on the phenyl ligands, while the LUMO was found along the W(S2C2)3 rings. The theoretical optical properties showed a slight blue shift in several low dielectric solvents. The solvatochromism effect was insignificant for high polar solvents.

Synthesis, characterization and structure of a low coordinate desoxomolybdenum cluster stabilized by a dithione ligand

Using an oxidized state of a dithiolene ligand, diisopropylpiperazine-2,3-dithione (i-Pr(2)Pipdt), two monooxo-molybdenum complexes have been synthesized. From one of them, a desoxomolybdenum cluster, [(i-Pr(2)Pipdt)Mo](4)[BF(4)](4) has been prepared. The molecular structure of this cluster reveals metal-metal interactions and weak coordination by the BF(4) anion.