James F. Fait

Syntheses, crystal structures and spectroscopic characterization of some confacial bioctahedral ditungsten(III) complexes with thioether bridges: [Cl3W(µ-Et2S)3WCl3]·MeCN and [SMe3][Cl3W-(µ-Me2S)2(µ-Cl)WCl3]·EtCN

Reduction of WCl4 with 1 equivalent of Na/Hg in a refluxing thioether solution produced [Cl3W(µ-L)3WCl3][L = tetrahydrothiophene(tht) or Et2S] in ca. 80% yields. Subsequent recrystallization from CH2Cl2 and MeCN gave [Cl3W(µ-tht)3WCl3]1 and [Cl3W(µ-Et2S)3WCl3]·MeCN 2, respectively. These complexes can also be prepared, in lower yields, by the same reactions carried out at ambient temperature or by refluxing WCl4, thioether and Na/Hg in toluene solution. Analogous reactions with Me2S yield exclusively [SMe3][Cl3W(µ-Me2S)2(µ-Cl)WCl3] which was recrystallized from EtCN to yield the monosolvate, 3. The structures of 2 and 3 were determined by single-crystal X-ray diffraction, which showed that both complexes possess a confacial bioctahedral framework, with three Et2S bridges in 2 and two Me2S and one Cl in 3. The W–W distances, 2.4990(9) in 2 and 2.4752(8)A3 are compatible with triple bond character, while the W–(µ-S) distances are relatively short. The structure of compound 1 was shown spectroscopically to be analogous to that of 2. Proton NMR spectroscopic studies show that the W(µ-thioether)3W unit is resistant to attack by halide ions.

Heterocycles from Silylated Amidines. Preparation of 1,3,2,4,6-Dithiatriazines; Preparation and E.S.R. Characterization of New 1,2,3,5-Dithia- and Diselenadiazolyl Radicals; the Conversion of Dithiadiazolyls to 1,5,2,4,6,8-Dithiatetrazocines by Reaction With O2

Abstract The synthesis of 3- and 4-substituted aryl dithiatriazines, {XC6H4CN3S 2}2, (X = 4-CH3,4-Cl, 3-CF3,4-CF3, 4-C3O, 4-C6H5); dithiadiazolyl radicals 4-X-C6H4CN2S2 (X = CH3, CH3O, Cl, NO2 and CF3) and their dimers in the solid state and four new diselenadiazolyl radicals 4-X-C6H4CN2Se2 (X = CH3, CH3O, Cl, and CF3) as well as CF3CN2Se2 and their dimers are reported. The crystal structure of the 4-Cl dithiatriazine dimer was determined. The sulphur radicals, either in bulk or in higher yield when produced in situ with Ph3Sb, react with O2 to give the corresponding 3- and 4-substituted 1,5,2,4,6,8-dithiatetrazocines, {X-C6H4CN2}2S2, X = 4-H, 4-CH3,4-CH3O,4-Cl, 3-CF3,4-CF3. Physical properties (mp, colour, IR andNMR data) of the derivatives withX = CH3 and 4-CF3 differ substantially from those in a previow report.

A simple synthesis of [NS]+[AlCl4]− and the insertion reaction with alkylselenium halides: X-ray structure of [N2S2SeCl]+[AlCl4]−

The reaction of (NSCl)3 with aluminium trichloride at 50 °C without solvent, preferably with ultrasonic irradiation, produces [NS]+[AlCl4]– in good yields; the thiazyl salt reacts with alkylselenium halides to give [N2S2SeCl]+[AlCl4]–, in which the cation is shown by X-ray crystallography to be a five-membered ring with chlorine attached to selenium.

Diphosphadiselenatetrazocines: preparation and structural characterization of a PV2N4Se2 ring

The reaction of Ph2P(NSiMe3)[N(SiMe3)2] with RSeCl3(R = Ph, Me, Et) in acetonitrile produces 1,5-Ph4P2N4Se2R2[R = Ph, (1a); Me, (1b); Et, (1c)] and 1,5-Ph4P2N4Se2, (2a) when R = Me or Et; X-ray crystallography shows that (1b) is an eight-membered chair with the two selenium atoms displaced on either side of the P2N4 plane by 1.073(2)A.

Synthesis, X-ray crystal structure, and electronic structure of a trinuclear WCu2 cluster containing a hexathiolato tungsten(IV) core

In the new compound (PPh3)Cu(µ-Sptol)3W(µ-Sptol)3Cu(PPh3), (ptol = 4-methylphenyl, p-tolyl), the tungsten is homoleptically ligated by six thiolate ligands, and co-ordinates to two copper(I) atoms in a biconfacial octahedral/tetrahedral geometry; density functional calculations of an idealized model show that the major component of the bonding is transfer of charge from S to Cu, with a smaller contribution from a metal–metal bonding interaction.