SYNTHESES AND CRYSTAL-STRUCTURES OF TUNGSTEN COMPLEXES CONTAINING VARIOUS (THIAZOLIUMYL)DIPHENYLPHOSPHINE LIGANDS

Alkylation reactions at the S atom of the anionic PPh2C(=NPh)S- ligand coordinated to a tungsten pentacarbonyl group afford the neutral comp lexes W(CO)(5)PPh2C(=NPh)SR (4, R = CH2C=CH; 5, R = CH2C=N; 6, R = CH2 CONH2; 7, R = CH2CH=CH2; 8, R = CH2CO2Me). Protonation of 4 with HBF4 at room temperature causes cyclization to the cationic complex W(CO)(5 )PPh2[CSCH2C(CH2)NPh]BF4 (10), which contains a (thiazoliumyl)diphenyl phosphine ligand. Similarly, protonation reactions of 5 and 6 with HBF 4 give the cationic complex [W(CO)(5)PPh2CSCHC(NH2)NPh]BF4 (11) and th e neutral complex W(CO)(5)PPh2CSCHC(OBF3)NPh (12), respectively, both of which contain (thiazoliumyl)diphenylphosphine ligands. The structur es of 10 and 12 are determined by X-ray diffraction analyses.