Preparation, characterization, and properties of various novel ionic derivatives of pentacarbonyltungsten

The complexes [Li(DIME)(2)][W(CO)(5)L] [L = OCN 2, NCS 3a, PPh2 4, SiMe2Ph 8, N(SiMe3)(2) 9, CH2Ph 10, Si6Me11 11; DIME = diethylene glycol dimethyl e ther] have been prepared by reaction of [Li(DIME)(2)][W(CO)(5)I] (1) with K OCN, KSCN, NaPPh2, LiSiMe2Ph, LiN(SiMe3)(2), PhCH2MgCl, and KSi6Me11, respe ctively Photochemical ligand substitution in W(CO)(6) has been used as an a lternative method for the preparation of pentacarbonyl tungstates; [K(DIME) (2)][W(CO)(5)NCS] (3b), [Na(DIME)(2)][W(CO)(5)N-3] (5), [Li(DIME)(2)][W-2(C O)(10)(mu-H)] (6), and [K(DIME)2][W-2(CO)(10)(mu-CN)] (7) were synthesized in this manner. The molecular structure of [Li(DIME)(2)][W(CO)(5)-Si6Me11] (11) has been determined by X-ray diffraction analysis. The spectral and ch emical properties of 2-11 are discussed. Pyrolysis of 11 leads to tungsten silicide and tungsten carbide.