Studies on molybdenocene derivatives: Reactions of [Cp 2Mo(η 2-NCMe)] and preparation of alkyl hydride complexes. Crystal structure of [Cp 2Mo(PMe 3)

Abstract

Reaction of [Cp 2Mo(η 2-NCMe)] ( 1) with PMe 3 affords [CP 2Mo(PMe 3)] ( 2), which is readily alkylated go give [Cp 2MoR(PMe 3)]PF 6( 3a, R = Me; 3b, R = Et). The crystal structure of 2 shows tricoordination around the Mo atom. Cyclic voltammetry of 3a and 3b and the analogues [Cp 2MoR(CNMe)]I, ( 4a, R = Me; 4b, R = Et) and [Cp 2MoMe(PPh 3)]PF 6 ( 7) shows one reversible one-electron oxidation, but the potential is independent of R, in contrast to the complexes [Cp 2MoR 2]. Oxidative addition of Et 2S 2, Ph 2Se 2 or (PhCOO) 2 to 1 yields [Cp 2Mo(ER) 2] (E = O, S or Se). The molybdenocene alkyl hydrides [Cp 2Mo(H)Me] ( 5) and [Cp 2MoH(CH 2PPh 3)]I·THF ( 6) are prepared from [Cp 2MoHI]. Thermal decomposition of 6 as well as reaction Of [Cp 2MoMe 2] + with Ph 3C . provide evidence for transient formation of the methylidene complex [Cp 2MoH(CH 2)] +.