Complexes Containing Phosphorus and Arsenic as Terminal Ligands

摘要

Alkali metal bis(trimethylsiiyl)phosphanides react with different halogenophosphorus compounds to form multiple P-P bonds. The alkali metal phosphanide serves as a reagent for metalation of silylphosphorus functionalities with the elimination of P(SiMe_3)_3 and as a source for the central phosphorus atom in the resulting tri- and isotetraphosphanes. Our interests have focused on the extension of the above concept by the use of transition metal halides and the heavier homologues [E(SiMe_3)_2]~-(E =As, Sb, Bi). The paramagnetic W~(IV) halogenide [(N_3N)WCl] 1b [(N_3N) = N(CH_2CH_2NSiMe_3)_3] serves as an ideal starting material in both respects. With this species and the corresponding molybdenum compound 1 a. Schrock et al. were able to synthesizethe first examples of compounds containing a metal- phosphorus triple bond (2) [Eq. (a)] that were structurally characterized. At the same time Cummins et al. reported the synthesis of a complex containing a Mo-P triple bond by using [Mo(NAr'R)_3] (Ar' =3.5-C_6H_3Me_2, R = C(CD_3)_2CH_3) and white phosphorus as starting materials.