Bis(alkylidynyl)arsines.

The synthesis and characterization of the first examples of bimetallic bis(alkylidynyl)arsines, [RAs{C[triple bond, length as m-dash]M(CO)2(Tp*)}2] (M = Mo, R = Ph, Me; M = W, R = Ph, Me, nBu; Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) are described. For the tungsten complexes, these may be prepared by a potentially generalizable route: successive treatment of [W([triple bond, length as m-dash]CBr)(CO)2(Tp*)] with nBuLi, ACl3 (A = P, As) and a nucleophilic source of R-via the inferred intermediacy of [ClA{C[triple bond, length as m-dash]W(CO)2(Tp*)}2].