Transition-Metal-Substituted Arsaalkenes. 7.¹ Coupling of Transition Metal Carbynes with a Methylene Arsane Moiety:  Structure of Tp‘(CO)₂W⋮C−AsC(NMe₂)₂ [Tp‘ = HB(3,5-Me₂HC₃N₂)₃]

Abstract

Condensation of Tp‘(CO) 2 M⋮CCl [ 1a, M = Mo; 1b, W; Tp‘ = HB(3,5-Me 2 HC 3 N 2 ) 3 ] with the arsaalkene Me 3 SiAs C(NMe 2 ) 2 afforded the novel arsaalkenyl carbyne complexes Tp‘(CO) 2 M⋮C−As C(NMe 2 ) 2 ( 2a ) (M = Mo) and 2b (M = W). Methylation of 2a and 2b occurred at the arsenic atom to give the complexes [Tp‘(CO) 2 M⋮CAs(Me)C(NMe 2 ) 2 ](SO 3 CF 3 ) 3a (M = Mo) and 3b (M = W). Compounds 2a, b and 3a, b have been characterized by IR and 1 H and 13 C NMR spectroscopy. In addition, the molecular structure of 2b has been determined by a single-crystal X-ray structural analysis.