The role of C-chlorocarbenemetal complexes in carbene– and carbyne–metal complex chemistry; experiments with [Cr(CO)5{C(Cl)NMe2}] and [Cr(CO)5(CNMe2)]+

Abstract

Low temperature reaction of [Cr(CO)₅{C(Cl)MNe₂}], (I), with (a) AgQ yields [Cr(CO)₅(CNMe₂]⁺Q^–(Q = BF₄, PF₆, or ClO₄), (II), (b) BCl₃ gives (II, Q = BCl₄), (c) PPh₃ affords cis-[Cr(CO)₄(PPh₃){C(Cl)NMe₂}], and (d) KCN gives [Cr(CO)₅{C(CN)NMe₂}]; the latter is also obtained from (II, Q = BF₄), which additionally with LiNMe₂ furnishes [Cr(CO)₅{C(NMe₂)₂}] and with PEt₃ or [Bu₄N]⁺I^– the carbyne complexes trans-[Cr(CO)₄-(PEt₃)(CNMe₂)]⁺[BF₄]^– or trans-[Cr(CO)₄I(CNMe₂)].