Reactions of [Cu(X)(BPEP-Ph)] (X = PF6, SbF6) with silyl compounds. Cooperative bond activation involving non-coordinating anions.

Bond activation of silyl compounds, assisted by the cooperative action of non-coordinating anions, is achieved using Cu(I) complexes coordinated with a PNP-pincer type phosphaalkene ligand, [Cu(X)(BPEP-Ph)] (X = PF6 (1a), SbF6 (1b); BPEP-Ph = 2,6-bis[1-phenyl-2-(2,4,6-tri-tert-butylphenyl)-2-phosphaethenyl]pyridine). Complexes 1a and 1b react with Me3SiCN to form Me3SiF and Cu(i) cyanide complexes of the formula [Cu(CN-EF5)(BPEP-Ph)] (E = P (2a), Sb (2b)), in which the CN ligand is associated with the EF5 group arising from EF6(-). Formation of the intermediary isonitrile complex [Cu(CNSiMe3)(BPEP-Ph)](+)SbF6(-) (3b) is confirmed by its isolation.

Synthesis and coordination behavior of Cu(I) bis(phosphaethenyl)pyridine complexes.

Cu(I) complexes bearing BPEP as a PNP-pincer type phosphaalkene ligand undergo effective bonding interactions with SbF(6)(-) and PF(6)(-) as non-coordinating anions to give [Cu(SbF(6))(BPEP)] and [Cu(2)(BPEP)(2)(μ-PF(6))](+), respectively [BPEP = 2,6-bis(1-phenyl-2-phosphaethenyl)pyridine]. NMR and theoretical studies indicate a reduced anionic charge of the μ-PF(6) ligand, which is induced by the strong π-accepting ability of BPEP.