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 SbF6- and PF6- as non-coordinating anions to give [Cu(SbF6)(BPEP)] and [Cu-2(BPEP)(2)(mu-PF6)](+), respectively [BPEP = 2,6-bis(1-phenyl-2-phosphaethenyl)pyridine]. NMR and theoretical studies indicate a reduced anionic charge of the mu-PF6 ligand, which is induced by the strong p-accepting ability of BPEP.