PNNL

Abstract

A series of new iron(II)-hydride complexes that contain diphosphine ligands with pendant amine bases of the formula cis-[HFeL(PNP)2]+, where PNP = Et2PCH2NMeCH2PEt2 and L = CH3CN (3), CO (4), and P(OEt)3 (5), have been synthesized and characterized. Protonations of the pendant bases in the PNP complexes have been characterized, and for selected complexes, pKa values have been determined. Unlike the previously studied hydride complexes [HNi(PNP)2]+ and trans-[HFe(CH3CN)(PNP)(dmpm)]+, the new hydride complexes reported here do not show rapid intramolecular exchange between the protonated base of the diphosphine and the hydride ligand. “This work was supported by the Office of Basic Energy Sciences of the Department of Energy. The Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.”