Synthesis and Structures of Dinitrosyl Iron Complexes Containing Bisphosphine Ligands

A series of dinitrosyl iron complexes with the formula [(L)Fe(NO)2], {L = ), 2,2'- bis(diphenylphosphino)-1,1'-binaphthyl (1), 1,1’-bis(diphenylphosphino)ferrocene (2B), and 1,4’-bis(diphenylphosphino)butane (3B)} has been prepared and characterized through a combination of FT-IR, NMR, UV-Vis, X-ray crystallography, CV and EPR techniques. IR spectroscopy showed NO shifts to the ranges of 1708 cm-1 – 1702 cm-1 and 1661 cm-1 – 1654 cm-1 for the chelated products 1, 2B and 3B. Molecular structures products 1 and 2B were confirmed by X-ray crystallography and confirmed to be chelated structures and in the “attracto” conformation. CV study of product 2B displayed two quasi-reversible processes with E1/2 values of -0.091 V and 0.451 V at the dinitrosyl iron center. The EPR spectroscopy confirmed that product 2B is EPR active with an EPR peak of a triplet of a quintet with a gfactor calculated of 2.033. calculated g-factor aligns with the signature non-heme dinitrosyl iron complexes with g-factor of “2.03”