Infrared spectra and structures of di-µ-carbonyl-(π-cyclopentadienylnickelio)carbonyl-π-cyclopentadienyliron(Ni–Fe), (π-C5H5)2FeNi(CO)3 and di-µ-carbonyl-bis-(π-cyclopentadienylnickel)(Ni–Ni), [(π-C5H5)Ni(CO)]2

Abstract

The i.r. spectra of [(π-C₅H₅)₂FeNi(CO)₃] and [(π-C₅H₅)Ni(CO)]₂ have been investigated. They are independent of solvent, and are consistent with molecular structures which possess an almost-planar Fe·µ(CO)₂·Ni and a puckered Ni·µ(CO)₂·Ni bridging system respectively. Simple force-constant calculations which ignore interactions in v(CO) for bridging and terminal CO groups have been carried out. They accurately predict the frequencies of the v(CO) modes of molecules containing one ¹³CO ligand for both compounds.