THE VIBRATIONAL SPECTRA AND STRUCTURE OF SOME METAL ALKYL COMPLEXES

Abstract

Following an examination of the “red” pentaamminenitrosylcobalt complex, which is a trans hyponitrito bonded dimer, an investigation has been undertaken to assign a single structure to this complex from similar complexes. We have worked on ethylene bridged dimers and ethane bridged dimers of the pentacyanocobalt ion and have been able to show conclusively that the C--C symmetric stretching mode for these trans complexes is as expected inactive in the infrared and very intense in the Raman spectrum. These findings support our original proposition that the hyponirito bridge is indeed asymmetric because its infrared spectrum contains a strong N--N stretching mode. White undertaking this investigation several complexes with simple alkyl ligands were prepared and examined to facilitate band assignments in the more complicated systems. Systems examined were $K_{3} Co(CN)_{5} CH_{3}$] and $Mn(CO)_{5} CH_{3}$ along with their deuterated and fluorocarbon analogues, as well as the compound $K_{6}[ (CN)_{5} CoC_{2} F_{4}Co(CN)_{5}$].