Mass spectra of inorganic molecules. Part I. Some bridged nitrosyl complexes of iron and cobalt

Abstract

The mass spectra of the iron and cobalt complexes [(NO)₂MX]₂(M = Co; X = Cl, Br, l: M = Fe; X = Cl and Br) have been measured. The relative nature and abundances of the ions in the spectrum have been related to the presence of “metal–metal” interaction in the iron complexes. Fragmentation occurs by primary loss of nitric oxide for the dimeric ions, whilst both halide and nitric oxide loss occurs for the uninuclear ions.

A related series of sulphur-bridge complexes, [(NO)₂MSR]₂(M = Co; R = Bu, Et, Ph: M = Fe; R = Bu, Et, Ph, Me) have also been studied. For the phenyl derivatives the decomposition pattern may also be related to the presence of a metal–metal bond in the iron adduct; however, the spectra are modified by the higher stability of the metal–sulphur cluster. The butyl and ethyl compounds give a type of spectra which is dominated by the formation of rearrangement ions which could be formulated as metal hydride adducts and liberation of the corresponding olefin. A novel reaction has been observed on the probe leading to the formation of the compound [(NO)₄Co₂BrCl].