High-Resolution electron impact mass spectrometry of five novel organoiron complexes

The high resolution mass spectra of five novel η¹-R substituted Fe(II)(CO)₂ η⁵-C₅H₅ complexes are reported. Fragmentation behavior common to all the studied compounds is noted, as well as some ligand-specific fragmentation. Fragment ions associated with ligand recoordination, ligand substituent transfer and inter-ligand bond formation are noted. The role of the electron density around the metal center, and in particular the ‘18-electron’ configuration, on the fragmentation of these compounds is discussed.