Comparative mass spectrometric investigation of transition metal polymethylcyclopentadienylcarbonyl complexes: I. Mass spectra of RnC5H5−nRe(CO)3 (R = CH3, n = 0-5; R = t-C(CH3)3, n = 1)

Abstract Investigation of π-(CH 3 n C 5 H 5 –n Mn(CO) 3 (Me n -CpMnT) n = 0−5 and t-butyl CpMnT mass spectra showed that Me n CpMnT molecular ion ( M + ) fragmentation occurs by a simpler scheme than that for Me n CpReT M + molecular ions. The reason is that MnCp and MnCO bonds are not as strong as the ReCp and ReCO bonds, and the relative “inertness” (compared to Re) of the Mn atom (ion), coordinated to the methylcyclopentadienyl ligand. Variations of M + molecular ion intensity with different values of n are probably due to a complexity of electronic and spatial methyl-carbonyl group interactions in M + .