Abstract
The i.r. spectra of the compounds (π-MeC5H4)Mn(CO)3, [(π-MeC5H4)Fe(CO)2]2, (π-MeC5H4)Fe(CO)2X (X = Cl or I), and [(π-MeC5H4)Mn(CO)2NO]2PtCl6 have been measured in the region 3500–200 cm.–1 and assignments have been made. Particular reference is made to the assignment of the methyl-π-cyclopentadienyl ring modes.