Metal Complexes with Biologically Important Ligands. CLXVI Tetracarbonyl Complexes of Chromium(0) and Molybdenum(0) with Schiff Bases from Pyridine-2-carboxaldehyde and α-Amino Acid Esters as N,N-Chelate Ligands

The complexes [M(CO)4(pyridyl‐CH=N‐CHRCO2R′)] (M = Cr, Mo; R = H, CH3, CH(CH3)2, CH2CH(CH3)2) were obtained by reaction of the Schiff bases from pyridine‐2‐carboxaldehyde and glycine, L‐alanine, L‐valine or L‐leucine esters with the norbornadiene complexes [M(CO)4(nbd)] and were characterized by IR, 1H and 13C NMR and UV‐vis spectra. The deeply colored complexes exhibit solvatochromism.