Optisch aktive übergangsmetall-komplexe: XIX. Optisch aktive cyclopentadienyl-dicarbonyl-molybdän-derivate der schiffschen base von pyrrolcarbaldehyd(2) mit S-(−)-α-methylbenzylamin

C₅H₅Mo(CO)₃Cl reacts with the sodium salt II of the Schiff base I derived from pyrrol carbaldehyde(2) and S-(−)-α-methylbenzylamine with the formation of the neutral diastereoisomeric complexes IIIa and IIIb of tetragonal pyramidal structure. The properties and spectra of IIIa and IIIb are described and it is shown that the diastereoisomers can be separated by chromatography and fractional crystallisation. IIIa and IIIb are configurationally stable at room temperature and at higher temperatures they isomerise. The epimerisation of IIIa and IIIb, measured polarimetrically in the temperature range between 85.0 and 95.0°C in toluene and dimethylformamide, follows a first order rate law and probably represents a regular pentatopic skeletal rearrangement.