Heterozyklen als liganden: XVIII. Synthese und struktur von tricarbonyl(1,2,3,4,5-pentamethylpyrrol)chrom(O) -der Einfluß der methylsubstituenten auf die koordinationseigenschaften des pyrrol-liganden

Tricarbonyl(1,2,3,4,5-pentamethyl)chromium(O) (II) is obtained from pentamethylpyrrole and tetracarbonyl(norbornadiene)chromium(O) in good yield. The molecular geometry of II calculated from X-ray data indicates pentamethylpyrrole to be a stronger donor ligand on comparison with N-methylpyrrole in tricarbonyl(N-methylpyrrole)chromium(O) (I). This result is confirmed by an AM1 calculation of N-methylpyrrole and pentamethylpyrrole.