The chiral-at-metal cycloheptatrienyl-molybdenum complexes (R Mo ,S C )-[(η 7 -C 7 H 7 )Mo(iminphos)(CO)]BF 4 (2a) and (S Mo ,S C )-[(η 7 -C 7 H 7 )Mo(iminphos)(CO)]BF 4 (2b) (iminphos ϭ 2-[N-(S)-1-phenylethylcarbaldimino]phenyl(diphenyl)phosphane), which only differ in the molybdenum configuration, were prepared and separated by fractional crystallization. The absolute configuration Optisch aktive Übergangsmetall-Komplexe. 128 [1] Synthese, Charakterisierung und Molekülstrukturen von chiralen CycloheptatrienylIminphos-Molybdän-Komplexen mit unterschiedlicher Metallkonfiguration