FIRST SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF NEUTRAL CHELATED SYN-FACIAL BIMETALLIC (ETA(5)-CYCLOHEXADIENYL)BENZYLIDENE COMPLEXES FROM ROMIUM(0)-KAPPA-C-2')PYRIDINE-KAPPA-N]MANGANESE(I) DERIVATIVES

Reaction of rbonyl[2-{(eta(6)-phenyl)tricarbonylchromium-kappa C-2'} p yridine-kappa N]manganese(I), 2a, with phenyllithium quantitatively af fords an acylmanganese anion 3a that can be isolated and spectroscopic ally characterized. Insitu O-alkylation of the latter anion by means o f MeOSO2CF3 at low temperature, yields a new neutral syn-facial hetero bimetallic analog 4a of (eta(5)-cyclohexadienyl)-benzylidene complexes . The treatment of bimetallic carbonyl complexes of S-methyl, 2-phenyl -pyridine and 2-phenyl-quinoline, 2b and 2c, with PhLi and subsequentl y with MeOSO2CF3 affords deep purple crystalline products 4b and 4c th at have been structurally characterized by X-ray diffraction analyses. The molecular structures of 4b and 4c display, among other features, an overall helical shape with a pronounced pi-stacking of the aromatic groups and a weak interaction between the chromium and the manganese centered units.