Coordination complexes of chromium(0) with a series of 1,3-diphenyl-6-aryl-fulvenes.

The synthesis and structural properties of a series of chromium tricarbonyl 'piano-stool' complexes bearing substituted penta-fulvene ligands were studied. The complexes, tricarbon-yl(1,3,6-tri-phenyl-fulvene)chromium(0) benz-ene hemisolvate, [Cr(CH)(CO)]·0.5CH (), tricarbon-yl[1,3-di-phen-yl-6-(3-vinyl-phen-yl)fulvene]chromium(0), [Cr(CH)(CO)] (), and tricarbon-yl[1,3-diphenyl-6-(pyren-1-yl)fulvene]chromium(0), [Cr(CH)(CO)] (), each have a distorted octa-hedral geometry, with the fulvene coordinated in a π-η:π-ηπ-η fashion. Significant deviation of the exocyclic fulvene double bond from the cyclo-penta-diene plane accompanies coordination. Evidence of non-covalent π-π inter-actions was observed in both () and (), with centroid-to-centroid distances ranging from 3.330 (8) to 3.494 (8) Å.