exo-pi-(benzonorbornadiene)tricarbonylchromium

The title compound, tricarbonyl[(4a,5,6,7,8,8a-eta)-1,4-dihydro-1,4-methanonaphthalene]chromium, [Cr(C11H10)-(CO)(3)], is a complex of chromium(0) in which the arene ring of the organic ligand is hexahapto-coordinated to the Cr atom. Three terminal carbonyl ligands form the triangular base of the molecule. The mode of coordination of the Cr(CO)(3) moiety to the ligand is such that the free double bond of the benzonorbornadiene is oriented away from the Cr atom. The chromium-carbonyl tripod is rotated slightly from a perfectly staggered arrangement with respect to the arene ring and, hence, the molecule does not possess a plane of symmetry.