The crystal structure of the bis-tricarbonylchromium complex of dibenzo[a,e]cyclooctatetraene: Cr(CO)3 orientation controlled by short C–H⋯O hydrogen bonding

The structure of the title compound, 1, was determined by X-ray crystallography. One tricarbonylchromium [syn-Cr(CO)3] moiety is bound to the concave side of the dibenzo[a,e]cyclooctatetraene ligand while the other metal is bound to the convex side yielding an anti-Cr(CO)3. There are four independent molecules in the crystal with the main difference between them being the orientation of the anti-Cr(CO)3. Analysis of intermolecular interactions in the solid state confirms that the variable tripodal rotations are the result of short C–H···O(carbonyl) hydrogen bonds. In 1, the organic framework has flattened slightly relative to uncoordinated dibenzo[a,e]cyclooctatetraene.