Tricarbonyl-6,6′-dimethylfulvene chromium(0) – Structural properties

The crystal structure of tricarbonyl-6,6′-dimethylfulvene chromium(0) was determined using X-ray diffraction at room temperature and at 120 K. The title compound crystallizes in the centrosymmetric, monoclinic space group P21/n (no. 14) with one complete molecule in the asymmetric unit. The deviation of the chromium(0) complex from Cs(m) symmetry is negligible in agreement with results derived from density functional calculations using three different methods as well as ab initio calculations (MP2). The 6,6′-dimethylfulvene ligand is bent by 30.9° as a result of the π-η2:π-η2:π-η2 coordination to the Cr(0) metal. In addition, the chromium(0) complex was studied by IR and Raman spectroscopy and selected vibrational data are compared to values derived from DFT calculations.