The crystal and molecular structure of phenanthrenechromium tricarbonyl

Abstract

The crystal structure of the orthorhombic form of phenanthrenechromium tricarbonyl has been determined by X-ray analysis. There are eight molecules in a cell of dimensions a= 12·14, b= 18·08, and c= 12·34 Å. The space group is Pbca. The structure has been refined to an R-value of 0·12 for 4169 reflections. The molecular structure is similar to that found in the monoclinic modification, with the chromium bonded to a side ring of the phenanthrene ligand. The Cr–C_sp² bonded distances range from 2·206 ± 0·005 to 2·289 ± 0·004 Å and correlate with the free valences of the carbon atoms involved.