The crystal structure of cupric tropolone: a refinement

Abstract

The crystal structure of cupric tropolone has been refined using three-dimensional crystallographic data. The bond length alternation around the molecule, found in an earlier twodimensional analysis, has been confirmed. The molecule is not planar although the seven carbon atoms of the ring are coplanar. The plane of the copper and oxygen atoms makes an angle of 4.9° with the plane of the carbon atoms. The departure of the molecule from planarity permits more effective van der Waals bonding between successive molecules. It is believed that the resulting gain in crystal energy more than compensates for the loss of delocalization energy by the molecule in adopting symmetry I rather than symmetry mmm .