SPATIAL ELECTRON-DENSITY DISTRIBUTION OF CHLORINE ATOMS IN MOLECULE OF THE SERIES 4-XC6H4MCCL2C(0)C6H5 (M=S AND SE)

The Cl-35 NQR frequencies and EFG asymmetry parameters at the Cl-35 nu clei have been measured for compounds of the series 4-XC6H4MCCl2C(O)C6 H5 (M = S and Se, X = H and CH3) at 77 K. The electron distribution at the Cl atoms in all the compounds studied differs from axial symmetry , and is unequal for the two Cl atoms of the CCl2 group. The results o f the measurements imply p(sigma)-electron density nonequivalence of C l atoms in the CCl2, group of these molecules.