Crystal Structure of the Carbon Tetrabromide p-Xylene Complex

Abstract

According to an x‐ray diffraction study, crystals of the compound of carbon tetrabromide with p‐xylene are orthorhombic, space group Cmcm, with a=8.48±0.03, b=8.89±0.03, and c=17.46±0.05 Å. With four molecules per cell, the density is calculated as 2.209 g cm^—3. Each aromatic ring has a bromine atom on each face at a distance of 3.34 Å from the center of the ring. This configuration involving half of the bromine atoms is compatible with charge‐transfer bonding. The structure consists of zigzag strings of alternate carbon tetrabromide and xylene molecules. Bond distances and angles within these molecules are normal with standard deviations of 0.02 to 0.05 Å for bond distances.