INVESTIGATIONS ON SOLID CHLORINE DIOXIDE - TEMPERATURE-DEPENDENT CRYSTAL-STRUCTURE, IR-SPECTRUM, AND MAGNETIC-SUSCEPTIBILITY

Single crystals of chlorine dioxide were grown in situ on a four-circle diffractometer, and the crystal structures were solved at five different temperatures (-75, -90, -110, -130, and -150-degrees-C). At -150-degrees-C, the crystal system, space group, unit cell parameters, and R factor are as follows: orthorhombic, Pbca, a = 10.767 (12) angstrom, b = 6.654 (3) angstrom, c = 5.518 (1) angstrom, V = 395.29 (48) angstrom3, Z = 8, R = 0.024. In the solid state, the ClO2 molecules associate to form weakly bonded dimers which are "head to tail" with respect to one Cl-O bond. The intermolecular interaction was confirmed by magnetic measurements, which show a steep decrease to negative chi values below -93-degrees-C, and by IR spectroscopy.