ELECTRONIC-STRUCTURE AND PROPERTIES OF THE GROUP-4, GROUP-5, AND GROUP-6 HIGHEST CHLORIDES INCLUDING ELEMENT-104, ELEMENT-105, AND ELEMENT-106

Results of the Dirac-Slater discrete variational calculations for the group 4, 5, and 6 highest chlorides including elements 104, 105, and 1 06 have shown that the groups are not identical with respect to trends in the electronic structure and bonding. The charge density distribut ion data show that notwithstanding the basic increase in covalency wit hin the groups this increase diminishes in going from group 4 to group 6. As a result, E106Cl(6) will be less stable toward thermal decompos ition than WCl6, which is confirmed by an estimated low E106-Cl bond e nergy. Delta H-form equal to -90.3 +/- 6 kcal/mol is obtained for E106 Cl(6) in the gas phase, which is indicative of a very low stability of this compound. The stability of the maximum oxidation state is shown to decrease in the direction E104(+4) > E105(+5) > E106(+6).