HOMOPOLYATOMIC AND HETEROPOLYATOMIC HALOGEN CATIONS

This review is not exhaustive in scope but rather focuses on the most recent years of work in the field of cationic halogens, covering the l iterature up to mid 1992. This area is still currently developing. The review summarizes structure, preparation, and reactivity of cationic halogens. Modern theoretical aspects (ab initio MO calculations) as we ll as the energetics (thermodynamics) of these species are also includ ed. In particular, the symmetric and unsymmetric structures of heterop olyatomic cations, the charge delocalization and bond lengths alternat ion in nppi-nppi species (n < 2), and the dimerization by pi-pi intera ctions are discussed.