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 literature 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 well as the energetics (thermodynamics) of these species are also included. In particular, the symmetric and unsymmetric structures of heteropolyatomic cations, the charge delocalization and bond lengths alternation in nppi-nppi species (n < 2), and the dimerization by pi-pi interactions are discussed.