ENERGIES AND PROPERTIES OF IONS INVOLVED IN ELECTROPHILIC HALOGENATIONS - SINGLET AND TRIPLET-STATES OF HALOGEN CATIONS (X+, X3+, AND X4(2+)) AND HYDROHALONIUM IONS (HX2+ AND H2X+)

The geometries and relative energies of the singlet and triplet states of halogen cations, X+(X = F, Cl, Br), X3+(X = F, Cl), and hydrohalonium ions H2X+and HX2+ (X = F, Cl), were studied with ab initio molecular orbital calculations. The monatomic halogen cations have triplet ground states, but most of the triatomic cations and hydrohalonium ions have singlet ground states. The optimization of the corresponding triplet complexes led to geometries of diatomic radical cations associated loosely with atom. The geometries of X42+(X = F, Cl) dications were also examined by ab initio calculations. © 1990, American Chemical Society. All rights reserved.