MOLECULAR AND ELECTRONIC-STRUCTURE, AND STABILITY OF ORGANIC CATIONS,DICATIONS AND DONOR-ACCEPTOR COMPLEXES .1. MNDO CALCULATIONS OF POSSIBLE INTERMEDIATES IN MECOCL-CENTER-DOT-N ALCL3 SYSTEMS

The MNDO method with optimization of geometric parameters has been use d to study the fragments of the potential energy surface for the acyli um cation MeCO+. radical dication MeCO2+., and the (1:n) complexes of general formula MeCOCl.nAlCl3 (where n = 1, 2, 3). The stability of th ese complexes with respect to certain dissociation mechanisms has been studied. The calculations show that the the hitherto unknown RCOCl.2A lCl3 and RCOCl.3AlCl3 can actually exist. Moreover, it has been shown that there can be complexes where the charge on the strongly electroph ilic carbon atom is greater than that of the carbon in the acylium cat ion. The result of the study provided an explanation for the superacid ity of the RCOX.2AlX3 systems in reactions with saturated hydrocarbons .