G1 AND G2 STUDY OF THE TRIPLET [H-4, C, O, P](-ENERGY SURFACE - MECHANISMS FOR THE REACTION OF P+ (P-3) WITH METHANOL() POTENTIAL)

A G1 and G2 study of the triplet [H-4, C, O, P](+) potential energy su rface (PES) has been carried out, along with a study of a number of me chanisms for the reaction of the P+ ((3)p) ion with methanol. The most stable isomer, which corresponds to the insertion of the phosphorus c ation into the C-O bond of methanol, lies 79.5 kcal/mol below the reac tant level. The P+-H3COH ion molecule complex has also a remarkable st ability, -72.0 kcal/mol, showing that methanol exhibits greater basici ty than water or formaldehyde. Bond properties have also been evaluate d for all the minima encountered on the PES. Several barrier-free reac tion paths have been characterized. The most exothermic channel involv es abstraction of H-2, although this path is kinetically disfavored. I n this sense, the most favored reaction leads to the formation of the doublet POH+ ion with the release of doublet CH3, in agreement with ex perimental evidence. However, other barrier-free channels were also fo und, pointing to a variety of possible products for the P+ + H3COH rea ction.