
%0 Journal Article
%A Schiesser, CH 
%A Wild, LM 
%T Homolytic Substitution at Phosphorus: An <I>Ab initio</I> Study of the Reaction of Hydrogen Atom and Methyl Radical With Phosphine and Methylphosphine
%J Australian Journal of Chemistry
%D 1995/02/01
%V 48
%N 2
%P 175-184
%K 
%R https://doi.org/10.1071/CH9950175
%U https://www.publish.csiro.au/paper/CH9950175 
%X Homolytic substitution reactions of hydrogen atom and methyl radical at the phosphorus atom in phosphine and methylphosphine have been examined by high-level ab initio molecular orbital theory. MP4SDTQ/6-31G**//MP2(FC)/6-31G** calculations predict that free-radical attack at the phosphorus atom in phosphines is facile, with energy barriers of 14-33 kJ mol-1 and likely to involve hypervalent phosphoranyl radical intermediates. These intermediates, in turn, are found to have dissociative energy barriers of 10-31 kJ mol-1, depending on leaving group, and are unlikely to undergo pseudorotation prior to dissociation. MP5/6-31G**//MP2/6-31G** calculations indicate that permutational isomerism of phosphoranyl radical is likely to involve barriers of 145 and 127 kJ mol-1 for mechanisms involving transition states of D4h and C4v symmetry respectively. 
