Picosecond absorption spectroscopy is used to study the dynamics of bond homolysis and heterolysis of diphenylmethyl bromide and bis(4-methoxyphenyl)methyl bromide in acetonitrile. Combining these kinetics results with our previous study of diphenylmethyl chlorides, the nature of the conversion of the geminate radical pair into contact ion pairs is addressed. Also a qualitative potential energy diagram, based upon a valence bond description, that accounts for the factors that determine the partitioning between geminate radical pair and contact ion pair subsequent to the decay of the first excited singlet state is presented.