ELECTRON PHOTODETACHMENT FROM ORGANOPHOSPHIDE IONS - ELECTRON-AFFINITIES AND SUBSTITUENT EFFECTS IN ORGANOPHOSPHINES AND THEIR CONJUGATE RADICALS

Electron photodetachment from methylphosphide, cyclohexylphosphide, and phenylphosphide ions was carried out using an ion cyclotron resonance (ICR) spectrometer to generate, trap, and detect the ions. The electron affinities of the corresponding radicals inferred from the onsets were as follows: methylphosphinyl, 21.6 +/- 0.4 kcal/mol; cyclohexylphosphinyl, 23.8 +/- 0.4 kcal/mol; and phenylphosphinyl, 35.1 +/- 0.9 kcal/mol. The acidity of methylphosphine was determined by bracketing reactions to be DELTA-H-degrees(acid) between 371.5 and 366.4 kcal/mol, giving a P-H bond energy in methylphosphine between 74 and 79.5 kcal/mol.