61580-09-4Relevant articles and documents
Effects of Molecular Structure on basicity. Gas-Phase Proton Affinities of Cyclic Phosphites
Hodges, Ronald V.,Houle, F. A.,Beauchamp, J. L.,Montag, R. A.,Verkade, J. G.
, p. 932 - 935 (2007/10/02)
The proton affinities of several monocyclic and bicyclic phosphite esters are determined by ion cyclotron resonance spectroscopy.The order of proton affinities is identical with the solution basicity order reported earlier.Thus, increasing steric constraint decreases the proton affinity of the phosphorus lone pair in phosphites.Moreover, the phosphorus lone pair in monocyclic six-membered-ring phosphites is more basic in the axial than in the equatorial position.Adiabatic ionization potentials are obtained from photoelectron spectra of the phosphites.Increases in ionization potential are found to parallel decreases in proton affinity.This relationship between the ionization potential and proton affinity suggests that the first ionization potential of the phosphites corresponds to ionization from the phosphorus lone pair orbital.These trends are rationalized in terms of changes in the interactions of the oxygen lone pair orbitals with the phosphorus lone pair and ?-bonding orbitals.
