X-ray photoelecton spectroscopic (ESCA) study of 1,2-bis(diphenyl-phosphino)-ethane, 1-(diphenylphosphino)-2-(dimethylamino)-ethane and related compounds

Abstract

ESCA spectra for compounds of the type φ 2P-CH 2CH 2-Pφ 2, φ 2PCHCHPφ 2, φPCCPφ 2 and, Me 2NCH 2CH 2Pφ 2 are reported along with similar compounds having positive charges on one or both of the heteroatoms. For uncharged molecules, group electronegatives correlated with P(2 p) binding energies. For molecules having a charged site, the inductive effect of the charged atom was a major factor determining binding energies for both heteroatoms. Among similar compound types, anion effects were absent. For molecules containing nitrogen, the smaller (CH 3) 2N-group allowed anion shielding of the positive charge, causing smaller shifts than for similar compounds containing only phosphorus. Correlations between charge, calculated from Sanderson electronegatives, and P(2 p) and N(1 s) binding energies are reported.