Electron spin resonance studies of .gamma.-irradiated phosphorus compounds containing phosphorus-chlorine bonds

Journal Article · Sat Nov 01 04:00:00 EST 1975 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100591a016· OSTI ID:4139883

Kerr, Carolyn M. L.; Webster, Kathleen; Williams, Ffrancon

ESR experiments similar to those described in the preceding paper were used to identify the radicals produced in a series of $gamma$-irradiated phosphorus compounds containing phosphorus--chlorine bonds. The principal species formed from diethyl chlorophosphite are the neutral radicals P(OEt)$sub 2$ and (EtO)$sub 2$PCl$sub 2$ presumably by loss and addition of chlorine atoms, although there is evidence that the former species is produced at least in part by dissociative electron capture. On the other hand, the major radical derived from a series of chlorophosphate esters is invariably the chlorophosphoranyl radical anion formed by simple electron attachment to the parent molecule. In the dichlorophosphoranyl radicals, there is a large $sup 35$Cl coupling from the two equivalent chlorines in the apical positions of a trigonal bipyramidal structure. Evidence for the anisotropy of this coupling suggests that a significant spin density resides in the 3p/sub sigma/ orbitals of these chlorine ligands, in agreement with recent single crystal studies on POCl$sub 3$$sup -$. The much greater stability of radical anions derived from chlorophosphates relative to those from di- and trialkyl phosphate esters, which undergo efficient dissociation, is interpreted in terms of the effect of ligand electronegativity on the spin density distribution. This effect is consistent with recent MO descriptions which indicate that the half-occupied orbital in phosphoranyl radicals is largely localized along the axial three-center bond.

• Research Organization: Univ. of Tennessee, Knoxville
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-008921
• OSTI ID: 4139883
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 24 Vol. 79; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

*ORGANIC CHLORINE COMPOUNDS-- RADIOLYSIS
*ORGANIC PHOSPHORUS COMPOUNDS-- RADIOLYSIS
*OXYCHLORIDES-- RADIOLYSIS
*PHOSPHORIC ACID ESTERS-- RADIOLYSIS
*PHOSPHORUS CHLORIDES-- RADIOLYSIS
*PHOSPHORUS COMPOUNDS-- RADIOLYSIS
400600* --Chemistry--Radiation Chemistry
AROMATICS
ELECTRON CAPTURE
ELECTRON SPIN RESONANCE
GAMMA RADIATION
LOW TEMPERATURE
MOLECULAR STRUCTURE
N40300* --Chemistry--Radiation Chemistry
RADICALS
SPECTROSCOPY