204275-75-2Relevant academic research and scientific papers
Characterization of transient radicals in the reduction product of the -P=C=C=P- system: EPR and theoretical studies
Sidorenkova, Helena,Chentit, Mostafa,Choua, Sylvie,Geoffroy, Michel,Ellinger, Yves
, p. 4931 - 4936 (2002)
The EPR spectrum obtained at room temperature after electrochemical or chemical reduction of a solution of Ar-P=C=C=P-Ar in THF exhibits hyperfine interaction (165 MHz) with two equivalent 31P nuclei. Additional couplings with two equivalent 13C are observed with Ar-P=13C=13C=P-Ar. The 31P anisotropic coupling constants could be obtained from spectra recorded at low temperature. They indicate that the unpaired electron is mainly localized (78%) on the two phosphorus atoms. Quantum chemical calculations (DFT and ab initio SCI) were performed on the various isomers of the two radical anions: [H-P=C=C=P-H]?-and [H-P=CH-CH=P-H]?-. Although the optimized geometries of these two species are clearly di3erent, neither of them leads to 13C/31P hyperfine tensors in conflict with the experimental results. The absence of any 1H splitting on the EPR spectrum together with the quasi-reversibility of the reduction wave make the identification of [Ar-P=C=C=P-Ar]?-more probable.
