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ESR. Spectra of the Radical Anion of Dimethyl‐phenyl‐phosphine
Author(s) -
Gerson F.,
Plattner G.,
Bock H.
Publication year - 1970
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19700530710
Subject(s) - chemistry , substituent , trimethylsilyl , ion , phosphine , ring (chemistry) , delocalized electron , alkali metal , benzene , electron delocalization , coupling constant , spectral line , photochemistry , radical ion , radical , reaction rate constant , medicinal chemistry , crystallography , organic chemistry , kinetics , catalysis , physics , particle physics , astronomy , quantum mechanics
ESR. spectra of the radical anion (I ⊖ ) produced from dimethyl‐phenyl‐phosphine (I) both by electrolysis and reaction with alkali metals have been studied upon variation of temperature. The coupling constant assigned to the 31 P nucleus depends strongly on temperature, whereas the coupling constants attributed to protons do not exhibit such a dependence. The π‐spin populations at the benzene ring of I ⊖ give evidence ‐ in accordance with other experimental data [1] [2] – that the dimethylphosphino substituent is electron‐attracting. This effect is thought to be due mainly to P ← C π delocalization, which is analogous to the SiC π interaction in trimethylsilyl‐substituted π‐systems [3]. The ESR. spectrum previously [4] ascribed to I ⊖ is shown to arise from a secondary radical. The formation and structure of this radical are briefly discussed.