Substituent effects on the zero-field splitting parameters of diarylmethylene. Evidence for merostabilization in appropriately substituted diphenylmethylenes

RWR Humphreys, DR Arnold

Index: Humphreys,R.W.R.; Arnold,D.R. Canadian Journal of Chemistry, 1979 , vol. 57, # 19 p. 2652 - 2661

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Citation Number: 30

Abstract

An analysis of the temperature dependence (4-30 K) of the electron spin resonance (esr) spectra of substituted diphenylmethylenes (eg para-, para'-; methoxy, cyano, dimethylamino, and nitro) indicates all of these species have a triplet ground state. The variation in the zero- field splitting parameter D for this series of methylenes provides evidence that the average separation of the unpaired electrons is greatest for the unsymmetrically substituted ...