EPR, ENDOR and TRIPLE resonance characterization of three paramagnetic reduction stages of 5-(9′-fluorenylidene)-5H-dibenzo[a,d] cycloheptene. Radical anions, radical trianions and radical penta-anions
作者:M. Celina R. L. R. Lazana、M. Luisa T. M. B. Franco
DOI:10.1039/ft9959103821
日期:——
5-(9′-Fluorenylidene)-5H-dibenzo[a,d]cycloheptene (1) has been chemically reduced with alkali metals (Li, Na, K, Cs) to the respective radical anions, radical trianions and radical penta-anions, which have been studied by EPR, ENDOR and TRIPLE resonance spectroscopies. The absolute assignment of the proton hyperfine splitting (hfs) to the 10 (11) positions and to positions in the fluorenyl moiety was
5-(9'-氟亚烯基)-5 H-二苯并[ a,d ]环庚烯(1)已被碱金属(Li,Na,K,Cs)化学还原为相应的自由基阴离子,自由基三阴离子和自由基五-阴离子,已通过EPR,ENDOR和TRIPLE共振光谱学进行了研究。通过合成和研究选择性氘代衍生物2-6的还原,将质子超细分裂(hfs)的绝对分配分配给10(11)位置和芴基部分的位置是可行的。将实验性hfs与通过INDO方法计算的实验性hfs进行比较,可提供有关还原引起的结构变化的重要信息。