Pulse radiolysis study of ion pairing of diphenylpolyene radical anions with tetrabutylammonium and sodium cations in tetrahydrofuran
作者:Takahisa Aoyama、Yukio Yamamoto、Koichiro Hayashi
DOI:10.1039/f19898503353
日期:——
diphenylpolyene radical anions are shifted to shorter wavelengths by ion pairing with Bu4N+ and Na+ as well as that of the trans-stilbene radical anion previoulsy investigated. When Ph(CHCH)nPh˙–(n= 1–4) is paired with Bu4N+, the magnitude of the spectroscopic shift is larger for n= 2–4 than for n= 1. On the other hand, the magnitude of the spectroscopic shift due to the ion pairing with Na+ decreases with
全反式α,ω-二苯基取代的多烯,例如1,4-二苯基丁-1,3-二烯,1,6-二苯基六-1,3,5-三烯和1的四氢呋喃(THF)溶液的脉冲辐射分解在不存在和存在Bu 4 NPF 6和NaBPh 4的情况下进行了1,8-二苯基辛基-1,3,5,7-四烯。在盐的存在下,通过与Bu 4 N +和Na +以及已研究的反式-苯乙烯基阴离子的离子配对,二苯基聚亚烷基自由基阴离子的吸收最大值移至较短的波长。当PH(CH CH)ñ PH - (n = 1-4)与Bu 4 N +配对,n = 2-4的光谱位移幅度大于n = 1的光谱位移。另一方面,离子对引起的光谱位移幅度Na +随n的增加而降低,而在n = 3或4的情况下变得非常小。自由基阴离子的衰变是由于与THF(H +)被盐的添加所阻碍。盐的阻滞作用归因于反应物离子与衍生自盐的抗衡离子的离子配对。在乙腈溶液中,自由基阴离子的吸收光谱和衰减速率不受添加盐的