原位光谱法研究烷基紫精电氧化还原的缔合行为

The Association Behaviour of Alkyl Viologens in Electroredox Studied by In -situ Spectroscopy

用原位光谱法研究了烷基紫精和相应聚紫精第一还原态（Ｖ＋）的缔合行为，电还原过程中，在电极表面烷基紫精的Ｖ＋主要以缔合体存在，这与电极对Ｖ＋的吸附有关．具有较短烷基的聚紫精，Ｖ＋也主要以缔合体存在，但具有较长烷基的聚紫精，Ｖ＋则主要以单分子体存在，可能是柔顺的烷基链节会减弱Ｖ＋的缔合．缔合平衡随时间向单分子体移动，这与电极对Ｖ＋的吸附和解吸附有关，电还原的缔合行为还与光还原和化学还原进行了比较，同时，也观察了β－环糊精的包结作用对紫精在电还原过程中Ｖ＋缔合行为的影响．

The association behaviour of the first reduced state of alkyl viologens and the correspording polyviologens (V+) has been studied by in -situ spectroscopy. In electroreduction process, V+ of alkyl viologens exist predominantly in the association form on the electrode surface, this phenomenon is attributed to the absorption of V+ on theelectrode. V+ of polyviologens with shorter alkyl groups also exist mainly in the association form. However, V+ of polyviologens with longer alkyl groups exist mainly in the monomeric form because the flexible segments may weaken the V+ association. The equilibrium shifts to the monomeric form gradually during the electroreduction process,which is attributed to the absorption and desorption of V+ on the electrode. The association behaviour of electroreduction has been compared with that of photoreduction as well as chemical reduction. In addition, the effect of β-cyclodextrin inclusion on the association behaviour of V+ in electroreduction has also been investigated.