Metal-Promoted Intermolecular Electron Transfer in Tetrathiafulvalene–Thiacalix[4]arene Conjugates and Tetrachlorobenzoquinone
作者:Bang-Tun Zhao、Qi-Ming Peng、Xiao-Min Zhu、Zhen-Ning Yan、Wei-Min Zhu
DOI:10.1021/jo502390z
日期:2015.1.16
In this work, two series of tetrathiafulvalene (TTF) and thiacalix[4]arene (TCA) conjugates (TTFTCA) were designed by CuAAC click reactions. The results obtained from NMR and H-1 NMR NOE indicated that their conformations of thiacalix[4]arene framework may prefer to 1,3-alternate. The cyclic voltammograms of four TTFTCA compounds containing electroactive TTF units were provided. Meanwhile, their intermolecular electron-transfer (ET) behaviors with tetrachlorobenzoquinone (Q) mediated by different metal ions, Sc3+, Pb2+, Ag+, Cd2+, and Zn2+, in CH3CNCH2Cl2 (V/V = 1:1) solution were studied and analyzed via UVvis spectroscopy. It was determined that intermolecular ET between each TTFTCA and Q ensemble was not observed without introduction of the metal ions mentioned above. The added specified metal ions most likely induced the intermolecular ET between TTFTCA and Q ensemble, and the effects of Sc3+ functions were the most imperative. The intermolecular ET also proved to be reliant on the structure of TTFTCA, where TTFTCA 7a and 7b were more effective than TTFTCA 6a and 6b. The difference may be credited to TTFTCA 7a or 7b possessing two independent TTF pendants and providing a more synergic coordination among the TTF radical cation and Q radical anion with a metal ion.