含吡啶基四硫富瓦烯衍生物的合成、结构和电化学性质

在乙酰乙酸乙酯和氧化亚铜共同催化下,二-(1,3-二硫环戊烯-2-硫酮-4,5-二硫)合锌酸四乙基铵盐分别与2-碘吡啶(1a)、3-碘吡啶(1b)和4-碘吡啶(1c)反应,制得硫酮化合物2,3-二(2-吡啶硫基)-1,3-二硫环戊烯-2-硫酮(2a)、2,3-二(3-吡啶硫基)-1,3-二硫环戊烯-2-硫酮(2b)和2,3-二(4-吡啶硫基)-1,3-二硫环戊烯-2-硫酮(2c).在醋酸汞催化下,硫酮化合物2a,2b和2c分别被氧化为2,3-二(2-吡啶硫基)-1,3-二硫环戊烯-2-酮(3a)、2,3-二(3-吡啶硫基)-1,3-二硫环戊烯-2-酮(3b)和2,3-二(4-吡啶硫基)-1,3-二硫环戊烯-2-酮(3c).以亚磷酸三乙酯为偶联剂,氧酮化合物3a,3b和3c分别发生自偶联反应生成2,3,6,7-四(2-吡啶硫基)四硫富瓦烯(4a)、2,3,6,7-四(3-吡啶硫基)四硫富瓦烯(4b)和2,3,6,7-四(4-吡啶硫基)四硫富瓦烯(4c).采用核磁共振波谱(NMR)、傅里叶变换红外光谱(FTIR)和质谱(MS)分析了所合成化合物的结构和组成,通过X射线衍射分析确认了吡啶基四硫富瓦烯衍生物4b和4c的晶体结构.循环伏安法研究结果表明,化合物4a,4b和4c呈现准可逆的两电子转移过程,结合量子化学计算,分析了不同位置取代的吡啶基对四硫富瓦烯电化学电势的影响.

Synthesis,Structures and Electrochemical Properties of Pyridine-based Tetrathiafulvalene Derivatives?

Using the ethyl acetoacetate/Cu2O system, 4,5-bis(pyridin-2-ylthio)-1,3-dithiole-2-thione(2a), 4,5-bis ( pyridin-3-ylthio )-1, 3-dithiole-2-thione ( 2b ) and 4, 5-bis ( pyridin-4-ylthio )-1, 3-dithiole-2-thione (2c) were prepared by the reaction of di(tetraehylammonium)-bis(1,3-dithiol-2-thione-4,5-dithiocate) zinc-ate with 2-iodopyridine(1a), 3-iodopyridine(1b) and 4-iodopyridine(1c) with the yields of 88%, 55% and 60%, respectively. Thiones 2a, 2b and 2c were conversed to 4,5-bis(pyridin-2-ylthio)-1,3-dithiole-2-one (3a), 4,5-bis(pyridin-3-ylthio)-1,3-dithiole-2-one(3b) and 4,5-bis(pyridin-4-ylthio)-1,3-dithiole-2-one (3c) under the presence of Hg(OAc)2 in almost quantitative yields. Consequently, the pyridine-tetrathiaful-valene compounds 2,3,6,7-tetrakis(pyridine-2-ylthio) tetrathiafulvalene(4a), 2,3,6,7-tetrakis(pyridine-3-ylthio) tetrathiafulvalene(4b) and 2,3,6,7-tetrakis(pyridine-4-ylthio) tetrathiafulvalene(4c) were obtained correspondingly through triethylphosphite-mediated self-coupling reactions of 3a, 3b and 3c with the yields of 80%, 74% and 69%. All novel compounds were characterized by proton and carbon nuclear magnetic reso-nance spectroscopy(1H NMR and 13C NMR), fourier transform infrared spectroscopy(FTIR) and mass spec-troscopy( MS) methods. Meanwhile, the structures of 4b and 4c was identified by X-ray diffraction analysis. The cyclic voltammograms showed that the pyridine-tetrathiafulvalene 4a, 4b and 4c displayed two-electron quasi-reversible redox processes. Combined with quantum chemical calculations, the effects of the different pyridyl substituted tetrathiafulvalenes 4a, 4b and 4c on electrochemical potentials were analysised.