Zhu Qin-Yu, Liu Yu, Lu Wen, Zhang Yong, Bian Guo-Qing, Niu Gai-Yan, Dai Jie
Department of Chemistry & Key Laboratory of Organic Synthesis of Jiangsu Province, Suzhou University, Suzhou 215123, P.R. China.
Inorg Chem. 2007 Nov 26;46(24):10065-70. doi: 10.1021/ic700672e. Epub 2007 Oct 31.
A protonated bifunctional pyridine-based tetrathiafulvalene (TTF) derivative (DMT-TTF-pyH)NO3 and a copper(II) complex Cu(acac)2(DMT-TTF-py)2 have been obtained and studied. Electronic spectra of the protonated compound show a large ICT (intramolecular charge transfer) band shift (Deltalambda=136 nm) compared with that of the neutral compound. Cyclic voltammetry also shows a large shift of the redox potentials (DeltaE1/2(1)=77 mV). Theoretical calculation suggests that the pyridium substituent is a strong pi-electron acceptor. Crystal structures of the protonated compound and the metal complex have been obtained. The dihedral angle between least-squares planes of the pyridyl group and the dithiole ring might reflect the intensity of the ICT effect between the TTF moiety and the pyridyl group. It is also noteworthy that the TTF moiety could be oxidized to TTF2+ dication by Fe(ClO4)(3).6H2O when forming a metal complex, while the protonated TTF derivative can only be oxidized to the TTF*+ radical cation by Fe(ClO4)(3).6H2O even with an excess amount of the Fe(III) salt, which can be used to control the oxidation process to obtain neutral TTF, TTF*+ radical cation, or TTF2+ dication.
已制备并研究了一种质子化的基于双功能吡啶的四硫富瓦烯（TTF）衍生物（DMT-TTF-pyH）NO₃和一种铜（II）配合物Cu(acac)₂(DMT-TTF-py)₂。与中性化合物相比，质子化化合物的电子光谱显示出较大的分子内电荷转移（ICT）带移（Δλ = 136 nm）。循环伏安法也显示出氧化还原电位的较大偏移（ΔE₁/₂(1)=77 mV）。理论计算表明吡啶鎓取代基是一种强π电子受体。已获得质子化化合物和金属配合物的晶体结构。吡啶基和二硫醇环的最小二乘平面之间的二面角可能反映了TTF部分与吡啶基之间ICT效应的强度。还值得注意的是，在形成金属配合物时，TTF部分可被Fe(ClO₄)₃·6H₂O氧化为TTF²⁺二价阳离子，而即使使用过量的Fe（III）盐，质子化的TTF衍生物也只能被Fe(ClO₄)₃·6H₂O氧化为TTF⁺·自由基阳离子，这可用于控制氧化过程以获得中性TTF、TTF⁺·自由基阳离子或TTF²⁺二价阳离子。
