Ground-State Equilibrium Thermodynamics and Switching Kinetics of Bistable [2]Rotaxanes Switched in Solution, Polymer Gels, and Molecular Electronic Devices
作者:Jang Wook Choi、Amar H. Flood、David W. Steuerman、Sune Nygaard、Adam B. Braunschweig、Nicolle N. P. Moonen、Bo W. Laursen、Yi Luo、Erica DeIonno、Andrea J. Peters、Jan O. Jeppesen、Ke Xu、J. Fraser Stoddart、James R. Heath
DOI:10.1002/chem.200500934
日期:2006.1
with electrochemically driven molecular mechanical switching of three bistable [2]rotaxanes in acetonitrile solution, polymer electrolyte gels, and molecular-switch tunnel junctions (MSTJs). For all rotaxanes a pi-electron-deficient cyclobis(paraquat-p-phenylene) (CBPQT4+) ring component encircles one of two recognition sites within a dumbbell component. Two rotaxanes (RATTF4+ and RTTF4+) contain tetrathiafulvalene
我们报告了与乙腈溶液,聚合物电解质凝胶和分子开关隧道结(MSTJs)中的三种双稳态[2]轮烷的电化学驱动分子机械转换相关的动力学和基态热力学。对于所有轮烷,π电子缺陷的环双(百草枯-对亚苯基)(CBPQT4 +)环组分环绕哑铃组分内的两个识别位点之一。两个轮烷(RATTF4 +和RTTF4 +)包含四硫富瓦烯(TTF)和1,5-二氧萘(DNP)识别单元,但具有不同的亲水性塞子。对于这些轮烷,CBPQT4 +环在平衡状态下主要围绕(> 90%)TTF单元,并且该平衡状态与温度无关。在第三种轮烷中(RBPTTF4 +),TTF单元被pi扩展类似物(双吡咯并四硫富瓦烯(BPTTF)单元)取代,而CBPQT4 +环在平衡时几乎相等地包围了两个识别位点。这种平衡表现出强烈的温度依赖性。通过参考等温滴定量热法获得的结合常数,将CBPQT4 +主体在乙腈中络合,可以合理地确定这些热力学差异。对于所有双稳