Shen Jun-Jian, Zhong Yu-Wu
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Sci Rep. 2015 Sep 7;5:13835. doi: 10.1038/srep13835.
The studies of long-range electronic communication are hampered by solubility and potential-splitting issues. A "hybridized redox-asymmetry" method using a combination of organic and inorganic redox species is proposed and exemplified to overcome these two issues. Complexes 1(PF6)-6(PF6) (from short to long in length) with the organic redox-active amine and inorganic cyclometalated ruthenium termini bridged by the para-oligophenylene wire have been prepared. Complex 6 has the longest Ru-amine geometrical distance of 27.85 Å. Complexes 3(PF6) and 4(PF6) show lamellar crystal packing on the basis of a head-to-tail anti-parallelly aligned dimeric structure. Two redox waves are observed for all complexes in the potential region between +0.2 and +0.9 V vs Ag/AgCl. The electrochemical potential splitting is 410, 220, 143, 112, 107, and 105 mV for 1(PF6) through 6(PF6), respectively. Ruthenium (+2) to aminium (N(•+)) charge transfer transitions have been identified for the odd-electron compounds 1(2+)-6(2+) by spectroelectrochemical measurements. The electronic communication between amine and ruthenium decreases exponentially with a decay slope of -0.137 Å(-1). DFT calculations have been performed to complement these experimental results.
长程电子通信的研究受到溶解性和电位分裂问题的阻碍。本文提出并举例说明了一种使用有机和无机氧化还原物种组合的“杂化氧化还原不对称”方法，以克服这两个问题。已经制备了由对亚苯基线桥接的有机氧化还原活性胺和无机环金属化钌端基的配合物1(PF6)-6(PF6)（长度从短到长）。配合物6的Ru-胺几何距离最长，为27.85 Å。配合物3(PF6)和4(PF6)基于头对头反平行排列的二聚体结构呈现层状晶体堆积。在相对于Ag/AgCl为+0.2至+0.9 V的电位区域中，所有配合物均观察到两个氧化还原波。1(PF6)至6(PF6)的电化学电位分裂分别为410、220、143、112、107和105 mV。通过光谱电化学测量，已确定奇数电子化合物1(2+)-6(2+)的钌(+2)到铵(N(•+))的电荷转移跃迁。胺与钌之间的电子通信以-0.137 Å(-1)的衰减斜率呈指数下降。已进行密度泛函理论计算以补充这些实验结果。
