Mechanically Stabilized Tetrathiafulvalene Radical Dimers

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• 作者：Ali Coskun ; Jason M. Spruell ; Gokhan Barin ; Albert C. Fahrenbach ; Ross S. Forgan ; Michael T. Colvin ; Raanan Carmieli ; Diego Ben铆tez ; Ekaterina Tkatchouk ; Douglas C. Friedman ; Amy A. Sarjeant ; Michael R. Wasielewski ; William A. Goddard ; III ; J. Fraser Stoddart
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：March 30, 2011
• 年：2011
• 卷：133
• 期：12
• 页码：4538-4547
• 全文大小：1195K
• 年卷期：v.133,no.12(March 30, 2011)
• ISSN：1520-5126

文摘

Two donor鈭抋cceptor [3]catenanes鈥攃omposed of a tetracationic molecular square, cyclobis(paraquat-4,4鈥?biphenylene), as the 蟺-electron deficient ring and either two tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP) containing macrocycles or two TTF-butadiyne-containing macrocycles as the 蟺-electron rich components鈥攈ave been investigated in order to study their ability to form TTF radical dimers. It has been proven that the mechanically interlocked nature of the [3]catenanes facilitates the formation of the TTF radical dimers under redox control, allowing an investigation to be performed on these intermolecular interactions in a so-called 鈥渕olecular flask鈥?under ambient conditions in considerable detail. In addition, it has also been shown that the stability of the TTF radical-cation dimers can be tuned by varying the secondary binding motifs in the [3]catenanes. By replacing the DNP station with a butadiyne group, the distribution of the TTF radical-cation dimer can be changed from 60% to 100%. These findings have been established by several techniques including cyclic voltammetry, spectroelectrochemistry and UV鈭抳is鈭扤IR and EPR spectroscopies, as well as with X-ray diffraction analysis which has provided a range of solid-state crystal structures. The experimental data are also supported by high-level DFT calculations. The results contribute significantly to our fundamental understanding of the interactions within the TTF radical dimers.