Phenalenyl-Based Highly Conductive Molecular Systems with Hydrogen-Bonded Networks: Synthesis, Physical Properties, and Crystal Structures of 1,3- and 1,6-Diazaphenalenes, and Their Protonated Salts and Charge-Transfer Complexes with TCNQ
作者:Tsuyoshi Murata、Yasushi Morita、Kozo Fukui、Koichi Tamaki、Hideki Yamochi、Gunzi Saito、Kazuhiro Nakasuji
DOI:10.1246/bcsj.79.894
日期:2006.6
Protonated salts and charge-transfer complexes of the 1,3- and 1,6-diazaphenalene (DAP) systems 5–7 have been investigated for new conducting molecule-based materials. Cyclic voltammetry measurements revealed that DAP derivatives are stronger electron donors than hydroquinone, and some of them possess comparable electron-donating abilities to TTF. X-ray crystal structure analyses of HX (X = Br− and BF4−) salts of 5b, 5c, and 6e confirmed their one-dimensional structures by N–H···X···H–N hydrogen bonds and their ability to form hydrogen-bonded networks in charge-transfer complexes. Actually, in the TCNQ salts of protonated 5c·H+ and 7b·H+, N–H···N≡C hydrogen-bonding interactions between DAP molecules and TCNQ molecules constructed a characteristic hydrogen-bonded cyclic tetramer and linear D–A–D triad, respectively. On the other hand, TCNQ complexes of 1,3- and 1,6-DAP derivatives, prepared by a conventional mixing method of each neutral component, were found to be partial charge-transfer complexes with segregated stacking columns as elucidated from IR and electronic spectra. Their compressed pellets exhibited high electrical conductivity (10−2–10−1 S cm−1) at room temperature with semiconducting behavior (activation energy, Ea = 40–80 meV).
已研究了1,3-和1,6-二氮苯膦(DAP)体系5–7的质子化盐和电荷转移复合物,以寻找新的导电分子基材料。循环伏安法测定表明,DAP衍生物的电子供体能力强于对苯二酚,其中一些与TTF的电子供体能力相当。5b、5c和6e的HX(X = Br−和BF4−)盐的X射线晶体结构分析通过N–H···X···H–N氢键证实了它们的单维结构,并显示了它们在电荷转移复合物中形成氢键网络的能力。实际上,在质子化的5c·H+和7b·H+的TCNQ盐中,DAP分子与TCNQ分子之间的N–H···N≡C氢键相互作用构建了特征性的氢键环四聚体和线性D–A–D三聚体。另一方面,通过常规混合中性成分的方法制备的1,3-和1,6-DAP衍生物的TCNQ复合物被发现是具有分隔堆叠柱的部分电荷转移复合物,IR和电子光谱对此进行了阐明。它们的压制颗粒在室温下表现出高电导率(10−2–10−1 S cm−1)和半导体行为(激活能,Ea = 40–80 meV)。