7,7,8,8-Tetracyano-2,3,4,5-tetrafluoroquinodimethane (F4TCNQ) in its dianionic form, F4TCNQ2−, is shown to form charge transfer complexes with a wide variety of organic cations. The structures and spectroscopic properties of fourteen F4TCNQ2− salts are described, thirteen of which have colours consistent with the formation of charge transfer complexes. Unlike neutral F4TCNQ charge transfer complexes, the dianion, F4TCNQ2− is able to act as a donor in its interaction with suitable cations that serve as acceptors in solid-state complexes. The F4TCNQ2− salts described in this work have been categorised into five different structural types according to the relative arrangements of cations and anions. In each case, structural and IR spectroscopic data indicate that the anions retain a formal −2 charge upon formation of the salt. The optical band gaps, determined from Vis-NIR spectra, are found to have the lowest values when the cation is a viologen, either methyl viologen or diphenylmethyl viologen.
研究表明,7,7,8,8-四
氰基-2,3,4,5-四
氟喹啉二
甲烷(F4TCNQ)的二离子形式 F4TCNQ2- 能与多种有机阳离子形成电荷转移络合物。文中描述了十四种 F4TCNQ2- 盐的结构和光谱特性,其中十三种盐的颜色与电荷转移络合物的形成一致。与中性的 F4TCNQ 电荷转移络合物不同,F4TCNQ2- 的二价离子在与固态络合物中充当受体的适当阳离子相互作用时,能够充当供体。根据阳离子和阴离子的相对排列,本研究中描述的 F4TCNQ2- 盐被分为五种不同的结构类型。在每种情况下,结构和红外光谱数据都表明阴离子在盐形成时保留了形式-2 电荷。根据可见光-近红外光谱测定的光带隙发现,当阳离子为
紫胶(甲基
紫胶或二苯基甲基
紫胶)时,其值最低。