Konarev Dmitri V, Khasanov Salavat S, Kuzmin Alexey V, Mikhailenko Maxim V, Otsuka Akihiro, Yamochi Hideki, Kitagawa Hiroshi, Lyubovskaya Rimma N
Department of Kinetics and Catalysis, Institute of Problems of, Chemical Physics RAS, 142432, Chernogolovka, Russian Federation.
Institute of Solid State Physics RAS, 142432, Chernogolovka, Russian Federation.
Chemistry. 2020 Dec 23;26(72):17470-17480. doi: 10.1002/chem.202002967. Epub 2020 Nov 24.
Crystalline {Cryptand2.2.2}{HAT(CN) }⋅0.5C H Cl (1), {Cryptand2.2.2}{HAT(CN) } (2), (CV ){HAT(CN) } (3), and (CV ){HAT(CN) }⋅2C H Cl (4) salts (where CV is the crystal violet cation) containing hexaazatriphenylenehexacarbonitrile radical anions have been obtained. The solid-state molecular structure as well as the optical and magnetic properties of HAT(CN) are studied. The formation of HAT(CN) in 1-4 leads to the appearance of new bands in the visible range, at 694 and 740 nm. The HAT(CN) radical anions have spin state S=1/2 and are packed in one-dimensional stacks containing the {HAT(CN) } dimers alternated with weaker interacting pairs of HAT(CN) in 1 and nearly isolated {HAT(CN) } dimers in 2. The {HAT(CN) } dimers are diamagnetic in 1 but they effectively mediate one-dimensional antiferromagnetic coupling of spins within the stacks with moderate exchange interaction of J/k = -80 K. The behaviour of salt 2 is described by a singlet-triplet model for the {HAT(CN) } dimers with an energy gap of 434(±7) K. Magnetic behaviour of both salts agree well with the data of extended Hückel calculations. Salts 3 and 4 contain isolated stacks of alternated HAT(CN) and CV ions, and in this case, nearly paramagnetic behaviour is observed with Weiss temperatures of -1 and -7 K, respectively. Narrow Lorentzian EPR signals with g = 2.0033-2.0039 were found for the HAT(CN) radical anions in 1 and 4 but in solution g-factor shifts to 1.9964. The electronic structure of HAT(CN) is analysed based on X-ray diffraction data for 2, showing a Jahn-Teller distortion of the radical anion that reduces the symmetry from D to C and splits the initially degenerated LUMOs.
已获得含有六氮杂三亚苯六腈自由基阴离子的结晶盐{穴醚2.2.2}{HAT(CN)₆}⋅0.5C₂H₄Cl₂(1)、{穴醚2.2.2}{HAT(CN)₆}(2)、(CV⁺){HAT(CN)₆}(3)和(CV⁺){HAT(CN)₆}⋅2C₂H₄Cl₂(4)（其中CV为结晶紫阳离子）。对HAT(CN)₆的固态分子结构以及光学和磁性性质进行了研究。在1 - 4中形成HAT(CN)₆导致在可见光范围内694和740 nm处出现新的谱带。HAT(CN)₆自由基阴离子的自旋态为S = 1/2，在1中堆积成一维堆叠结构，其中包含{HAT(CN)₆}二聚体与较弱相互作用的HAT(CN)₆对交替排列，在2中几乎是孤立的{HAT(CN)₆}二聚体。{HAT(CN)₆}二聚体在1中是抗磁性的，但它们有效地介导了堆叠结构内自旋的一维反铁磁耦合，交换相互作用适中，J/k = -80 K。盐2的行为由{HAT(CN)₆}二聚体的单重态 - 三重态模型描述，能隙为434(±7) K。两种盐的磁性行为与扩展休克尔计算数据吻合良好。盐3和4包含交替的HAT(CN)₆和CV离子的孤立堆叠结构，在这种情况下，分别观察到魏斯温度为 -1和 -7 K的近顺磁性行为。在1和4中发现HAT(CN)₆自由基阴离子的窄洛伦兹EPR信号，g = 2.0033 - 2.0039，但在溶液中g因子移至1.9964。基于2 的X射线衍射数据分析了HAT(CN)₆的电子结构，显示自由基阴离子存在 Jahn - Teller 畸变，使对称性从D降低到C，并使最初简并的LUMO分裂。
