Triplet Dication and Quartet Trication of a Triaminobenzene
Triplet Dication and Quartet Trication of a Triaminobenzene
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DOI：
10.1021/ja00104a051
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发表时间：
1994-12
影响因子：
15
通讯作者：
Kurt R. Stickley;S. C. Blackstock
中科院分区：
文献类型：
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作者：
Kurt R. Stickley;S. C. Blackstock
基于有机体系合成磁性材料的前景使得人们对高自旋有机分子的持续兴趣，其可能用作制备块体磁性材料的构建块。1-4自旋中心，如碳自由基，5-7三重态卡宾，8-11和氮氧自由基12· 13已被“铁磁”连接，得到高自旋多自由基分子。我们的方法利用氮阳离子自由基作为自旋单元。原则上，这种方法允许通过施加外部电势来控制分子或最终大块材料的氧化还原状态（和自旋状态），从而打开或关闭分子磁性，并打开或关闭分子磁性。为此，我们报道了溶液稳定的N，N，N '，N'，N”，N”-六茴香基-1，3，5-三氨基苯（HATAB）的阳离子，双阳离子和三阳离子态，我们观察到的双重，三重和四重态的自旋状态，分别。几十年来，对有机双自由基和多自由基中控制自旋态偏好的结构关系的基础研究已经为控制有机体系中的自旋偏好提供了一个连贯的理论基础。[14· 15]例如，奥夫钦尼科夫规则[16]可以用来预测交替系统的基态自旋多重性。这个规则指定非凯库勒结构，如间醌二甲烷（MQDM）17和四苯基间醌二甲烷18· 19为基态三重态，这也是实验上已知的。在理论上，苯核上第三个Meta位被第三个自旋中心取代会导致高自旋优先性的进一步传播
The prospect of synthesizing magnetic materials based on organic systems has led to continued interest in high-spin organic molecules which might serve as building blocks for the preparation of bulk magnetic materials. 1-4 Spin centers such as carbon radicals, 5-7 triplet carbenes, 8-11 and nitroxide radi-cals12· 13 have been “ferromagnetically” linked to give high-spin polyradical molecules. Our approach utilizes nitrogen cation radicals as the spin unit. This approach allows, in principle, molecular magnetism to be switched on or off and turned up or down by application of an external electric potential to control the redox state (and spin state) of a molecule or, ultimately, of a bulk material. To this end, we report the solution-stable cationic, dicationic, and tricationic states of N, N, N', N', N", N"-hexaanisyl-1, 3, 5-triaminobenzene (HATAB) for which we observe doublet, triplet, and quartet spin states, respectively. Several decades of fundamental research on the structural relationships that govern spin state preference in organic bi-and polyradicals have produced a coherent rationale for control-ling the spin preference in organic systems. 14· 15 For example, Ovchinnikov’s rule16 can be used to predict, to a first order, the ground state spin multiplicity of alternant systems. This rule specifies non-Kekulé structures such as m-quinodimethane (MQDM) 17 and tetraphenyl-m-quinodimethane18· 19 as ground state triplets, as is also known experimentally. Substitution of the third meta position on a benzene core with a third spincenter leads to further propagation of high-spin preference in theory