Study on Spin Crossover Complexes with Multi-dimensional Network Structure

低自旋（LS）和高自旋（HS）状态之间的自旋交叉现象，是由温度、压力和光辐射所定义的外部渗透（如温度、压力和光辐射）是分子性最明显的例子之一。旋转交叉行为的可持续性是由旋转交叉站点之间的合作交互管理的。因此，一个新的配体系统，它不仅提供旋转交叉器，而且还可以在旋转交叉器站点之间产生交互，现在是必需的。We synthesized here a new family of spin crossover complexes with the various oxidation states and the various degree of the depronation at the imidazole moiety， [Fe^<II>H_3L^<Me>]（NO_3）_2·1.5H_2O （1）， [Fe^<III>L^<Me>]·3.5H_2O （2）， [Fe^<II>H_3L ^<Me>][Fe^<II>L^<Me>]NO_3 （3）， and [<II><Me>Fe^<III>L^<Me>]（NO_3）_2 （4）。[Fe^<II>H_3L]^&lt;2+&gt; and [Fe^<II>L]-components with the same chirality.组件3和4也存在LIESST （光诱导刺激自旋状态陷阱）效应。更令人惊讶的是，一系列化合物将用于展示多功能化合物，以展示这种复杂的电子结构和批量光学活动，通过pH值的调整和一个单柱组装反应来获得。

The phenomenon of spin crossover between the low-spin (LS) and high-spin (HS) states, which is induced by external perturbation such as temperature, pressure, and light irradiation, is one of the most spectacular examples of molecular bistability. The bistability of the spin crossover behavior is governed by the cooperative interaction between the spin crossover sites. Therefore, a novel ligand system, which can provide not only spin crossover but also can produce interaction between spin crossover sites, is now required. We synthesized here a new family of spin crossover complexes with the various oxidation states and the various degree of the deprotonation at the imidazole moiety, [Fe^<II>H_3L^<Me>](NO_3)_2・1.5H_2O (1), [Fe^<III>L^<Me>]・3.5H_2O (2), [Fe^<II>H_3L^<Me>][Fe^<II>L^<Me>]NO_3 (3), and [Fe^<II>H_3L^<Me>][Fe^<III>L^<Me>](NO_3)_2 (4). The crystal structural analysis of 3 showed an unprecedented 2D homochiral assembly structure constructed by the imidazole-imidazolate hydrogen bonds between [Fe^<II>H_3L]^<2+> and [Fe^<II>L]-components with the same chirality. Compounds 3 and 4 also present the LIESST (light induced excited spin state trapping) effect. More surprisingly, a series of compounds involving the multi-functional compound exhibiting such complicated electronic structures and bulk optical activity is obtained by the adjustment of pH and by a one-pot assembly reaction of a programmed single molecule.