摘要
三联吡啶及其衍生物构筑的钴(Ⅱ)配合物构成了一大类钴(Ⅱ)自旋交叉家族化合物,然而目前报道的配合物大多由同种配体与钴(Ⅱ)离子组装形成。本文报道了3例由互补三联吡啶配体对定向组装的单核钴(Ⅱ)配合物的合成及自旋交叉性质,它们的固态自旋交叉行为可以通过三联吡啶4位的取代基有效调控。其中原型配合物1和三氟甲基取代的衍生物3在低温时为完全低自旋态(S=1/2),随着温度升高到400 K,部分铁(Ⅱ)离子的自旋态转变为S=3/2。氟取代衍生物表现出溶剂依赖的自旋转变行为,带有3个结晶水的配合物2晶体呈现与1和3类似的不完全自旋转变,然而在高温下完全脱除水分子的样品在260~340 K产生一个宽度约为50 K的热滞回线。有趣的是,配合物2晶格中的水分子的吸附和脱附在结构和磁性上均是可逆的。此外,吸收光谱和循环伏安测试表明配体上的取代基可以调控中心钴离子的电子结构。
The cobalt(Ⅱ)complexes containing terpyridine(terpy)and its derivatives compose a large family of Co(Ⅱ)SCO-active(SCO=spin-crossover)compounds and the reported cases are mainly built from homoleptic type terpy ligands.Herein we report the SCO properties in three mononuclear cobalt(Ⅱ)complexes constructed from complementary terpy ligand pairing.Their SCO behaviors are largely affected by the substituents of terpy at the 4-position.The archetypical complex 1 and its CF_(3)-substituted one 3 showed a gradual and incomplete spin transition from the low spin state of S=1/2 to the high spin state of S=3/2.The fluorine-substituted complex 2 exhibited a solventdependent spin transition phenomenon.The solvated form which contains three lattice water molecules showed a similar gradually incomplete spin transition.Whereas the entire removal of water molecules resulted in a repeatable thermal hysteresis loop with a width of ca.50 K.Impressively,the adsorption and desorption of water molecules are reversible in structure and magnetism.In addition,absorption spectroscopy and cyclic voltammetry show that the substituent on the ligands can regulate the electronic structures of the central cobalt ion.CCDC:2162742,1(150 K);2162743,2(120 K);2162744,2(299 K);2162745,3(120 K).
作者
杨蕊
张舒雅
王润国
孟银杉
刘涛
朱元元
YANG Rui;ZHANG Shu-Ya;WANG Run-Guo;MENG Yin-Shan;LIU Tao;ZHU Yuan-Yuan(State Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian,Liaoning 116024,China;Anhui Key Laboratory of Advanced Catalytic Materials and Reaction Engineering,School of Chemistry and Chemical Engineering,Hefei University of Technology,Hefei 230009,China)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2022年第8期1477-1486,共10页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.21771049,21871039,91961114,22025101,22173015)
中央高校基本研究基金(No.PA2021GDSK0063,PA2020GDJQ0028)资助。
