氰基桥联铁钴链状配合物的结构与磁性

Structure and magnetism of cyanide⁃bridged[FeCo]⁃based chain⁃like complexes

利用三氰基构筑单元(Bu_(4)N)[Fe(PzTp)(CN)_(3)](PzTp=tetrakis(pyrazolyl)borate)和(E)-1-苯乙烯基-1H-咪唑(Bzi),合成了2例氰基桥联的铁钴链状配位聚合物。单晶X射线衍射表明,配合物[Fe(PzTp)(CN)_(3)]_(2)[Co(Bzi)_(4)]_(2)(ClO_(4))_(2)·H_(2)O(1)为方波形单链结构,而配合物[Fe(PzTp)(CN)_(3)]_(2)[Co(Bzi)_(2)]·CH_(3)OH(2)则形成含有甲醇溶剂分子的双“之”字形双链结构。磁学研究显示,配合物1在360 K左右显示出热诱导的自旋转变,而配合物2在大约200 K显示出溶剂诱导的两步自旋转变。变温红外光谱证实了热诱导的金属间电荷转移行为。此外,光磁实验显示,当用808和532 nm的光交替照射时,1显示出可逆的光诱导电荷转移行为,而2的电荷转移行为可由808 nm光照射诱导。磁结构关系分析表明,配合物1和2中钴位点不同的氢键相互作用和局部配位环境是导致其不同电荷转移和光反应特性的主要因素。

We report two cyanide‑bridged mixed‑valence chain‑like coordination polymers by the self‑assembly reaction of tricyanoferrate􀃮building blocks(Bu_(4)N)[Fe(PzTp)(CN)_(3)](PzTp=tetrakis(pyrazolyl)borate)and Co􀃭ions in the presence of monodentate ligand(E)‑1‑styryl‑1H‑imidazole(Bzi).X‑ray diffraction analysis indicated that complex[Fe(PzTp)(CN)_(3)]_(2)[Co(Bzi)_(4)]_(2)(ClO_(4))_(2)·H_(2)O(1)adopts a square‑wave type chain structure,while complex[Fe(PzTp)(CN)_(3)]_(2)[Co(Bzi)_(2)]·CH_(3)OH(2)forms double zigzag chains that contain methanol solvent molecules.Magnetic studies revealed that complex 1 displayed a thermally induced spin transition at around 360 K,while complex 2 exhibited a solvent‑induced two‑step spin transition at approximately 200 K.Variable‑temperature infrared spectra confirmed the thermally induced intermetallic charge transfer behavior.Additionally,photomagnetic experiments revealed that complex 1 displayed reversible light‑induced charge transfer behavior when alternately irradiated with 808 and 532 nm light,while the charge transfer behavior of complex 2 could be induced by 808 nm irradiation.The magnetostructural relationship analysis indicates that the different hydrogen bonding interactions and local coordination environments of the cobalt sites in complexes 1 and 2 are the main factors contributing to their distinct charge transfer and light‑responsive properties.CCDC:2247684,1⁃120K;2247683,2⁃120K;2247682,2⁃190K;2247686,2⁃225K;2247685,2⁃desolvated.