含席夫碱类配体Fe(Ⅱ)配位聚合物的合成及自旋交叉性质研究

Spin-crossover iron(Ⅱ)coordination polymers with tetradentate Schiff-base ligands

通过常用的溶剂挥发法合成了四例含四齿席夫碱类配体的Fe(Ⅱ)配位聚合物:[(Fe^(Ⅱ))(L1)(4-abpt)](1)、[(Fe^(Ⅱ))(L2)(4-abpt)](2)、[(Fe^(Ⅱ))2(L3)2(4-abpt)·Me OH]·[(Fe^(Ⅱ))2(L3)2(4-abpt)](3)和[(Fe^(Ⅱ))3(L4)3(4-abpt)2·H2O](4)(H2L1=3,3′-((1,2-亚苯基双(亚胺基))双(亚甲烯))双(2,4-戊二酮),H2L2=二乙基-2,2′-((萘-2,3-双(亚胺基))双(亚甲烯))(2E,2′E)-双(3-氧丁酸甲酯),H2L3=二乙基-2,2′-((1,2-亚苯基双(亚胺基))双(亚甲烯))(2E,2′E)-双(3-氧丁酸甲酯),H2L4=二乙基-2,2′-(((4,5-二氟-1,2-亚苯基)双(亚胺基))双(亚甲烯))(2E,2′E)-双(3-氧丁酸甲酯),4-abpt=3,5-二(吡啶-4-基)-4-氢-1,2,4-三氮唑-4-胺).对化合物1~4进行了元素分析、X射线粉末衍射等表征,并利用X射线单晶衍射仪测定了它们的单晶结构.晶体结构分析表明,1~4均为一维链状结构.利用两电极法对1~4进行了变温电子导电性测试.变温磁学性质测试结果表明,3呈现出一步自旋转换(T1/2=115 K),4呈现两步自旋转换(T1/2=188和95 K)的性质.

A series of iron(Ⅱ)coordination polymers,named[(Fe^(Ⅱ))(L1)(4-abpt)](1),[(Fe^(Ⅱ))(L2)(4-abpt)](2),[(Fe^(Ⅱ))2(L3)2(4-abpt)·Me OH]·[(Fe^(Ⅱ))2(L3)2(4-abpt)](3)and[(Fe^(Ⅱ))3(L4)3(4-abpt)2·H2O](4)(H2L1=3,3′-((1,2-phenylenebis(azanediyl))bis(methanylylidene))bis(pentane-2,4-dione),H2L2=diethyl 2,2′-((naphthalene-2,3-diylbis(azanediyl))bis(methanylylidene))(2E,2′E)-bis(3-oxobutanoate),H2L3=diethyl 2,2′-((1,2-phenylenebis(azanediyl))bis(methanylylidene))(2E,2′E)-bis(3-oxobutanoate),H2L4=diethyl 2,2′-(((4,5-difluoro-1,2-phenylene)bis(azanediyl))bis(methanylylidene))(2E,2′E)-bis(3-oxobutanoate)),with tetradentate Schiff-base ligands and 3,5-di(pyridin-4-yl)-4H-1,2,4-triazol-4-amine(4-abpt)as a bridging ligand were obtained by solvent evaporation method and characterized by elemental analysis,X-ray powder diffraction,magnetic measurements,electrical resistivity and single-crystal X-ray diffraction.Compound 1–4 are one-dimensional(1D)chains.Magnetic measurements reveal that 3 posseses a one-step spin transition(T1/2=115 K),and compound 4 features two-step spin transitions(T1/2=188 and 95 K,respectively)at higher temperatures.