两个以3-硝基邻苯二甲酸为配体构筑的锌和钴配位聚合物的合成、晶体结构和性质(英文)

Syntheses, Structures and Properties of Two Coordination Polymers Constructed by 3-Nitrobenzene-1,2-dicarboxylate Acid and Zn/Co

通过水热法合成了2种配位聚合物{[Zn(3-Nbdc)(bpmp)]·H2O}n(1)和{[Co(3-Nbdc)(bpmp)(H2O)]·H2O}n(2)(3-Nbdc2-=3-硝基邻苯二甲酸根,bpmp=1,4-二(4-吡啶甲基)哌嗪),并通过X-射线单晶衍射、元素分析和红外光谱对其结构进行了表征。配合物1和2均为二维(4,4)格子层结构,其中1含有双核单元,2含有螺旋金属羧酸链。此外,对它们的热重、粉末X-射线衍射、固体荧光和磁性性能进行了考察。1显示与游离的3-硝基邻苯二甲酸相似的荧光性质,锌离子的配位环境和配体之间的耦合作用对其荧光性能几乎没有影响。2在低温区表现出铁磁耦合作用,高温区的χMT值降低主要是由于八面体钴的自旋轨道耦合导致的。

Two coordination polymers {[Zn（3-Nbdc）（bpmp）]. H2O}n （1） and {[Co（3-Nbdc）（bpmp）（H2O）]. H20}n （2） （3- Nbde2-=3-nitrobenzene-l,2-diearboxylate, bpmp=l,4-bis（4-pyridylmethyl）piperazine） were synthesized hydrother- mally and characterized structurally by single-crystal X-ray diffractions, elemental analysis and infrared spectros- copy （IR）. Both complexes 1 and 2 display （4,4） grid layers containing the dinuclear units in 1 and helix metal- earboxylate chains in 2. Thermogravimetrie Analyses （TGA）, powder X-ray diffractions （PXRD）, fluorescence property and magnetic property for compounds 1 and 2 are also investigated. The solid state fluorescence indicates that the complex 1 shows similar emission spectra to the free 3-NbdcH2 ligand due to little contribution from the Zn-O inorganic motifs to the emission and very little degree change of interligand coupling upon metal coordination. The complex 2 exhibits a ferromagnetic coupling between the metal centers in the low-temperature region, and the decrease of xMT value in the high-temperature region may be attributed to the strong spin-orbit coupling through the 4T1g state of the octahedral Co2＋ centers. CCDC： 1042678, 1; 1042679, 2.