两个镉(II)金属有机骨架的可控合成与结构相关性

Controllable Syntheses of Two Cd(II)Metal-organic Frameworks Possessing Related Structures

合成了2,5-二甲氧基-N,N'-双(4-吡啶基)对苯二甲酰胺(简称为dmbpt),并以其和1,3,5-苯三甲酸(简称为H_(3)btc)为配体合成了2个新配合物[Cd_(2)(dmbpt)_(2)(Hbtc)_(2)]·2DMF·C_(2)H_(7)N·H_(2)O(1)和[Cd_(3)(dmbpt)_(2)(btc)_(2)]·4H_(2)O(2).配合物1是具有3,5L2拓扑的二维金属有机骨架;配合物2是具有jcr7拓扑的三维金属有机骨架,这是一个稀有的拓扑结构.配合物1和2都含有二级结构单元Cd_(2)(—COO)_(4)(—Py)_(4).在结构关系上,配合物2的三维网络可以看作是由配合物1的二维网络通过形成新的配位键连接而成的.在原料和溶剂相同的溶剂热反应条件下,能以不同比例同时获得2种配合物.产物中配合物1和配合物2的比例可以通过改变反应物的浓度来调控,这可能与由DMF分解产生的二甲胺促进H_(3)btc的去质子化有关.

2,5-Dimethoxy-N,N'-bis(4-pyridyl)terephthalamide(abbreviated as dmbpt)was synthesized,and two new complexes,[Cd_(2)( dmbpt)_(2)(Hbtc)_(2)]·2DMF·C_(2)H_(7)N·H_(2)O(1)and[Cd_(3)( dmbpt)_(2)( btc)_(2)]·4H_(2)O(2),were further prepared,in which dmbpt and 1,3,5-benzenetricarboxylic acid(abbreviated as H_(3)btc)were used as ligands.Complex 1 is a 2D metal-organic framework(MOF)with 3,5L2 topology.Complex 2 is a 3D MOF with jcr7 topology,which is a rare topology.Both two complexes contain the secondary building unit,Cd(2—COO)(4—Py)_(4).Regarding structural relations,the 3D framework of complex 2 may be regarded as coordinate-bonded 2D frameworks,which can be found in complex 1.Under the solvothermal condition with the same reactants and solvents,two complexes can be simultaneously produced with different ratios.The ratio of complex 1 to complex 2 in the product can be con⁃trolled by changing the concentration of the reactants.This may be attributed to the effect of dimethylamine,which was generated by the decomposition of DMF,on the deprotonation of H_(3)btc.