Microwave Synthesis of Highly Functionalized Two-Dimensionally Assemblies of Transition Metal Comprexes

近年来对有序多金属链的合成、结构和磁性的研究为低维电子和磁性系统的研究开辟了新的前景。然而，在彻底了解这些系统的物理性质之前，发展合理综合的巨大努力是必要的。制备能提供晶体结构的晶型是一个很大的难点。铜-氧碳阴离子配体体系的晶体结构一直是许多研究者所追求的。然而，所有获得单晶的努力都没有成功。我们首次用微波法制备了铜（II）配位聚合物[Cu_2 (mu-ox) _2 (mu-pz) (pz) _2] _n (1) （ox=草酸盐，pz=吡嗪）的单晶。1结晶为三斜晶，空间群p1中a=10.578 (4)*, b=11.603 (5)*, c=8.027 (4)*, α =92.11 (5), β =103.10 (3), γ =76.32 (4)， V=932.3 (8) ^3， Z=2.1表现为由草酸阴离子和吡嗪桥接的铜（II）离子的扩展片状结构。(Cu_2 (mu-ox) _2 （mu-pz) (pz) _2）的重复单元包含两种与O_4N_2的4+2配位环境，具有pz配位的特征；两个铜原子中的一个只有末端配位的pz分子，而另一个通过桥接pz分子连接。cu -ox- cu -序列呈褶皱带状，CuO_4-ox-CuO_4平面呈船状构象。除化合物1外，还得到了[Cu (C_6O_4Cl_2) (pz)] _n、[Cu (C_6O_4Cl_2) (MeOH) _2] _n和{[Cu (C_6O_4Cl_2) (H_2O) _2] (H_2O)} _n的单晶。磁化率被测量到2 K以下，并使用海森堡线性链理论进行分析，表明有趣的磁性行为。通过密度泛函MO计算和EHMO波段计算来描绘电子结构。

Recent studies on syntheses, structures, and magnetic properties of ordered polymetallic chains opened a new perspective in the field of low dimensional electronic and magnetic systems. However, very great endeavors to develop the rational synthesis will be necessary before the physical properties of these systems are thoroughly understood. The great difficulties are faced with the preparation of crystalline form, which can provide crystallographic structure. The crystal structures of copper-oxocarbon anion ligand systems have long been seeked by many researchers. However, all the efforts to obtain single crystals have been unsuccessful. We first succeeded in obtaining single crystals of a copper (II) coordination polymer, [Cu_2 (mu-ox) _2 (mu-pz) (pz) _2] _n (1) (ox=oxalate ; pz=pyrazine), by use of microwave oven. 1 crystallizaes in the triclinic, space group P 1 with a=10.578 (4)*, b=11.603 (5)*, c=8.027 (4)*, alpha=92.11 (5)ﾟ, beta=103.10 (3)ﾟ, gamma=76.32 (4)ﾟ, V=932.3 (8)*^3, and Z=2.1 shows an extended sheet structure of copper (II) ions bridged by oxalate anions and pyrazines. The repeating unit of (Cu_2 (mu-ox) _2 (mu-pz) (pz) _2) contains two types of 4+2 coordination environments with O_4N_2, which are characteristic of pz coordination ; one of the two copper atoms has only terminally coordinated pz molecules while the other is linked by bridging pz molecules. The Cu-ox-Cu-sequence displays pleated ribbon, thus planes of CuO_4-ox-CuO_4 forming a boat conformation. In addition to the compound 1, single crystals of [Cu (C_6O_4Cl_2) (pz) ] _n, [Cu (C_6O_4Cl_2) (MeOH) _2] _n, and { [Cu (C_6O_4Cl_2) (H_2O) _2] (H_2O) } _n were obtained. The magnetic susceptibilities were measured down to 2 K and analyzed using the Heisenberg linear chain theory, indicating intersting magnetic behavior. The density functional MO calculation and EHMO band claculations were carried out to delineate the electronic structure.