新型一维梯状双链配位聚合物{[Cu(malate)(2,2′-bipy)]·3H_2O}_∞的合成、晶体结构与表征

Syntheses, Characterization and Crystal Structure of a Novel Polymeric Complex {[Cu(malate)(2,2′-bipy)]·3H_2O}_∞ (malate=malate dianion) with Ladder-Shaped Double Chains Structure

合成了铜(II)与羟基丁二酸和2,2′-联吡啶形成的配位聚合物{[Cu(malate)(2,2′-bipy)]?3H2O}∞(其中malate=羟基丁二酸根,2,2'-bipy=2,2'-联吡啶),通过X射线衍射测定了单晶结构,并进行了元素分析、红外光谱、紫外光谱、热分析等研究.配合物属单斜晶系,空间群P2(1)/c;晶胞参数a=0.70132(10)nm,b=1.9730(3)nm,c=1.18998(16)nm,β=94.551(3)°;Z=2;最终偏离因子R=0.0483.配合物中每个铜(II)原子与来自2,2'-联吡啶的两个氮原子和两个羟基丁二酸根的三个氧原子配位,形成畸变的三角双锥结构单元.每个羟基丁二酸根以R构型方式桥联两个三角双锥结构单元,沿a轴方向无限延伸形成一维链.两条平行链以面对面的方式重叠,彼此吡啶环之间存在强的π-π相互作用,加之C吡啶环—H…O羧基弱相互作用形成新颖的梯状双链结构,比邻的梯状双链又通过分子间O羟基—H…O羧基氢键沿a轴方向共同构筑了具有隧道的三维结构.

Copper(II) malate polymeric complex with 2,2'-bipy, {[Cu(malate)(2,2′-bipy)]?3H2O}∞, has been synthesized and characterized by means of elemental analysis, thermal analysis, IR and UV-vis spec- troscopy. The single crystal X-ray diffraction study shows that the complex is monoclinic, with space group P2(1)/c, a=0.70132(10) nm, b=1.9730(3) nm, c=1.18998(16) nm, β=94.551(3)°, Z=2 and R=0.0483. Each Cu(II) atom is coordinated by two nitrogen atoms from 2,2'-bipy and three oxygen atoms from two different malate dianions with a distorted trigonal bipyramidal geometry. The malate dianion adopts an R conformation bridging two copper centers, giving rise to a 1-D polymeric chain along the crystallographic axis a, and two parallel 1-D chains are constituted to form a novel ladder-shaped double chain structure through π-π interactions between the pyridine rings and Cpyridine—H…Ohydroxyl weak interactions. On the other hand, the neighboring double chains are extended into a 3-D structure with channels via intramolecular Ohydroxyl—H…Ocarboxyl hydrogen bonds in the direction of axis a.