摘要
将醋酸铜、L-谷氨酸和无水醋酸钠按1∶2∶4摩尔比经室温固相反应,合成了一种新的配合物[Cu(C5H7NO2)·H2O]·H2O。通过元素分析、红外光谱、差热-热重及X射线单晶衍射测试技术对其结构进行了表征。差热-热重分析显示,该配合物含有1分子结晶水和1分子配位水。晶体结构解析表明,晶体属正交晶系,P2(1)2(1)2(1)空间群,晶胞参数为:a=0.7244(2)nm,b=1.0330(3)nm,c=1.1075(3)nm,Z=4,V=0.8288(4)nm3,Dc=1.961g/cm3,μ=2.635mm-1,F(000)=500,R1=0.0307,wR2=0.0696,GOF=1.012。该化合物由L-谷氨酸中C1羧基上氧原子、氨基氮原子、C5羧基上氧原子及1个水分子中氧原子与中心Cu(Ⅱ)离子配位,形成五配位的畸变四方锥构型。四方锥之间通过羧基氧原子与结晶水或配位水形成分子间氢键,这种氢键及弱相互作用相互连接构成了L-谷氨基酸铜配合物的三维网状超分子体系。旋光活性测定表明,配合物为左旋体,比旋光度为[α]1D5=-38.5°(水),其旋光方向与配体相反,这是由于氨基氮及羧基氧参与配位形成五元环,改变了手性碳原子周围环境,从而使旋光方向改变。
A new compound, [ Cu （ C5 H7 NO2 ）· H2O ] · H2 O, was synthesized via solid state reaction of L-glutamic acid, copper acetate and non-aqueous sodium acetate, which had a mole ratio of 1 ： 2： 4. The crystal structure was characterized by means of elemental analysis, infrared spectrum, thermo-gravimetric analysis and differential thermal analysis, single crystal X-ray diffraction analysis. Thermo-gravimetric analysis and differential thermal analysis reveal that the compound contains one water molecule of crystallization and one coordinating water molecule. The analysis of crystal structure indicates that the crystal belongs to the ortho-gonalsystem with space group P2（1）2（1）2（1）, a=0.724 4（2） nm, b=1.033 0（3） nm, c= 1. 107 5（3） nm, Z=4, V=0.828 8（4） nm^3, Dc =1.961 g/cm^3,/x=2.635 mm^-1, F（000） =500, R1 = 0. 030 7, wR2 = 0. 069 6, GOF = 1. 012. The configuration of the compound is a deformed tetragonal pyramid, which is composed of the oxygen atom of C1 and C5 carboxyls, the nitrogen atom of amino group in L-glutamic acid, the oxygen atom of hydrone and copper ion. The intermolecular hydrogen bonding in the tetragonal pyramid was formed by means of carboxyl and crystalline water or coordinated water. So the three-dimensional supermo-lecular structure of the compound was formed via the hydrogen bonding and weak interaction. Optical activity analysis results show that the construction of the compound is laevorotary, and [α ]D^15 = - 38.5 °, and its optical direction differed with that of ligand. It is attributed to the formation of the pentabasic ring consisting of the oxygen atom of the carboxyl and the nitrogen atom of the amino group, and then the environment ot the chiral carbon atom was changed, which resulted in the change of optical direction.
出处
《应用化学》
CAS
CSCD
北大核心
2007年第3期318-322,共5页
Chinese Journal of Applied Chemistry
基金
河南省自然科学基金项目(0511044900)
河南省教育厅自然科学基金项目(2006150019)
关键词
三维超分子体系
L-谷氨酸
铜(Ⅱ)配合物
晶体结构
旋光活性
three-dimensional supermolecular system, L-glutamic acid, copper （ Ⅱ compound, crystal structure, optical activity
