有机-无机复合杂多化合物的合成、结构及表征

Syntheses,structures and characterization of organic-inorganic composite heteropoly compounds

利用常规水溶液法制备了三种基于饱和Keggin结构阴离子的有机-无机复合杂多化合物[Pr(pydc)(H2O)6]2H[PMo12O40].4H2O(1)、[Nd(pydc)(H2O)6]2H[PMo12O40].4H2O(2)和[Tb(pydc)(H2O)6]2H[PMo12O40].4H2O(3)(pydc=2,6-吡啶二羧酸),并借助元素分析、IR、UV、热分析和X射线单晶衍射分析对三种化合物进行了表征.结果表明,三种化合物均属四方晶系,I4(1)/a空间群.晶胞参数分别为:1:a=1.521 94(11)nm,b=1.521 94(11)nm,c=2.848 1(4)nm,Z=4,R1=0.067 3,wR2=0.167 3;2:a=1.532 57(14)nm,b=1.532 57(14)nm,c=2.848 5(5)nm,Z=4,R1=0.045 4,wR2=0.118 1;3:a=1.527 68(16)nm,b=1.527 68(16)nm,c=2.833 7(6)nm,Z=4,R1=0.061 2,wR2=0.162 3.化合物1～3分子均含有一个Keggin阴离子[PMo12O40]3-和两个稀土配离子[Ln(pydc)(H2O)6]+,二者通过静电引力相结合.分子与分子之间通过静电引力及π-π堆积作用在c轴方向形成了大小约为0.5×1nm的孔道.

Three organic-inorganic composite heteropoly compounds based on saturated Keggin polyoxoanions [Pr（pydc）（H2O）6]2H[PMo12O40]·4H2O（1）,[Nd（pydc）（H2O）6]2H[PMo12O40]·4H2O（2） and [Tb（pydc）（H2O）6]2H[PMo12O40]·4H2O（3）（pydc = 2,6-pyridine dicarboxylic acid） have been prepared and characterized by elemental analyses,IR spectra,UV spectra,TG analyses,and X-ray single-crystal diffraction analyses.Results shown that compound 1,2,and 3 crystallizes all in the tetragonal system,I4（1）/a space group and the cell parameters are that 1：a = 1.521 94（11） nm,b = 1.521 94（11） nm,c = 2.848 1（4） nm,Z = 4,R1 = 0.067 3,wR2 = 0.167 3;2：a = 1.532 57（14） nm,b= 1.532 57（14） nm,c = 2.848 5（5） nm,Z = 4,R1 = 0.045 4,wR2 = 0.118 1;3：a = 1.527 68（16） nm,b= 1.527 68（16） nm,c = 2.833 7（6） nm,Z = 4,R1 = 0.061 2,wR2 = 0.162 3.Compounds 1-3 all consist of a Keggin polyoxoanion [PMo12O40]3-and two rare earth coordination ions [Ln（pydc）（H2O）6]＋,which connected by electrostatic attraction.Moreover,0.5×1 nm apertures along c axis were generated by electrostatic attraction and π-π packing arrangement.