双核铕-间甲基苯甲酸邻菲罗琳[Eu(m-MBA)_3PHEN](H_2O)_2三元配合物的晶体结构和荧光光谱

Crystal Structure and Luminescence Spectra of Binuclear Europium m-Methylbenzoate Ternary Complex with 1,10-phenanthroline, [Eu(m-MBA)_3PHEN](H_2O)_2

标题配合物晶体属Cc空间群,a=1.5955(6)nm,b=1.8508(6)nm,c=2.2595(9)nm,β=97.79(4)°,Z=4,Dx=1.52g/cm^3,T=295K.用I>3σ(I)的7316个可观察衍射数据对92个非氢原子的原子坐标和各向异性温度因子进行全矩阵最小二乘法精修,最终的偏离因子R=0.043.中心Eu(Ⅲ)离子与周围6个氧和一对氮原子配位,配位多面体属四方反棱柱体,其点对称性为C_1.以Eu(Ⅲ)离子为荧光探针,77K下测得配合物多晶样品的高分辨激光激发光谱和发射光谱,激发光谱表明配合物中Eu(Ⅲ)离子仅有一种晶格格位.~5D_0→~7F_J(J=0～2)跃迁光谱表明中心Eu(Ⅲ)离子在77K下具有C_1对称性.

The crystal structure of the title compound has been solved by the heavy-atom, direct method, and by using the three dimensional Patterson-Fourier synthesis. The crystallographic data are: M=1511. 22, space group Cc, a=l. 5955(6) nm, b=1. 8508(6) nm, c=2. 2595(9) nm, β = 97. 79(4)°, V = 6. 610(4) nm3, Z = 4, F(000) = 3040, Dx=1. 52 g/cm3, μ=19. 47 cm-1, and R = 0. 043 for 7316 observed reflections. Both europium ions in the binuclear complex are octa-coordinated with six oxygen atoms of m-methylbenzoates and two nitrogen atoms of 1, 10-phenathroline, to give the square antiprisms with C1 site symmetry for the Eu( Ⅲ ) ions. The high resolution excitation spectrum at 77K indicates that only one Eu( Ⅲ ) site exists in the complex. 5D0→7FJ(J=0-2) transition fluorescence spectra confirm the C1 symmetry of the Eu( Ⅲ ) site.