硝酸铕二甲亚砜配合物的光谱与磁性

SPECTROSCOPIC AND MAGNETIC PROPERTIES OF DIMETHYL SULFOXIDE COMPLEX OF EUROPIUM NITRATE

本文合成了硝酸铕二甲亚砜配合物Eu(NO_3)_3 ·4(CH_3)_2SO的晶体,测定了它的组成、结构、荧光光谱和摩尔磁化率.从光谱求得Eu^(3+)在此晶体中的能级.根据所得的能级数据,计算了此晶体的摩尔磁化率的倒数,与实验值基本相符.

Dimethy] sulf oxide complex of europium nitrate was synthesized. Its composition is Eu(NO3)3 ??? 4(CH3)2SO. The crystal structure of this complex belongs to monoclinic system. Its lattice parameters are:aaaaaaaaa = 1.4806 nm, bbbbbbbb = 1.09'48nm, c = 1.5335nm. BBBBBBB = 108.07???????? and Z= 4 . Space group is C2/c-C2k6. Coordination number of Eu3 + is 10. Its luminescence spectra weredetermined at liquid nitrogen temperature (Fig. 3). Argon laser was used for excitation. The excitation wavelength is 457.9nm. 6D0??????7F0 transi tioa was observed. This shows that Eu3+ is located in a site without inverse center. Multiplets of 7F1, 7F2 and 7F4 are splitted into 3, 5 and 9 energy levels respectively. It shows that the local symmetry of Eu3+ site in this complex is low and its point group maybe belongs to C2 or Cs. This result is consistent with the crystallographic data (Fig. 2 ). Energy levels for Eu3 + ion in this complex were determined (Table 1). The observed J-level barycenters (W1) of 7F1, 7F2, 7F3 and 7F4 are 369, 995, 1942 and 2873 cm-1 respectively. The molar magnetic susceptibilities of this complex were calculated from liquid nitrogen to room temperature by these WJ data. The calculated values are consistent with the experimental data (Fig. 4 ). This result shows that the magnetic property of Eu3+ is correlated closely with its spectroscopic property. Because the energy difference between the ground state (7F0) and the nearest mul-tiplet (7F1) of Eu3+ is the smallest in lanthanides (Fig. 1) and closes to the value of kT, the contributions of those parts of Eu3 + located in mul-tiplets 7FJ on the molar magnetic susceptibilities must be considered.