U(Ⅳ)配合物UNa_2(pdc)_3·6H_2O的合成、结构及磁性研究

Synthesis,Structure and Magnetic Property of a Novel U(Ⅳ) Coordination Compound:UNa_2(pdc)_3·6H_2O

合成了一种含有+4价铀的配合物UNa2(pdc)3.6H2O(H2pdc=吡啶-2,6二-羧酸),并详细研究了其晶体结构和磁学性质.晶体属于单斜晶系,P21/n空间群,晶胞参数a=1.020 5(2)nm,b=2.222 1(4)nm,c=1.253 7(3)nm,β=94.98(3)°,V=2.832 3(10)nm3,Z=4.化合物的中心铀原子为九配位,π-π相互作用和氢键使得该化合物形成了三维立体结构.

Uranium is the most extensively studied element in actinide chemistry. In the past few years, many uranyl coordination compounds had been synthesized, whereas the report on the U （ Ⅳ ） cooridination compounds is much less. Here we reported the synthesis, crystal structure and magnetic property of a novel U（ Ⅳ） coordination compound UNa2 （ pdc ） 3 · 6H2O（ H2pdc = pyridine-2,6-dicarboxylic acid ）. The title compound crystallized in the monoclinic space group P21/n, with unit cell parameters a = 1. 020 5 （2） nm, b =2. 222 1（4） nm, c =1. 253 7（3） nm, β =94.98（3）°, V=2. 832 3（10） nm^3, Z =4. The centered uranium atom is bonded to three pdc ligands via three nitrogen atoms and six oxygen atoms in a tricapped trigonal prismatic coordination. The temperature dependence of magnetic susceptibility reciprocal curve shows that the title compound has a paramagnetic behavior which obey to Curie-Weiss equation above 50 K（ C = 1.01 cm^3 · K· mol^-1, θ= -63.21 K）.