The Lanthanum picrate complex with 1,10 phenanthroline was synthesized, whose chemical formula can be written in [La(pic)3(phen)2]·CH3CN. The crystal X ray diffraction analysis shows that crystal belongs to monoclinic with space group P21/a and unit cell parameters:a=17.072(4),b=16.083(4),c=17.789(4),β=106.34(2)°,V=4687(4)3, Z=4,Dc=1.735g·cm3, μ=10.106cm 1,F(000)=2448,R=0.0589,Rw=0.0589. The coordination number of La3+is nine. Acetonitrile, a solvent molecule is not coordinated. Between three Pic ligands, that possesses 2 bidentate forms six member ring with La. The other is unidentate ligand. As usually, phen is bidentate ligand.
