烟酸镨Pr_2(C_5H_4NCOO)_6(H_2O)_4的晶体结构

CRYSTAL STRUCTURE OF PRASEODYMIUM NICOTINATE QUADRIHYDRATE Pr_2(C_5H_4NCOO)_6(H_2O)_4

从ＬｎＡｌａＮＡ溶液（Ｌｎ＝Ｎｄ，Ａｌａ＝Ｌ丙氨酸；ＮＡ＝烟酸）中得到烟酸镨晶体，并用四圆Ｘ射线衍射技术重新测定其结构．配合物为二聚体结构，属单斜晶系，Ｐ２１／ｃ空间群，晶胞参数：ａ＝９．７１２５（９），ｂ＝１２．０４９８（１１），ｃ＝１７．１５１（２），β＝９２．６８８（６）°，Ｖ＝２００５．１（３）３，Ｚ＝２，Ｄｃ＝１．８００ｇ／ｍＬ．其配位数为８，配位多面体为四方反棱柱．本文讨论了稀土烟酸配合物结构规律性．

The complex crystal is obtained from the solution with LnAlaNA(Ln=Praseodymium, Ala=LAlanine, NA=Nicotinic Acid). Its crystal structure has been redetermined by Xray single diffraction analysis. The compound is dimer.Its crystal is monolinic space group P21/c with unit cell parameters: a=9.712 5(9) ,b=12.049 8(11) ,c=17.151(2) ,β=92.688(6)°,V=2 005.1(3) 3,Z=2,Dc=1.800 g/mL. The Pr ions have 8coordinated in a tetragonal antiprism.The regularities of crystal structures in lanthanides with nicotinic acid are discussed.