3D Bi(Ⅲ)-La(Ⅲ)异金属配位聚合物的合成、结构和热稳定性

A new Bismuth(Ⅲ)-Lanthanum(Ⅲ) heterobimetallic polymer complex,{(H_2O)_5La(μ_4-edta)Bi(NO_3)_2]·3H_2O}_n(edta=diaminetetraacecarboxylate),has been hydrothermally synthesized and characterized by elemental analysis,FT-IR,and X-ray diffraction single crystal structure analysis.It crystallizes in the monoclinic system,with space group P2(1)/n,a=1.27395(5)nm,b=0.82608(4) nm,c=2.38819(11) nm,β=104.9000(10)°,V=2.42879(19) nm~3,Z=4,Dc=2.438 g·cm- 3,μ=9.077mm~(-1),F(000)=1678,R_1=0.0343,wR_2=0.0906.In this complex,Bi atom is coordinated by four carboxyl O atoms from a single edta~(4-) anion.La atom is bonded to four O atoms from four bridging carboxyl O atoms belonging to four different edta~(4-) anions and five O atoms from five H_2O molecules.Bi atoms and La atoms are linked by bridged edta~(4-) anions,resulting into a novel infinite 3D network structure.TG-DSC and IR indicate that thermal decomposition proceeds in several stages,dehydration,pyrolysis of ligand,and finally decomposition of salt,and the residue is composite oxide based on δ-Bi_2O_3 at the temperature of 600℃.