A new coordination polymer, [Gd（III）（3-H-5-hydroxynicotinato）（ox）l.s（H20）2]n, has been synthesized by a hydrothermal reaction of gadolinium nitrate with 5-hydroxynicotinic acid and ammonium oxalate, and its st...A new coordination polymer, [Gd（III）（3-H-5-hydroxynicotinato）（ox）l.s（H20）2]n, has been synthesized by a hydrothermal reaction of gadolinium nitrate with 5-hydroxynicotinic acid and ammonium oxalate, and its structure has been determined by X-ray crystallography with the following data： triclinic space group PI, CgHgNOIlGd, Mr = 464.42, a = 7.5545（11）, b = 8.1094（12）, c = 10.6947（16） A, a= 103.493（2）, β = 98.385（2）, y= 92.117（2）°, Z= 2, V= 628.5706） A3, F（000） = 444, Dc = 2.454 g.cm^-3,/2 = 5.341 mm^-1, the final R = 0.0188 and wR = 0.0392 for 2634 observed reflections （I 〉 2σ（I））. In the asymmetric unit of the compound, each Gdm ion is bonded to nine oxygen atoms from 3-H-5-hydroxynicotinato and oxalate groups and terminal-coordinated water molecules, respectively, resembling a highly distorted three-capped trigonal geometry. Adjacent GdO9 coordination polyhedra are bridged by three identical independent oxalate groups in a side-by-side manner forming brickwall-like 2D grids, and then further linked through intermolecular hydrogen bonds generating a 3D supramolecular network. Magnetic analysis of the compound shows that weak antiferromagnetic coupling exists among the adjacent Gdm ions.展开更多
文摘A new coordination polymer, [Gd（III）（3-H-5-hydroxynicotinato）（ox）l.s（H20）2]n, has been synthesized by a hydrothermal reaction of gadolinium nitrate with 5-hydroxynicotinic acid and ammonium oxalate, and its structure has been determined by X-ray crystallography with the following data： triclinic space group PI, CgHgNOIlGd, Mr = 464.42, a = 7.5545（11）, b = 8.1094（12）, c = 10.6947（16） A, a= 103.493（2）, β = 98.385（2）, y= 92.117（2）°, Z= 2, V= 628.5706） A3, F（000） = 444, Dc = 2.454 g.cm^-3,/2 = 5.341 mm^-1, the final R = 0.0188 and wR = 0.0392 for 2634 observed reflections （I 〉 2σ（I））. In the asymmetric unit of the compound, each Gdm ion is bonded to nine oxygen atoms from 3-H-5-hydroxynicotinato and oxalate groups and terminal-coordinated water molecules, respectively, resembling a highly distorted three-capped trigonal geometry. Adjacent GdO9 coordination polyhedra are bridged by three identical independent oxalate groups in a side-by-side manner forming brickwall-like 2D grids, and then further linked through intermolecular hydrogen bonds generating a 3D supramolecular network. Magnetic analysis of the compound shows that weak antiferromagnetic coupling exists among the adjacent Gdm ions.
