title: Influence of steric hindrance of organic ligand on the structure of Keggin-based coordination polymer.
abstract: Five Keggin-based 3D coordination polymers, namely, [Cu3(pz)3(PW12O40)] (pz = pyrazine) (1), [Cu3(2,3-Me2pz)3(PW12O40)] (2,3-Me2pz = 2,3-dimethylpyrazine) (2), [Cu2(2,5-Me2pz)(1.5)(2,5-HMe2pz)(PW12O40)] (2,5-Me2pz = 2,5-dimethylpyrazine) (3), [Cu3(2,3-Me2pz)3(PMo12O40)] (4), and [Ag3(pz)3(PW12O40)].0.5H2O (5), were synthesized and structurally characterized. Crystal data are as follows: trigonal, space group R3c, a = 18.4070(14) angstroms, c = 22.544(3) angstroms, gamma = 120 degrees, and Z = 6 for 1; orthorhombic, space group Pccn, a = 16.599(2) angstroms, b = 20.470(3) angstroms, c = 14.3757(18) angstroms, and Z = 4 for 2; triclinic, space group P1, a = 10.667(2) angstroms, b = 11.147(2) angstroms, c = 20.207(4) angstroms, alpha = 90.983(4) degrees, beta = 108.128(3) degrees, gamma = 92.150(4) degrees, and Z = 2 for 3; orthorhombic, space group Pccn, a = 16.450(3) angstroms, b = 20.170(4) angstroms, c = 14.244(3) angstroms, and Z = 4 for 4; and rhombohedral, space group R32, a = 18.2047(13) angstroms, c = 23.637(3) angstroms, gamma = 120 degrees, and Z = 6 for 5. Their structural differences were investigated using crystal structure analysis, revealing that the influence of steric hindrance of organic ligand on the structures of Keggin-based coordination polymers is realized through changing the number of metal-organic units surrounding the POM anion.
authors: State Key Laboratory of Physical Chemistry of Solid Surface, Key Laboratory of Analytical Sciences, Ministry of Education, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors: Yan-Ping
authors: YP
authors: Ren
authors: Xiang-Jian
authors: XJ
authors: Kong
authors: Xiang-Yang
authors: XY
authors: Hu
authors: Meng
authors: M
authors: Sun
authors: La-Sheng
authors: LS
authors: Long
authors: Rong-Bin
authors: RB
authors: Huang
authors: Lan-Sun
authors: LS
authors: Zheng