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Two new cadmium(II) coordination polymers based on imidazole‐containing ligands: synthesis, structural characterization and fluorescence properties
Author(s) -
Li Bing-Feng,
Xu Xi-Ting,
Dong Tong-Min,
Zhou Wan-Ying,
Gu Yang,
Gong Lei,
Zhong Kai-Long
Publication year - 2020
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229620002594
Subject(s) - denticity , supramolecular chemistry , hydrogen bond , imidazole , chemistry , crystal structure , crystallography , pentagonal bipyramidal molecular geometry , ligand (biochemistry) , benzene , coordination polymer , coordination geometry , octahedral molecular geometry , stereochemistry , molecule , organic chemistry , biochemistry , receptor
The judicious selection of suitable ligands is vitally important in the construction of novel metal–organic frameworks (MOFs) with fascinating structures and interesting properties. Recently, imidazole‐containing multidentate ligands have received much attention. Two new Cd II coordination frameworks, namely, poly[tris{μ‐1,4‐bis[(1 H ‐imidazol‐1‐yl)methyl]benzene‐κ 2 N 3 : N 3′ }tetrakis(nitrato‐κ 2 O , O ′)dicadmium], [Cd 2 (NO 3 ) 4 (C 14 H 14 N 4 ) 3 ] n , (I), and poly[[bis{μ 3 ‐1,3,5‐tris[(1 H ‐imidazol‐1‐yl)methyl]benzene‐κ 3 N 3 : N 3′ : N 3′′ }cadmium] hexafluorosilicate], {[Cd(C 18 H 18 N 6 ) 2 ](SiF 6 )} n , (II), have been synthesized and characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction. In polymer (I), the 1,4‐bis[(1 H ‐imidazol‐1‐yl)methyl]benzene ligand bridges Cd 2+ ions with a distorted seven‐coordinated pentagonal bipyramidal geometry, forming a one‐dimensional ladder chain, and the nitrate anions coordinate to the Cd 2+ ions in a terminal bidentate fashion. In the crystal, adjacent chains are further connected by C—H…O hydrogen bonds to generate a two‐dimensional (2D) supramolecular structure. Polymer (II) exhibits a 2D layered structure in which 1,3,5‐tris[(1 H ‐imidazol‐1‐yl)methyl] benzene ligands join Cd 2+ centres having a six‐coordinated octahedral structure. The layers are connected by hexafluorosilicate anions via C—H…F hydrogen‐bond interactions, giving rise to a three‐dimensional supramolecular network structure in the solid state. In addition, powder X‐ray diffraction (PXRD) patterns were recorded, thermogravimetric analyses (TGA) carried out and fluorescence properties investigated.