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A two‐dimensional cadmium(II) coordination polymer constructed from 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1 H ‐imidazole‐5‐carboxylate and 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1 H ‐imidazole‐4‐carboxylate ligands
Author(s) -
Li Fenfang,
Zhu Miaoli,
Lu Liping
Publication year - 2018
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/s2053229618010239
Subject(s) - carboxylate , imidazole , chemistry , octahedral molecular geometry , ligand (biochemistry) , molecule , octahedron , stereochemistry , crystallography , medicinal chemistry , coordination geometry , crystal structure , cadmium , hydrogen bond , organic chemistry , biochemistry , receptor
Crystals of poly[[aqua[μ 3 ‐4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1 H ‐imidazole‐5‐carboxylato‐κ 5 O 1 O 1′ : N 3 , O 4 : O 5 ][μ 4 ‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1 H ‐imidazole‐4‐carboxylato‐κ 7 N 3 , O 4 : O 4 , O 4′ : O 1 , O 1′ : O 1 ]cadmium(II)] monohydrate], {[Cd 2 (C 15 H 14 N 2 O 4 )(C 16 H 14 N 2 O 6 )(H 2 O)]·H 2 O} n or {[Cd 2 (Hcpimda)(cpima)(H 2 O)]·H 2 O} n , (I), were obtained from 1‐(4‐carboxybenzyl)‐2‐propyl‐1 H ‐imidazole‐4,5‐dicarboxylic acid (H 3 cpimda) and cadmium(II) chloride under hydrothermal conditions. The structure indicates that in‐situ decarboxylation of H 3 cpimda occurred during the synthesis process. The asymmetric unit consists of two Cd 2+ centres, one 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1 H ‐imidazole‐5‐carboxylate (Hcpimda 2− ) anion, one 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1 H ‐imidazole‐4‐carboxylate (cpima 2− ) anion, one coordinated water molecule and one lattice water molecule. One Cd 2+ centre, i.e. Cd1, is hexacoordinated and displays a slightly distorted octahedral CdN 2 O 4 geometry. The other Cd centre, i.e. Cd2, is coordinated by seven O atoms originating from one Hcpimda 2− ligand and three cpima 2− ligands. This Cd 2+ centre can be described as having a distorted capped octahedral coordination geometry. Two carboxylate groups of the benzoate moieties of two cpima 2− ligands bridge between Cd2 centres to generate [Cd 2 O 2 ] units, which are further linked by two cpima 2− ligands to produce one‐dimensional (1D) infinite chains based around large 26‐membered rings. Meanwhile, adjacent Cd1 centres are linked by Hcpimda 2− ligands to generate 1D zigzag chains. The two types of chains are linked through a μ 2 ‐η 2 bidentate bridging mode from an O atom of an imidazole carboxylate unit of cpima 2− to give a two‐dimensional (2D) coordination polymer. The simplified 2D net structure can be described as a 3,6‐coordinated net which has a (4 3 ) 2 (4 6 .6 6 .8 3 ) topology. Furthermore, the FT–IR spectroscopic properties, photoluminescence properties, powder X‐ray diffraction (PXRD) pattern and thermogravimetric behaviour of the polymer have been investigated.