Design and synthesis of four coordination polymers generated from 2,2′-biquinoline-4,4′-dicarboxylate and aromatic bidentate ligands

Four coordination polymers [Zn(bqdc)(phen)]n (1), [Zn(bqdc)(bpy)(H2O)]n (2), [Mn(bqdc)(bpy)(H2O)2]n (3) and [Mn(bqdc)(phen)(H2O)2]n (4) (H2bqdc=2,2′-biquinoline-4,4′-dicarboxylic acid, phen=1,10-phenanthroline and bpy=2,2′-bipyridyl) have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. Crystal data for 1: monoclinic system, C2/c  , a=14.141(3)Å, b=10.021(2)Å, c=18.511(4)Å, β=103.78(3)°β=103.78(3)°, V=2547.6(9)Å3, Z=4Z=4. Crystal data for 2: monoclinic system, p21/n  , a=13.656(3)Å, b=10.015(2)Å, c=19.127(4)Å, β=107.13(7)°β=107.13(7)°, V=2500.1(9)Å3, Z=4Z=4. Crystal data for 3: monoclinic system, C2/c  , a=14.5050(8)Å, b=15.1932(8)Å, c=12.7549(6)Å, β=116.8010(11)°β=116.8010(11)°, V=2508.9(2)Å3, Z=4Z=4. Crystal data for 4: monoclinic system, C2/c  , a=14.1732(17)Å, b=16.115(3)Å, c=12.809(3)Å, β=117.04(3)°β=117.04(3)°, V=2605.7(8)Å3, Z=4Z=4. Single helix-like chains exist in 1. The supramolecular structure of 1 exhibits extended two-dimensional network while 2–4 display extended three-dimensional architectures based on interchain hydrogen bonding and π–ππ–π interactions. Compounds 1 and 2 show blue photoluminescence under UV light suggesting that they may be employed to develop luminescent materials. Compounds 3 and 4 show interesting magnetic behaviors.

Graphical abstractOne-dimensional coordination polymer chains.Figure optionsDownload full-size imageDownload as PowerPoint slide