Five bis(imidazole)-based Coordination Polymers Tuned by Central Metal Ions and S-containing Dicarboxylates: Syntheses, Structures, and Properties

Abstract

Five new coordination polymers, namely [Zn(2-CMSN)(biim-4)] (1), [Co2(2-CMSN)2(biim-4)(H2O)4] (2), [Ni(2-CMSN)(biim-4)0.5(H2O)2] (3), [Cd(2-CMSN)(biim-4)0.5(H2O)2] (4), and [Cd(ADTZ)(biim-4)1.5]·5H2O (5), (2-H2CMSN = 2-carboxymethylsulfanyl nicotinic acid, H2ADTZ = 2,5-(S-acetic acid) dimercapto-1,3,4-thiadiazole, biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole)) have been synthesised under hydrothermal conditions and structurally characterised by single-crystal X-ray diffraction analysis, infrared spectroscopy, elemental analysis, thermogravimetric analysis, and powder X-ray diffraction. Complex 1 shows a 2D undulated sheet, which is constructed from 1D meso-helical [Zn-(biim-4)]n chains and linear [Zn-(2-CMSN)]n chains. Complexes 2–4 exhibit a similar 2D (4,4) grid network constructed from zigzag [M-(2-CMSN)]n chains and linear [M-(biim-4)]n chains (M = CoII, NiII and CdII), which possesses a ‘4+2’ type six-membered ring. Complex 5 displays a 3D architecture derived from 2D Cd-(biim-4) layers and double ADTZ linkers with diamond-type 66 topology. The effects of the central metals and S-containing dicarboxylates on the structures of the title coordination polymers have been discussed. The luminescent properties of complexes 1, 4, and 5 have been studied. Complex 5 exhibits photocatalytic activity for dye degradation under ultraviolet light and good stability towards photocatalysis.

Structural Influencing Factors on ZnII/CdII Coordination Polymers Based on Tri‐pyridyl‐bis‐amide: Assembly, Structures, Fluorescent Sensing and Selective Photocatalysis

“…From the above photocatalytic results, 1 – 8 , 7a and 8a have good photocatalytic activitity and selectivity for the degradation of CR equal to that of [Cd 2 (oba)(4‐bpdb) 2 ] n · (DMF) and [Cd 2 (oba)(4,4′‐bipy) n ] n · (DMF) (H 2 oba = 4,4′‐oxybis(benzoic acid), 4‐bpdb = 1,4‐bis(4‐pyridyl)‐2,3‐diaza‐1,3‐butadiene, 4,4′‐bipy = 4‐bpdb) 20 . 1a , 2a , 3a and 6a are better than other reported catalysts such as [Zn(2‐CMSN)(biim‐4)] and [Cd(2‐CMSN)(biim‐4) 0.5 (H 2 O) 2 ] [2‐H 2 CMSN = 2‐carboxymethylsulfanyl nicotinic acid, biim‐4 = 1,1′‐(1,4‐butanediyl)bis(imidazole)]21 for the degradation of MB. The 1a have photocatalytic activitity for the degradation of MO but poorer than that of reported catalysts {[Cd3L2(H 2 O)5] · H 2 O}n and {[Cd6L4(bipy)2(H 2 O)6] · 3H 2 O}n [H3L = 3,4‐bi(4‐carboxyphenyl)benzoic acid, 4,4′‐bipy = 4,4 ′‐bipyridine] 22.…”

Four CoII/MnII Coordination Compounds Constructed from Dipyrido[3,2‐d:2′,3′‐f]quinoxaline and Different Dicarboxylates: Electrochemical, Photoluminescent, and Magnetic Properties

“…Based on above viewpoints and as a continuation of our research on the dicarboxylate‐based coordination compounds,21,22 in this work, we selected a large chelating N‐donor ligand dipyrido [3,2‐d:2′,3′‐f]quinoxaline (dpq) as the main ligand, three structurally related dicarboxylates, 5‐methylisophthalic acid (H 2 L1), 5‐hydroxyisophthalic acid (H 2 L2), and bis(sulfanediyl) thiadiazole diacetic acid (H 2 L3) as the secondary ligands (Scheme ) to react with cobalt(II)/manganese(II) salts, aiming at investigating the effects of metal ions and dicarboxylates with different spacers on the structure of target compounds. The selection of the dpq, H 2 L1, H 2 L2, and H 2 L3 ligands is basing on the following consideration: (a) compared with 2,2′‐bipy and 1,10‐phen, dpq has the larger aromatic‐ring system and may provide potential supramolecular recognition sites for π–π aromatic stacking interactions to form interesting supramolecular structures;23 (b) compared to 1,3‐benzenedicarboxylic acid (1,3‐bdc), H 2 L1 and H 2 L2 contain different substituent groups in the meta position (–CH 3 in H 2 L1 and –OH in H 2 L2), and exhibit various steric effects and potential supramolecular recognition abilities for hydrogen bonding interactions, which may conduce to form diverse coordination structures and supramolecular networks;14,15 (c) compared to the V‐type dicarboxylates ligands (1,3‐bdc, H 2 L1, H 2 L2), H 2 L3 not only possesses a similar V‐type spacer (2,5‐substitutional thiadiazole derivative), but also has two flexible –SCH 2 – groups, which have stronger bending and rotating ability and may be favorable to generate high‐dimensional frameworks 24,25…”