Three Silver(I) Coordination Polymers Constructed from Flexible Bis(benzimidazole) and Carboxylates Ligands

Abstract

Under hydrothermal conditions, three new Ag I coordination polymers, [Ag(L1)(Hmip)] n (1), [Ag(L2) 0.5 (ndc) 0.5 ] n (2), and {[Ag(L3) 0.5 (Htbi)]·0.25H 2 O} n (3) [H 2 mip = 5-methylisophthalic acid, L1 = 1,4-bis(2-methylbenzimidazol-1-ylmethyl)benzene, H 2 ndc = 2,6naphthalenedicarboxylic acid, L2 = 1,3-bis(2-methylbenzimidazol-1ylmethyl)benzene, H 2 tbi = 5-tert-butyl isophthalic acid, L3 = 1,4bis(5,6-dimethylbenzimidazole)butane] were synthesized by employing flexible bis(benzimidazole) and dicarboxylic acid ligands. Polymer 1 displays a 2D 4-connected 4L2 underlying net topology with the point symbol of (6 5 .8) in standard representation. Compound 903 2 possesses a 2D uninodal 4-connected Shubnikov tetragonal plane net (sql) based on a dinuclear Ag I clusters with the point symbol (4 4 .6 2 ), which is further extended into a 3D supramolecular framework by ππ interactions. Compound 3 possesses dinuclear molecular complex groups, which form chains by weak Ag-O (2.6 Å) coordination bonds, and further assembled into a 2D supramolecular layer by hydrogen bonds and π-π stacking interactions. These complexes exhibit intense fluorescent emissions in solid state. UV/Vis diffuse reflection spectra and the excellent catalytic activity for the degradation of the congo red azo dye in a Fenton-like process are discussed. 904 and H 2 mip. Colorless block crystals of 2 were obtained. The yield was 65 % based on AgOAc. C 18 H 14 AgN 2 O 2 : calcd. C 54.30; H 3.54; N 7.04 %; found C 54.06; H 3.46; N 6.90 %. IR (KBr): ν = 2923 (w), 1600 (m), 1564 (s), 1520 (m), 1452 (m), 1403 (s), 1354 (s), 1290 (m), 1130 (m), 980 (m), 779 (s), 784 (s) cm -1 . www.zaac.wiley-vch.de ARTICLE Figure 5. (a) Experimental results of the catalytic degradation of congo red. (b) Photographs for 1-3 and free congo red after catalytic experiments from left to right. ConclusionsThree new metal-organic coordination complexes were successfully synthesized under hydrothermal condition. Topological analysis reveals that complex 1 is a new representative in rare isoreticular series of 2D 4-connected networks with 4L2 topology, which is constructed from four-coordinate Ag I ions and bridging bidentate ligands. Polymer 2 forms a 3,4-coordinated net with 3,4L13 topology in standard representation and a uninodal 4-connected net with widespread sql topology in cluster representation, which is further extended into a 3D supramolecular framework by the interlayer π-π stacking. Complex 3 shows a dinuclear structure, and a 2D supramolecular network was obtained by hydrogen bonding and π-π interactions. The variation of the organic ligand plays an important role in the construction of these complexes. 1-3 exhibit strong emission in the solid-state at room temperature. Moreover, 1-3 show promising catalytic activities in the Fenton-like decomposition of congo red.

Tungsten Carbide–Nitride on Graphene Nanoplatelets as a Durable Hydrogen Evolution Electrocatalyst

“…Generation of hydroxyl radicals occurs either using UV radiation or through the use of a catalyst (transition metal ion and related complexes). Herein, as an extension of our previous work,4,5 three complexes 1 – 3 were used as Fenton‐like catalysts for oxidation discoloration congo red dye. As shown in Figure 7, when the complex is added as catalyst, rapid degradation ensues and the degradation efficiency can reach 78.8 % for 2 and 68.5 % for 3 within 30 min, respectively; after which congo red oxidation proceeds at a reduced rate, reaching up to 92.2 % for 2 and 85.6 % for 3 in 120 min.…”

Syntheses, Structures, and Catalytic Properties of Two 2D Manganese(II) Coordination Polymers Containing Flexible Bis(benzimidazole) Ligands

“…There is no absorption peak around 1700 cm –1 for complex 1 , indicating that all the carboxyl groups of the organic moieties are deprotonated, but a characteristic absorption band at 1674 cm –1 for 2 suggests incomplete deprotonation of the carboxylic acid 24. The asymmetric and symmetric stretching vibrations of carboxylate groups occur at 1684, 1535, and 1420 cm –1 for 1 , 1634 and 1374 cm –1 for 2 .…”

Structural modulation and properties of silver(I) coordination polymers from 2,6-naphthalenedicarboxylic acid and flexible N-donor linkers

“…Silver complexes may have a number of functionalities; they may conduct electric current or luminesce and display catalytic or antimicrobial activity [8,9]. Recent research has shown that these MOCPs materials, acting as catalysts, are quite effective in the catalytic degradation of organic pollutants which is generally accomplished with an oxidizing agent such as dilute hydrogen peroxide [10][11][12][13].…”