Assembly of 1D and 3D cobalt(II) coordination polymers based on isophthalic acid and flexible benzimidazolyl-based ligands

Abstract

Two new metal-organic coordination polymers {[Co(L1)(nip)]ÁH 2 O} n (1) and [Co(L2)(ip)] n (2) (H 2 ip = isophthalic acid, L1 = 1,3-bis(benzimidazol-1-ylmethyl) benzene, L2 = 1,4-bis(5-methylbenzimidazol-1-ylmethyl) benzene, H 2 nip = 5-nitroisophthalic acid) have been synthesized under hydrothermal conditions and characterized by physicochemical and spectroscopic methods as well as single-crystal X-ray diffraction analysis. The analysis reveals that complex 1 has a 1D double chain structure connected by L1 and nip 2-ligands, which is further assembled into a 3D bbf (moganite network) supermolecular framework via two types of C-HÁÁÁO hydrogen bond interactions. Complex 2 possesses a 3D MOF with a fourconnected cds (CdSO 4 network) topology. The fluorescence and catalytic properties of the complexes for the degradation of Congo red have been investigated.

Three novel Co(ii)-based MOFs: syntheses, structural diversity, and adsorption properties

“…It is evident from the available studies that functionalized ligands containing pyridyl/imidazolyl N-nitrogen atoms and carboxyl O-oxygen atoms have been shown to be good building blocks for the construction of multidimensional MOFs, which can contribute greatly in providing more chemical interactions such as H-bonding, weak interactions, and π–π stacking during adsorption, and active sites between MOFs and organic dye molecules. 31–34 Herein, 3-(3,5-dicarboxylphenoxy)-6-carboxylpyridine (H 3 L), which contains conjugate groups (benzene ring and pyridine ring) and carboxylate groups, was used as a bridging ligand, 1,3,5-tirs(1-imidazolyl)benzene (tib), 4,4′-bis(imidazolyl)biphenyl (bibp), and 3,5-bis(imidazoly-1-yl)toluene (bip) with iminazole groups were used as auxiliary ligands, and three new Co-based MOFs, namely, {[Co(HL)(tib)(H 2 O)]·2H 2 O} n ( 1 ), [Co 3 (L) 2 (bibp) 4 (H 2 O) 2 ] n ( 2 ) and [Co 2 (L)(bip)(μ 3 -OH)] n ( 3 ), were designed and synthesized by the solvothermal method. The crystal solution obtained by the solvothermal method was filtered to obtain relatively pure bulk crystals, which were then washed several times with the mother liquor and methanol, respectively, and dried in air.…”

“…29,30 It is evident from the available studies that functionalized ligands containing pyridyl/imidazolyl N-nitrogen atoms and carboxyl O-oxygen atoms have been shown to be good building blocks for the construction of multidimensional MOFs, which can contribute greatly in providing more chemical interactions such as H-bonding, weak interactions, and π-π stacking during adsorption, and active sites between MOFs and organic dye molecules. [31][32][33][34] Herein, 3-(3,5dicarboxylphenoxy)-6-carboxylpyridine (H 3 L), which contains conjugate groups (benzene ring and pyridine ring) and carboxylate groups, was used as a bridging ligand, 1,3,5tirs(1-imidazolyl)benzene (tib), 4,4′-bis(imidazolyl)biphenyl (bibp), and 3,5-bis(imidazoly-1-yl)toluene (bip) with iminazole groups were used as auxiliary ligands, and three new Cobased MOFs, namely, {[Co(HL…”