Zi-Ao Zong

Syntheses, structural diversity and photocatalytic properties of various Co(II) coordination polymers based on a “V”-shaped 1,3-di(4′-carboxyl-phenyl)benzene acid and different imidazole bridging ligands

Four novel Co(II) coordination polymers (CPs) based on a “V”-shaped 1,3-di(4′-carboxyl-phenyl)benzene acid (H2dpb), namely {[Co2(dpb)2(4,4′-bibp)2]·2(CH3CN)}n (1), [Co(Hdpb)2(4,4′-bibp)]n (2), {[Co2(dpb)2(tib)2]·H2O}n (3) and {[Co(dpb)(bimb)0.5]·DMF·0.5(CH3CN)}n (4) (4,4′-bibp = 4,4′-bis(imidazol-1-yl)biphenyl, tib = 1,3,5-tris(1-imidazolyl)benzene and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene), have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric (TG) analysis and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis reveals that complex 1 possesses a uninodal 4-connected 3D (three-dimensional) cds topology framework with the Schlafli symbol (65·8). Complex 2 shows 1D zigzag chains, which are further assembled into a 3D supramolecular structure by O–H⋯O hydrogen bonds. Complex 3 shows an unprecedented 3-nodal (3,4,6)-connected 3D framework with the Schlafli symbol (62·7)2(64·75·84·9·10)(64·82), while complex 4 displays a {Co2(COO)4} binuclear SBU-based 3D 6-connected (44·611)-unprecedented framework. Moreover, the photocatalytic degradation of the four Co(II) compounds (complexes 1–4) has been investigated.

Syntheses, structures, luminescent and photocatalytic properties of various polymers based on a “V”-shaped dicarboxylic acid

Solvothermal reactions of “V”-shaped 3,5-di(4′-carboxyl-phenyl)benzene acid (H2dpb), and Cd(II)/Zn(II) salts in the presence of four ancillary bridging imidazole linkers afford four novel luminescent coordination polymers (LCPs), namely, {[Cd(dpb)2(bimb)2]·0.5H2O}n (1), [Cd(dpb)(tib)]n (2), [Zn(Hdpb)2(4,4′-bibp)]n (3) and [Cd(dpb)(1,3-bitl)]n (4), (bimb = 1,4-bis(imidazol-1-ylmethyl)benzene, tib = 1,3,5-tris(1-imidazolyl) benzene, 4,4′-bibp = 4,4′-bis(imidazol-1-yl)biphenyl and 1,3-bitl = 1,3-bis(1-imidazoly)toluene). Then complexes 1–4 are characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric (TG) analysis and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis shows that complex 1 shows an unprecedented 3-nodal (2,2,4)-connected 2D + 2D → 3D two-fold interpenetration framework with the Schlafli symbol (125·16)(12)2. Complexes 2 and 3 show a 2D layer structure and 1D zigzag chain, which are further assembled into a 3D supramolecular structure by π⋯π interactions and H-bonds, respectively. While complex 4 displays a 3-nodal (2,2,8)-connected network with a –ABAB– fashion. The luminescent recognition properties of polymers 1–4 to metal cations and anions have also been explored systematically. The results demonstrate that 2 and 3 display highly sensitive and selective luminescence sensing towards Fe3+ ions, and 4 displays highly sensitive and selective luminescence sensing towards Cu2+ ions. 1–4 can work as highly sensitive sensors to Cr2O72− by luminescence quenching. Moreover, the photocatalytic properties of four Cd(II)/Zn(II) compounds (complex 1–4) have also been investigated.

Two 3D ZnII Metal–Organic Frameworks with 3- and 8-Fold Interpenetration: Syntheses, Structures, Photodegradation, and Photoluminescent Properties

Two novel coordination polymers, namely {[Zn(sbdc)(bmib)]·0.4H2O}n (1) and {[Zn(sbdc)(bibd)]·DMF}n (2) (H2sbdc = 4,4′-stilbenedicarboxylic, bmib = 1,4-bis(2-methylimidazol-1-yl)butane, bibd = 1,1′-(1,4-butanediyl)bis(imidazole), DMF = N,N-dimethylformamide), have been acquired under solvothermal conditions, and have been characterised by elemental analysis, infrared spectra, thermogravimetric analysis, and single-crystal X-ray diffraction (XRD). Single-crystal XRD analysis reveals that 1 shows eight-fold interpenetrating 3D frameworks with a four-connected (66) sqc6 topology and 2 displays four-connected three-fold interpenetrating 3D frameworks. The flexible N-donor ligands play an important role in the construction of the final topological structures for 1 and 2. Furthermore, 1 and 2 exhibit good photodegradation capability and photoluminescence properties.

Structure, sensing and photocatalytic properties of two multifunctional 3D luminescent coordination polymers based on an N-heterocyclic carboxylic acid

Two novel luminescent coordination polymers, namely, {[Zn(tmlb)(H2tmlb)]·H2O}n (1) and [Zn(tmlb)(bbibp)]n (2) ((bbibp = bis(benzoimidazo-1-ly)biphenyl), H2tmlb = (1H-1,2,4-triazol-1-yl)methylenebis(benzoic acid)), have been rationally designed and successfully solvothermally synthesized. Complexes 1 and 2 have been characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction, thermogravimetric (TG) analysis and powder X-ray diffraction (PXRD). Complex 1 possesses a 2-fold interpenetrating 3-connected 3D framework with a point symbol of (63) topology. Complex 2 exhibits a two-fold interpenetrating uninodal 4-connected 3D framework with a (65·8) topology. The luminescence studies reveal that complexes 1 and 2 display highly sensitive and selective luminescent sensing towards Cr(VI) (CrO42− and Cr2O72−) anions, and complex 2 displays highly sensitive and selective luminescence sensing towards Fe(III) cations. In addition, photocatalytic studies show that complex 1 could be a good candidate for the photocatalytic degradation of methylene blue (MB), and complex 2 could be a good candidate for the photocatalytic degradation of methylene violet (MV) and Rhodamine B (RhB).

A penetrating metal-organic framework based on N-heterocyclic carboxylic acid with sensing properties toward Cr(VI)/Fe(III) and nitrobenzene

Abstract A luminescent metal-organic framework, [Cd(tmlb)(bbibp)]n (1) (H2tmlb = (1H-1,2,4-triazol-1-yl)methylenebis(benzonic acid), bbibp = bis(benzoimidazo-1-ly)biphenyl), has been solvothermally synthesized and characterized by elemental analysis, infra-red spectroscopy, single-crystal X-ray diffraction, thermogravimetric analysis, and powder X-ray diffraction. Complex 1 exhibits two interpenetrating uninodal 4-connected 3-D frameworks with a (65·8) topology. The luminescence studies reveal that the complex displays sensitive and selective luminescence sensing toward Cr(VI) (CrO42− and Cr2O72−) anions, Fe(III) cation, and nitrobenzene. The potential quench mechanism was discussed. Graphical Abstract

Rational assembly of functional Co-MOFs via a mixed-ligand strategy: synthesis, structure, topological variation, photodegradation properties and dye adsorption

Four novel Co(II) metal–organic frameworks, namely [Co2(4,4′-cpmb)2(1,1′-bbi)2]n (1), [Co(4,4′-cpmb)(4,4′-bbibp)]n (2), {[Co(4,4′-cpmb)(tib)]·3(H2O)}n (3) and {[Co(4,4′-sdc)(tib)]·(H2O)}n (4) (flexible 4,4′-cpmb = 4-(4-carboxylphenylmethylthio)benzoic acid, rigid 4,4′-sdc = 4,4′-stilbenedicarboxylic acid, flexible 1,1′-bbi = 1,1′-(1,4-butanediyl)bis(imidazole), rigid 4,4′-bbibp = 4,4′-bis(benzoimidazo-1-ly)biphenyl and rigid tib = 1,3,5-tris(1-imidazolyl)benzene) were synthesized employing a rational design approach under solvothermal conditions and further characterized by elemental analysis, IR spectra, thermogravimetric (TG) analysis, powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction. The four Co-MOFs display different interpenetrated structures due to the flexibility of O/N-donor ligands. Single-crystal X-ray diffraction analysis reveals that complex 1 displays a 6-fold interpenetrating class Ia net with the point Schlafli symbol of (66). Complex 2 shows a 3-fold interpenetrating sqc5 net with the point Schlafli symbol of (66·8). Complexes 3 and 4 exhibit a 2-fold interpenetrating 4-connected sql topology with the point Schlafli symbol of (44·62). The photodegradation properties and dye adsorption capacity of complexes 1–4 are investigated, and the framework integrity of complexes 1–4 can be well-retained.

Synthesis, structure, and photocatalytic activity of a novel Ni (II) coordination polymer based on p-aminohippuric acid

ABSTRACT A novel Ni(II) coordination polymer, {[Ni(C9H9N2O3)2(H2O)2]·H2O}n(1)(C9H11N2O3, p-Aminohippuric acid, PAH), has been synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra, and thermal analysis. Single-crystal X-ray analysis reveals that each Ni(II) ion is six-coordinated by two coordinated water molecules, two carboxylate oxygen atoms, and two nitrogen atoms from PAH forming a octahedral geometry. The complex features a 2-nodal 2,4-connected network with unprecedented Schläfli symbol of (42)(4)2. In addition, the photocatalytic studies indicate that this complex is a good candidate for the photocatalytic degradation of rhodamine B.