A new three-dimensional bis(benzimidazole)-based cadmium(II) coordination polymer

Luminescent binuclear Zinc(II) organic framework as bifunctional water-stable chemosensor for efficient detection of antibiotics and Cr(VI) anions in water

To achieve the ultrastable LMOFs with predominant luminescent sensing performances, the aromatic π-electron mixed ligands strategy was introduced, and the ternary LMOF of {[Zn₂(HDDB)(bib)_1.5]·3H₂O}_n (1), was fabricated based on 3,5-di(2',4'-dicarboxylphenyl)benozoic acid (H₅DDB) and the N-donor of meta-bis(imidazol-1-yl)benzene (bib) under mixed solvothermal condition. LMOF 1 features the first reported 3D 3,4,4-c {6².8³.10}{6².8}₂{6³.8².10}₂ framework with 21.2 % porosity as well as high thermal and chemical stability. Further luminescent sensing showed that LMOF 1 as a bifunctional chemosensor possessing predominant detectability for sensitive detect the hexavalent chromates and nitroimidazoles/nitrofurans antibiotics in water through strong luminescent quenching effects, with excellent reusability as well as trace detection limits. Moreover, luminescent quenching mechanisms were further investigated from electron transfer and energy transfer viewpoints.

1,3-Bis(4′-carboxylatophenoxy)benzene and 3,5-bis(1-imidazoly)pyridine derived Zn(ii)/Cd(ii) coordination polymers: synthesis, structure and photocatalytic properties

Zn(ii) and Cd(ii)-based CPs derived from a 1,3-bis(4′-carboxylatophenoxy)benzene and 3,5-bis(1-imidazoly)pyridine synthesized and their photocatalytic properties for decomposition of methylene blue investigated.

Four dual-functional luminescent Zn(ii)-MOFs based on 1,2,4,5-benzenetetracarboxylic acid with pyridylbenzimidazole ligands for detection of iron(iii) ions and acetylacetone

Four Zn-MOFs with different topological types were synthesized and characterized, MOFs 1–4 have excellent sensitivity, selectivity, recyclability and structural stabilities for detecting acac/Fe³⁺ in the naked eye range.

Two cadmium(II) coordination polymers as multi-functional luminescent sensors for the detection of Cr(VI) anions, dichloronitroaniline pesticide, and nitrofuran antibiotic in aqueous media

Two ternary cadmium(II) coordination polymers, with the formulas being {[Cd(tptc)_0.5(bpz)(H₂O)]·0.5H₂O}_n (CP 1), and [Cd(tptc)_0.5(bpy)]_n (CP 2), were designed through mixed ligands strategy. Benefiting from the excellent chemical stability and luminescent property, two Cd(II) CPs possessing efficient multi-functional fluorescent responses toward Cr(VI) anions, 2,6-dichloro-4-nitroaniline pesticide, and nitrofuran antibiotic in aqueous media with high sensitivity, selectivity, and excellent recyclable behaviors with the detection limits (LODs) are 235 ppb for CrO₄^2- anion, 343 ppb for Cr₂O₇^2- anion, 112 ppb for DCN pesticide, 62 ppb for NFT antibiotic for CP 1, and 173 ppb for CrO₄^2- anion, 270 ppb for Cr₂O₇^2- anion, 638 ppb for DCN pesticide, 184 ppb for NFT antibiotic for CP 2, respectively. Besides, the mechanisms of luminescence quenching were revealed from the viewpoint of internal filter effect (IFE) and photoinduced electron transfer (PET).

Sonochemical synthesis and characterization of four nanostructural nickel coordination polymers and photocatalytic degradation of methylene blue

Four nanostructural nickel(II) coordination polymers {[Ni(ttpa)(1,4-ndc)(H₂O)₂]·2H₂O}_n (1), {[Ni(ttpa)(1,3-bda)]·2H₂O·DMF}_n (2·2H₂O·DMF), {[Ni(ttpa)(1,4-bdc)]·H₂O}_n (3) and {[Ni(ttpa)(aip)(H₂O)]·3H₂O}_n (4·3H₂O) were synthesized using hydrothermal and sonochemical methods (ttpa = tris(4-(1,2,4-triazol-1-yl)phenyl)amine, 1,4-ndc = 1,4-naphthalenedicarboxylate, 1,3-bda = 1,3-benzenediacetate, 1,4-bdc = 1,4-benzenedicarboxylate, aip = 5-aminoisophthalate), and characterized by elemental analysis, IR spectra, scanning electron microscopy, single-crystal and powder X-ray diffraction analysis, optical band gaps, VB XPS spectra and luminescence. The effects of sonication power, time and frequency on the size and morphology of nano-sized 1-4 have been studied. 1 exhibits an unusual 2D + 2D → 3D inclined polycatenated motif based on the (3,3)-coordinated 6³-hcb topology. 2 shows a (3,4)-coordinated 2D network of the bey topology. 3 presents a rare example of the 4-fold interpenetrating array of (3,5)-coordinated 3D network belonging to the 35T1 topology type. 4 displays an unusual 2D → 3D polythreaded network based on 2D sql networks. 1-4 exhibit luminescent emissions at 409, 399, 413 and 402 nm, respectively. 1-4 are semiconducting in nature, with E_g of 2.12 eV (1), 2.34 eV (2), 2.32 eV (3), and 2.47 eV (4). 1-4 are good catalysts for the degradation of MB under visible light irradiation. The effects of the size and morphology of nano-sized 1-4 on the photocatalytic efficiencies were studied. The higher sonication frequency obtains uniform and smaller nano-sized coordination polymers which have higher catalytic efficiencies.

Synthesis, structure, spectral characteristic and photocatalytic degradation of organic dyes of a copper metal-organic framework based on tri(triazole) and pimelate

A copper(II) metal-organic framework {[Cu(ttpa)(pim)]·H₂O}_n (1) was synthesized and characterized by EA, IR, X-ray powder diffraction, optical band gaps, VB XPS spectra and luminescence (ttpa = tris(4-(1,2,4-triazol-1-yl)phenyl)amine, pim = pimelate). 1 exhibits the 3D pcu topology containing the [Cu₂(COO)₄] dimer building block. E_g, E_v and E_c of 1 were 2.37, 1.64 and -0.73 eV, respectively. MOF 1 exhibits a highly photocatalytic efficiency for the degradation of methylene blue and rhodamine B by visible light irradiation. The photocatalyst 1 is very stable after photocatalytic experiment and can be reused for at least five times. The photocatalytic mechanism was detailedly assumed and confirmed by the photocatalytic reaction in the presence of the hydroxyl radical scavenger mannitol and trapping agent 1,4-benzenedicarbolic acid.

Copper(ii)-benzotriazole coordination compounds in click chemistry: a diagnostic reactivity study

This diagnostic study aims to shed light on the catalytic activity of a library of Cu(ii) based coordination compounds with benzotriazole-based ligands. We report herein the synthesis and characterization of five new coordination compounds formulated as [Cu^II(L⁴)(MeCN)₂(CF₃SO₃)₂] (1), [Cu^II(L⁵)₂(CF₃SO₃)₂] (2), [Cu^II(L⁶)₂(MeCN)(CF₃SO₃)]·(CF₃SO₃) (3), [Cu^II(L⁶)₂(H₂O)(CF₃SO₃)]·(CF₃SO₃)·2(Me₂CO) (4), and [Cu(L¹)₂(L^1')₂(CF₃SO₃)₂]₂·4(CF₃SO₃)·8(Me₂CO) (5), derived from similar nitrogen-based ligands. The homogeneous catalytic activity of these compounds along with our previously reported coordination compounds (6-13), derived from similar ligands, is tested against the well-known Cu(i)-catalysed azide-alkyne cycloaddition reaction. The optimal catalyst [Cu^II(L¹)₂(CF₃SO₃)₂] (10) activates the reaction to afford 1,4-disubstituted 1,2,3-triazoles with yields up to 98% and without requiring a reducing agent. Various control experiments are performed to optimize the method and examine parameters such as ligand variation, metal coordination geometry and environment, in order to elucidate the behaviour of the catalytic system.