Mixed-ligand Zn Research Articles

Statement of Retraction: A mixed-ligand Zn(II)-coordination polymer: local analgesia activity by reducing content of local acetylcholine.

Statement of Retraction: A mixed-ligand Zn(II)-coordination polymer: local analgesia activity by reducing content of local acetylcholine.

Pentacoordinate Mixed-Ligand Zn(II) Complexes with Flufenamato and Niflumato Ligands: Crystal Structure, Spectral Characterization and Biological Properties

Mixed-ligand complexes featuring a carboxylato ligand and bidentate chelate N,N′-donor ligands along with a single halogenido ligand are rarely subjected to studies despite their interesting physical, chemical and biological properties. A direct synthesis involving non-steroidal anti-inflammatory drugs flufenamic acid and niflumic acid and sterically hindering N,N′-donor ligands (neocuproine and 2,2′-biquinoline) has been used to prepare mononuclear mixed-ligand zinc complexes with a composition of [ZnCl(flu)(neo)] (1A and 1B) and [ZnCl(nif)(biq)] (2). Single-crystal X-ray diffraction data have shown that the carboxylate binding mode differs in the two polymorphs 1A and 1B, which form molecules of same composition, and the deviations in molecular geometry are further reflected in their supramolecular structures. The inter- and intramolecular interactions and their contributions to the stability of the crystal structures has been investigated by Hirshfeld surface analysis. The spectral properties of the prepared complexes in solid-state and solution have been analyzed. Additionally, the interaction with the biomacromolecules (fish sperm DNA, human and bovine serum albumins), studied by fluorescence assays, showed a stronger binding of 1A and 1B in comparison with 2.

New mixed-ligand Zn(ii)-based MOF as a nanocarrier platform for improved antibacterial activity of clinically approved drug levofloxacin

The advancement of metal–organic frameworks (MOFs) operating as drug delivery systems is of extensive interest as their controlled drug release and specific delivery are very propitious.

Synthesis, spectral characterization, and biological studies of Schiff bases and their mixed ligand Zn(II) complexes with heterocyclic bases

In the present study, six mononuclear Zinc(II) complexes, [Zn(L1)(6-Methyl-2,2′-bpy)] (1), [Zn(L1)(1,10-Phen)] (2), [Zn(L1)(5-Amino-1,10-Phen)] (3), [Zn(L2)(6-Methyl-2,2′-bpy)] (4), [Zn(L2)(4,4′-Di-tert-butyl-2,2′-bpy)] (5), and [Zn(L2)(1,10-Phen)] (6) formed from Schiff bases, 2-methyl-1-phenyl-1-(pyridin-2-ylmethylimino)propan-2-ol (L1) and 4-chloro-5-methyl-2-(1-(pyridin-2-ylmethylimino)ethyl)phenol (L2) were synthesized. The synthesized Schiff base ligands and metal complexes were characterized by different spectroscopic techniques such as FTIR, UV–Visible, 1H & 13C NMR spectroscopy, in addition to Powder X-ray diffraction and cyclic voltammetry. Further, the synthesized metal complexes (1–6) and their parental Schiff bases (L1, L2) were evaluated for antibacterial, antifungal, and antioxidant activities. Of those, Complex 1 was shown to have significant antibacterial activity against all of the evaluated microorganisms. Schiff base ligands, L1 and L2, complexes 1, 4, and 5 were shown to have superior antifungal activity against Aspergillus niger than the standard drug, fluconazole. In addition, the synthesized compounds achieved good antioxidant activities when compared to the standard Ascorbic acid.

From a Well-Defined Organozinc Precursor to Diverse Luminescent Coordination Polymers Based on Zn(II)-Quinolinate Building Units Interconnected by Mixed Ligand Systems.

Introduction of photoactive building blocks into mixed-ligand coordination polymers appears to be a promising way to produce new advanced luminescent materials. However, rational design and self-assembly of the multi-component supramolecular systems is challenging from both a conceptual and synthetic perspective. Here, we report exploratory studies that investigate the potential of [Zn(q)2]2[tBuZn(OH)]2 complex (q = deprotonated 8-hydroxyquinoline) as an organozinc precursor as well as a mixed-ligand synthetic strategy for the preparation of new luminescent coordination polymers (CPs). As a result we present three new 2D mixed-ligand Zn(II)-quinolinate coordination polymers which are based on various zinc quinolinate secondary building units interconnected by two different organic linker types, i.e., deprotonated 4,4′-oxybisbenzoic acid (H2obc) as a flexible dicarboxylate linker and/or selected bipyridines (bipy). Remarkably, using the title organozinc precursors in a combination with H2obc and 4,4′-bipyridine, a novel molecular zinc quinolinate building unit, [Zn4(q)6(bipy)2(obc)2], was obtained which self-assembled into a chain-type hydrogen-bonded network. The application of the organometallic precursor allowed for its direct reaction with the selected ligands at ambient temperature, avoiding the use of both solvothermal conditions and additional base reagents. In turn, the reaction involving Zn(NO3)2, as a classical inorganic precursor, in a combination with H2obc and bipy led to a novel 1D coordination polymer [Zn2(q)2(NO3)2(bipy)]. While the presence of H2obc was essential for the formation of this coordination polymer, this ditopic linker was not incorporated into the isolated product, which indicates its templating behavior. The reported compounds were characterized by single-crystal and powder X-ray diffraction, elemental analysis as well as UV-Vis and photoluminescence spectroscopy.

A mixed-ligand Zn(II)-MOF: sensitive detection of Cr(VI) ion in water and neuroprotective effect on CO poisoning patients by reducing ROS production and oxidative stress

A mixed-ligand Zn(II)-MOF: sensitive detection of Cr(VI) ion in water and neuroprotective effect on CO poisoning patients by reducing ROS production and oxidative stress

Crystal structures, luminescence, and DFT study of mixed-ligand Zn(II) and Cd(II) complexes with phenyl-containing benzimidazole derivatives with linker C[dbnd]N or N[dbnd]N group

The peculiarities of photoluminescence of zinc(II) and cadmium(II) compounds with benzimidazole derivatives L1 (1-methylbenzimidazo-2-yl-methyleneaniline) and L2 (1-ethyl-2-(4-methoxyphenyl)azobenzimidazole) containing electron-donating ligands Cl−, NO3−, or [B10H10]2– were studied. It was found that most compounds with L1 are green luminophores, while compounds with L2 are red luminophores. The intensity of the luminescence and the position of the emission band depending on the composition and structure of the complexes were analyzed. The use of the single-crystal X-ray diffraction data and the density functional theory (DFT) calculations made it possible to determine the general relationships between the structural and spectroscopic characteristics of the compounds.

RETRACTED ARTICLE: A mixed-ligand Zn(II)-coordination polymer: local analgesia activity by reducing content of local acetylcholine

We, the Editors and Publisher of the journal Inorganic and Nano-Metal Chemistry, have retracted the following article: Qian Han, Wen-Yu Yao, Hai-Jun Chen, Shui-Shui Wu & Chuan-Suo Zhang. A mixed-ligand Zn(II)-coordination polymer: local analgesia activity by reducing content of local acetylcholine, Inorganic and Nano-Metal Chemistry. 2022. Volume 52: issue number 4, 589–594, DOI: 10.1080/24701556.2021.1916756 Since publication, concerns have been raised about the integrity of the data in the article. When approached for an explanation, the authors have been unable to address the concerns raised and have not been able to provide sufficient supporting information. As verifying the validity of published work is core to the integrity of the scholarly record, we are therefore retracting the article. The corresponding author listed in this publication has been informed. The authors have agreed to retract the article. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

A mixed-ligand Zn(II)-coordination polymer: selective detection of Fe3+ ion and promotion activity on the flap transplantation via increasing the vascular endothelial cells proliferation

In the current study, on the basis of 1,3,5-tris(2-methylimidazol-1-yl)benzene (timb), a designed tripodal connector, a novel two-dimensional luminescent Zn(II)-coordination polymer whose chemical formula is {[Zn5(timb)4(OH–IPA)4]·2NO3·2DMA·2H2O}n was generated through the reaction between timb and Zn(NO3)2·6H2O in the presence of the OH functionalized isophthalic acid ligand (OH-H2IPA). Furthermore, for the Fe3+ ion, complex 1 reflects superb luminescence sensing performances in the water solution with high selectivity and high sensitivity. The assessment of its promotion activity on the flap transplantation was implemented. Meanwhile, its detailed mechanism was also studied. First of all, the detection of the proliferation activity levels on vascular endothelial cells was conducted with the Cell Counting Kit-8. Subsequently, the signaling pathway of HIPPO activation level was further detected in the vascular endothelial cells after compound treatment.

Three mixed ligand mononuclear Zn(II) complexes of 4-acyl pyrazolones: Synthesis, characterization, crystal study and anti-malarial activity

Three novel mixed ligand Zn(II) complexes {complex 1 = [Zn(L1)2(bpy)], complex 2 = [Zn(L2)2(bpy)], complex 3 = [Zn(L2)2(phen)], where bpy = 2,2′-bipyridine and phen = 1,10-phenanthroline} of 4-(4-chlorobenzoyl)-2-(3-chlorophenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one (HL1) and 4-(4-chlorobenzoyl)-5-methyl-2-(p-tolyl)-2,4-dihydro-3H-pyrazol-3-one (HL2) were synthesized and characterized by 1H and 13C NMR, FTIR, TG-DTA, UV–Vis, elemental analysis, molar conductance and single crystal X-ray structure determination. Based on analytical and spectroscopic techniques, all the three Zn(II) complexes were found to have a distorted octahedral geometry. The ligands and the complexes were screened for antimalarial activity against plasmodium falciparum. The zinc(II) complexes showed greater antimalarial activity than their parent ligands.

Zn(ii)/Cd(ii) based mixed ligand coordination polymers as fluorosensors for aqueous phase detection of hazardous pollutants

The recent developments and prospects of fluorosensors with a handful of recent examples based on mixed ligand Zn(ii)/Cd(ii) coordination polymers for aqueous phase detection of organic as well as inorganic pollutants have been discussed.

A Mixed-ligand Zn(II)-based Coordination Polymer for Selectively Detect 2,4,6-Trinitrophenol (TNP) and Treatment Effect on Periodontal Diseases via Inhibition Effect on P. gingivalis Growth.

A new difunctional Zn(II) coordination polymer (CP) with the chemical formula of [Zn(TBTA) (L)1.5]n (1) has been synthesized hydrothermally from tetrabromoterephthalic acid (H2TBTA) and 4,4'-bis(imidazole-1-yl)-biphenyl (L) ligands. Furthermore, due to its strong intense emission and open N donor sites, complex 1 could be used as a light-emitting sensor to determine 2,4,6-trinitrophenol (TNP) which has high selectivity and sensitivity. Furthermore, the anti-bacterial effect of the compound against P. gingivalis in vitro was evaluated by measuring the P. gingivalis growth curves after compound treatment. And the RT-PCR assay was performed to detect the relative expression of ragA and ragB, which are important for the P. gingivalis growth. The potential anti-infectious mechanism was further studied by using molecular docking technique.

Synthesis and characterization of mixed-ligand Zn(II) and Cu(II) complexes including polyamines and dicyano-dithiolate(2-): In vitro cytotoxic activity of Cu(II) compounds

Potentially bi-, tri- and tetra-dentate polyamines (1,3-diaminopropane (pn); diethylenetriamine (tren), tris(2-aminoethyl)amine (tetraen)) react with divalent zinc and copper nitrate salts in the presence of 1,1-dicyano-2,2-ethylenedithiolate dipotassium salt (K2i-mnt) to afford a variety of mixed ligand complexes. X-ray diffraction analysis evidences that dithiolate acts as a counter di-anion in the octahedral zinc derivative [Zn(tren)2(i-mnt)] (1), or participates directly in metal coordination in the trigonal–bipyramidal complex [Zn(tetraen)(i-mnt)] (2). Various interactions in the crystal packing of 1 and 2 are substantiated by Hirshfeld Surface analysis study. The antiproliferative activity of metal complexes has been studied toward a panel of human tumor cell lines of different histology, with different cisplatin-sensitivity, grown as 2D cultures. In addition, as cell spheroids generated from 3D cell cultures are more similar to real tumors in terms of tissue morphology, biology and gene expression, a 3D cell culture efficacy study with copper complexes across colon and non-small lung cancer cells has been performed.

Dynamic, breathing, water-stable, mixed-ligand ZnII metal–organic frameworks with differing water and vapour sorption properties

Dynamic, breathing, water-stable, mixed-ligand Zn^II metal–organic frameworks with differing water and vapour sorption properties

A Dynamic, Breathing, Water-Stable, Partially Fluorinated, Two-Periodic, Mixed-Ligand Zn(II) Metal–Organic Framework Modulated by Solvent Exchange Showing a Large Change in Cavity Size: Gas and Vapor Sorption Studies

A mixed-ligand, partially fluorinated, 2-periodic metal–organic framework [Zn(hfipbb)(bpt)]n·n(DMF)2·n(H2O) (1) has been synthesized from the unique combination of a V-shaped dicarboxylic acid ligand, H2hfipbb = 4,4′-(hexafluoroisopropylidene)bis(benzoic acid) and a bent pyridyl based colinker, bpt = 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole. This framework undergoes single-crystal-to-single-crystal solvent exchange that leads to the formation of four additional structures [Zn(hfipbb)(bpt)]n·n(EtOH)2 (2), [Zn(hfipbb)(bpt)]n·n(DCM)2·n(H2O) (3), [Zn(hfipbb)(bpt)]n·n(DMA)2·n(H2O)2 (4), and [Zn(hfipbb)(bpt)]n·n(H2O)3 (5). The solvent-induced “breathing” of the 2-periodic frameworks results in potential void spaces varying from 15.2 to 35.4%, resulting mainly from the conformational twisting and ligation angle of the bpt ligand accompanied by rotation of the carboxylate group of the hfipbb ligand causing a change from mono- to bidentate ligation. Variable-temperature powder X-ray diffraction shows that removal...

Selective and reversible adsorption of cationic dyes by mixed ligand Zn(ii) coordination polymers synthesized by reactant ratio modulation.

Dye capture and separation through coordination polymers (CPs) has been a promising research field in recent times due to the toxic and nondegradable nature of organic dyes released into the environment from various industries as well as the reusability of CPs for the said purpose. Here, we report the synthesis and characterization of two mixed ligand CPs {[Zn2(HBTC)2(L)(H2O)2](C2H5OH)3}n (CP1) and {[Zn5(BTC)2(L)3(OH)4(H2O)2](H2O)4(CH3OH)11}n (CP2) (where H3BTC = 1,3,5-benzene tricarboxylic acid and L = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene) by the stoichiometric variation of the precursors. The crystal structure analysis revealed that CP1 is a 2D network composed of a [Zn2(HBTC)2(H2O)2]n motif linked via terminal nitrogen atoms of L and CP2 is a 3D framework in which symmetrically disposed two-dimensional {[Zn5(BTC)2(L)3(OH)4(H2O)2]}n sheets composed of pentanuclear [Zn5(RCO2)6(μ3-OH)2(μ2-OH)2(H2O)2] SBUs are pillared by L ligands. Adsorption and separation of cationic dyes by CP1 and the solid-state fluorescence properties of both CPs have been investigated. Cationic dyes (RhB, MB, and MV) can be effectively adsorbed by CP1 from their aqueous solution (61%, 90%, and 97%, respectively) while the anionic dye methyl orange (MO) remains uncaptured. Dye desorption studies and CP1 as a column chromatographic filler for the separation of cationic dyes in water have also been demonstrated.

Structural Diversity in Six Mixed Ligand Zn(II) Metal–Organic Frameworks Constructed by Rigid and Flexible Dicarboxylates and Different N,N′ Donor Ligands

Three different N,N′-donor ligands with Zn(NO3)2·6H2O and two different dicarboxylates, flexible succinate (suc) and rigid fumarate (fum) afforded six different metal–organic frameworks (MOFs). Among the N,N′-donor ligands, one bent 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene (3-bpdb) gives two isostructural two-dimensional MOFs, {[Zn(3-bpdb)(suc)]·(H2O)2}n (1) and {[Zn(3-bpdb)(fum)(H2O)2]}n (2). The use of a straight N,N′-donor ligand, i.e., 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (4-bpdb), results in two three-dimensional (3D) MOFs, {[Zn4(4-bpdb)2(suc)3(OH)2]·5(H2O)}n (3) and {[Zn(4-bpdb)(fum)]·(H2O)2}n (4). Here, 3 is a pillared layer structure, whereas 4 has a 5-fold interpenetrated dimondoid network. For both the bent and straight N,N′-donor ligands an imine alike motif is embedded in the structure. When this motif is replaced by a C–C double bond by using the ligand 1,2-bis(4-pyridyl)ethylene (bpee), it produces two MOFs, {[Zn(bpee)(suc)]2·(H2O)3}n (5) and {[Zn2(bpee)2(fum)2]·(H2O)}n (6), having a...

Sonochemical synthesis and characterization of microrod to nanoparticle of new mixed-ligand zinc(II) fumarate metal-organic polymer

Micro and nano-structures of a new mixed-ligand Zn(II) fumarate metal-organic polymer, {[Zn(tptz)(fum)].DMF}n (1), (tptz=2,4,6-tris(2-pyridyl)-s-triazine, fum=fumarate, DMF=N,N-dimethylforamide), were synthesized by sonochemical method. These new micro and nano-structures were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), IR spectroscopy and elemental analyses. Compound 1 was structurally characterized by single-crystal X-ray diffraction and consists of the primary unit of [Zn(tptz)(fum)]. Self assembly between the units of [Zn(tptz)(fum)] from Zn–O bonds results in the formation of a one-dimensional zinc(II) coordination polymer. The ZnII-ion in compound 1 has ZnO2N3 coordination sphere with a trigonal bipyramidal molecular geometry. Compound 1 was synthesized by ultrasound irradiation under different concentrations and times. The microrods structure of compound 1 with increasing of concentration and ultrasound radiation time were synthesized as nanoparticles structure successfully. So ultrasound radiation change morphology from microrods to nanoparticles.

Mixed-ligand Zn(II) complexes of 1-phenyl-3-methyl-4-formylpyrazole-5-one and various aminoheterocycles: Synthesis, structure and photoluminescence properties

A series of eight adducts of aminoazoles and aminoazines of a bis-chelate Zn(II) on the basis of 1-phenyl-3-methyl-4-formylpyrazole-5-one (HL) of common formula [ZnL2(NH2Het)n] (n=1, 2) (3a–h), where NH2Het=1-aminoisoquinoline (3a), 6-aminoquinoline (3b), 3-aminoquinoline (3c), 5-amino-4,6-dimethylquinoline (3d), 2-aminopyridine (3e), 2-amino-5-bromopryridine (3f), 3-amino-5-methylisoxazole (3g), and 2-amino-1-ethylbenzimidazole (3h), were synthesized. Formulation of all compounds is based upon satisfactory C, H, N, Zn elemental analyses, IR, and 1H NMR spectrоscopies. The structure of complex 3a has been determined by X-ray single-crystal diffraction. Optical properties of zinc complexes were investigated by UV–vis and photoluminescence spectroscopy.

Catenation and encapsulation induce distinct reconstitutions within a dynamic library of mixed-ligand Zn4L6 cages.

Two new Zn4L6 cages composed of diamine subcomponents containing either naphthalene diimide (NDI) or porphyrin moieties are described. Their structural differences allow these cages to exhibit distinct interactions with different chemical stimuli, yielding different supramolecular products. The electron-poor NDI subunits of the first cage were observed to thread through electron-rich aromatic crown-ether macrocycles, forming mechanically-interlocked species up to a [3]catenane, whereas the porphyrin ligands of the second cage interacted favourably with C70, causing it to be bound as a guest. When mixed, the two cages were observed to form a dynamic combinatorial library (DCL) of seven constitutionally distinct mixed-ligand Zn4L6 cages. The DCL was observed to reconstitute in opposing ways when treated with either the crown ether or C70: the electron-rich macrocycle templated the formation of heteroleptic catenanes, whereas C70 caused the DCL to self-sort into homoleptic structures.