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The employment of the hexyl-substituted anion [HexCB11 Cl11 ]- allowed the synthesis of a ZnII species, Zn[HexCB11 Cl11 ]2 , 3, in which the Zn2+ cation is only weakly coordinated to two carborate counterions and that is soluble in low polarity organic solvents such as bromobenzene. DOSY NMR studies show the facile displacement of at least one of the counterions, and this near nakedness of the cation results in high catalytic activity in the hydrosilylation of 1-hexene and 1-methyl-1cyclohexene. Fluoride ion affinity (FIA) calculations reveal a solution Lewis acidity of 3 (FIA=262.1 kJ mol-1 ) that is higher than that of the landmark Lewis acid B(C6 F5 )3 (FIA=220.5 kJ mol-1 ). This high Lewis acidity leads to a high activity in catalytic CO2 and Ph2 CO reduction by Et3 SiH and hydrogenation of 1,1-diphenylethylene using 1,4-cyclohexadiene as the hydrogen source. Compound 3 was characterized by multinuclear NMR spectroscopy, mass spectrometry, single crystal X-ray diffraction, and DFT studies.

Aggregation-induced emission (AIE) compounds display a photophysical phenomenon in which the aggregate state exhibits stronger emission than the isolated units. The common term of “AIEgens” was coined to describe compounds undergoing the AIE effect. Due to the recent interest in AIEgens, the search for novel hybrid organic–inorganic compounds with unique luminescence properties in the aggregate phase is a relevant goal. In this perspective, the abundant, inexpensive, and nontoxic d10 zinc cation offers unique opportunities for building AIE active fluorophores, sensing probes, and bioimaging tools. Considering the novelty of the topic, relevant examples collected in the last 5 years (2016–2021) through scientific production can be considered fully representative of the state-of-the-art. Starting from the simple phenomenological approach and considering different typological and chemical units and structures, we focused on zinc-based AIEgens offering synthetic novelty, research completeness, and relevant applications. A special section was devoted to Zn(II)-based AIEgens for living cell imaging as the novel technological frontier in biology and medicine.

This work aims to study the impact of zinc cation and 2-mercaptobenzoxzole (MBO) on the corrosion protection of a silane sol-gel coating on mild steel. First, effectiveness of the organic and inorganic inhibitors on the corrosion of bare mild steel in a NaCl solution was shown to be linked to formation of a surface film. Using electrochemical data as well as results of surface analysis, a sharp inhibition synergism was found when an equal mole percentage of ZnCl 2 and MBO was added to the NaCl solution. Finally, electrochemical data indicated superior performance of the coating with the combination of inhibitors.

International audience; Numerous adsorbent materials are developed and are able to face specific types of pollution, but none of them can manage the whole pollution. The purpose of this work is to develop a novel hybrid adsorbent, based on chitosan (CS) biopolymer, clay minerals and activated carbon (AC), having complementary adsorption properties and achieving a wide-spectrum water decontamination in a single treatment. Hybrid CS beads, containing dispersed clay and AC, were prepared from dispersions of solid adsorbents in a CS solution and its further coagulation in a basic medium. The porosity and the homogeneity of the hybrid beads were characterized by N 2 adsorption at 77 K and Cryo-Scanning Electron Microscopy respectively. The interaction between CS and clay was characterized using X-ray diffraction. Water content and the amount of each adsorbent in the hydrogel beads were determined by thermogravimetric analysis. Such a composite material was still porous and presented a wide adsorption spectrum. As shown by their adsorption kinetics, hydrophobic anionic clofibric acid (CBA) and cationic metoprolol (MTP) were well adsorbed on AC containing beads (21 and 26 mg/g), respectively. Clays containing beads showed interesting adsorption properties towards cationic Zn 2+ and MTP. The obtained composite beads were able to adsorb all the pollutant types: Zinc cations, and hydrophobic-charged organic molecules, such as pharmaceutical derivatives (clofibric acid and MTP).

A new imidazolium macrocycle based on tetraphenylethylene (TPE) has been synthesized. This positively charged macrocycle showed a typical aggregation-induced emission (AIE) effect but fluorescence emission could not be induced by common inorganic anions in aqueous solution, including pyrophosphate bearing four negative charges. However, in the presence of a half equivalent of zinc(II) ions, the addition of pyrophosphate anions could arouse a strong fluorescence while other common inorganic anions gave almost no response. The macrocycle has an inherent cavity with the correct size for binding a pyrophosphate anion, so that the pyrophosphate anion can be easily aggregated together with the macrocycle and a zinc cation, which selectively triggers a turn-on fluorescence.

International audience; We report the solid-state structure of an unexpected trinuclear zinc dimeric porphyrin complex resulting of zinc insertion into a single strap porphyrin. The latter bears an overhanging carboxylic acid which usually interacts with metal cations either in out-of-plane (OOP) or in hanging-atop (HAT) coordination mode by changing its location above the porphyrin coordination site. However, in the present studies, the overhanging carboxylic group acts as a bidentate ligand and binds the OOP-bound zinc cation together with another zinc cation bridging two porphyrin units.

Direct voltammetric determination of oxytetracycline (OTC) at a zinc cation-exchanged montmorillonite modified glassy carbon electrode (Zn-Mt/GCE) was described. The OTC yielded one well-defined oxidation peak at the Zn-Mt/GCE. The experimental parameters, which influence the voltammetric responses of OTC, e.g., the pH value, scan rate and accumulation condition, were optimized. The oxidation peak current changed with the OTC concentration over the range from 0.80 to 40 μM. The detection limit was 0.12 μM for an accumulation time of 4 min. The coefficient of variation, determined at 10 μM OTC, was 3.4% (n = 10). Using this method, OTC in the real food and feedstuff samples was determined.

Basic properties of bis[5-(3-oxyphenyl)-2,8,12,18-tetrabutyl-3,7,13,17-tetramethylporphyrinyl]-3,6,9-trioxyundecane-1,11 and bis[5-(3-oxyphenyl)-2,8,12,18-tetrabutyl-3,7,13,17-tetramethylporphyrinyl]-3,6,9,12-tetraoxytetradecane-1,14 were studied spectrophotometrically in an ethanol-sulfuric acid system; the influence of the basicity of the inner cycle nitrogen atom on the complexation properties of these polyethylene oxide-substituted porphyrins towards zinc cation in ethanol was considered.

A new 3D porous zinc phosphonate, Zn6(HL)4 · 6H2O 1 (H4L = C6H11N(CH2PO3H2)2) has been synthesized by hydrothermal reaction at 180 °C and structurally characterized by X-ray diffraction as well as by infrared spectroscopy, elemental and thermogravimetric analysis. The structure of compound 1 features a 3D open-framework built from ZnO4 tetrahedra linked together by bridging phosphonate groups. Each zinc cation is tetrahedrally coordinated by four phosphonate oxygen atoms from four ligands, each of which connects with six zinc atoms, resulting in channel systems of different size.

This Perspective starts with the discussion of the properties of an interesting metalloenzyme (carbonic anhydrase, CA) that performs extremely successfully the activation of carbon dioxide. Conclusions from that are important for many synthetic procedures and include experimental and theoretical investigation (DFT calculations) of such metal mediated processes in the condensed and in the gas phase in which the zinc cation plays a dominant role. This is extended to the bio-analogue activation of further heterocumulenes such as COS, an important atmospheric trace gas, and CS(2). Novel metal complexes which serve as useful catalysts for the reactions (copolymerisations and cyclisation) of CO(2) and oxiranes are discussed subject to the inclusion of recently published DFT calculations. We continue with the discussion of the very general aspect of the insertion of CO(2) into metal-nitrogen bonds (formation of carbamates). This again is closely related to many biological or bio-analogue processes. We describe the synthesis and mechanistic aspects of characteristic metal carbamates of a wide variety of metals and include a discussion of the mechanistic aspects, especially for the formation of Mg(2+) and Li(+) carbamates and the formation of related cyclic products after addition of the heterocumulenes CO(2), Ph-NCO or CS(2) to novel ligands, the 4H-pyridin-1-ides which finally result in the formation of e.g. 1,3-thiazole-5(2H)-thiones.

The synthesis of four new tetraamido-type p-tert-butylcalix[4]arenes presenting two proximal binding subunits is reported. Complexation of alkalimetals and zinc picrates with these ligands have been carried out and monitored by 1H-NMR inCDCl3. It is shown that hard cations are included in the tetraamido cavity while thezinc cation is chelated to the pyridine rings of one of the ligands. The formation of a 1:1:1heterobinuclear complex is also described

1,1-Diacetates were produced from a variety of aromatic aldehydes using Zn-montmorillonite as a catalyst. The procedure generally resulted in good yields (98%) of aromatic aldehydes including those carrying electron donating- or withdrawing substituents. The great advantage of the application of Zn-montmorillonite catalyst is that the reaction takes place under mild conditions. In addition, the zinc cation exchanged form of montmorillonite has a minimal environmental impact.

The structure of the title complex, [ZnCl2(C11H9N3)2], comprises two 2-(phenyldiazenyl)pyridine ligands coordinating to a central ZnIIdichloride unitviathe pyridyl N-atom donors, resulting in a slightly distorted tetrahedral geometry. The complex exhibits twofold rotation symmetry, with the rotation axis bisecting the zinc cation. The structure is stabilized by weak intermolecular C—H...Cl interactions [C...Cl = 3.411 (2) and 3.675 (2) Å], connecting neighbouring molecules into layers perpendicular to thecaxis.

Energies and structures of six different isomers resulted of complex between glycylglycine dipeptide and zinc cation were calculated at the BLYP and B3LYP levels of theory with 6-311G** and 6-311++G** basis sets. The energies of the glycylglycine-Zn2+different complexes at the BLYP/6-311++G** obtained more stable than another methods. In this method, the most stable complex was zinc cation bound to the two oxygen sites of the glycylglycine zwitterion and acted as a bidentate ligand. The vibrational frequencies, thermodynamic and electronic properties, HOMO, LUMO, and energy gap for the most stable isomer in different solvents were calculated at the BLYP/6-311++G** level of theory.

Di-aza-benzo crown etherp-tert-butyl calix[4]arene (1) has been prepared by hydrogenating the already known Schiff-base precursor (2). The metal ion complexing ability of (1) toward zinc cation is presented. The formation of a 2:1 (Zn: (1) complex and the location of zinc cations were deduced from1H-NMR investigations.

The asymmetric unit of the title compound, [Zn(NCS)(2)(C(6)H(7)N)(2)], consists of one Zn(2+) cation and two thio-cyanate anions, all situated on special positions with site symmetry .m., and one 3-methyl-pyridine ligand. The zinc cation is coordinated by four N atoms of two terminal N-bonded thio-cyanate anions and of two symmetry-related 3-methyl-pyridine co-ligands, defining a slightly distorted tetra-hedral coordination polyhedron.

In diacetato-O,O',-O-(2,9-dimethyl-1,10-phenanthroline-N,N')zinc(II), [Zn(C 2 H 3 O 2 ) 2 (C 14 H 12 N 2 )], the zinc cation has a pentacoordinated environment consisting of the two N atoms of 2,9-dimethyl-1,10-phenanthroline, one O atom from a monodentate acetate group and two O atoms from a bidentate acetate group.

In the crystal structure of the title compound, [Zn(H2O)6](C(6)H(2)N(3)O(7))2.3H2O, the zinc cation complexes and picrate anions are stacked separately, extending along the b axis. No picrate species ligate to the metal cation. This lack of picrate coordination is atypical among metal picrate salts. We speculate that the size of the metal-aqua complex as related to the intermolecular distance of the picrate anions in the pi stack can be a measure of the formation of such separated stacks in the crystal structures of divalent metal complexes with picrate anions. Picrate ions are linked to each other with short intermolecular C...C contacts of 3.223 (6) and 3.194 (6) A in the stack.

In the title complex, [Zn(C7H4NO3S)2(C8H22N4)]·H2O or [Zn(sac)2(paen)]·H2O [sac = saccharinate and paen = N,N′-bis(3-aminopropyl)ethylenediamine], the zinc cation is octahedrally coordinated. The equatorial plane of the octahedron is formed by N atoms of the paen ligand, whereas the axial positions are occupied by the carbonyl O atoms of the two sac ligands. One of the sulfonyl groups of the sac ligands shows disorder and was modelled with two different orientations and site occupancies of 0:38 (1):0.62 (1). The molecular packing is stabilized by intermolecular O—H...O and N—H...O hydrogen bonds between water molecules and neighbouring [Zn(sac)2(paen)] molecules, which form chains running parallel to [010]. The crystal used was an inversion twin.

A simple determination of cyclopiazonic acid by HPLC is elucidated. The zinc cation in the mobile phase and indomethacin as an internal standard made quantitation higher and peak identification of cyclopiazonic acid easier. In the combination with a TLC analysis, production of cyclopiazonic acid by some species of aspergilli could be analyzed both in a liquid culture and in a solid culture on wheat bran without a prior clean-up operation.

2-(3,5,6-Trifluoro-2-hydroxy-4-methoxyphenyl)benzoxazole (3) and benzothiazole analogue (4) are prepared by the two-step procedures from the corresponding 2-(pentafluorophenyl)benzazoles. Benzoxazole 3 is applicable to a fluorescent probe sensing magnesium cation, and 4 is suitable for sensing zinc cation. Both fluorophores 3 and 4 are sensitive to the pH change at pH 7−8, resulting in large fluorescence enhancement under basic conditions. Their high sensitivity to pH and selectivity in metal cations are ascribed to the high acidity of the fluorophenol moiety.

The title compound, [Zn(NO3)(C8H8N2O)2]NO3·H2O, consists of a tris-chelated zinc cation and a nitrate anion, along with an uncoordinated water mol­ecule. These inter­act through O—H⋯O and N—H⋯O hydrogen bonds, giving rise to a three-dimensional network structure. The ZnII ion has an octa­hedral coordination.

The title compound, [Zn(C8H4N4O2)]n, is a coordination polymer prepared by the hydro­thermal reaction of zinc chloride and 3-(1H-tetrazol-5-yl)­benzoic acid. The zinc cation is tetrahedrally coordinated by two N atoms and two O atoms from four ligands, resulting in a three-dimensional framework encapsulating one-dimensional channels.

The asymmetric unit of the title compound, [Zn(NCSe)(2)(C(4)H(4)N(2))(2)](n), consists of one Zn(2+) cation located on a special position with site symmetry 2/m, one seleno-cyanate anion on a mirror plane and one pyrimidine ligand on a twofold rotation axis. The zinc cation is coordinated by six N atoms of four pyrimidine ligands and two N-bonded seleno-cyanate anions in mutually trans orientations within a slightly distorted octa-hedral coordination environment. The Zn atoms are μ-1,3-bridged via the pyrimidine ligands into a polymeric layer extending parallel to (100).

Elastomere de masse moleculaire 8000 neutralise avec: Ca 2+ , Sr 2+ , Ni 2+ , Zn 2+ et Cd 2+

Bei der ionotropen Gelbildung von anionischen Cellulosederivaten wurde Ionenspezifitat und Synergismus von Pb-, La-, Tl- und Zn-Kationen auf die Kapillarbildung bei gleichzeitiger Anwesenheit von zwei verschiendenen, auf unterschiedliche Gegenionen ansprechende anionische Gruppen (Carboxymethyl- und Xanthogenatgruppen) an der gleichen Polymerkette untersucht. Dabei wurde das System des doppelanionischen Polyelektrolyten mit der Mischung aus Carboxymethylcellulose und Cellulosexanthogenat verglichen. Die mittels Licht- und Elektronenmikroskopie erhaltenen Ergebnisse zur Morphologie werden mitgeteilt und interpretiert. The ion specifity and the synergism of Pb, La, T1 and Zn cations in the capillar formation in presence of two different anionic groups (carboxymethyl and xanthate groups), responding to different counter ions, at the same polymer chain have been investigated. The double-ionic polyelect,rolyte was compared with the mixture of carboxymethyl cellulose and cellulose xanthate. The optical and electron microscopic results with respect to the morphology of these gel structures are presented and interpreted.

Theoretical ab initio pseudopotential SCF computations performed on a model of the Glu 106 – Thr 199 – water H-bonded chain, free and bound to the zinc cation at the active site of carbonic anhydrase show that whereas the Glu – Thr – water form of the unbound chain is stable, the same chain, when bound to zinc, is more stable in the Glu - Thr - OH form, and the proton-relay process to that form occurs with no barrier.