Tetrahedral Geometry Research Articles

Copper(II) complexes incorporated with 2,2-bipyridyl and 2,2′-(((1E,1′E)-1,4-phenylene-bis(methanylylidene))bis(azanylylidene)) diphenol derivatives: In-vitro interaction with DNA/BSA, DFT, molecular docking and cytotoxicity

Certain metal complexes have created their own benchmark in the category of cytotoxic drugs. Down the line, copper metal complexes are found among the most prominent biologically active agents of high reputation. Considering breast cancer as one of the epicenters in malignant tumors, a series of three new derivatives of copper(II) CuL1, CuL2 and CuL3 have been synthesized and characterized associated with newly developed ligands 2,2′-(((1E,1′E)-1,4-phenylene-bis(methanylylidene))bis(azanylylidene)) diphenol supported by 2,2-bipyridine. All the complexes appeared in tetracoordination with tetrahedral geometry. The complexes were made to bind with ct-DNA through groove binding as established by molecular docking and computational DFT studies carried out for the determination of the HOMO and LUMO interactions and ESP mapping. Further, confirmation of BSA binding with complexes was confirmed by UV and fluorescence spectral studies. All these copper complexes were subjected for DPPH assay to determine the antioxidant properties, cytotoxicity towards the breast adenocarcinoma was retrieved by MTT assay, dual staining and cell cycle analysis against MCF7 cell line. Eventually, new copper derivative CuL2 (IC50 = 30.20 μg/mL) was found to exhibit the highest anticancer activity as compared to CuL1 (IC50 = 41.07 μg/mL) and CuL3 (IC50 = 42.01 μg/mL).

Unveiling the mutual effects of hydroxyl and dibenzhydryl groups in α‐diimino‐nickel precatalysts for direct synthesis of polyethylene elastomers

The properties and practical applications of polyethylene are closely associated with the polymer molecular weight, polydispersity, degree of branching, and the type of branches and its arrangement within microstructure. In this study, a set of structurally diverse unsymmetrical 1‐(2,6‐dibenzhydryl‐4‐hydroxylphenylimino)‐2‐(2,6‐(R)‐4‐(R1)phenylimino)acenaphthene‐nickel dibromide precatalysts (where Ni2Me [R = Me, R1 = H], Ni2Et [R = Et, R1 = H], Ni2iPr [R = iPr, R1 = H], Ni3Me [R, R1 = Me], Ni2Et,Me [R = Et, R1 = Me]) has been prepared and studied for ethylene polymerization. Molecular structure analysis of Ni2Me and Ni2Et complexes revealed distorted tetrahedral geometries at nickel. The polymerization activities are extremely high for all precatalysts upon activation with either EASC or MMAO aluminum reagents, a trend notably pronounced in the case of the EASC‐activated systems, entering activity in the range of 10 million g mol−1 h−1 at 30°C. The Ni2Me demonstrated exceptional performance at higher temperatures, achieving an activity of 2.4 × 106 g mol−1 h−1 at 100°C and generated high molecular weight polyethylene (Mw = 105 g mol−1) with narrow polymer dispersity across all reaction temperatures (Ð ≈ 1.5). High temperature 13C NMR spectra identified 97–142/1000C branches in resulting polyethylene, a feature significantly dependent on the reaction temperature. In terms of mechanical properties, stress–strain analysis indicated that polyethylene synthesized at lower temperatures displayed superior tensile strength compared with that produced at higher reaction temperatures, while a reverse trend was observed in strain recovery analysis. The high strain recovery (up to 72%) of these polyethylene highlights the characteristic properties of thermoplastic elastomers.

Osme Bond: Geometric and Energetic Features in the Adducts between OsO4 and Lewis Bases.

Adducts between OsO4 and Lewis bases exert a role in important oxidation processes such as epoxidation and dihydroxylation. It has been shown that the attractive interaction driving the formation of these adducts is a σ-hole bond involving the metal as the electrophilic species; the term Osme Bond (OmB) was proposed for designating it. Here some new adducts between OsO4 and various bases have been characterized through single crystal x-ray diffraction (XRD) and computational studies (density functional theory, DFT), confirming the existence of a robust correlation between σ-hole interaction energy and deformation of the tetrahedral geometry of OsO4. Also, some adducts formed by RuO4 with nucleophiles were investigated computationally.

Synthesis and Investigations of the Antitumor Effects of First-Row Transition Metal(II) Complexes Supported by Two Fluorinated and Non-Fluorinated β-Diketonates.

The 3d transition metal (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)) complexes, supported by anions of sterically demanding β-diketones, 1,3-dimesitylpropane-1,3-dione (HLMes) and 1,3-bis(3,5-bis(trifluoromethyl)phenyl)-3-hydroxyprop-2-en-1-one (HLCF3), were synthesized and evaluated for their antitumor activity. To assess the biological effects of substituents on phenyl moieties, we also synthesized and investigated the analogous metal(II) complexes of the anion of the less bulky 1,3-diphenylpropane-1,3-dione (HLPh) ligand. The compounds [Cu(LCF3)2], [Cu(LMes)2] and ([Zn(LMes)2]) were characterized by X-ray crystallography. The [Cu(LCF3)2] crystallizes with an apical molecule of solvent (THF) and features a rare square pyramidal geometry at the Cu(II) center. The copper(II) and zinc(II) complexes of diketonate ligands, derived from the deprotonated 1,3-dimesitylpropane-1,3-dione (HLMes), adopt a square planar or a tetrahedral geometry at the metal, respectively. We evaluated the antitumor properties of the newly synthesized (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)) complexes against a series of human tumor cell lines derived from different solid tumors. Except for iron derivatives, cellular studies revealed noteworthy antitumor properties, even towards cancer cells endowed with poor sensitivity to the reference drug cisplatin.

Single-Crystal X-ray Structure Determination of Tris(pyrazol-1-yl)methane Triphenylphosphine Copper(I) Tetrafluoroborate, Hirshfeld Surface Analysis and DFT Calculations

The tetrafluoroborate salt of the cationic Cu(I) complex [Cu(CHpz3)(PPh3)]+, where CHpz3 is the tridentate N-donor ligand tris(pyrazol-1-yl)methane and PPh3 is triphenylphosphine, was synthesized through a displacement reaction on the acetonitrile complex [Cu(NCCH3)4][BF4]. The compound crystallizes in the monoclinic P21/c space group. The single-crystal X-ray diffraction revealed that the copper(I) centre is tetracoordinated, with a disposition of the donor atoms surrounding the metal centre quite far from the ideal tetrahedral geometry, as confirmed by continuous shape measures and by the τ4 parameter. The intermolecular interactions at the solid state were investigated through the Hirshfeld surface analysis, which highlighted the presence of several non-classical hydrogen bonds involving the tetrafluoroborate anion. The electronic structure of the crystal was modelled using plane-wave DFT methods. The computed band gap is around 2.8 eV and separates a metal-centred valence band from a ligand-centred conduction band. NMR spectroscopy indicated the fluxional behaviour of the complex in CDCl3 solution. The geometry of the compound in the presence of chloroform as implicit solvent was simulated by means of DFT calculations, together with possible mechanisms related to the fluxionality. The reversible dissociation of one of the pyrazole rings from the Cu(I) coordination sphere resulted in an accessible process.

Direct Experimental Observation of the Tetrabromine Cluster Br4 by Synchrotron Photoionization Mass Spectrometry.

We present a first spectroscopic characterization of the homoatomic polyhalogen tetrabromine, Br4, in the gas phase. Photolysis of CHBr3 at 248 nm is used to generate atomic bromine radicals in a flow tube reactor. Resulting combination products are detected by photoionization mass spectrometry at the Advanced Light Source of the Lawrence Berkeley National Laboratory. Interpretation of the experimental mass spectra is informed by calculated adiabatic ionization energies carried out at the CCSD(T)/aug-cc-pVTZ//M06-2X/aug-cc-pVTZ and CCSD(T)/aug-cc-pVTZ//cam-B3LYP/6-311++g** levels of theory. Tunable VUV synchrotron radiation enables the collection of the mass-selected photoionization spectra by which Br4 is assigned using Franck-Condon simulations of a Br2 dimer with a stretched tetrahedral geometry.

Pyrrole βC-B-N Fused Porphyrins: Molecular Structures and Opto-Electrochemical Studies.

Herein, we report the design, synthesis, structure, and electrochemical study of doubly βC-B-N fused Ni(II) porphyrins (1-trans, 1-cis, 2-trans, and 2-cis). These compounds have been synthesized from A2B2 type dipyridyl Ni(II) porphyrins (Ar=Ph for 1 a; Ar=C6F5 for 2 a) via Lewis base-directed electrophilic aromatic borylation reactions. The solution state structures of these compounds have been established using 1H NMR, 11B NMR, 1H-1H COSY, 1H-13C HSQC, and 19F-13C HSQC NMR techniques. Single crystal X-ray analysis have revealed that 1-trans, 1-cis, and 2-trans adopt ruffled conformations, with alternate meso-carbons on the opposite sides of the mean porphyrin plane. The Soret bands in the absorption spectra of the B-N fused molecules are ~40 nm redshifted compared to unfused Ni(II) porphyrin precursors. The B-N fusion have diminished the redox potential of fused porphyrins. Although 1-trans and 1-cis, show four oxidation processes, 2-trans and 2-cis show only three oxidation processes. DFT studies have revealed that the tetrahedral geometry of the boron has induced a twist in the π-conjugation, which destabilizes the HOMO and stabilizes the LUMO in 1-trans, 1-cis, 2-trans, and 2-cis.

Synthesis and Characterization of Complex Compounds of Cadmium (II) Nitrate, Potassium Thiocyanate, and 2,2-Bipyridine Ligand

A complex compound of a central atom of cadmium(II), potassium thiocyanate, and a 2,2'-bipy ligand with a stoichiometric ratio of 1:2:2 has never been reported. The aim of this research is to determine the coordination pattern of the 2,2'-bipy ligand and thiocyanate ion and the stability of the compounds formed. Synthesis of complex compounds was carried out using the direct reaction method, characterization of the complex compounds produced using the melting point test, FTIR analysis, SEM-EDX analysis, DHL test, thiocyanate ion qualitative test, and Gaussian 09W analysis. This synthesis produces a block-shaped colorless complex compound with a melting point of 159-161°C and has a distorted tetrahedral geometry around the central cadmium(II) atom and a free energy of -740 kJ/mol and a free energy per bond of -25 kJ/ mol.

Inducing Ferrimagnetic Exchange in 1D-FeSe2 Chains Using Heteroleptic Amine Complexes: [Fe(en)(tren)][FeSe2]2.

[Fe(en)(tren)][FeSe2]2 (en = ethylenediamine, C2H8N2, tren = tris(2-aminoethyl)amine, C6H18N4) has been synthesized by a mixed-ligand solvothermal method. Its crystal structure contains heteroleptic [Fe(en)(tren)]2+ complexes with distorted octahedral coordination, incorporated between 1D-FeSe2 chains composed of edge-sharing FeSe4 tetrahedra. The twisted octahedral coordination environment of the Fe-amine complex leads to partial dimerization of Fe-Fe distances in the FeSe2 chains so that the FeSe4 polyhedra deviate strongly from the regular tetrahedral geometry. 57Fe Mössbauer spectroscopy reveals oxidation states of +3 for the Fechain atoms and +2 for the Fecomplex atoms. The close proximity of Fe atoms in the chains promotes ferromagnetic nearest neighbor interactions, as indicated by a positive Weiss constant, θ = +53.8(6) K, derived from the Curie-Weiss fitting. Magnetometry and heat capacity reveal two consecutive magnetic transitions below 10 K. DFT calculations suggest that the ordering observed at 4 K is due to antiferromagnetic intrachain interactions in the 1D-FeSe2 chains. The combination of two different ligands creates an asymmetric coordination environment that induces changes in the structure of the Fe-Se fragments. This synthetic strategy opens new ways to explore the effects of ligand field strength on the structure of both Fe-amine complexes and surrounding Fe-Se chains.

Guanine Metal Complexes: Spectroscopic Studies, Dying Performance and as Indicator

Azo dyes are the most common and widely used dyes, accounting for more than half of each year's dyes. In this work, a complete description of a new innovative series of compounds with the elements [Ag (I), Zn (II)] generated from the guanine azo dye ligand (GAB) 8-[1-(3-carboxy) azo] guanine has been studied. The structural formula was studied using several physicochemical analyses and spectroscopic techniques (FT-IR spectra, UV-Vis). The FTIR spectrum of the ligand (GAB) was compared to the spectra of the metal ion complexes formed to determine its identity. Chelating caused some changes in the spectra of the complexes to appear to demonstrate that they could be linked to the ligand. The complexes have a tetrahedral geometry shape, the ligand functions as a bidentate ligand, and thermogravimetric analysis (TGA) is used to measure the thermal stability of compounds. The findings and equation presented by the analytical data seemed to be in good accord with the conclusions of the thermogravimetric investigation, which demonstrated that the disintegration of the ligand (GAB) and its complexes occur in multiple steps. The configuration that follows weakens thermal stability: GAB(35.52%)>[Ag(GAB)(H2O)2]NO3.2H2O(34.6%)>[Zn(GAB)Cl2].H2O(31.54%), and the complexes have tetrahedral geometry shape. Furthermore, elemental analysis, mole ratio, and the mole ratio of each complex (1:1) (M:L). The ligand was effective as an acid-base indicator when the pH changed; they exhibited a striking color change, similar to how the ligand (GAB) and its complexes can be used to dye wool textiles due to their wide range of colors. It investigated how well the ligand (GAB) and its complex worked as a wool dye. The ligand GAB and its metal complexes were used to color most of the protein filaments in wool fiber, which have a complex structure with amino and carboxyl groups and colors ranging from orange to green.

Microwave-assisted synthesis of Schiff base metal complexes: Biological, photocatalytic activity and fabrication of their metal oxide nanoparticles

Three transition metal complexes of the type [M(ABzC)(H2O)(CH3COO)] denoted as M-ABzC where M = Cu(II), Ni(II) & Zn(II), and ABzC = 3-((5‑chloro-2-hydroxybenzylidene)amino)benzoic acid; were synthesized under microwave irradiation and characterized by using spectroscopic methods, including 1H & 13CNMR, UV–vis, FTIR, and EI-MS. All the synthesized compounds were optimized using the DFT approach. The ligand-to-metal coordination was established by spectroscopic and DFT analyses, which suggest that ligand coordinated through O, N donor atoms. According to the electronic and DFT optimized data, Zn(II) complex showed distorted tetrahedral geometry, whereas geometry of Ni(II) and Cu(II) complexes is square planar. The complexes were calcined at 560 °C to obtain the metal oxide nanoparticles (CuO, NiO, and ZnO). XRD, HR-TEM, SEM, EDX, and UV–vis spectrophotometer were used to characterize the nanoparticles. The DNA interaction activity of the synthesized complexes were performed using electronic absorption and fluorescence spectroscopy. The complexes displayed effective intercalative binding mode with CT-DNA having a binding constant in the range 105 M−1. Based on the antioxidant activity data, it can be inferred that Ni(II) and Cu(II) complexes have better activity than Zn(II) complex. Photodegradation experiment of metal complexes and oxide nanoparticles were performed without hydrogen peroxide using crystal violet dye as model pollutant in aqueous solution under sun light. The results established that the highest degradation was achieved with ZnO, which is 95.5 %. Further, the enzyme structures of B-DNA and 1HD2 have been used in molecular docking simulations to determine the potential binding energies of inhibitors.

Crystal structure of poly[hexa-μ-bromido-bis{2-[1-(pyridin-2-yl)ethylideneamino]ethanolato}tetracopper(II)

The reaction of the Schiff base 2-[1-(pyridin-2-yl)ethylideneamino]ethanol (HL), which is formed by reaction of 2-aminoethanol and 2-acetylpyridine with CuBr2 in ethanol results in the isolation of the new polymeric complex poly[hexa-μ-bromido-bis{2-[1-(pyridin-2-yl)ethylideneamino]ethanolato}tetracopper(II)], [Cu4Br6(C9H11N2O)2] n or [Cu4Br6 L 2] n . The asymmetric unit of the crystal structure of the polymeric [Cu4Br6 L 2] n complex is composed by four copper (II) cations, two monodeprotonated molecules of the ligand, and six bromide anions, which act as bridges. The ligand molecules act in a tridentate fashion through their azomethine nitrogen atoms, their pyridine nitrogen atoms, and their alcoholate O atoms. The crystal structure shows two types of geometries in the coordination polyhedrons around Cu2+ ions. Two copper cations are situated in a square-based pyramidal environment, while the two other copper cations adopt a tetrahedral geometry. Bromides anions acting as bridges between two metal ions connect the units, resulting in a tetranuclear polymer compound.

Perfluoroalkyl-Decorated Noble-Metal-Free MOFs for the Highly Efficient One-Pot Four-Component Coupling between Aldehydes, Amines, Alkynes, and Flue Gas CO2.

The non-noble-metal catalysed-multicomponent reactions between flue gas CO2 and cheap industrial raw stocks into high value-added fine chemicals is a promising manner for the ideal CO2 utilization route. To achieve this, the key fundamental challenge is the rational development of highly efficient and facile reaction pathway while establishing compatible catalytic system. Herein, through the stepwise solvent-assisted linker installation, post-synthetic fluorination and metalation, we report the construction of a series of perfluoroalkyl-decorated noble-metal-free metal-organic frameworks (MOFs) PCN-(BPY-CuI)-(TPDC-Fx ) [BPY=2,2'-bipyridine-5,5'-dicarboxylate, TPDC-NH2 =2'-amino-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid] that can catalyze the one-pot four-component reaction between alkyne, aldehyde, amine and flue gas CO2 for the preparation of 2-oxazolidinones. Such assembly endows the MOFs with superhydrophobic microenvironment, superior water resistance and highly stable catalytic site, leading to 21 times higher turnover numbers than that of homogeneous counterparts. Mechanism investigation implied that the substrates can be efficiently enriched by the MOF wall and then the adsorbed amine species act as an extrinsic binding site towards dilute CO2 through their strong preferential formation to carbamate acid. Moreover, density functional theory calculations suggest the tetrahedral geometry of Cu in MOF offers special resistance towards amine poisoning, thus maintaining its high efficiency during the catalytic process.

Perfluoroalkyl‐Decorated Noble‐Metal‐Free MOFs for the Highly Efficient One‐Pot Four‐Component Coupling between Aldehydes, Amines, Alkynes, and Flue Gas CO2

AbstractThe non‐noble‐metal catalysed‐multicomponent reactions between flue gas CO2 and cheap industrial raw stocks into high value‐added fine chemicals is a promising manner for the ideal CO2 utilization route. To achieve this, the key fundamental challenge is the rational development of highly efficient and facile reaction pathway while establishing compatible catalytic system. Herein, through the stepwise solvent‐assisted linker installation, post‐synthetic fluorination and metalation, we report the construction of a series of perfluoroalkyl‐decorated noble‐metal‐free metal–organic frameworks (MOFs) PCN‐(BPY‐CuI)‐(TPDC‐Fx) [BPY=2,2′‐bipyridine‐5,5′‐dicarboxylate, TPDC‐NH2=2′‐amino‐[1,1′:4′,1′′‐terphenyl]‐4,4′′‐dicarboxylic acid] that can catalyze the one‐pot four‐component reaction between alkyne, aldehyde, amine and flue gas CO2 for the preparation of 2‐oxazolidinones. Such assembly endows the MOFs with superhydrophobic microenvironment, superior water resistance and highly stable catalytic site, leading to 21 times higher turnover numbers than that of homogeneous counterparts. Mechanism investigation implied that the substrates can be efficiently enriched by the MOF wall and then the adsorbed amine species act as an extrinsic binding site towards dilute CO2 through their strong preferential formation to carbamate acid. Moreover, density functional theory calculations suggest the tetrahedral geometry of Cu in MOF offers special resistance towards amine poisoning, thus maintaining its high efficiency during the catalytic process.

SYNTHESIS, CRYSTAL STRUCTURE, OPTICAL AND ANTIMICROBIAL PROPERTIES OF 2-NITROBENZYL TRIPHENYLPHOSPHONIUM TETRABROMOCOBALTATE(II)

A novel organic-inorganic hybrid multifunctional crystalline material, 2-nitrobenzyl triphenylphosphonium tetrabromocobaltate(II) [2-NO2BzTPP]2[CoBr4](1), has been synthesized using [2-NO2BzTPP]Br and CoBr2 in methanol solution acidified with hydrobromic acid and characterized using single-crystal X-ray diffraction and spectroscopic techniques. The single-crystal X-ray diffraction analysis showed that the hybrid [2-NO2BzTPP]2[CoBr4](1) belongs to the triclinic space group P–1 with a = 11.1815(17) Å, b = 12.954(2) Å, c = 19.426(3) Å, α = 99.312(5)°, β = 100.654(5)°, γ = 113.746(5)°, V = 2442.3(7) Å3, Z = 2, which consists of two [2-NO2BzTPP]+ cations and a [CoBr4]2– anion. The Co(II) ion in the [CoBr4]2– anion is coordinated to four Br– ions and has a tetrahedral geometry. The C–H···O hydrogen bonds, O···π and O···Br interactions in the crystal can favor crystal stacking and stabilization. The bulk phase purity, homogeneity, and morphology of the desired compound are checked using powder XRD, and SEM-EDX analysis. The hybrid crystal showed an emission peak near 468 nm at room temperature under the excitation of UV light at 241 nm. The low energy gap (2.85 eV) indicated that the crystal was a semiconductor suitable for optical applications. Furthermore, the compound exhibited good bactericidal activity against E. coli and S. aureus.

Structurally diverse zinc(II) complexes containing tripodal tetradentate phenoxido-amines with promising antiproliferative effects.

Structurally diverse zinc(II) complexes with tripodal tetradentate phenolic-amines of variable substituents in the phenol and amine moieties were synthesized and thoroughly characterized. The two dinuclear [Zn2(L1)2](ClO4)2·MeOH (1), [Zn2(L2)2](ClO4)2 (2), and four mononuclear [Zn(L3)(H2O)]·MeOH (3), [Zn(L4)] (4), [Zn(L5)] (5) and [Zn(L6)] (6) complexes revealed distorted octahedral, trigonal-bipyramidal or tetrahedral geometries. The free HL1 and H2L3-6 ligands, and complexes 1-6 were evaluated for in vitro cytotoxicity against human cancer cell lines (A2780, A2780R, PC-3 and 22Rv1) and normal healthy MRC-5 cells. Overall results revealed high-to-moderate cytotoxicity (with the best IC50 values for complex 6 ranging from 2.4 to 4.5 μM), which is however, significantly higher than that of the reference drug cisplatin. The moderately active complexes 1-4 showed considerable selectivity on A2780 cells (IC50 ≈ 16.3-19.5 μM) over MRC-5 ones (with IC50 >50 μM for 1, 2 and 4, and with IC50 >25 μM for 3). The complexes 1, 2, and 6 and the ligand H2L6 were chosen for subsequent deeper biological evaluations. Their time-resolved cellular uptake and other cellular effects in A2780 cells were studied, such as cell cycle profile, intracellular ROS production, induction of apoptosis and activation of caspases 3/7. Complexes 1 and 2 caused significant G0/G1 cell cycle arrest in A2780 cells and antioxidant effects at normal conditions. They showed only limited effects on cellular processes connected with cytotoxicity, i.e. induction of apoptosis, depletion of mitochondrial membrane potential, and autophagy. These findings can be at least partly attributed to the low ability of the complexes to enter the A2780 cells and the depression of metabolic activity of the target cancer cells.

Synthesis and anion recognition characteristics of a trapezoidal benzene cage

A novel trapezoidal cage was exclusively prepared and exhibits high binding affinity for anions with tetrahedral geometry and alkaline features.

SYNTHESIS AND CHARACTERIZATION OF Mn+2 , Co+2 , Ni+2 , Cu+2 AND Zn+2 COMPLEXES WITH 4-(2-(BENZO-1,3-DIOXOL-5-YL)-4,5-DIPHENYL-2,5- DIHYDRO-1H-IMIDAZOL-1-YL)ANILINE AND EVALUATION OF THEIR BIOLOGICAL ACTIVITY

The aim of this work was to create new ligand complexes and evaluate their effectiveness against certain strains of bacteria. A Brucker Tensor 27co FTIR spectrophotometer was used to record the infrared spectra. Elemental analysis (C, H, N) was carried out on an AA670 atomic absorption spectrophotometer to determine mineral content, and the conductivity of PCM3 Jenway was measured to record electronic spectra. The ligand was prepared, that possessed physical constants and spectroscopic properties. The complexes [M(L)2Cl2] and [M(L)4Cl2] were also prepared, where M=Mn(II), Co(II), Ni(II), Cu(II), and Zn(II), which were synthesized by direct reaction of the above ligand with metal chlorides in (2:1) or (4:1) (Ligand : metal) molar ratio in the ethanol medium. The ligand compound 4-(2-(benzo-1,3-dioxol-5-yl)-4,5-diphenyl-2,5-dihydro1H-imidazol-1-yl)aniline (L) was obtained. The prepared complexes were shown by elemental analysis, spectroscopic studies (FTIR, UV/vis), 1H-NMR measurement, conductivity measurements, and electron spectrometry value, which indicate the presence of tetrahedral and octahedral geometry around the metal ions. The biological antibacterial activity of the compounds and complexes has been demonstrated against specific strains of G+ Staph. aureus and G− Bacillus. The bonding compound L coordinates the metal in a tetrahedral and octahedral N-M-N manner. The compound and its complexes had activity against specific strains of bacteria. The ligand (L1) and the complex (3) had a greater effect on different types of bacteria than the rest of the complexes, which had a lower efficiency rate.

Zinc and cadmium thioamidate complexes: rational design of single-source precursors for the AACVD of ZnS.

A series of zinc(II) thioamidate complexes [Zn{SC(iPr)NR}2]n for R = iPr (n = 2) (2), tBu (3) (n = 1), Ph (4) (n = 2) and Cy (5) (n = 2) and one cadmium(II) thioamidate complex [Cd{SC(iPr)NtBu}2]3, (6), were designed and synthesised as single-source precursors for AACVD ZnS and CdS. Solid-state structures of all four zinc(II) compounds revealed distorted tetrahedral or trigonal bipyramidal geometries, with varying tendencies for dimeric association, mediated by {Zn-S} bridging bonds. The thermogravimetric analysis identified the {tBu} derivertive, 3, as the most promising precursor based on its low decomposition onset (118 °C) and clean conversion to ZnS. This was attributed to the greater availability of β-hydrogen atoms promoting the pyrolysis mechanism. The corresponding cadmium thioamide 6 was found to crystallise as a trimetallic molecule which lacked the thermal stability to be considered viable for AACVD. Hence, 3 was used to deposit ZnS thin films by AACVD at 200-300 °C. Powder X-ray diffraction confirmed phase-pure growth of hexagonal wurtzite ZnS, with approximate crystallite sizes of 15-20 nm. Scanning electron microscopy revealed densely packed spherical nanoclusters. The morphology and crystallinity were most consistent for depositions between 250-300 °C. Energy dispersive X-ray spectroscopy indicated slightly sulfur-deficient stoichiometries.

Crystal structure and Hirshfeld surface analysis of 2-picolyllithium·3thf.

In the title compound, (2-methyl-idene-1,2-di-hydro-pyridinium-κN)tris-(tetra-hydro-furan-κO)lithium, [Li(C6H6N)(C4H8O)3], the lithium ion adopts a distorted LiNO3 tetra-hedral coordination geometry and the 2-picolyl anion adopts its enamido form with the lithium ion lying close to the plane of the pyridine ring. A methyl-ene group of one of the thf ligands is disordered over two orientations. In the crystal, a weak C-H⋯O inter-action generates inversion dimers. A Hirshfeld surface analysis shows that H⋯H contacts dominate the packing (86%) followed by O⋯H/H⋯O and C⋯H/H⋯C contacts, which contribute 3% and 10.4%, respectively.