IR Studies Research Articles

CHARACTERISTICS OF THE BINDING BETWEEN THE ENZYME PREPARATION RAPHANUS SATIVUS L. AND NATURAL LAYERED ALUMOSILICA IN THE PRESENCE OF IRON OXIDES

IR and X-ray analyses of bentonite modified with magnetite and enzyme established the dependence of enzyme immobilization on the presence of iron oxides. IR studies have proven that the binding of the enzyme to the carrier is adsorption in nature without stable chemical interactions. This type of binding does not significantly affect the change in the structure of the enzyme module. Characte­ristic bands of vibrations of amide groups of proteins were detected at 1637 cm-1 ( ν-vibrations of C=O bonds (amide I)), 713 cm-1 (δ – vibrations of O=C-N in the plane (amide IV)), which can participate in the sorption binding of the enzyme to bentonite and the SiO2 group, which is characterized by a weak connection of the outer part of protein with the formation of a surface structure, which disappears over time due to the diffusion of molecules into the pores of the mineral. Comparison of the basal distances in the samples established the following dependence: 12.43 Å bentonite+ Fe3O4+enz (48 h) > 12.38; Å natural bentoni­te> 12.31; Å bentonite+ Fe3O4+enz (2 hours) > 11.91; Å bentonite+ Fe3O4 , which indicates a high probability of iron compounds entering the interlayer space due to the hydrolysis of magnetite with the formation of Fe-(OH)n bonds and unstable compounds. According to the research results, a scheme of the interaction of the enzyme with modified layered iron aluminosilicate is proposed: 1 – transport of the enzyme to the surface (phase distribution boundaries); 2 – deformation of the enzyme under the action of the surface as a result of a polycondensation reaction with the formation of water molecules; 3 – entry of water molecules into the interlayer space; 4 – hydrolysis of magnetite particles; 5 – extraction of iron hydroxide from the interlayer space due to the formation of aggregates with an enzyme molecule that has a related adsorption center.

Design, development, and evaluation of docetaxel-loaded niosomes for the treatment of breast cancer

BackgroundDocetaxel (DTX) has been used to treat numerous types of cancers. Poor solubility, lower bioavailability, and serious side effects limit its use in cancer treatment. The objective of the present research work was to develop DTX-loaded niosomes to overcome these issues and investigate the anticancer effect on breast cancer. Niosomes of DTX were prepared and evaluated to estimate particle size, surface potential, morphology by TEM, %EE, in vitro drug release, %hemolysis, in vitro cytotoxicity, and stability. The cytotoxicity effect of plain DTX and DTX-loaded niosomes was performed on MCF-7 cell lines.ResultsThe mean particle size, zeta potential, and %EE of DTX-loaded niosomes were 244.9 nm, − 7.1 mV, and 97.43%, respectively. Besides, combining the DTX with polymers enhanced drug loading capacity. The TEM images confirmed spherical-shaped niosomes. The IR, DSC, and P-XRD studies indicate no chemical interaction between drug and excipients. The developed DTX niosomes showed a sustained release behavior and lower in vitro cytotoxicity when compared to plain DTX.ConclusionThe current research work demonstrates the suitability of co-loading of DTX in niosomes as a promising approach to enhance the efficiency of DTX.Graphical

Copper(II), Cobalt(II), Nickel(II) And Zinc(II) Complexes Obtained From Dipicolinic Acid And Morpholine: Synthesis, Characterization, Biological Evaluation And In Silico Studies

With morpholinium counter ion a set of new complexes of Copper(II), Cobalt(II), Nickel(II) and Zinc(II) ions were synthesized and characterized. UV-visible, IR, powder XRD and thermal studies have been utilized to characterize the synthesized complexes. The structures of the complexes were optimized using DFT studies and screened for their antioxidant and anti-inflammatory activities. The results of In vitro antioxidant and anti-inflammatory activity studies indicated the appreciable biological activity of the synthesized complexes. All the synthesized complexes exhibited very good stability under physiological conditions for 72 h. Molecular docking studies performed with cyclooxygenase enzymes (COX-1 and COX-2) revealed the significant interaction between the complexes and the enzymes through many hydrogen bonds with very good binding energies.

Hierarchical mesoporous spherical Zn(4-hzba) MOF for efficient adsorption of Strontium and Caesium ions from aqueous solution

This paper describes the synthesis of mesoporous spherical Zn(4-hzba) MOF with the formula of {[Zn(μ-4-hzba)2]2}n utilizing 4-hydrazinyl benzoic acid (4-hzba) linker by solvothermal method. And investigates its adsorptive efficiency towards strontium (Sr2+) and caesium (Cs+) by varying contact time, pH, and feed solution concentration. 10 mg of Zn(4-hzba) MOF show maximum adsorption capacity of 275.2 mg/g for Sr2+ and 335.05 for Cs+ at pH 4 from a 100 mg/L sample solution within 100 min at room temperature. Among the Langmuir, Freundlich and Temkin adsorption isotherms studies, the Langmuir isotherm was well fitted for Sr2+ and Cs+ adsorption onto MOF, demonstrating the monolayer adsorption. Experimental data and pseudo-second-order kinetic studies showed that chemisorption is the dominant process. High adsorption efficiency was demonstrated by electrostatic interaction between positively charged Sr2+/Cs+ and the negatively charged surface of the MOF at pH 4 was proved by zeta potential analysis. IR, SEM, XPS analysis and Langmuir adsorption studies support the monolayer surface complexation mechanism. While the ion exchange mechanism followed by surface complexation of Sr2+/ Cs+ with replacement of hydrogen in H2NNH- of the MOF. In order to acquire a good picture of the ion exchange mechanism, and Sr2+/Cs+ exchanged MOF were optimized, and the binding energies of Sr2+ (2.19 kJ/mol) and MOF Cs+ (2.06 kJ/mol) were calculated by DFT method using Gaussian 16. Recycle studies of Zn(4-hzba) MOF show 80% recovery of Sr2+ and Cs+ even after seven cycles. The adsorption of Sr2+ and Cs+ was influenced by dosage, initial concentration of metal ions, pH solution, contact time, and coexisting ions of Na, K, Ca, and Mg. Adsorption efficiency of Sr2+ and Cs+ ions in simulated seawater was 92.3% and 96.7%, respectively.

PHYSICAL AND CHEMICAL PROPERTIES OF BLEACHING CLAY

The paper presents the study results of physicochemical properties of used (fatty) bleaching clay after using it at an oil extraction plant to purify vegetable oil from colored substances. In the studies X-ray phase, IK-spectral, granulometric, electron microscopic analyzes were used. The original and fattened heat-treated at 300 °C and 350 °C сlay was studied. It was revealed that the studied clay is monomineral with a predominance of the montmorillonite component and quartz is present as an impurity. Laser granulometric analysis of the studied clay samples showed that the bleaching clay particles in their bulk have a size not exceeding 100-200 μm and a porous highly developed surface. The specific surface area (Ssp) determined by the BET method on a TriStar II 3020 unit manufactured by Micromeritics (US) is 32 m2/g. Studies of the bleaching clay sorption properties showed that the sorption capacity determined under static conditions for the original clay by Ni2+ ions is 0.25 mmol/g. And for the fired clay it is 0.428 mmol/g, which is 1.7 times higher compared to the original clay. This, apparently, can be explained by an increase in the specific surface area and porosity during heat treatment. Analysis of micrographs obtained using a high-resolution scanning electron microscope TESCAN MIRA3 LMU (Czech Republic) showed that the bleaching clay structure consists of a porous inert material, and its porosity and roughness increase as a result of heat treatment. The IR study of clay samples has shown that during the heat treatment of used greased bleached clay, its structural features change: the destruction of triglycerides of fatty acids and other organic compounds present in the oil after bleaching occurs. For citation: Sverguzova S.V., Shaikhiev I.G., Sapronova Zh.A., Lupandina N.S., Voronina Yu.S., Gafarov R.R. Physical and chemical properties of bleaching clay. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 6. P. 76-84. DOI: 10.6060/ivkkt.20236606.6780.

Absorption dominant electromagnetic interference shielding in the novel polypyrrole-CaCu3Ti4O12-CoFe2O4 nanocomposites

Polypyrrole-CaCu3Ti4O12-CoFe2O4 (PPy-CCTO-CFO) nanocomposites have been synthesized by in-situ chemical oxidative polymerization. Nanocomposites consisting of pyrrole monomer: CCTO: CFO by weight as 1:0.5:0, 1:0.5:0.1, 1:0.5:0.3 is nominated as PC5F0, PC5F1 and PC5F3 nanocomposites respectively. IR and XRD studies confirmed the incorporation of CCTO and CFO in polypyrrole matrix. Surface morphology exhibits the cup like structure resulting from the interfacial interaction. The PC5F3 nanocomposite shows absorption dominant total shielding effectiveness ∼30 dB (corresponds to 99% attenuation of microwave) which consists shielding effectiveness by absorption SEÃ 22 dB along with least reflection ∼ 8 dB. The absorption efficiency for PC5F3 nanocomposite is ∼99%. The enhanced absorption efficiency and shielding effectiveness of PC5F3 nanocomposite is attributed to the synergistic role of dielectric and magnetic losses, losses due to free charges in interfacial layer, interfacial polarization and wedge effect.

Organic and Hybrid Diode Features of an n-Type 1,8-Naphthalimide Derivative

Organic–inorganic hybrid photodiodes have garnered research interest to achieve high-performance optoelectronic devices with longer lifetime. In the present study, a fluorescent 1,8-naphthalimide (NI) derivative BHSHNI was synthesized through bromination of 3-hydroxy naphthalic anhydride and subsequent imidation reaction with salicyloyl hydrazide. The IR, NMR and mass spectrometry studies confirmed the molecular structure of the NI derivative. Intramolecular charge transfer was confirmed using theoretical and fluorescence emission studies. Thermal investigations suggested good stability of BHSHNI and cyclic voltammetry indicated an electrochemical band gap of 1.10 eV. Surface uniformity and pit-free morphology was observed in SEM and AFM images of thin films formed by BHSHNI. The organic (PEDOT:PSS) and hybrid (organic–inorganic) p–n type diodes were successfully constructed using BHSHNI. The hybrid diode exhibited better features with ideality factors of 9.3 and 15.2 in dark and visible light, respectively, with a dielectric constant of 7.65 at 30 kHz. The calculated responsivity of the hybrid diode was found to be 66.26 mu mathrm{A}/mathrm{W}. The device incorporating BHSHNI as functional material with NiO can be further explored for photodiode applications.Graphical

Activation Cross Section Measurement of the (n,2n) Reaction on 203Tl at 16.4 MeV, 18.9 MeV and Theoretical Calculations via the EMPIRE code

The aim of the present work was to study the cross-section of the (n,2n) and (n,3n) reactions on 203Tl, by irradiating a natural TlCl pellet target with monoenergetic neutron beams at 16.4, and 18.9 MeV. The cross section measurements were carried out using the activation method, with respect to the 197Au(n,2n)196Au and 27Al(n,α)24Na reference reactions. The monoenergetic neutron beams were generated in the 5.5 MV Tandem accelerator of NCSR “Demokritos”, using the 3H(d,n)4He reaction. Monte Carlo simulations have been performed to take into account the gamma-ray self-absorption results as well as the estimation of the neutron flux through the reference foils. Theoretical calculations with the code EMPIRE have also been performed, using the same parameterization implemented in the theoretical study of Ir and Au nuclei in an attempt to find a suitable model for the description of all the experimental results in this mass region.

Simultaneous Activation of Carbon Dioxide and Epoxides to Produce Cyclic Carbonates by Cross‐linked Epoxy Resin Organocatalysts

AbstractThe development of efficient bifunctional organocatalysts for the catalytic conversion of CO2under mild conditions remains particularly challenging. Inspired by the synergistic mechanism of intramolecular Lewis acid‐base active sites, we report a series of bifunctional cross‐linked epoxy resin organocatalysts containing multiple active sites for the cycloaddition reaction of dilute CO2with epoxides. These catalysts exhibit high reactivity and product selectivity (10 examples, >99 %) for the cycloaddition reactions of a variety of epoxides and CO2, and surprisingly, epichlorohydrin (ECH), can be converted under ambient temperature and pressure (25 °C, 1.0 bar) without co‐catalysts.1H NMR,13C NMR,19F NMR and in situ IR studies suggest that the simultaneous and efficient activation of CO2and epoxides is responsible for the improved catalytic activity. Upon an insightful investigation of the catalytic mechanism, this protocol will contribute to the development of efficient and environmentally friendly metal‐free catalysts.

New phenylisoxazole derivatives: Synthesis, spectroscopic, X-ray, IR, DFT calculation and biological activity studies

A series of new phenylisoxazole derivatives were successfully designed and synthesized for developing antitumor compounds. The final compounds were characterized through 1HNMR , 13CNMR , and HRMS. Moreover, (Z)-2-(5-((3-(4-bromophenyl)isoxazole-4-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)-N-cyclopentylacetamide (5a) was confirmed by FT-IR and X-ray single crystal diffraction (XRD). The density functional theory (DFT) calculation of compound 5a was carried out at the B3LYP/6–311 level. The calculated parameters were in good agreement with the real experimental structures. The frontier molecular orbitals (FMO) and the molecular electrostatic potential (MEP) of compound 5a were also calculated and discussed. In addition, the antitumor activity of the ten compounds was evaluated by MTT assay against A549 cell.

Hydrogen Bonding with Hydridic Hydrogen–Experimental Low-Temperature IR and Computational Study: Is a Revised Definition of Hydrogen Bonding Appropriate?

Spectroscopic characteristics of Me3Si-H···Y complexes (Y = ICF3, BrCN, and HCN) containing a hydridic hydrogen were determined experimentally by low-temperature IR experiments based on the direct spectral measurement of supersonically expanded intermediates on a cold substrate or by the technique of argon-matrix isolation as well as computationally at harmonic and one-dimensional anharmonic levels. The computations were based on DFT-D, MP2, MP2-F12, and CCSD(T)-F12 levels using various extended AO basis sets. The formation of all complexes related to the redshift of the Si-H stretching frequency upon complex formation was accompanied by an increase in its intensity. Similar results were obtained for another 10 electron acceptors of different types, positive σ-, π-, and p-holes and cations. The formation of HBe-H···Y complexes, studied only computationally and again containing a hydridic hydrogen, was characterized by the blueshift of the Be-H stretching frequency upon complexation accompanied by an increase in its intensity. The spectral shifts and stabilization energies obtained for all presently studied hydridic H-bonded complexes were comparable to those in protonic H-bonded complexes, which has prompted us to propose a modification of the existing IUPAC definition of H-bonding that covers, besides the classical protonic form, the non-classical hydridic and dihydrogen forms.

Thione-thiol tautomerism in new 4-methyl-3-nitopyridine derivative in the solid state – X-ray, electron absorption and emission, IR and Raman studies discussed in term of quantum chemical DFT calculations

Theoretical and experimental studies of new 4-methyl-3-nitropyridine-2-thione and its thiol tautomer were synthesized and characterized by means of structural and spectroscopic studies. X-ray diffraction, IR, Raman, UV–VIS and emission spectra were measured and analyzed. The quantum chemical DFT calculations were applied in the analysis of the obtained results. The effect of the temperature change on the structural and spectroscopic properties was studied. The vibrational characteristics and dynamical properties of the ϕ-S-H and ϕ=S type compounds are discussed where ϕ is a heterocyclic ring. The results of structural and spectroscopic studies were used to find a diagnostic tool on the structure of thione and tiol forms and their optic properties.

Synthesis of water-soluble novel bioactive pyridine-based azo coumarin derivative and competitive cytotoxicity, DNA binding, BSA binding study, and in silico analysis with coumarin

The diazo coupliling reaction of 3- amino pyridine with coumarin in water medium produces water soluble 6-[3-pyridyl]azocoumarin. The synthesised compound has been fully charecterised by IR, NMR, and Mass spectroscopy. The frontier molecular orbital calculations reveal that 6-[3-pyridyl]azocoumarin is more biologically and chemically active in comparison to coumarin. The cytotoxicity evaluation confirms that 6-[3-pyridyl]azocoumarin is more active than coumarin against human brain glioblastoma cell lines, LN-229 with IC50 value 9.09 μM (IC50 value for coumarin is 9.9 μM). The compound (I) has been synthesized by coupling of diazotized solution of 3-aminopyridine with coumarin in an aqueous medium at ∼ pH 10. The structure of the compound (I) has been characterized using UV–vis, IR, NMR, and Mass spectral studies. Frontier molecular orbital calculations reveal that 6-[3-pyridyl]azocoumarin (I) is more active chemically and biologically in comparison to coumarin. IC50 value 9.09 and 9.9 μM of 6-[3-pyridyl]azocoumarin and coumarin respectively obtained in cytotoxicity evaluation confirms the enhanced activity of the synthesized compound against human brain glioblastoma cell lines, LN-229. The synthesized compound also shows strong binding interactions with DNA and BSA in comparison with coumarin. The DNA binding study shows groove binding interaction of the synthesized compound with CT-DNA. The nature of interaction, binding parameters and structural variations of BSA in the presence of the synthesized compound and coumarin have been evaluated using several usefull spectroscopy approaches such as UV –Vis, time resolved and stady state flurescence. The molecular docking interaction has been carried out to justify the experimental binding interaction with DNA and BSA.

The Reactions of Orthodox Churches to Russia’s Aggression towards Ukraine in the Light of the Postsecular Approach to IR Studies

Russia’s war against Ukraine, in which the aggressor has been making use of religion, including theological rhetoric, to achieve its aims, has sparked reactions from Orthodox Churches all over the world. This has led to a revitalisation of social teaching, including discussions on war and peace within the Orthodox tradition. This may well become a further impetus for more in-depth research on religion and international relations, and possibly for more reappraisals of the secular identity of IR studies. An analysis of the attitudes of Orthodox Churches towards this war indicated that the authority of the Russian Orthodox Church, which considers itself the most important centre of Orthodox culture and civilisation, is waning. The reaction of other local churches showed that it is difficult to recognise the Russian Orthodox Church as such an authority. These revaluations may have a significant impact on Russia’s place in the new international order, although much depends on the final outcome of the war it has started. We explain the different reactions of the churches, and we refer to the social teaching(s) on war of the Russian Church and the Ecumenical Patriarchate according to their official synodal documents. In this teaching, we can see two different approaches—Russian and Constantinopolitan. In the world of the Orthodox tradition, the former, whose practical expression was the atrocities committed during the ongoing war, seems to be rejected in favour of the latter, Constantinople. Finally, there is the question of how the reaction of the Orthodox Churches (analysed below), which have clashed with secularism in a different manner than the Western Churches, might contribute to the development of a postsecular awareness and, consequently, a postsecular identity for IR studies.

Interplay between Catalyst Complexes and Dormant States: In Situ Spectroscopic Investigations on a Catalyst System for Alkene Hydroformylation

Results from a detailed in situ IR and NMR spectroscopic study on a monophosphite-modified rhodium catalyst system are presented. Equilibria that occur between the catalytically active hydrido rhodium(I) complexes and formally inactive dinuclear rhodium(0) complexes as well as mononuclear ortho-metalated rhodium(I) complexes have been investigated. The latter can be considered as “dormant states”, which are formed at conditions with lower hydrogen pressures or [H2]/[Rh] ratios. It was found that dimer formation is dominant at lower temperatures and higher rhodium concentrations, whereas ligand metalation is effective at higher temperatures. At the appropriate partial pressure of hydrogen, the regeneration of hydrido rhodium(I) complexes takes place on a short time scale from both states. Especially, the temporary stabilization of the catalyst via ligand metalation during a catalyst recycling procedure represents a feasible approach.

Synthesis, Computational and Pharmacological Evaluation of 7-(2-(2- (3- (Substituted Phenyl) Acryloyl) Phenoxy) Ethoxy)-4-Methyl-2H-Chromen- 2-Ones as CNS Agents.

Motivated by the exciting biological potential for the use of hybrid molecules in medicine and therapy. It is anticipated that the coumarin-chalcone hybrids for skeletal muscle and antianxiety action will be investigated using a chemical hybridization technique. Due to its numerous benefits, including high effectiveness, mode of action at receptors, minimal adverse effects, and improved pharmacokinetic features, naturally occurring and synthesized hybrid compounds are prospective sources for novel drug development techniques. In opinion of these applications, we here designed some coumarin-chalcone hybrids and explored them for skeletal muscle and antianxiety potential. Using a chemical hybridization strategy, coumarin-chalcone hybrids have been synthesized and evaluated for skeletal muscle and antianxiety activity. The target compounds were synthesized by reaction of 7-hydroxy-4-methylcoumarion with haloalkane to afford 7-(2- bromoethoxy)-4-methyl-2H-chromen-2-one which was further treated with hydroxychalcones. The structures of target compounds were confirmed on the basis of their Melting Point, Thin Layer Chromatography, IR, 1HNMR and Mass studies. The computational properties of target compounds were also determined through online software. Skeletal muscle and antianxiety potential were performed in Swiss albino mice. The coumarin-chalcones hybrids showed skeletal muscle and antianxiety potential in Swiss albino mice and computational properties of the target compounds were also showed similarity as compared with diazepam. Among the target compounds, the fluoro group containing compound was found to be more potent as compared to the standard drug diazepam.

Hepatoprotective activity of Tridecan-1-ol isolatedfrom Flaveria trinervia (Speng). C. Mohr

Background- Flaveria trinervia (Asteraceae), a medicinal herb has been used in Indian traditionl medicine to cure jaundice. Reports on phytochemical and pharmacological investigations are very scarce. A phytoconstiuent Tridecan-1-ol and screened for hepatoprotective activity. -To evaluate hepatoprotective effects of Tridecan-1-ol against CCl4 induced hepatic damage on Wister albino rats. Methods- Tridecan-1-ol was isolated from petroleum extract of Flaveria trinervia using silica gel column chromatography and the structure was confirmed by IR, MASS,and 1H NMR spectroscopic studies. The parameters employed to confirm the hepatoprotectivity were the estimation of liver function serum markers such as total bilirubin, total protein, alanine transaminase, aspartate transaminase, alkaline phosphatase activities and the histological profile of the liver tissue. Results-The LD50 of petroleum ether extract and the constituent Tridecan -1-ol was found to be 500 and 150 mg/kg body weight respectively. Tridecan -1-ol showed significant hepatoprotective activity than the crude extract and it was compared with the standard hepatoprotective drug silymarin. The histological profile of the liver tissue ofTridecan-1-ol administered rats showed the presence of normal hepatic cords, absence of necrosis and fatty infiltration as similar to the controls. Conclusion-Tridecan-1-ol afforded significant hepatoprotectivity against CCl4 induced liver damage and supported the traditional claim of Flaveria trinervia as a hepatoprotective herb.

N-Heterocyclic carbene: thiazolylidene–Cu(I) complexes: microwave-assisted synthesis and use as catalyst in A3 reaction

A simple method involving microwave-assisted reaction of 3-benzylthiazolium/benzothiazolium bromides with cuprous oxide has been developed for the synthesis of four new N-heterocyclic carbene (NHC): thiazolylidene/benzothiazolylidene–Cu(I) complexes. Structures of the complexes could be established on the basis of the IR, 1H, and 13C NMR studies and elemental analysis. A representative NHC:benzothiazolylidene–Cu(I) complex was used as catalyst for the microwave-assisted A3 reaction of phenylacetylene with a secondary amine and aldehyde to obtain new substituted propargylamines in excellent yields. A theoretical investigation of the model A3 reaction at the DFT level reveals initial coordination of the alkyne with the NHC–Cu(I) complex followed by its attack on the iminium ion generated from the reaction of secondary amine with aldehyde. In the presence of the catalyst, the activation free energy barrier (ΔG#) is lowered by ca. 3 kcal mol−1.

Synthesis, characterization, DFT, docking, antimicrobial and thermal study of pyrimidine - carbonitrile ligand and its metal complexes

Elements, molar conductivity, IR, electronic absorption, magnetic susceptibility, and thermal decomposition data were used to describe single-core pyrimidine-carbonitrile complexes of the type [M(L)2(H2O)2]Cl2. (M = Co(II), Ni(II), Mn(II), Zn(II), Cu(II)and Cd(II)) and [Fe(L)2(H2O)2]Cl3. Elemental analyses, IR, 1HNMR , and mass spectral study were used to establish the identification and purity of the synthesized pyrimidine ligand (L). The DFT-B3LYP computational approach was used to conduct a theoretical analysis of (L) to support experimental findings. According to X-ray powder diffraction, the Fe(III) complex is amorphous, but the Cu(II), Co(II), Ni(II), and Mn(II) complexes also contain crystalline phases. Through molecular docking studies, it revealed good docking in the minor groove of the DNA of the Gram-negative bacteria (E. coli (3t88) and 5i39—P. aeruginosa), the Gram-positive bacteria (3ty7—S. aureus), and the fungi (C. albicans (1M78) receptors. When tested against multi-stranded microorganisms such as Gram-positive bacteria (Staphylococcus aureus and Staphylococcus mutans), Gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa), and fungal species (Candida albicans and Aspergillusniger), the ligand and its metal complexes were found to have very good potency for their antibacterial and antifungal activity.

Synthesis, Crystal Structures and Urease Inhibition of Zinc Complexes Derived from 4-Chloro-2-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol.

Three new zinc(II) complexes, [Zn3(μ2-η1:η1-OAc)2(μ2-η2:η0-OAc)2L2] (1), [Zn3(μ2-η1:η1-OAc)2(μ1,1-N3)(N3)L2] (2), [Zn2(μ1,3-N3)(N3)(H2O)L2] (3), with the Schiff base ligand 4-chloro-2-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol (HL) have been synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopic studies. Crystal structures of the complexes were confirmed by single crystal X-ray diffraction. Complex 1 is a bidentate acetato, monoatomic bridging acetato, and phenolato co-bridged trinuclear zinc compound. The Zn atoms are in octahedral and square pyramidal coordination. Complex 2 is a bidentate acetato, end-on azido, and phenolato co-bridged trinuclear zinc compound. The Zn atoms are in trigonal bipyramidal and square pyramidal coordination. Complex 3 is an end-to-end azido bridged dinuclear zinc compound. The Zn atoms are in square pyramidal and trigonal bipyramidal coordination. The Schiff base ligands in the complexes coordinate to the Zn atoms through the phenolate oxygen, imino nitrogen and pyrrolidine nitrogen. The complexes have interesting inhibitory activity on Jack bean urease, with IC50 values of 7.1-15.3 μmol·L-1.