5^th International Conference on Organic and Inorganic Chemistry July 12-13, 2018 Paris, France
Venue: Holiday Inn Paris Marne La Vallee

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Dumitrela Cucu is a PhD student at Alexandru Ioan Cuza University of Iasi, under the supervision of Prof. Ionel Mangalagiu.

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Don Coltart obtained his Master’s degree from the University of Manitoba under the supervision of Professor James L. Charlton, and he then joined the research group of Professor Derrick L. J. Clive at the University of Alberta where he obtained his Ph.D.  His postdoctoral work was conducted at the Memorial Sloan-Kettering Cancer Center as an NSERC, AHFMR, and CRI Scholar under the supervision of Professor Samuel J. Danishefsky.  Don began his independent career at Duke University in 2004 and moved to the University of Houston in 2012 where he is an associate professor.  His research group studies the development of methods for asymmetric carbon–carbon bond formation, the application of those methods to the total synthesis of structurally complex biologically active natural products, and the study of those compounds in biological systems.

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Nitrogen heterocycles are among the most important structural motifs found in natural products, drugs, and related compounds.  While many nitrogen-containing natural products contain chiral nitrogen heterocycles, relatively few drugs do despite being chiral themselves.  In the latter case, this limitation is due in large part to a lack of reliable, effective, and broadly applicable methods for the preparation of such heterocycles.  However, as drug development moves away from the use of unsaturated (flat), structurally simple achiral compounds and seeks out more stereochemically sophisticated chiral compounds having higher degrees of saturation, the need for methods for the synthesis of chiral nitrogen/oxygen heterocycles has become increasingly important.  In response to this, we have undertaken a research program aimed at the use of dipolar 3-hetero-functionalized azoalkenes for the synthesis of various saturated and partially saturated chiral nitrogen/oxygen heterocycles via novel annulation strategies.  In this seminar, we will describe a variety of methods that we have been developed for the preparation of different 3-hetero-functionalized azoalkenes and their use in dipolar coupling reactions leading to a range of chiral nitrogen/oxygen heterocycles.

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Yuichi Shimazaki was born in 1970 in Toyama prefecture, Japan. He received his Doctor’s degree in science from Nagoya University in 2000 under the supervision of Professor Osamu Yamauchi.  He joined Professor Yoshinori Naruta’s group at Kyushu University as Assistant Professor and worked on the redox behavior of various metal porphyrin complexes as models of the active site of metalloenzymes.  In 2008 he was promoted to Associate Professor at the College of Science, Ibaraki University.  His research interests include the oxidation chemistry of the complexes of various metal ions, model studies of metalloenzymes, bioorganometallic chemistry, and weak interactions in metal-organic molecule systems.

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Chemistry of redox active transition metal complexes with pro-radical ligands and their detailed electronic structures have been actively pursued in recent years. An “experimental” valence state in metal complexes is sometime different from the “formal” oxidation state, especially in the species having redox active ligands. This difference can be also seen in biological system, such as iron(IV)-porphyrin p-cation radical in some heme proteins and copper(II)-phenoxyl radical in galactose oxidase (GO). Many efforts for determination of the experimental oxidation number have been close to the goal of the “truth oxidation state” in various oxidized metal complexes with redox-active ligands. Depending on the relative energies of the redox-active orbitals, metal complexes with the redox active ligands exist in two limiting descriptions, either a metal-ligand radical (Mⁿ⁺(L^·)) or a high valent metal (M⁽ⁿ⁺¹⁾⁺(L^-)) complex. The reaction mechanisms of artificial and biological catalysts depend on the electronic structures of the high valent intermediates. However, geometric and electronic structural characterizations of the high valent species have been rare due to their stability. Recently, some artificial metal−phenoxyl radical complexes as models of GO have been synthesized and successfully characterized by X-ray crystal structure. The one-electron oxidized metal-phenolate complexes showed various electronic structures depending on small perturbations, such as substitution of the phenolate ring and the chelate effect of the phenolate ligands and so on.

In this presentation, I will focus on X-ray crystal structures of the one- and two-electron oxidized metal(II)–phenolate complexes  (Ni(II), Pd(II), Pt(II) and Cu(II)) with Schiff base ligands of 2N2O donor sets. Especially electronic and geometric structure relationship such as differences of metal-phenoxyl radical and high-valent metal phenolate complexes, and the effect of different oxidation locus of the radical electron on the ligands in oxidized forms will be discussed.

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Richard Wong received his Ph.D. degree from Australian National University in 1989. Subsequently, he held postdoctoral position at IBM Kingston and Yale University. Currently, he is a full professor and head of department at the National University of Singapore. He was the recipient of Fukui Award recently on his outstanding work in theoretical and computational chemistry. Richard has published about 200 scientific publications, which received over 9300 citations and H-index of 43. His research interests include application of computational quantum chemistry to a range of chemical problems, include reactive intermediates, catalysis, materials design, chemical sensors, and weak intermolecular interactions. He is an international advisory board member of Asian Journal of Chemistry, Journal of Analytical and Applied Pyrolysis and Advanced Theory and Simulations.

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Halogen bond, a noncovalent interaction involving a halogen atom as an acceptor of electron density, has emerged in recent years as an important element of molecular recognition and has numerous applications such as molecular self-assembly of functional materials and protein-drug interaction. Due to its bond strength and directionality, halogen bonding has great potential to become a complementary molecular tool to hydrogen bonding in rational catalyst design. Using density functional calculations, we have shown the use of halogen-bond donors as noncovalent activators in Lewis acid catalysis. In particular, we have proposed a new type of triaryl benzene organocatalysts via multiple halogen bond donors (e.g. perfluoro-iodophenyl group). This in silico designed halogen bonding (XB) based catalyst was applied to several important types of organic reaction, namely Diels-Alder reaction, Claisen rearrangement and cope-type hydroamination. The calculated catalytic mechanisms and activation barriers of these reactions readily demonstrate that the designed system is a promising Lewis acid catalyst via halogen bond mode of activation.^[1] On the basis of our DFT calculations and calculated turnover frequencies, the XB-catalyzed reactions are found to be competitive with the corresponding hydrogen bonding catalysis reported in literature. The calculated transition states unravel multiple halogen bonds between the iodine atoms and various types of halogen bond acceptors (lone pair, p and s bonds). These cooperative non-covalent interactions provide efficient binding between the catalyst and substrate (~15 kcal/mol binding energy) and are the key factors for transition-state stabilization and molecular recognition.

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The research project of this work may be summarized in the synthesis, spectroscopic characterizations and electrochemical behavior of the tetradentate copper (II)-Schiff base complex^[1] with its two wings as ferrocenylaniline moieties^[2]. This new ferrocenic derivative with two ferrocenylaniline entities surrounding the copper (II)-Salen complex (5) was synthesized from N-ferrocenmethyl-N-phenyl-5-aminomethyl-2-hydroxyacetophenone (3) and one half equivalent of 1,2-diaminoethane in absolute ethanol. As for the intermediates involved in this synthetic sequence, the compound (3) was prepared in tetrahydrofuran (THF) by reacting N-ferrocenmethylaniline (2) with 5-chloromethyl-2-hydroxyacetophenone^[3] (1) in presence of sodium hydrogenocarbonate (NaHCO3). The compound (3) condensed on the diamine yields the Schiff base ligand^[4] (4)  which reacts with copper acetate monohydrate yielding the tetradentate Cu(II)-Schiff base complex (5). Their purities were estimated from elemental analysis while the molecular structures were elucidated with FT-IR, UV–Vis, ¹H- and ¹³C- NMR. The electrochemical behaviors of the synthesized compounds were investigated using cyclic voltammetry in diverse solvents like dichloromethane (DC), acetonitrile (AN), dimethylformamide (DMF) and dimethylsulfoxide (DMSO). The anilinic entity grafted on these compounds may be modulated by using other electropolymerizable units as pyrrole,  thiophene and carbazole etc.

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Leishmanisis is a parasitic disease which affects over one million people worldwide. It is transmited by certain types of sandflies and is closely associated with poverty. The most common form of the disease is the cutaneous Leishmaniasis. Current treatments, including pentamidine and imidazoquinolines, are used for treatment of cutaneous disease, however, they have some limitations due tue their toxicity, relatively high cost and drug resistance.  

Nitrogen heterocyclic compounds are invaluable constituents of molecules with various biological importance, being essential components in drug designing programs.

The emphasis of the current research work consists in the design, synthesis, characterization and antileishmanial activity evaluation of a new class of nitrogen heterocyclic derivatives, new bis-pyridazine molecules (BP), structurally related to pentamidine.

Three new classes of BP-derivatives were designed (BP I-III), their synthesis being straightforward and efficient. The BP-I derivatives were obtained through an N-alkylation of the starting BP heterocycle, which subsequently, by substitution with hydrazine conducted to BP-II derivatives. A final condensation with aromatic aldehydes yielded the BP-III class of compounds. 

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The reaction of FcSeSiMe₃ (Fc = Fe(h⁵-C₅H₅)(h⁵-C₅H₄)) (1) with equimolar amounts of the acid chlorides Cl(O)C-2-^cC₄H₃X (2a, X = O; 2b, X = NMe) gave the ferrocenyl selenoesters FcSe(C(O)-2-^cC₄H₃X) (3a, X = O; 3b, X = NMe). Upon exposure to silica gel compounds both 3a and 3b underwent an intermolecular conversion followed by transesterification with the silica surface to afford diferrocenyl methanols Fc₂C(OH)(2-^cC₄H₃X) (4a, X = O; 4b, X = NMe). Compounds 3a, 3b, 4a and 4b have been characterized by elemental analysis, IR and NMR (¹H, ¹³C{¹H}, ⁷⁷Se{¹H}) spectroscopy and ESI-TOF mass spectrometry (4a and 4b). The molecular structures of 3a, 4a and 4b in the solid state were determined by single crystal X-ray diffraction studies. The electrochemical studies exhibit for 3a and 3b reversible one-electron Fc/Fc⁺ redox processes. During the electrochemical investigations of 4a and 4b two well-separated one-electron redox events could be determined (4a, ∆E^0’ = 330 mV; 4b, 367 mV). UV-Vis/NIR spectroelectrochemical studies on 4a and 4b reveal a weak electronic coupling between the iron centers in the corresponding mixed-valent species of [4a]⁺ and [4b]⁺ according to Robin and Day classification.

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Quinoline and imidazole derivatives are invaluable scaffolds for medicinal chemistry. Pharmaceutical industry and modern medicinal chemistry pay a lot of effort in their combat with two aggressive life-threatening diseases: cancer and tuberculosis (TB). Both diseases are leading cause of death worldwide, millions of people dying every year, the incidence of both are continually increasing and the treatment became more and more complicated and sophisticated. The cancer chemotherapy is complex, expensive and often rather inefficient, because of the large variety of neoplasm types, high toxicity levels and non specificity of drugs, and the emergence of drug resistance and multi-drug-resistance (MDR). On the other hand, because of the Mycobacterium tuberculosis (Mtb) versatility, the treatment against TB became a challenging and difficult task and, the situation begin to be even worse because of the phenomena of drug resistance, MDR, extensively-drug-resistant (XDR), association of TB with AIDS, etc.

As part of our ongoing research aiming the design and synthesis of novel anticancer and anti-TB derivatives with azaheterocycles skeleton, we report here the design, synthesis, structure and in vitro anticancer and anti-TB activity of some new quinoline derivatives bearing an imidazole moiety. The strategy adopted for synthesis is straight and efficient, involving a three step setup procedure: N-acylation, quaternization of nitrogen heterocycle and a [3+2] cycloaddition.

The solubility in microbiological medium, anticancer and antimycobacterial activity of a selection of new synthesized compounds were evaluated. Some of the tested compounds have an excellent solubility in microbiological medium and exhibit a very good and selective antitumor activity against Renal, Breast and Prostate cancer (the assay was performed in a 60 human tumour cell line panel, representing leukemia, melanoma and cancers of lung, colon, brain, breast, ovary, kidney and prostate, in accordance with the protocol of the NCI). Some of the compounds show also a very good antimycobacterial activity. SAR correlations have been performed.

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Methanol extract of Spathodea campanulata leaves was obtained by cold extraction, and partitioned into hexane, ethyl acetate and methanol fractions. Phytochemical screenings of the fractions were carried out using standard procedures to identify the class of constituents present in each of them. Ethyl acetate fraction was subjected to column chromatographic separations by gradient elution, and isolates were TMS (Trimethylsilyl) derivatised and characterized by GC-MS (Gas chromatography-mass spectrometry). Antioxidant content was also evaluated on the three fractions using 2, 2-diphenyl-picrylhydrazyl (DPPH) freeradicalscavenging method. Percentage of inhibition and IC50 values were obtained for each fraction.

Phytochemical screenings revealed presence of alkaloids, tannins, saponin, resins, phenol, cardiac glycosides, steroids, flavonoids, anthraquinones and terpenoids in the three fractions in varying concentrations. Alkaloids, resins, phenol and cardiac glycosides were found to be intense in the three fractions while phylobatannin was found to be absent in all the three fractions. Three compounds isolated from the ethyl acetate fraction were characterized based on MS and IR spectral interpretations as palmitic acid, ethylamine and caffeic acid. Percentage of inhibition of the three fractions indicates that they have substantial antioxidant activity with the standards at high concentration of 250 to 1000 μg/mL. The hexane fraction has the highest antioxidant activity with an IC50 of 178.46 μg/mL when compared to other fractions.

This paper reports phytochemical constituents and high antioxidant activity (at concentrations of 250 μg/ mL and above) of the African tulip tree (Spathodea campanulata) when compared to the standards. This has not been earlier reported in literature, our results supports its wide ethno-medicinal applications.

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Chemical rection involoves transformation of reactant into product.Rate of chemical reaction is the measure of how fast these changes are taking place. Some rections occur very rapidly, others very slowly. For example,ionic reactions are very fast,while those taking place in water treatment plant may last upto few days.The speed at which the reaction happens is the rate of chemical reaction.If a chemical reaction has high rate, shows that molecule combines at ahigher rate than the reaction has slow rate. The rate of chemical reaction can also depends on type of molecules that are combining.If there are low concentration of an essential element or compund, the rection will be slower. In this paper we present optimized rate of chemical reaction using for different nature inspired algorithms i.e. random, Genetic Algorithm, Differential Evolution and Particle Swarm Optimization to maximize the rate of chemical reaction. Tests show that different algorithms perform significantly better for different reacions and have different convergence rate. In this paper we use a object oriented software tool named Cantera to calculate the rate of rection which uses modified Arrhenius equation.

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Recent efforts is to develop cure for chronic diabetic complications results in the discovery of potent inhibitors against aldose reductase (ALR2, EC 1.1.1.21) whose role in diabetes is well-evident. In the present work, two new natural products were isolated from the ariel part of Ocimumbasilicum;7-(3-hydroxypropyl)-3-methyl-8-β-O-D-glucoside-2H-chromen-2-one (1) and E-4-(6'-hydroxyhex-3'-en-1-yl)phenyl propionate (2) and confirmed their structures with different spectroscopic techniques including NMR spectroscopyetc. The isolated compounds (1, 2) were evaluated for in vitro inhibitory activity against aldose reductase (ALR2) and aldehyde reductase (ALR1).The natural product (1) showed better inhibitory activity for ALR2 with IC₅₀ value of 2.095 ± 0.77 µM compare to standardsorbinil (IC₅₀ = 3.14 ± 0.02µM). Moreover, the compound (1) also showed multifoldshigher activity (IC₅₀ = 0.783 ± 0.07µM) against ALR1 as compared to standard valproic acid (IC₅₀ = 57.4 ± 0.89µM). However, the natural product (2) showed slightly lower activity for ALR2 (IC₅₀ = 4.324 ± 1.25µM). Moreover, the molecular docking studies of the potent inhibitors were also performed to identify the putative binding modes within the active site of aldose/aldehyde reductases.

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Synthesis of two new analogues (1a) and (1b) of a natural product antheminone A (1c) and their evaluation of anti-cancer activities are hereby described. The synthesis involved a multi-step reaction sequence involving the use of natural product (-)-quinic acid (1d) as a precursor. The compounds which were obtained in good to moderate yields (51-67%) exhibited toxicity towards the non-small cell lung cancer cell line, A549.

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A wide  range  of  synthetically  valuable  transformations  in  organic  chemistry  involve  reduction process through which functionalization can be easily performed in the course of the reaction. While several reduction methodologies utilizing transition metals as catalysts, non-catalytic methods are of more interest as they offer safe and inexpensive synthetic protocols. Most reports on dehalogenation of pyrimidines include reduction in the presence of transition metal catalysts such as palladium, zinc dust, etc, while for halouraciles dehalogenation goes through irradiation in aqueous alcoholic solvents, thermolysis in acetamide, sonication in the presence of Indium metal, and reduction under physiological conditions. To the best of our knowledge, metal catalyst-free dehalogenation of halogenated uracils/ pyrimidines has not been reported in the literature. This report presents a novel metal catalyst-free dehalogenation procedure in a mixture of DMF and trialkylamines introducing the combination of DMF- R₃N as a potential reductive system. The system can tolerate amine and sulfide functionalities. Our results may provide a new route to the reduction of more other organic compounds in the future.

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Over the past few years, several analytical techniques for the determination of metal ions have been developed.  These include, spectrophotometry, inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectrometry (ICP-AES), voltammetric, atomic fluorescence spectrometry (AFS), cold vapor atomic absorption spectroscopy (CV-AAS) and neutron activation analysis.  The disadvantages of these methods is that, they require expensive instruments, well-controlled experimental conditions, time consuming and complicated sample preparations.¹   On the other hand, the use of chemosensors has attracted a great deal of attention due to their simplicity and selective for the detection of metal ions.  

The application of fluorescent conjugated polymers as chemosensors for metal ions has been a powerful tool in the recent years¹. The use of these chemosensors have attracted considerable attention due to their ability to detect metal ions at very low concentrations^2-3

In this study, fluorescent poly(coumarin-triazole) A and B were prepared in excellent yields by a well-established Cu(I)-catalysed click polymerization.  The application of these novel polymers as chemosensors was investigated using a range of metal ions.

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Cancer is a dreadful disease and any practical solution in combating this disease is of paramount importance to public health. Cancer patients have burdened by drug induced toxic side effects, and no turned to seek help from the complementary and alternative medicine hoping for a better cure. Research on Platinum based drugs and Non Platinum based drugs is a Multi-Million Dollar Industry in USA and there is every need to produce safe drugs for the cure of this monstrous disease. Flavonoids have a long history of use in traditional medicines in many cultures. The phytochemical, curcumin is one of the major dietary flavonoid, belonging to a group of flavonol, Curcumin is a natural polyphenol. It is highly potential molecule capable of preventing and treating various cancers.  Various dietary chemo preventive agents, turmeric powder or its extract are broadly used as therapeutic preparations in Indian System of medicine. We provide a summarized synthesis and structural determination of Curcumin Oxime, Curcumin Thiosemicarbazone derivative of Gold (III) complex. The use of these analogs for prevention of cancer tumor progression and treatments of human malignancies. A pharmacologic agent for treating and/or preventing cancer, among other diseases and conditions, and particularly breast, prostate, and pancreatic cancer, in humans and animals. The novel pharmacologic agent is an isoflavonoid or isoflavonoid mimetic covalently attached to a cytotoxic pharmacophore that, preferably has the ability to conjugate with a metal salt to form a more potent metal complex, particularly a Au (III) complex and other complexes of Platinum, Palladium, Ruthenium, Copper etc.

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The crystal defect is the region of parts of atoms being grown out of the periodic lattice structures peculiar to the crystal due to the external environment as it grows. For semiconductor materials, proper amount of crystal defects could greatly improve the photoelectric properties of materials, thus improving their catalytic activities. In this work, different crystal defects were successfully fabricated in bismuth-related nanomaterials by changing the reaction conditions, which realized the regulation of the activation of molecular oxygen, thus producing different reactive oxygen species (ROS). For example, the Z-scheme BiO_1-XBr/Bi₂O₂CO₃ photocatalytic system with rich oxygen defects, Ce-doped Bi₂MoO₆ system, Bi-loaded BiPO_4-X system and Br-O-Bi ternary defects cluster system. The construction of crystal defects in bismuth-related materials effectively improved the photocatalytic performance, and showed a great potential in the application of the organic pollutants degradation and organic synthesis. The mechanism of the enhanced photocatalytic performance was also elucidated in depth.

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Benzimidazole dimers are recognized as nucleic acid minor groove binding agents, they are strongly candidate to act via DNA or RNA grooves and can directly or indirectly recognize sequences in these grooves resulting in inhibition of transcription at A/T sites consequently an effect drug to fight cancer [1,2].

3-(4-fluorophenyl)-2-methyl-[1,2a] benzimidazolo-1,3,5-triazin-4-thione was synthesized and electrochemically oxidized in an acetonitrile solution by means of cyclic voltammetry and controlled potential electrolysis on platinum, leading to its corresponding dimer through the anodic oxidation as a deposit material. In the voltammetric study, three irreversible oxidation waves were observed. When sweeping the potential repetitively about the first anodic one, a growing film was deposited on the platinum disk. With cupper as anode, an adherent coverage by the oxidation product of the benzimidazole derivative was immediately observed, preventing the dissolution of the metallic electrode. On the preparative scale, the electrolysis at a potential located on the first wave yielded similarly to a deposit, but in addition to several oxidation products, in soluble and insoluble forms. The deposit was characterized by LC-MS and 1H NMR as a dimer formed via one electron transfer followed by a C-S linkage, an intramolecular proton transfer, a C-C coupling and an elimination of two fluorine anions. The results were rationalized on the basis of quantum-chemical calculations, using the PCM approach with the density functional theory. 

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A simple and rapid method based on oxidative-coupling reaction for determination of dopamine using chronoamperometry was developed. Based on oxidative-coupling reaction, dopamine was transformed into red azo dye by reacting with 2,4-dinitrophenylhydrazine (DNPH) oxidized. Subsequently, the concentration of dopamine can be determined indirectly from azo dye. Taking account of the advantage of their low-cost and the convenience in manipulation, chronoamperometry was employed to investigate the response of dopamine-derived azo dye. Square wave voltammetry and impedimetric studies were done to characterize the dopamine-derived azo dye. Various factors that influence reaction and amperometric intensity were investigated. Under the optimal conditions, the linearity was observed in the range of 0.1–0.0005 mmol L-1 with good correlation coefficient (R2= 0.9793). The relative standard deviation (RSDs) for five replicate measurements 3.37 %. The limit of detections of the method (S/N=3) was 0.02.36 mmol L-1. The performance of the proposed method to determine the concentration of dopamine in pharmaceuticals samples was evaluated.

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A series of pyrazine derivatives were synthesized from 2-chloropyrazine and 2-choropyrazine-5-carboxylic acid methyl ester respectively. Fluorescence characteristic of these derivatives were studied in various solvents and various pHs. The effect of donating and withdrawing groups will be discussed.

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A green, efficient and rapid procedure for the synthesis of novel chalcone derivatives containing pyrazole moiety has been developed through the condensation of various pyrazole aldehyde and ketone, in the presence of Potassium Hydroxide (KOH) in Ethanol (EtOH). This method has the advantages of operational simplicity, and high yield of products via a simple experimental and work-up procedure. 

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Thermochemical energy storage is a qualified indirect storage. In contrast to sensible or latent heat storage, energy is stored through a physico-chemical process that consumes energy during the charging (dehydration) phase and releases it during the discharging (hydration) phase. It is not directly accessible, which has the advantage of not causing significant losses.

Hydrate salts used for thermal energy storage have been always attracting topic within the research community thanks to their good performance on energy conservation applied for energy efficiency in buildings, such applications as solar domestic hot water systems. Thermochemical storage materials (TCMs) should have a high-energy storage density, multiple sources, rational price and relatively good thermal conductivity. This characteristics make of hydrate salts a worthy candidate used for heat storage.  

This study is focused on development of new mixed hydrated salts in order to explore new temperature range by means of salts incorporated. For the present work, structural and thermal investigations of blödite-type structure Na₂M (SO₄)₂.4H₂O (M=Zn, Mg) and Kröhnkite compounds Na₂Cu (SO₄)₂.2H₂O are reported. The preliminary results show a complete reversibility of mixed salts confirmed by XRD, FTIR and RAMAN spectroscopy. On other hand, the thermal analyses show different dehydration temperatures for each material. The mechanism and kinetics of dehydration/hydration reactions under water vapor sorption measurements were studied as well as the thermal efficiency to evaluate the promising salt for solar domestic hot water systems application.

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The emergence of pathogenic bacteria in surface water poses serious threats to public health worldwide, which commonly cause infectious waterborne diseases in human. Thus, it is of great importance to develop effective disinfection strategies for adequate inactivation of pathogenic microorganisms in water. In recent years, semiconductor photocatalysis has attracted growing interest as a promising technique for removal of bacterial contaminations owing to its powerful photocatalytic ability. However, the solid photocatalysts usually make the recovery inevitably depend on expansive separation processes. The great challenge of photocatalyst recovery severely limits their industry applications. Herein, Bi/BiOBr mesh with flower-like hierarchical microstructure was fabricated on the 304 stainless steel wire mesh substrate via a one-pot solvothermal route.  This Bi/BiOBr mesh showed a rapid photocatalytic inactivation of >99.98% E. coli and >99.92% S. aureus in 180 min under visible light irradition. More importantly, the Bi/BiOBr mesh was easily separated and recycled, which is a significant advance in comparison with the previously reported photocatalysts in form of powders and nanoparticles. Therefore, with a marvelous combination of facile fabrication, visible-light response and easy recycling characteristic, this novel photocatalyst is expected to have great potential applications in water purification and disinfection.

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Treatment of tuberculosis (TB) still remains an important and challenging problem because of a combination of factors including increasing number of multi-drug resistance to the existing tuberculosis drugs and co morbidity of TB with HIV. The World Health Organization recently reported TB as one of the leading cause of death from infectious disease especially in Africa. Discovery of new compounds with anti-tuberculosis (anti-TB) effect and possibly with mechanism of action different from those of well known TB drugs is highly desirable. Schiff bases and their metal complexes represent major investigational compounds. The Schiff bases were obtained by the condensation reaction of salicylaldehyde with 2 (L1-L4) and 4- aminopyridine (L4-L7). They were reacted with CuCl₂.H₂O and CoCl₂.6H₂O to form Cu(II) and Co(II) complexes.  ¹H, ¹³C NMR, IR, electronic absorption and elemental analysis confirm the formation of the ligands. The metal complexes were also characterised on the basis of various spectroscopic techniques. The compounds were screened for their anti-TB activity using the proportion method and isoniazid (INH) as a reference compound. The complexes showed enhanced in-vitro anti-tuberculosis activity against Mycobacterium tuberculosis H₃₇RV compared to the free ligands and the reference compound (INH). Co(II) complex containing the nitro substituent exhibited significant anti-TB activity with an MIC of 0.05 µg/mL. The results demonstrate that compounds with imine group and  metal ion can display strong anti-TB activity making them suitable as lead compound in the development of new TB drugs. 

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A new layered noncentrosymmetric (NCS) bismuth oxyfluoride-nitrate was synthesized by a hydrothermal reaction. The crystal structure was determined by powder and single-crystal X-ray diffraction. The material crystallizes in a NCS trigonal space group, R3 (No. 146). The constituting [Bi₆O₇F₃]⁺ cationic layer contains H₂O and nitrate anion makes a charge balance. The powder second harmonic generation (SHG) measurements indicate the title compound is phase-matchable (Type I) and exhibits a strong SHG efficiency of about 90 times that of α-SiO₂. Detailed structural examination suggests that the π-conjugate system of nitrate anion directly influence the nonlinear optical (NLO) properties of the material. Infrared and UV–vis diffuse–reflectance spectroscopy, energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), and local dipole moment calculations are also presented.

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To overcome the issue of UV-light response character of Bi₂O₂CO₃ due to its wide band gap, we attempted to improve the photocatalytic activity of Bi₂O₂CO₃ through g-C₃N₄ surface-decoration, which was primarily evaluated by the theoretical analysis. Subsequently, g-C₃N₄ surface-decorated Bi₂O₂CO₃ was successfully prepared via a facile hydrothermal method. It was found that all the g-C₃N₄ surface-decorated Bi₂O₂CO₃ samples exhibited enhanced activities for antibiotic tetracycline photodegradation compared with pure Bi₂O₂CO₃ upon simulated solar light irradiation, among which the 10 wt% g-C₃N₄ surface-decorated Bi₂O₂CO₃ sample showed the highest efficiency. Both first principle calculation and experimental data confirmed that the charge transfer at the interface between g-C₃N₄ and Bi₂O₂CO₃ could significantly suppress the recombination of photo-generated electron-holes pairs, thus improving the photocatalytic performance. The mechanism for the enhanced photocatalytic activity was also proposed by the electrochemical measurement and PL testification result. Moreover, the g-C₃N₄ surface-decorated Bi₂O₂CO₃ was explored for antibiotics treatment in actual water.

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Zinc oxide (ZnO) grown on the silicon (Si) substrates by spray pyrolysis, shown Herein; a comparative study We used several experimental methods that are compatible  with each other in order to ascertain the result in studying the physical characteristics of the surface by the photoluminescence PL and we use both characterized by XPS (X Rays Photoelectron Spectroscopy); and AES (Auger Electron Spectroscopy), In addition to UPS (Ultraviolet photoelectron spectroscopy) EELS (Electron energy loss spectroscopy) and AFM (Atomic force microscopy) Illustration of the picture and We have also made a comparison between several operations at the same time During each study to several processors.

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Applications of ZnO nanomaterials in optoelectronics are still limited due to their insufficient photoluminescence efficiency. The ZnO nanostructures were synthesized by a soft chemical method. X-ray diffraction analysis confirmed that all the synthesized samples have hexagonal wurtzite structure. X-ray diffraction, photoluminescence confirmed that the dopant ions substitute for some of the lattice zinc ions, and furthermore, that Sr²⁺ and Sr³⁺ ions coexist.Comparison of the photoluminescence spectra of undoped and strontium-doped ZnO confirmed that strontium is responsible for the novel morphology. The average crystallite size of the nanoparticles was in the range of 42-56 nm. FESEM images reveal the synthesized NPs are in nanometer range with shapes are observed. The presence of strontium (Sr) in the host lattice was confirmed by EDAX spectroscopy. Similarly, an improved antibacterial activity against one Gram-positive as well as one Gram-negative bacteria was also observed for the ZnO:Sr nanoparticles.

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Global environmental and resource concerns dictate that future energy supply and security will become increasingly dependent upon the development of accessible, sustainable and scalable energy technologies. Intensive research efforts from both academia and industry have been dedicated in state-of-art solution-processed organic solar cells for the development of the next-generation solar cell technology. Owing to the readily available carbon feedstock as well as the numerous and flexible synthetic pathways, polymer solar cells (PSCs) gained tremendous attentions over silicon solar cell in the past decay due to development of low- cost and quick energy pay-back, solution processable, lightweight, and flexible/stretchable, large area photovoltaic panels.

Thienylenevinylene (TV) based conjugated materials have showed higher charge-carrier mobilities as a result of large planarity introduced by the vinylene group that is inserted between the two thiophene rings, moreover, it has an important role in lowering the band gap of the conjugated polymers. . In addition, electron rich thiophene-phenylene-thiophene fused ring based materials having different substituents like carbon, nitrogen, silicon and germanium could effectively tune the materials properties. Herein, we report the synthesis, characterization and optoelectronic properties of copolymers containing alkyl-substituted and un-substituted thienylenevinylene and thiophene-phenylene-thiophene.

Biography:

Abstract:

We designed four series of isomeric palladium(II) complexes with normal and abnormal N-Heterocyclic Carbenes (NHCs) ligands. These complexes were characterized by ¹H and ¹³C NMR spectroscopy, elemental and X-ray crystallography. Their potential application as catalysts in direct C5-arylation reaction between imidazoles and aryl halides were investigated. Using a mere 0.5 mol % Pd loading, coupled products were obtained with moderate to excellent yields. Normal NHCs complexes have better catalytic activity than their abnormal counterpart. DFT calculations were performed to explain the difference.

Biography:

Abstract:

In this study, we investigated the photovoltaic properties of newly synthesized low bandgap conjugated polymers, poly(4-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b0 ]dithiophen-2-yl)-8-(5-(2,6-didodecylbenzo[1,2-d:4,5-d0 ]bis(thiazole)-4-yl)thiophen-2-yl)-2,6-didodecylbenzo[1,2-d:4,5-d0 ]bis(thiazole)) (P1) and poly(4-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b0 ]dithiophen-2-yl)-8-(5-(2,6-didodecylbenzo[1,2-d:4,5-d0 ]bis(thiazole)-4-yl)selenophen-2-yl)-2,6-didodecylbenzo[1,2-d:4,5-d0 ]bis(thiazole)) (P2). P1 is a thiophene-based conjugated polymer (TCP), and P2 is a selenophene-based conjugated polymer (SCP). These two different conjugated low bandgap polymers were characterized by NMR and gel permeation chromatography. The physical properties of the polymers were studied by thermogravimetric analysis and conductivity. Moreover, we also investigated the optical, electrochemical and morphological properties of both polymers by UV-vis spectroscopy, cyclic voltammetry and atomic-force microscopy (AFM), respectively. Later, we studied the photovoltaic properties of both low bandgap polymers blended with PC61BM in different ratios with different thicknesses. In addition, post thermal annealing at different temperatures for both polymers was investigated, and the results show that P2 (SCP) exhibited stronger molecular orientation properties as compared to P1 (TCP).

Biography:

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Biography:

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Biography:

Abstract:

Despite the progress achieved by modern medicinal science in tuberculosis (TB) therapy, TB remains seriously life-threatening disease among humans, annually being registered about 9 (nine) million new cases and about 1.5 million people are dying from TB.  Severely infectious caused by Mycobacterium tuberculosis (Mtb), have substantially increased over the last few years mostly due to development of drug resistance TB, Multi-Drug Resistant (MDR) TB, Extensively Drug Resistant (XDR) TB and association with human immunodeficiency virus (HIV). Therefore, the search for new antituberculous drugs active against Mtb remains one of the priority tasks of medicinal chemistry. Nitrogen heterocyclic compounds, especially five and six member rings derivatives, represent the most effective and administered class of drugs in TB therapy.

As part of our ongoing research aiming the design and synthesis of novel anti-TB derivatives with azaheterocycles skeleton, we report here the design, synthesis, structure and in vitro antimycobacterial activity of new six membered ring with azaheterocyclic skeleton. The synthesis of compounds was straight and efficient, and the antimycobacterial activity against Mtb was evaluated, some of the compounds showing a very good to excellent anti-TB activity. SAR correlations have been done. The most active compounds passed the second stage of anti-TB testing, the assay demonstrating that our compounds are potent against both replicating and non-replicating Mtb, have a bactericidal mechanism of action, are active against drug-resistant Mtb strains, present a moderate to good activity against nontuberculous mycobacteria, a good intracellular activity, and a moderate to low cytotoxicity. For the most promising compounds with anti-TB profile, a complete absorption, distribution, metabolism, excretion and toxicity (ADMET) study has been performed (including Plasma Protein Binding, Caco-2 Permeability, Cytochrome P450 Inhibition and in vitro Microsomal Stability studies), the results beeing very promising.

Biography:

Prof. Dr. Zanariah Binti Abdullah is a Dean of Faculty of Science, University of Malaya. She has earned PhD from UNIVERSITY OF LONDON, UK.

Abstract:

A series of pyrazine derivatives were synthesized from 2-chloropyrazine and 2-choropyrazine-5-carboxylic acid methyl ester respectively. Fluorescence characteristic of these derivatives were studied in various solvents and various pHs. The effect of donating and withdrawing groups will be discussed.

Biography:

Chunping Su is a Ph. D. candidate majored in applied chemistry from Wuhan Institute of Technology, China. Her research focuses on environmental catalytic materials and functional interface materials. At present, she has published 3 papers in international journals as the first author.

Abstract:

The emergence of pathogenic bacteria in surface water poses serious threats to public health worldwide, which commonly cause infectious waterborne diseases in human. Thus, it is of great importance to develop effective disinfection strategies for adequate inactivation of pathogenic microorganisms in water. In recent years, semiconductor photocatalysis has attracted growing interest as a promising technique for removal of bacterial contaminations owing to its powerful photocatalytic ability. However, the solid photocatalysts usually make the recovery inevitably depend on expansive separation processes. The great challenge of photocatalyst recovery severely limits their industry applications. Herein, Bi/BiOBr mesh with flower-like hierarchical microstructure was fabricated on the 304 stainless steel wire mesh substrate via a one-pot solvothermal route.  This Bi/BiOBr mesh showed a rapid photocatalytic inactivation of >99.98% E. coli and >99.92% S. aureus in 180 min under visible light irradition. More importantly, the Bi/BiOBr mesh was easily separated and recycled, which is a significant advance in comparison with the previously reported photocatalysts in form of powders and nanoparticles. Therefore, with a marvelous combination of facile fabrication, visible-light response and easy recycling characteristic, this novel photocatalyst is expected to have great potential applications in water purification and disinfection.

Biography:

He received his Ph.D. in inorganic chemistry at the University of Hong Kong in the fields of biological inorganic chemistry. Following a 2-years research associate appointment working at the University of Hong Kong, he accepted a position as Professor of Applied Chemistry at Wuhan Institute of Technology. Prof. Chen is also the Dean of School of Chemistry and Environmental Engineering (2014-2017) at Wuhan Institute of Technology. Prof Chen’s current research interest involves the development of novel functional nanomaterials with controllable sizes, unusual morphologies and interesting architectures that give rise to desirable properties and potential applications in environmental photocatalysis, water treatment, gas-phase catalysis, gas-sensors, antibacterial agents etc

Abstract:

The crystal defect is the region of parts of atoms being grown out of the periodic lattice structures peculiar to the crystal due to the external environment as it grows. For semiconductor materials, proper amount of crystal defects could greatly improve the photoelectric properties of materials, thus improving their catalytic activities. In this work, different crystal defects were successfully fabricated in bismuth-related nanomaterials by changing the reaction conditions, which realized the regulation of the activation of molecular oxygen, thus producing different reactive oxygen species (ROS). For example, the Z-scheme BiO_1-XBr/Bi₂O₂CO₃ photocatalytic system with rich oxygen defects, Ce-doped Bi₂MoO₆ system, Bi-loaded BiPO_4-X system and Br-O-Bi ternary defects cluster system. The construction of crystal defects in bismuth-related materials effectively improved the photocatalytic performance, and showed a great potential in the application of the organic pollutants degradation and organic synthesis. The mechanism of the enhanced photocatalytic performance was also elucidated in depth.

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Biography:

Min Sup Kim has completed his undergraduate studies at Kwangwoon University, Department of Chemistry at the age of 25 years. He is currently working on a master's degree in Kwangwoon University and majoring in polymer chemistry. 

Abstract:

In this study, we investigated the photovoltaic properties of newly synthesized low bandgap conjugated polymers, poly(4-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b0 ]dithiophen-2-yl)-8-(5-(2,6-didodecylbenzo[1,2-d:4,5-d0 ]bis(thiazole)-4-yl)thiophen-2-yl)-2,6-didodecylbenzo[1,2-d:4,5-d0 ]bis(thiazole))(P1) and poly(4-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b0 ]dithiophen-2-yl)-8-(5-(2,6-didodecylbenzo[1,2-d:4,5-d0 ]bis(thiazole)-4-yl)selenophen-2-yl)-2,6-didodecylbenzo[1,2-d:4,5-d0 ]bis(thiazole)) (P2). P1 is a thiophene-based conjugated polymer (TCP), and P2 is a selenophene-based conjugated polymer (SCP). These two different conjugated low bandgap polymers were characterized by NMR and gel permeation chromatography. The physical properties of the polymers were studied by thermogravimetric analysis and conductivity. Moreover, we also investigated the optical, electrochemical and morphological properties of both polymers by UV-vis spectroscopy, cyclic voltammetry and atomic-force microscopy (AFM), respectively. Later, we studied the photovoltaic properties of both low bandgap polymers blended with PC61BM in different ratios with different thicknesses. In addition, post thermal annealing at different temperatures for both polymers was investigated, and the results show that P2 (SCP) exhibited stronger molecular orientation properties as compared to P1 (TCP).

Biography:

Dr. Monirah Al-Alshaikh has completed her PhD in Organic Chemistry in 1993. She is an Associate Professor from Chemistry Department, King Saud University. She has published more than 36 papers in reputed journals.

Abstract:

Biography:

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Biography:

Abstract:

We designed four series of isomeric palladium(II) complexes with normal and abnormal N-Heterocyclic Carbenes (NHCs) ligands. These complexes were characterized by ¹H and ¹³C NMR spectroscopy, elemental and X-ray crystallography. Their potential application as catalysts in direct C5-arylation reaction between imidazoles and aryl halides were investigated. Using a mere 0.5 mol % Pd loading, coupled products were obtained with moderate to excellent yields. Normal NHCs complexes have better catalytic activity than their abnormal counterpart. DFT calculations were performed to explain the difference.