Sistan and Baluchestan
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Department of Chemistry
Sistan and Baluchestan
Sistan and Baluchestan
Sistan and Baluchestan
Acta Chimica Slovenica Journal Help User Username Password Remember me Notifications View Subscribe Journal Content Search Search Scope Browse By Issue By Author By Title Other Journals Article Tools How to cite item Home About Login Register Search Current Archives Archives (1954 - ) ACSi Main Page ASAP Home > Vol 65, No 3 (2018) > Beyzaei Cover Image Multicomponent Solvent-free Synthesis, Antibacterial Evaluation and QSAR Study of 2-(Bis(benzylthio)methylene)malononitriles Multicomponent reaction of malononitrile, carbon disulphide and various benzyl halides was developed as an efficient strategy for the synthesis of 2-(bis(benzylthio)methylene)malononitrile derivatives via two different procedures: (a) in the presence of K2CO3 as a base in acetonitrile and (b) under solvent-free conditions in the presence of triethylamine. Higher yields with shorter reaction times were obtained from the latter procedure. Inhibitory activity of all derivatives was evaluated against 22 pathogenic bacteria including both Gram-negative and Gram-positive strains. Thioether 4b showed broad-spectrum antibacterial activities according to the antibiogram tests. DFT calculations (B3LYP/6-311++G**) were performed to determine the type of drug–receptor interactions. It was found that reversible dipole–dipole forces play a key role in most interactions.
The chelating reagent is one of effecting factors which determines the properties of CdS films. Film morphology and roughness are very crucial in determining the further photovoltaic performance of the device. In this work, CdS film was synthesized by successive ionic layer adsorption and reaction (SILAR) method on FTO/TiO 2 substrate. Different chelating reagents with N and S donating atoms were used in Cd 2+ solution to investigate their effect on CdS film properties. X-ray diffraction spectroscopy (XRD), atomic force microscopy (AFM), ul-traviolet-visible  spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy were used for char-acterization of the films. Quantum dot-sensitized solar cells (QDSCs) were fabricated by using different produced photoanodes and the photocurrent density–voltage curves of the assembled solar cells were measured. Com-putational quantum chemistry methods were used for calculation of binding energy, topological propertiesbetween chelating reagents and CdS film. The HOMO and LUMO molecular orbitals were calculated and vi-sualized. Experimental and theoretical results confirmed that the ligand containing S donating atom results information of CdS film with the lowest surface roughness and the highest photovoltaic conversion efficiency compared to the other ligands.
5-Amino-1,3,4-thiadiazole-2-thiol was used to synthesize a novel fluorescent functionalizing group on a Fe 3 O 4 @SiO 2 magnetic nanocomposite surface for detection of heavy metal ions in water samples. The prepared probe was characterized by using X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and a vibrating sample magnetometer. Among various tested ions, the new nanocomposite responded to Hg 2+ ions with an intense fluorescence “turn-off”. The limit of detection of the probe shows that it is sensitive to the minimum Hg 2+ concentration of 48.7 nM. Theoretical calculations were done for estimating binding energies of the three possible bonding modes.
The synthesis of pyrazolo[3,4-d]pyrimidine derivatives is important due to their presence in various biologically active compounds such as anticancer, antimicrobial, antiparasitic, anti-inflammatory and antidiabetic agents. In this project, a new and efficient approach for the synthesis of some novel 4-imino-5H-pyrazolo[3,4-d]pyrimidin-5-amines from reaction of 5-amino-pyrazole-4-carbonitrile with various hydrazides in ethanolic sodium ethoxide medium was reported. Antimicrobial activities of all synthesized derivatives were evaluated against eight Gram-positive and five Gram-negative pathogenic bacteria. The moderate to good inhibitory effects were observed based on inhibition zone diameter (IZD), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. In order to determine the reasonable relationship between antibacterial activities and physiochemical properties of the derivatives, computational studies were carried out in terms of geometry optimization, short-range van der Waals forces, dipole moments, atomic charges and frontier orbital energies. It was found that both short-range forces and covalent bonds are important in the observed inhibitory effects of the molecules. The results suggested that pyrazolo[3,4-d]pyrimidine derivatives prefer a soft nucleophilic attack on bio-macromolecular targets. Furthermore, our models proposed that the antibacterial activities of these derivatives can be improved by substituting large electron donating groups on the 6-phenyl rings.
A pyrazole derivative-functionalized Fe 3 O 4 @SiO 2 fluorescent probe was designed and its application for detection of Hg 2+ in aqueous solutions was investigated. The sample was characterized by using trans- mission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometer, and thermogravimetric-differential. Different cations were investigated against the newly prepared probe and the results showed that Hg 2+ was the one with the most fluorescence quenching ability. The sensitivity of the probe was determined and it was shown that the new probe could detect Hg 2+ with the detection limit of 7.6 nM. The prepared nanocomposites were easily separated from aqueous solution by an external magnet. Theoretical calculations were used for estimating the most stable bonding mode of the ligand with mercury ion.
Among the most well-known members of the mitotic protein kinase family are polo-like kinases. Polo- like kinase 4 as a type of this family is used as a therapeutic target in the treatment of proliferative diseases. A three- dimensional quantitative structure activity relationship study with comparative molecular field analysis and comparative molecular similarity indices analysis was car- ried out on a data set of 47 molecules consisting of (E)-3- ((1H-indazol-6-yl)methylene) indolin-2-ones derivatives of polo-like kinase 4 inhibitors to rational design of new drug. The validity of model was tested with a data set divided into training and test set. All constructed models show good statistical reliability in terms of predicting polo-like kinase inhibitory activity of the molecules, based on molecular property fields like steric, electrostatic, hydrophobic, hydrogen bond donor and hydrogen bond acceptor fields. Moreover, molecular docking with CDOCKER algorithm was done to investigate interactions of between ligand and protein and to achieve bioactive ligand conformer. The energy difference between the highest occupied mole- cular orbital and the lowest unoccupied molecular orbital (gap) implicitly stated the high reactivity of the most active molecule in the active site of protein. Furthermore, the molecular electrostatic potential energy at density functional theorylevel confirm the results from molecular docking.
Benzofuran derivatives have many useful applications. Computational quantum chemistry method was used to study the relationship between energy data and molecular properties of the 5,6-dihydroxy-2-methyl-1- benzofuran-3-carboxylate derivatives (molecules 3a– 3f). Results indicate that there is a good relationship between intramolecular hydrogen bond lengths and energy data of these molecules. Also, X-ray of molecule 3e was used to compare experimental and computational geometrical parameters. Chemical hardness, chemical potential and electronegativity values were calculated to recognize relation between energy data and reactivity of these molecules. Atomic net charges and molecular electrostatic potential values were employed for better insight regarding energy data of the molecules. Electronic charge densities were calculated using atoms in molecules method. The correlation coefficients between experimental and computational 13C NMR chemical shifts were examined. Total spin– spin coupling constant and its components were evaluated to understand the contribution of these properties in energy data of the molecules. The relation between energy data of the molecules and aromaticity of the rings was also determined.
Density functional theory (DFT) was utilized to study intermolecular interactions between caffeine (CAF) and cytarabine (CYT) using B3LYP, PBEKCIS and MPWPW91 methods. Also, the mentioned interactions were investigated using MP2 method. Effects of various factors on stability of the most stable conformers of binary complex CAF-CYT were examined. Results indicate that competition between hydrogen bond and CH…N bond interactions influences the binding energy values of the conformers of binary complex CAF-CYT. Indeed, results of electronic charge densities, population analyses and charge transfer studies were considered. CAF is the analogue base of adenine (A) and may pair with thymine (T) to form CAF-T instead of A-T base pair and so has mutagenic effects. It seems that the intermolecular interactions between CAF and CYT play an interference role on mutagenic effects of this molecule. A new aspect was proposed for CYT in addition to traditional anti-cancer quality of this drug.
New trans-A2B2-porphyrins substituted at phenyl positions were synthesized from 4-methylphthalic acid as a starting material through sequential multistep reactions. These macrocycles were characterized by 1H NMR, 13C NMR, 19F NMR, 1H–1H COSY NMR, and MALDI-TOF mass spectrometry. Computational studies were performed on the porphyrins to investigate various factors such as structural features, electronic energy, energy gaps, and aromaticity. Energy band gap values of these compounds especially N-hydroxyphthalimide-functionalized porphyrins were small that makes them as good candidates for solar cell systems and photocatalysis. Relationships between electronic energies and aromaticity of the compounds were then investigated. The data indicated that the aromaticity features at the center of two series of these compounds (fluorinated and non-fluorinated porphyrins) were in the opposite manner.
Intramolecular hydrogen bonding interactions together with non-covalent cation-p interactions of the Naþ cation in 4-substituted-8-hydroxyquinolines were investigated using quantum mechanical calculations to know results of reciprocal effects of these interactions. Also, cation-p interactions of Naþ cation on 4-substituted-quinolines as a similar system without intramolecular hydrogen bonding were considered to compare binary complexes Naþ-X-8-hydroxyquinolines and Naþ-X-quinolines (where X is used as a replacement for 4-substituted and X ¼OH, CH3, H, F, Cl, CF3, and CN). Geometrical parameters, Hammett constants, and electronic properties were studied to interpret the binding energies. A new formulation was proposed to compute energy of intramolecular hydrogen bonding interactions based on atoms in molecules (AIM) analysis and properties of electron charge densities at ring critical points (RCPs). Also, population analysis was performed using natural bond orbital (NBO) method to find role of donor-acceptor interactions on stability of the complexes. Indeed, localized molecular orbital energy decomposition analysis (LMO-EDA) was employed to realize contribution of components of energy in stability of the complexes.
In this work, a novel temperature controlled switchable solvent based microextraction method has been developed for the extraction and preconcentration of four PAEs from water samples prior to GC–MS analysis. For the first time, the effect of temperature in the switching of extracting solvent has been studied and the application of cooling/heating processes instead of addition of chemicals in the switchable solvent based microextraction has been used for PAEs extraction. Several parameters including solvent type, solvent volume, temperature of dissolution, temperature of separation, and salt addition are optimized. A theoretical study also has been provided to reveal the effect of cooling/heating effects on the homogenization and separation of phases. The proposed method provided some advantages such as simplicity, using low volumes of inexpensive and less hazardous reagents, rapid extraction and reduced analysis time. For the developed method, LODs and LOQs were obtained in the ranges of 0.03–0.06 and 0.1–0.2 μgL−1 respectively. Also, calibration curves were linear within the range of 0.2–100 μgL−1 for dimethyl phthalate and dibutyl phthalate, and 0.1–100 μgL−1 for diethyl phthalate and dioctyl phthalate. Enrichment factors were found to be in the range of 110.9–116.3. The proposed method was applied for the determination of PAEs in real water samples.
Intra- and intermolecular hydrogen bonding interactions in some pyridine-based complexes that have R groups without (H, eC2H5, and eC4H9) and with (C2H3, eC4H5, eC6H7, and eC8H9) p-conjugated system were investigated using quantum mechanical calculations to know role of resonance on strength of interactions. Geometrical parameters and electronic properties based on atoms in molecules (AIM) analysis were studied to interpret the interactions. Also, aromaticity of the rings of the complexes was evaluated using aromatic fluctuation index (FLU) and para-delocalization index (PDI) to connect the mentioned benchmark to energy of the hydrogen bond interactions. Indeed, localized molecular orbital energy decomposition analysis (LMO-EDA) was employed to realize contribution of components of energy in stability of the complexes.
5-Amino-1,3,4-thiadiazole-2-thiol was used to synthesize a novel fluorescent functionalizing group on a Fe3O4@SiO2 magnetic nanocomposite surface for detection of heavy metal ions in water samples. The prepared probe was characterized by using X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and a vibrating sample magnetometer. Among various tested ions, the new nanocomposite responded to Hg2+ ions with an intense fluorescence “turn-off”. The limit of detection of the probe shows that it is sensitive to the minimum Hg2+ concentration of 48.7 nM. Theoretical calculations were done for estimating binding energies of the three possible bonding modes and the visualized molecular orbitals were presented.
A novel fluorescent nanocomposite based on 6-amino-2-mercaptobenzothiazole (AMBT) was synthesized, characterized, and used as high-performance probe for detection of trace amounts of Fe3+ ions in water. The prepared AMBT-based ligand was grafted on Fe3O4@SiO2 nanocomposites, which provide both high surface area for hosting the ligand and easy magnetic removal of the nanoprobe from water. The prepared nanoprobe was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis, and vibrating sample magnetometer. Moreover, the designed nanocomposite showed spectroscopic colorimetric properties against low concentrations of Fe3+ ions in water. The detection limits of the probe for fluorometric and colorimetric detection of Fe3+ were 16.0×10−9M and 0.75×10−6 M, respectively. Finally, the performance of the probe was tested in a natural water sample for detecting trace amounts of Fe3+. The theoretical calculations of the molecular structure for the designed organic ligand and its interaction with different ions confirmed strong binding energy of iron atom with thiol group of the ligand.
Cation-π and anion-π interactions were studied in the Na + -substituted-COT and F-substituted- COT complexes (where substituted-COT is planar cyclooctatetraene with four X-C≡C-substituents (X = OH, CH 3 , H, F, and CN) using computational quantum chemistry methods. There are no direct electrostatic interactions of substituents with cations and anions in these complexes. The electron-donating and electron- withdrawing substituents lead to increase of the strength of cation-π and anion-π interactions, respectively. There are meaningful correlations between the Hammett constants and binding energies. The AIM analysis shows that the electron-donating and electron-withdrawing substituents lead to increase in electronic chargedensity values at ring critical points (RCPs) of the Na + -substituted-COT and F – -substituted-COT com-plexes, respectively (compared to complexes with X = H). NMR calculations demonstrate that the cation-πinteractions are consistent with more anti-aromatic rings and the anion-π ones are in accord with less anti-aromatic rings.
Computational quantum chemistry methods are used to study simultaneous cation-S and S—S stacking interactions with a graphene sheet and on the inner and outer faces of some bent gra- phenes as curved surfaces of carbon nanohorns (CNHs). Structural parameters and energy data of ternary benzene—graphene—Na + and benzene-bent graphene—Na + complexes are studied. Also, effects of charge transfer and aromaticity are estimated to determine how changes in the structure influences the above interactions. The results indicate that the graphene curvature leads to structural changes affecting simultaneous interactions of the Na + cation and benzene with bent graphenes. Also, the results show that although S—S stacking is a weak interaction, it can manipulate the order of binding energies in complexes involving both mentioned inter- actions and affect drug delivery abilities of these systems.
A C 102 H 30 graphene sheet has been rolled up to construct Single-Walled Carbon NanoTube Fragments (SWCNTFs) as parts of armchair carbon nanotubes by computational quantum chemistry methods. Non-covalent cation-π interactions of the Na + cation on the central rings of SWCNTFs have investigated. The binding energies of the Na + -SWCNTF complexes versus true strain parameter (R) change in three brands. Structural parameters, electron charge density values, and also effects of aromaticity on the binding energies were gauged. Results show that partially localization of the π electron clouds of SWCNTFs enhances strength of the cation-π interactions in some cases. Thus, changing the π electron clouds of SWCNTs may help to improve surface modification of these materials through the cation-π interactions, which has important applications such as storage of electric energy by transportation of cations through the walls of SWCNTs and enhancement of the hydrogen adsorption compared to pure SWCNTs.
Because of low cost and preservation of time, bio-synthesis is better than custom physical and chemical methods for synthesis of nanoparticles. Bio-synthesis of silver nanoparticles was performed using extract of white tea. Effect of three concentrations 1 mM, 2 mM, and 3 mM on synthesis was examined. UV-Vis, FT-IR, and TEM analysis were employed to verify synthesis of silver nanoparticles. UV-Vis spectrophotometry records a peak in 420 nm which confirms bio-synthesis of these nanoparticles in the extract of white tea. FT-IR analysis highlights role of functional groups in the extract of white tea on synthesis of silver nanoparticles. Spherical shape of synthesized silver nanoparticles is in average size of 40 nm which was determined by TEM analysis. Results reveal that these nanoparticles have anti-bacterial activity against Staphylococcus aureu and Escherichiacoli bacteria