Electronegativity Values Research Articles

Investigation of a novel Schiff base Catena-((μ6-(E)-2-((4-methoxy-2-oxidobenzylidene)ammonio)ethane-1-sulfonato potassium as a potential antibacterial agent.

Schiff bases, which have intriguing properties in many areas, have been studied extensively in recent years due to their structural properties and biological activities. In this research, a novel water-soluble Schiff base complex, Catena-((μ6-(E)-2-((4-methoxy-2-oxidobenzylidene) ammonio) ethane-1-sulfonato potassium, C10H14KNO6S (CMOAESP), was synthesized by a one-step condensation reaction of 2-hydroxy-4-methoxy benzaldehyde and taurine with the yield of 65%, 0.333g. Spectral analysis of water-soluble crude product showed equilibria keto-enol tautomerism, by a resulting Zwitterionic form of the structure. The ADMET prediction showed that the CMOAESP obeys Lipinski's rule and was in bioavability range. The molecular docking results showed an inhibition ability for 1JIJ and MBT1 proteins which play an important role in antibacterial studies. The experimental end theoretical calculations were in a good agreement that CMOASP has inhibition efficiency against Escherichia coli and has inhibition at high concentrations against Staphylococcaceae aureus. The WinGX software system SHELXS direct technique was used to solve the structure, and SHELXL full-matrix least-squares approach on F2 was used to refine the results. The Gaussian 09W program was used to carry out the DFT calculations. The gap values for CMOAESP were calculated by using the B3LYP/6- 311 + + G(d,p) method in order to predict its reactivities and behaviors in the gas phase. The frontier orbitals, LUMO and HOMO together with some global parameters as electronegativity (μ), chemical potential (χ), hardness (η), electrophilicity index (ω), and softness (S) values were predicted from DFT calculations.

Effect of the electronic properties of the side charges of neutral solvent molecules on the charges of the N and H atoms of the carbazole molecule: IR experiment and DFT calculations

The IR spectral parameters of the absorption band of the valence vibration of the NH bond of the carbazole molecule in several neutral solvents (n-hexane C6H14, carbon tetrachloride CCl4, chloroform CHCl3, benzene C6H6) have been measured. It has been experimentally established that the position of the maximum of the NH vibrational band of the carbazole molecule in solvents undergoes a low-frequency shift relative to the gas phase. This shift increases in the series C6H14, CCl4, CHCl3, C6H6. The change in the magnitude of the linear shift is well described by the Kirkwood-Bauer-Magat KBM ratio in C6H14, CCl4, CHCl3. The presence of a linear shift may indicate that only universal interactions take place. The deviation of this ratio of shift magnitude for carbazole in benzene is interpreted as a manifestation of intermolecular complexation. Quantum-chemical calculations of the position of the absorption band position of the valence vibration of the NH bond of the carbazole molecule in these solvents, carried out by the electron density functional method B3LYP/6-311++G (d,r) using the Gaussian 09W program package, also showed a low-frequency shift relative to the gas phase.It was found that for the carbazole molecule in the condensed phase relative to the gas phase the following effects of changing the magnitude of charges on atoms N13 and H14 take place: 1 – increase in the positive sign of the charge on both atoms; 2 – the change in charge magnitude is larger on the nitrogen atom than on the hydrogen atom for both solvents (whose molecules have a dipole moment ∼0: C6H14, CCl4); 3 – the chlorine containing environment has a greater effect on the charge change in the carbazole molecule than the proton containing environment (whose molecules have a dipole moment ∼0: C6H14, CCl4).The correlation between the change of charges on atoms N13 and H14 with the value of electronegativity ξ of the side solvent atoms was established.Thus, it is shown that the charges on the 13N and 14H atoms of the carbazole molecule undergo changes in the presence of universal interactions, and the magnitude of the charge change depends on the electronic properties of the side atoms of the nearest solvent molecules. A hypothesis is proposed to explain the different frequency shift of the NH vibrational frequency of the molecule for chlorine-containing and hydrogen-containing side atoms of neutral solvent molecules, which takes into account different values of ξ for nitrogen and hydrogen atoms.

Periodic Trends and Fluxionality Effects on Transition Metal Catalyzed Sulfoxidation.

Despite the extended interest in d0 metal complexes as catalysts for peroxide activation and eventual oxygen transfer processes, there are still gaps in the understanding of how they proceed at the microscopic level. Herein, we have considered sulfide oxidation with cumyl hydroperoxide as a test system, performing the reaction with a series of eight different aminotriphenolate d0 metal complexes: Ti(IV), Zr(IV), Hf(IV), V(V), Nb(V), Ta(V), Mo(VI), and W(VI). The reactivity and selectivity of the catalytic systems, as well as the effect of a strong Lewis base (dimethylhexyl-N-oxide), have been determined experimentally, correlating kinetic values with Sanderson electronegativity values. Theoretical calculations of the catalytic cycles have been performed to have a clearer description of the role of the reactive peroxo species. Combining experimental results and DFT predictions, we propose suitable mechanisms for all eight metal aminotriphenolates, rationalizing the expected periodic trends, while also unveiling the unique reaction pathways available to highly flexible vanadium complexes.

A theoretical approach to study oxide-based perovskite materials XTiO3 (X = Be, Mg, Ca, Sr and Ba) for photovoltaic applications

Oxide-based perovskite materials have a large application in fuel and hydrogen sensors, non-volatile random access memory devices, semiconductor fabrications, optoelectronic, thermoelectric and photovoltaic devices. In this report, equilibrium geometries, and optoelectronic properties of oxide-perovskite materials XTiO3 (X = Be, Mg, Ca, Sr and Ba) are investigated through Conceptual Density Functional Theory (CDFT) technique. The HOMO–LUMO energy gap obtained from functional B3LYP/LANL2DZ and B3PW91/LANL2DZ are observed in the range of 1.201 eV–4.647 eV and 1.519 eV–4.903 eV respectively, which justifies their applications in solar cells and optoelectronic devices. HOMO–LUMO energy gap shows a downward trend when materials travel from Be to Mg to Ca to Sr to Ba, except for BaTiO3 in B3PW91/LANL2DZ. BeTiO3 displays the maximum value of HOMO–LUMO gap, hardness and electronegativity value. Hardness and softness of these substances are found between 0.600–2.452 eV and 0.204–0.788 eV respectively whereas refractive index and dielectric constant of XTiO3 are observed in the range of 2.017–3.684 and 4.067–13.574 respectively. Across all relationships, XTiO3’s dielectric constant and refractive index show a rising pattern from Be to Mg to Ca to Sr to Ba, except for BaTiO3 computed using B3PW91/LANL2DZ. The lowest refractive index and dielectric constant are displayed by the BeTiO3. TD-DFT calculation is performed to understand the absorption spectra of these materials. Optical transition energy and wavelength of XTiO3 are found between 0.339–3.535 eV and 350.68–3656.15 nm respectively. An interesting relationship is established between HOMO–LUMO energy gap, optical transition energy and wavelength of XTiO3 materials. The investigated compounds exhibit a linear pattern between HOMO–LUMO energy gap and optical transition energy whereas wavelength shows an inverse trend. MEP of these compounds are also discussed.

Study of the Molecular Structure, Spectroscopic Analysis, Electronic Structures and Thermodynamic Properties of Niacin Molecule Using First-principles

This work describes the different properties of Niacin's molecule using the density functional theory (DFT) B3LYP/6-311++G (d, p) basis set. The optimized energy for the Niacin molecule is -436.987 Hartree. The peak values from FT-IR spectra show the C=C, C-C vibrations, C-H stretching vibrations, C-H in-plane bending vibration, C-H out-of-plane bending vibration, C-O stretching vibration, C-N vibration and O-H vibration. The MEP and ESP analyses indicate that the oxygen and nitrogen atoms exhibit nucleophilic regions, while the hydrogen atoms exhibit electrophilic regions. The energy gap of the Niacin molecule is found to be 5.398 eV through HOMO-LUMO analysis. The electronegativity value of 4.847 eV signifies the molecules ability to attract electron and the calculated value of chemical hardness is 2.7 eV which reflects the molecular stability. The softness value of 0.370 eV-1 denotes the molecule polarizability. Also the chemical potential value is -4.847 eV which represent the ability to donate or accept electron. Similarly, electrophilic index with value 4.351 eV shows the electrophilic behavior that signifies its capacity to accept electron. Because of the larger energy gap, the molecule becomes hard and hardness is greater than softness. In this molecule, the C2 atoms have the highest positive charge along with C3 and all the hydrogen atoms, while C1 has the highest negative charge together with some negative charge on C4, C5, N6, C11, O12 and O13 atoms. When the temperature rises, the thermodynamic parameters such as heat capacity at constant volume and pressure, internal energy, enthalpy, and entropy increase, but Gibbs free energy decreases.

Phenolic Acid-β-Cyclodextrin Complexation Study to Mask Bitterness in Wheat Bran: A Machine Learning-Based QSAR Study.

The need to solvate and encapsulate hydro-sensitive molecules drives noticeable trends in the applications of cyclodextrins in the pharmaceutical industry, in foods, polymers, materials, and in agricultural science. Among them, β-cyclodextrin is one of the most used for the entrapment of phenolic acid compounds to mask the bitterness of wheat bran. In this regard, there is still a need for good data and especially for a robust predictive model that assesses the bitterness masking capabilities of β-cyclodextrin for various phenolic compounds. This study uses a dataset of 20 phenolic acids docked into the β-cyclodextrin cavity to generate three different binding constants. The data from the docking study were combined with topological, topographical, and quantum-chemical features from the ligands in a machine learning-based structure-activity relationship study. Three different models for each binding constant were computed using a combination of the genetic algorithm (GA) and multiple linear regression (MLR) approaches. The developed ML/QSAR models showed a very good performance, with high predictive ability and correlation coefficients of 0.969 and 0.984 for the training and test sets, respectively. The models revealed several factors responsible for binding with cyclodextrin, showing positive contributions toward the binding affinity values, including such features as the presence of six-membered rings in the molecule, branching, electronegativity values, and polar surface area.

Integrated quantum chemical calculations, predictive toxicity assessment, absorption, distribution, metabolism, excretion and toxicity profiling and molecular docking analysis to unveil the therapeutic potential of non‐oxovanadium(IV) and organotin(IV) complexes targeting breast cancer cells

AbstractIn this work, theoretical calculations of o‐phenylphenol‐based non‐oxovanadium(IV) and organotin(IV) complexes, previously prepared and reported by our group, have been carried out by density functional theory (DFT). Density functional theory quantum chemical computations were used to explore the structural and spectroscopic characteristics of the complexes in this study. The inhibitory nature of complexes were revealed via molecular docking research, which were performed against selected breast cancer cell proteins, 5NWH and 3HB5. The optimization and stability of complexes 1–6, were conducted using optimized DFT/B3LYP/6–311++G (d, p) level. Simulated computations of the molecular electrostatic potential surface were also performed to analyze the reactive behavior of the non‐oxovanadium(IV) and organotin(IV) complexes. The stability and molecular reactivity of the molecules were computed using the HOMO‐LUMO energies, energy gap, chemical potential (μ), electronegativity (χ), hardness (η), and softness (S) values. In silico analysis through molecular docking, ADMET properties and toxicity evaluation was used to assess its anticancer activity, drug‐likeness property and toxicity. The binding constant value, evaluated from molecular docking, was found to be very promising, −10.1 kcal mol−1 observed for vanadium complex 5 and the complexes were found to exhibit inhibition constant as low as 0.0378 μMol. Root‐mean‐square deviation (RMSD) has been carried out to validate molecular docking studies, which have been found to be below 2.0 Å for the complexes, indicating successful docking of the ligand‐protein complex by the program. The complexes, evaluated for their toxicity behavior in terms of Lethal Dose, based on Globally Harmonized System (GHS), have been found to be chemical safe falling under the category III and V and hence can find use as future metallo‐based drugs.

Experimental and numerical assessment on Pb-free alkaline mixed borate glasses for radiation resisting applications

Melt quenching technique has been used to fabricate calcium boro-phosphate glasses doped with praseodymium oxide ions. With increased P2O5 content, structural parameters like oxygen molar volume (Vo) and oxygen packing density (OPD) indicate an opposing trend. In addition to optical factors like optical electronegativity, absorption edge, and direct and indirect bandgap values being estimated and discussed, optical absorption spectra have been recorded for all the glasses. The presence of ionic bond behaviour confirms the strong structural and optical property changes caused by the P2O5 content. Using the Phy-X software application, the radiation shielding parameters were investigated. The incorporation of B2O3, CaCO3, and P2O5 offers more number of bridging oxygens which further leads to closely packed nature. Considering the glass sample B0PCM:Pr, the highest linear attenuation coefficient (LAC) is determined. The LAC results showed that at high energy levels, the glass's shielding performance became more consistent. The results of the effective atomic number analysis demonstrated the impact that CaCO3 has on the glass's shielding effectiveness, with a higher concentration of CaCO3 improving the material's defence against gamma radiation. For B0PCM:Pr glass, the half value layer (HVL) rises from 2.101 to 3.444 cm at 0.284–1.333 MeV. Certainly, it has been observed that the glass tends to have a smaller HVL when it contains more CaCO3 with lesser P2O5 content.

Synthesis, Cytotoxicity, and Photophysical Investigations of 2-Amino-4,6-diphenylnicotinonitriles: An Experimental and Theoretical Study.

In this study, we present a comprehensive investigation of 2-amino-4,6-diphenylnicotinonitriles (APNs, 1-6), including their synthesis, cytotoxicity against breast cancer cell lines, and photophysical properties. Compound 3 demonstrates exceptional cytotoxicity, surpassing the potency of Doxorubicin. The fluorescence spectra of the synthesized 1-6 in different solvents reveal solvent-dependent shifts in the emission maximum values, highlighting the influence of the solvent environment on their fluorescence properties. A quantum chemical TD-DFT analysis provides insights into the electronic structure and fluorescence behavior of 1-6, elucidating HOMO-LUMO energy gaps, electronegativity values, and dipole moments, contributing to a deeper understanding of their electronic properties and potential reactivity. These findings provide valuable knowledge for the development of APNs (1-6) as fluorescent sensors and potential anticancer agents.

A comprehensive investigation of Bi2O3 on the physical, structural, optical, and electrical properties of K2O.ZnO.V2O5.B2O3 glasses

The multi-component glass system has a composition of 10K2O–10ZnO–55 B2O3–(25–x)V2O5–xBi2O3 (x = 4, 5, 7.5, 9, 10 mol%) are synthesized by the melt-quenching method. Using X-ray diffraction examination, the amorphous phase in the material was confirmed. The physical characteristics of the produced compositions are examined using density (D) and molar volume (Vm). Calculations of physical properties showed that adding Bi2O3 from 4 to 10 mol% increased the glass density from 2.7878 to 3.3617 g cm−3 and decreased the molar volume from 40.4196 to 38.5895 cm3/mol. Studies of glass samples using the FTIR show bands of absorption for oxides in different structural groups. Octahedral [BiO6\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{BiO}}}_{6}$$\\end{document}], [BO4\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{BO}}}_{4}$$\\end{document}], and tetrahedral [BO3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{BO}}}_{3}$$\\end{document}] structural units are observed in the present glass matrices. The cutoff wavelength (λC\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\lambda }_{C}$$\\end{document}), and optical band gap energy were determined using UV absorption spectra. The increase in non-bridging oxygens can be linked to the decrease in optical band gap energy (Eopt\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${E}_{opt}$$\\end{document}) (direct and indirect) and the increase in cutoff wavelength with an increase in Bi2O3 content. This is attributed to the existence of bismuth ions and the creation of non-bridging oxygens. Besides that, the values of optical parameters, viz., optical electronegativity, refractive index, and molar refractivity, are calculated. The metallization criterion values are less than 1 and the glass samples exhibit an increased tendency towards metallization. Both the conductivity and the dielectric constant increase with the rise in Bi2O3 content, however, the dielectric loss and the impedance reduce. The behavior and values of conductivity for the studied glasses reveal the semiconducting properties of all glass samples. These results suggest that the produced glass samples may be employed as amorphous semiconductors in electronics and memory switching devices.

Reduction of Li+ within a borate anion

Group 1 elements exhibit the lowest electronegativity values in the Periodic Table. The chemical reduction of Group 1 metal cations M+ to M(0) is extremely challenging. Common tetraaryl borates demonstrate limited redox properties and are prone to decomposition upon oxidation. In this study, by employing simple yet versatile bipyridines as ligands, we synthesized a series of redox-active borate anions characterized by NMR and X-ray single-crystal diffraction. Notably, the borate anion can realize the reduction of Li+, generating elemental lithium metal and boron radical, thereby demonstrating its potent reducing ability. Furthermore, it can serve as a powerful two-electron-reducing reagent and be readily applied in various reductive homo-coupling reactions and Birch reduction of acridine. Additionally, this borate anion demonstrates its catalytic ability in the selective two-electron reduction of CO2 into CO.

Electronegativity Matching of Asymmetrically Coordinated Single‐Atom Catalysts for High‐Performance Lithium–Sulfur Batteries

AbstractAsymmetrically coordinated single‐atom catalysts are attractive for the implementation of high‐performance lithium–sulfur (Li─S) batteries. However, the design principle of the asymmetric coordination that can efficiently promote bidirectional conversion of polysulfides has not been fully realized. Herein, a series of Co─N3X1 (X refers to F, O, Cl, S, or P) configurations are established, and theoretically unravel that the relative electronegativity value (REV) can be used as an index parameter for characterizing the catalytic activity. By virtue of enhanced chemical affinity with sulfur species and lowered Li2S decomposition, chlorine‐atom‐constructed asymmetric configurations with an optimal REV exhibit stronger catalytic effect to inhibit shuttling. Such a REV‐related catalytic effect is termed as REV effect. Following this principle, a novel single‐atom catalyst with dominated Co─N3Cl1 configuration is successfully synthesized through an inside‐out thermal reaction strategy and used as a modified layer on the cathode‐side separator. Interestingly, the assembled Li─S batteries exhibit quite high rate capacity (804.3 mAh g−1 at 5.0 C), durable cyclability (0.023% capacity decay per cycle), and competitive areal capacity (7.0 mAh cm−2 under 7.5 mg cm−2 sulfur loading and lean electrolyte). The guideline provided in this work gives impetus to the pursuit of highly efficient single‐atom catalysts for practical Li─S batteries.

Computational exploration of oxide-based double perovskites Sr2MgWO6 and Ba2BiVO6 for photocatalysts for sustainable degradation processes

First-principles calculations have been utilized to investigate the photocatalytic degradation, structural properties, electronic properties, population inversion, effective mass, redox potential, and optical properties of oxide-based double perovskites Sr2MgWO6 and Ba2BiVO6. The calculated value of τG is 0.83 for Sr2MgWO6 and 0.97 for Ba2BiVO6. The electronic properties indicate the semiconducting behavior of studied materials, which enable the efficient formation of electron-hole pairs upon photon absorption. The photocatalytic efficiency of perovskite materials was determined by studying the effective mass ratio. The optical parameters exhibit a strong correlation with the underlying electronic band structure. The electronegativity values were computed to be 5.292 eV and 5.206 eV for Sr2MgWO6 and Ba2BiVO6, respectively. The conduction band edges value are found to be −0.523 eV for Sr2MgWO6 and 0.146 eV for Ba2BiVO6. Based on their redox potentials, the Sr2MgWO6 and Ba2BiVO6 oxide perovskites have a high potential for use in photocatalytic applications, specifically in the generation and degradation of organic pollutants. These perovskites degrade organic pollutants with high efficiency and can effectively contribute to environmental treatment. Their strong capacity for reduction and oxidation reactions gives them an advantageous capability to degrade organic pollutants.

Novel isatin-triazole based thiosemicarbazones as potential anticancer agents: synthesis, DFT and molecular docking studies.

Thiosemicarbazones of isatin have been found to exhibit versatile bioactivities. In this study, two distinct types of isatin-triazole hybrids 3a and 3b were accessed via copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC), together with their mono and bis-thiosemicarbazone derivatives 4a-h and 5a-h. In addition to the characterization by physical, spectral and analytical data, a DFT study was carried out to obtain the optimized geometries of all thiosemicarbazones. The global reactivity values showed that among the synthesized derivatives, 4c, 4g and 5c having nitro substituents are the most soft compounds, with compound 5c having the highest electronegativity and electrophilicity index values among the synthesized series, thus possessing strong binding ability with biomolecules. Molecular docking studies were performed to explore the inhibitory ability of the selected compounds against the active sites of the anticancer protein of phosphoinositide 3-kinase (PI3K). Among the synthesized derivatives, 4-nitro substituted bisthiosemicarbazone 5c showed the highest binding energy of -10.3 kcal mol-1. These findings demonstrated that compound 5c could be used as a favored anticancer scaffold via the mechanism of inhibition against the PI3K signaling pathways.

Electronegativity as a new case for emergence and a new problem for reductionism

AbstractThe potential reducibility of chemical entities to their physical bases is a matter of dispute between ontological reductionists on one hand, and emergentists on the other. However, relevant debates typically revolve around the reducibility of so-called ‘higher-level’ chemical entities, such as molecules. Perhaps surprisingly, even committed proponents of emergence for these higher-level chemical entities appear to accept that the ‘lowest-level’ chemical entities—atomic species—are reducible to their physical bases. In particular, the microstructural view of chemical elements, actively developed and defended by emergentists, appears to hold that the explanatory power of nuclear charge justifies being reductionist about atomic species. My first task in this paper is to establish that nuclear charge cannot ultimately provide explanations sufficient to justify a reductionist approach to atomic species, unless we abandon the persuasive intuition that the presence of an element in a substance ought to explain the properties of that substance. The ‘missing piece’ for explaining the properties of substances by way of their elemental constituents is the electronegativity values of participant atoms. But electronegativity is a strikingly disunified concept that appears distinctly unamenable to analysis by way of fundamental physical principles. Through evaluating the uncertain physical identity of electronegativity, as well as its widespread and indispensable epistemic utility in chemical practice, I argue that electronegativity provides compelling grounds to seriously consider emergence for atomic species.

STUDY OF GLASS FORMERS ON BASICS OF OPTICAL ELECTRONEGATIVITY

Concept of electronegativity is used by so many researchers to study Refractive index, Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study so many glass systems. Here the concept of optical electronegativity is used to study these parameters in glass formers. It is observed that on decreasing the values of optical electronegativity; optical band energy, metallization criterion, and bond ionicity decreases; where as optical dielectric constant, optical basicity, oxide ion polarizability refractive index and third order non linear optical susceptibility increases. All glass forming oxides are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory and rules for formation of glass and Sun’s single bond strength theory. For glass formers radius ratio rc/ra = 0.14-0.40, [except P2O5] and single bond strength greater than 90 Kcal/mol. Key Words: Band energy, Basicity, Optical dielectric constant, Oxide ion polarizability, Refractive index.

Study of Conditional Glass Formers (II) on Basics of Optical Electronegativity

Concept of Electronegativity is used by so many researchers to calculate Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study the so many glass systems. Here the concept of optical electronegativity is used to study these parameters for conditional glass formers refer as (II) of group V(A,B) and VI(A,B). They are Ta2O5, Nb2O5, V2O5, Cr2O3, Bi2O3, TeO2, MoO3, As2O3, WO3, Se2O3. It is observed that on decreasing the values of optical electronegativity, optical band energy, metallization criterion, and bond iconicity decreases; and optical dielectric constant, optical basicity, oxide ion polarizability refractive index, third order non linear optical susceptibility increases. All conditional glass forming oxides (II) are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory and rules for formation of glass and Sun’s single bond strength theory. For Conditional glass formers (II) radius ratio rc/ra = 0.250-0.492, [except Bi2O3 (0.75) & TeO2 (0.87)] and single bond strength greater than 90 Kcal/mol. According to Sun’s, high bond strength oxides are not good glass formers because they themselves do not forms glass; but when they forms small ring in the melt of these materials which would result in easy crystallization. Key Words: Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-liner optical susceptibility.

Computational and Experimental Investigation of Antibacterial Properties of Some Fluorinated Thioureas

Herein, fluorinated thioureas with various substituents (F1-F3) were synthesized and characterized spectroscopically and analytically to investigate their properties as antibacterial agents. Prior to experimental studies, Density Functional Theory (DFT) modeling was performed at B3LYP/6-31G (d,p) to complement and offer comparative overview with the experimental findings. With regards to all theoretical analyses, the Frontier Molecular Orbital (FMO) demonstrated a desirable low HOMO-LUMO gap for all three designated derivatives, particularly F1 (1.60 eV), which is consistent with its GCRDs values, namely its high electronegativity and low hardness values that corresponds to low LUMO energy, suggesting higher bacterial activity. Agar diffusion assay was used for the preliminary screening of in-vitro antibacterial activity against pathogenic Gram-positive and Gram-negative bacteria. All three derivates successfully inhibit at least two bacterial strains (B. cereus, S. aureus), but none were able to penetrate into E. coli. The highest inhibition rate was exhibited by F3 at 33.33 ± 0.71% against S. aureus, whilst F1 only managed to gain 29.63 ± 0.00% of inhibition rate for the same bacterium. Meanwhile, the lowest penetration rate was recorded at 1.53 ± 0.35% by F2 against B. cereus.

Study of Tl-based perovskite materials TlZX3 (Z = Ge, Sn, Be, Sr; X = Cl, Br, I) for application in scintillators: DFT and TD-DFT approach

Scintillators are designed significantly for utilization in a broad range of technology fields, notably nuclear physics, healthcare testing, and materials analysis. A number of applications involving scintillators, such as therapeutic image analysis, burglary prevention as well and nuclear investigation, have tempted scientists to establish novel and effective scintillators. In this report, thallium-based perovskite material TlZX3 (Z = Ge, Sn, Be, Sr; X = Cl, Br, I) has been examined by means of DFT and TD-DFT approaches. The structural, electronic, optical, and thermal properties of TlZX3 are calculated and discussed. The HOMO-LUMO energy gap of TlGeX3, TlSnX3, TlBeX3, and TlSrX3 are found in the range of 1.76 eV to 2.12 eV, 1.77 eV to 2.27 eV, 1.56 eV to 2.04 eV and 1.06 eV to 2.81 eV, respectively. Lattice constant, unit cell volume, formation energy, VEA, electrophilicity index, polarizability, refractive index, dielectric constant, entropy, and heat capacity of TlZX3 increase gradually from Cl to Br to I. However, HOMO-LUMO energy gap, tolerance factor, dipole moment, optical electronegativity, thermal energy, ZVPE, and Gibbs energy drop down from Cl to Br to I. Among the studied materials, TlGeI3 shows the maximum value of molecular hardness and electronegativity while TlSrCl3 exhibits the minimum value. The computed HOMO-LUMO energy gap and refractive index of the studied materials are in close agreement with the previously reported findings, it specifies their potential application in scintillator and solar cells.

Synthesis, Characterization and Calculations of Linear and Nonlinear Optical Properties of Acrylonitrile Substituted Spirocyclotriphosphazene Derivatives

There methoxy-substituted acrylonitrile compounds (2a, 2b and 2c) were synthesized using method described in the literature. Compounds 3a, 3b and 3c were obtained by using the microwave demethylation method for the first time, then they were reacted with 2,2-dichloro-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]-cyclotriphosphazene (DPP) to reach final products 4a, 4b and 4c. The structures of the substituted compounds were determined by elemental analysis, MALDI-TOF, 1H, [Formula: see text]C APT, [Formula: see text]P NMR and FT-IR spectroscopy. In order to investigate the usability potential of the synthesized products 4a, 4b and 4c in optoelectronic devices, we experimentally measured the band gaps and calculated their nonlinear optical properties by Density Functional Theory (DFT) method. Obtained results showed that the introduction of an electronegative substituent (F) or an electropositive substituent (CH[Formula: see text] to the parent compound 4a has minimal impact on the absorption spectra. However, the fluorine-substituted compound 4b exhibits considerably higher values in terms of dipole moment, averaged polarizability, and first-hyper polarizability when compared to compounds 4a and 4c. Calculated values of dipole moment, averaged polarizability, first-hyper polarizability, electronegativity and global hardness of the fluorine-substituted compound 4b were found to be 6.281 (debye), −393.592 (1.4818 × 10[Formula: see text] cm[Formula: see text], 899.857 (8.641 × 10[Formula: see text] cm5/e.s.u), 4.492 (eV) and 1.922 (eV), respectively. These values were the highest in magnitude in comparison to the associated values of 4a and 4c. Overall results indicated that the influence of introducing an electropositive substituent (CH[Formula: see text] to the parent compound 4a, resulting in decreased stability and increased reactivity. Conversely, the introduction of an electronegative substituent (F) to 4a leads to opposite effects.