Physics

Racecadotril (RCL), a sulfur-containing compound, was analyzed through theoretical and experimental techniques to explore its structural, spectroscopic, electronic, and biological properties. C–H bonds primarily contribute to bond distances, while C–C–H angles are the most dominant among bond angles. The impact of solvent polarity on the Frontier Molecular Orbitals (FMO), electronic spectra, and Molecular Electrostatic Potential (MEP) mapping was examined, with a focus on polar solvents such as DMSO, ethanol, methanol, and water, as well as non-polar solvents like cyclohexane, toluene, and chloroform. Vibrational spectra exhibited characteristic bands associated with CH3, CH2, CH, NH, CC, CO, and CS stretching and deformation modes. Excitation wavelengths were identified in polar solvents at approximately 253 nm, 231 nm, and 229 nm, with corresponding wavenumbers ranging from 39496 cm−1 to 43647 cm−1. In contrast, non-polar solvents caused a slight red shift, with wavenumbers ranging from 39241 cm−1 to 43605 cm−1, indicating solvent-dependent electronic transitions. Lone pair interactions played a crucial role in molecular stabilization, with nitrogen-to-oxygen charge transfer contributing 49.21 kJ/mol, oxygen-to-oxygen at 48.04 kJ/mol, and carbon-carbon delocalization within a conjugated system at 21.45 kJ/mol. Mulliken charge analysis and MEP mapping further confirmed the presence of nucleophilic nitrogen and oxygen, electrophilic carbonyl carbons, and electron-withdrawing sulfur, with H33 exhibiting the highest electrophilicity due to nitrogen polarization. A topological study identified localized, delocalized, and weak interactions, shedding light on its electronic characteristics. Furthermore, molecular docking conducted against SARS-CoV-2 main proteases, spike glycoprotein, and oncoproteins from the SMAD family demonstrated the RCL's potential antiviral and antiproliferative activity.

Thiocolchicoside (TCS), a colchicine derivative, was analyzed using experimental and theoretical spectroscopic methods. The bond angle C24-C30-C32 showed a simulated value of 136.0° and an observed value of 132.9°, higher than the standard value of 120°, due to the electronic or steric effects of the oxygen atom (O10). The vibrational spectra identified the stretching and deformation modes of several functional groups, including O–H, N–H, C–H, CH2, CH3, Cdouble bondO, C–O, C–C, and C–S. In polar solvents like water, DMSO, and acetone, the HOMO and LUMO energies were more stabilized compared to non-polar solvents like toluene, indicating stronger solvent–solute interactions. The FMO energy gap was largest in water and DMSO (3.53 eV) and smallest in toluene (3.51 eV), suggesting greater reactivity in non-polar solvents. Electron donation by nitrogen (N12) and oxygen (O10) lone pairs to the electron acceptors O11-C34 and N12-C34 resulted in the highest stabilization in NBO analysis, with energies of 44.62 and 25.34 kJ/mol, respectively, due to L(2)-π* and L(2)-σ* transitions. Topological analysis showed hydrogen atoms H54 and H43 in the sugar moiety, methoxy (O-CH3), and acetyl (CO-CH3) marked in red, indicating electron localization, while blue around C13, C15, and C32 indicated delocalized electron regions. ADME prediction shows that TCS has low GI absorption and no permeability across the BBB, with five hydrogen bond donors and ten acceptors. Molecular docking analysis confirmed TCS’s biological activity, demonstrating binding affinities for COVID-19 main proteases 6LU7, spike protein 6VXX, and SMAD proteins 1U7V (SMAD4) and 1U7F (SMAD3) with binding energies of −9.52, −3.59, −5.18, and −5.85 kcal/mol, indicating its potential antiviral and antitumor effects.Thiocolchicoside (TCS), a colchicine derivative, was analyzed using experimental and theoretical spectroscopic methods. The bond angle C24-C30-C32 showed a simulated value of 136.0° and an observed value of 132.9°, higher than the standard value of 120°, due to the electronic or steric effects of the oxygen atom (O10). The vibrational spectra identified the stretching and deformation modes of several functional groups, including O–H, N–H, C–H, CH2, CH3, Cdouble bondO, C–O, C–C, and C–S. In polar solvents like water, DMSO, and acetone, the HOMO and LUMO energies were more stabilized compared to non-polar solvents like toluene, indicating stronger solvent–solute interactions. The FMO energy gap was largest in water and DMSO (3.53 eV) and smallest in toluene (3.51 eV), suggesting greater reactivity in non-polar solvents. Electron donation by nitrogen (N12) and oxygen (O10) lone pairs to the electron acceptors O11-C34 and N12-C34 resulted in the highest stabilization in NBO analysis, with energies of 44.62 and 25.34 kJ/mol, respectively, due to L(2)-π* and L(2)-σ* transitions. Topological analysis showed hydrogen atoms H54 and H43 in the sugar moiety, methoxy (O-CH3), and acetyl (CO-CH3) marked in red, indicating electron localization, while blue around C13, C15, and C32 indicated delocalized electron regions. ADME prediction shows that TCS has low GI absorption and no permeability across the BBB, with five hydrogen bond donors and ten acceptors. Molecular docking analysis confirmed TCS’s biological activity, demonstrating binding affinities for COVID-19 main proteases 6LU7, spike protein 6VXX, and SMAD proteins 1U7V (SMAD4) and 1U7F (SMAD3) with binding energies of −9.52, −3.59, −5.18, and −5.85 kcal/mol, indicating its potential antiviral and antitumor effects.

Sol gel and the hydrothermal approach are two distinct techniques that have been successfully used
to synthesise lead nanoferrite (PbFe2
O4
). To determine which of the two approaches is superior,
the features of the sample prepared by each have been examined. Vibration Sample Magnetometer
(VSM), Fourier Transform Infrared Spectroscopy, UV-VIS Spectral investigations, Scanning
Electron Microscopy (SEM), X-Ray Diffraction, and Size, Band Gap Energies, Morphology, and
Magnetic Properties of Nanostructures were used to determine and compare its various aspects.
The mean diameters of the synthesised lead ferrite nanocrystalline were found to be 33 nm for the
sol gel method and 20 nm for the hydrothermal method, respectively, based on X-Ray Diffraction
analysis using Debye-Scherer’s formula with the peak. FTIR spectra are used to analyse the
vibration characteristics of nanomaterials. The optical characteristics of the synthesised
nanomaterials, such as their Energy Band Gap, were determined using UV-VIS Spectral
investigations. SEM is used for surface morphological investigations, allowing the structure
of the synthesised nanomaterials to be studied. Using VSM, the magnetisation of the produced
nanomaterials was examined, and the hysteresis loops were used to calculate the saturation
magnetisation (Ms), coercivity (Hc), and retainivity (Mr).

Morphology and properties of ceramics are first attributes of synthesis techniques and sitering temperature. In order to understand the effect of synthesis techniques and sintering temperature 0.55(Ba0.9Ca0.1)TiO3-0.45Ba(Sn0.2Ti0.8)O3(BCT-BST) is synthesized by solid state reaction (SSR), sol-gel method and molten-salt methods. The cubic crystal structure of all the synthesized BCT-BST is confirmed by X-ray powder diffraction analysis. Densification temperature varies between 1250 oC and 1400 oC depending on the synthesis technique. The morphology and particle size of each of BCT-BST is studied using scanning electron microscope. Particle size is found to be in the range of 32nm to 60nm. Dielectric studies on each of BCT-BST are carried out as a function of temperature and frequency. The morphotropic phase boundary is noticed at 71oC and a high dielectric constant of 18000 noticed for sol gel synthesized BCT-BST. A soft ferroelectric hysteresis curve is exhibited by each of BCT-BST.

Development of new superparamagnetic materials with narrow size distribution is crucial for biomedical and environmental applications. Hence, we report the synthesis of narrow size distributed single grain MnFe2O4 nanoparticles of average particle size 9 nm by solvothermal reflux method. Synthesized compound crystallized in face centered cubic spinel structure and is confirmed by X-ray diffraction profiles. Transmission electron micrograph shows narrow size distributed particles with an average particle size of 9 nm and is equal to crystallite diameter estimated from Scherrer equation. The spinel crystal structure is further confirmed by electron diffraction profiles, Fourier transformed infrared spectrum, and Raman spectrum at room temperature. Magnetic properties of the sample show superparamagnetic nature at room temperature with moderate saturated magnetization of 56.4 emug−1. Magnetic heating properties of nanoparticles dispersion show the attainment of hyperthermia temperature (43 °C) in a short span of time of 1.6 min for 2 mg/mL and 2.6 min for 1 mg/mL concentrations. Estimated specific heat generation rate or specific power absorption rate, from temporal temperature plots, is 145.78 Wg−1 and is useful for magnetic hyperthermia application in cancer therapy. Photocatalysis properties of sample show 96% of rhodamine B dye degradation in little less than 6 h under UV light irradiation and are useful for photocatalytic applications in wastewater treatment in industries.

Abstract: Lead free 0.55(Ba0.9Ca0.1) TiO3-0.45Ba
(Sn0.2Ti0.8) O3 (BCT-BST) ceramic is synthesized by three
different techniques viz solid state method, sol-gel method and
molten-salt method. The prepared BCT-BST ceramic samples
exhibited cubic crystal structure on X-ray powder diffraction
analysis. The morphology of the samples is analyzed using
transmission electron microscope. The lattice interactions with
ultrasonic waves and morphotropic phase boundary at 70oC is
confirmed from elastic and anelastic studies of the ceramic. High
piezoelectric coefficient d33 of 623 pC/N is achieved in the
prepared BCT-BST ceramics.

Spinel ferrites at nanoscale showed quite different properties rather than the bulk counterpart. Among all the ferrites, ZnFe2O4 compound is chemically stable and showed very good properties at room temperature. In this investigation, we reported the synthesis and characterization of ZnFe2O4 single-phase crystals of diameter 11 nm by solvothermal reflux method. Temperature-dependent dielectric constant, dielectric loss, and ac-electrical conductivity of the pellet were measured up to 450 °C under different alternating electric field frequencies from 1 kHz to 1 MHz. The obtained data revealed interfacial or space charge polarization mechanism. Furthermore, the sample showed superparamagnetic nature at room temperature. In addition, the magnetic hyperthermia value and specific heat generation rate (SHGR) of 128.76 J s−1 g−1 for ZnFe2O4 compound at 1 mg mL−1 concentration were evaluated. The data were interpreted by spin-relaxation mechanism. ZnFe2O4 nanoparticles showed good photocatalytic activity under UV light irradiation. The data were interpreted by electron–hole pair and radical formation and degradation of Rhodamine B dye.

In this paper, we focused on microwave sintered NiTiO3 nanoparticles synthesized via sol–gel method. The crystal structure was determined by the X-ray diffraction. Vibrational bands related to Ni–O and Ti–O bands were confirmed using the Fourier transform infrared spectrum. These NiTiO3 ceramics obeyed semiconductor behavior of Arrhenius type. The activation energy was found to be 0.04 μeV. The M–H curve exhibited superparamagnetic behavior at room temperature.

The microwave sintered NiTiO3 nanoparticles were synthesized by sol-gel method. The synthesized compound is found to be rhombohedral crystal structure and crystallite size of 46 nm from X-ray powder diffraction technique. The metal-oxide Ni-O and Ti-O bands were analyzed by Fourier Transform Infra-Red analysis. The average particle size is found to be 56 nm from High Resolution Scanning Electron Microscope analysis. The activation energy calculated from Arrhenius plot, the value is found to be 0.04 μeV. The Mr value is found to be 0.22 emu/g. At room temperature NiTiO3 exhibited superparamagnetic nature.

Of all the piezoelectric ceramics, lead titanate (PbTiO3) has an important place as an electromechanical transducer. In the present article PbTiO3 synthesized by sol–gel technique and microwave processed is presented. The sintered PbTiO3 is found to be of high density. The sintered PbTiO3 crystal structure and crystallinity confirmed by powder X-ray diffraction and sample weight loss and decomposition investigated by thermal analysis. Prepared PbTiO3 functional groups confirmed by FT-IR spectrum and phase formation analyzed by Raman spectra. Sample spherical morphology confirmed by high-resolution scanning electron microscopy (HRSEM) and transmission electron microscopy (TEM). The particle size found to be 77 nm from TEM. The variation of dielectric constant and ac conductivity with temperature and frequency of PbTiO3 are investigated. The value of σdc is found to be 1.767 × 10−2 S/cm at transition temperature using the Nyquist plot. The ferroelectric hysteresis loop and piezoelectric coefficient d33 confirm the ferroelectric and piezoelectric nature of the PbTiO3 (PT).

The series of Li(4−2x)NixTi2O6 (where x = 0, 0.25, 0.50 and 0.75) is synthesized by sol–gel method and further microwave processed. The X-ray diffraction confirmed the single phase formation of monoclinic crystal structure and the average crystal size is calculated to be between 35 and 44 nm. The Fourier transformation infra-red analysis confirmed the vibrational bond frequency of the sample. The high-resolution scanning electron microscope revealed uniform morphology and the average particle size is found to be 15–30 nm. The temperature dependent dielectric constant is measured in the temperature range 30–560 °C. A drastic change in the dielectric is noticed after 370 °C in all the compositions. The complex impedance spectrum confirms the electron hopping conduction and non-Debye type behaviour at all the recorded temperatures. The Cole–Cole plots suggested grain conduction for all the compositions except for x = 0.75, where other contributions are suspected.

This paper is reported on Ni-doped lithium titanate by sol-gel method and microwave processing. The structural formation of lithium nickel titanate is confirmed by powder X-ray diffraction technique. The AC conductivity and modulus study are discussed. The electrical conduction mechanism of lithium nickel titanate is small polarons. Introduction. Lithium ceramics have attractive property for fast tritium release, high density, thermal stability, low activation energy, Li-ion battery which is used in portable electronic devices, communication facilities, electronic vehicles and stationary energy storage systems [1-5]. Different techniques are used to produce lithium titanate ceramics such as sol-gel, other wet chemical methods and solution combustion and polymer solution. Among these methods, the sol-gel method is easy to synthesis and yields high homogeneity [6]. Microwave sintering of ceramics is the easiest and cheapest method, offering rapid heating rate, low sintering temperature and uniform sintering [7]. The electrical property of the material depends on structural changes in the material. The structural and electrical conductivity of the lithium nickel titanate (LNT) synthesized by sol-gel method [8] and microwave processing is discussed.

Silver niobate and barium niobate solid solution ferroelectric material with the general formula AgNbO3+BaNb2O6 (ABN) is synthesized by conventional ceramic route. X-Ray diffraction studies of ABN revealed AgNbO3 and BaNb2O6 phases distinctly. The solid solution is characterized for ferroelectric and dielectric properties. After poling, the sample is scanned for P-E loop. The solid solution has resulted in a dielectric constant of 162 at room temperature when frequency scanned in the range of 100 Hz to 5 MHz is studied.

This study delved into the electronic structure of Pyridine derivative 3-Chloro-2,6-difluoropyridin-4-amine (3C26D4A) using quantum-chemical computational calculations and employing the DFT/B3LYP/6-311++G(d,p) method and basis set. Spectroscopic, electronic, Mulliken population analysis and molecular electrostatic potential surface (MESP) calculations were carried out to gain deeper insights, shedding light on their bonding characteristics and reactive sites. The simulated electronic and frontier molecular orbitals (FMO) energy gaps of 3C26D4A in both polar (aniline, DMSO and methanol) and nonpolar (CCl4, chloroform, cyclohexane and toluene) confirm the stability and chemical reactivity. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy gap of 3C26D4A in the gas phase is found to be 6.0214 eV and shows low reactivity and stability as compared to the solvent phase. In parallel, in silico molecular docking investigated their promise as antimicrobial agents by targeting key enzyme DNA gyrase. The obtained binding energy revealed a significant inhibitory potential docking score of -4.07 kcal/mol.

Lithium titanate (LT) is an anode material used for storage devices. In this chapter, the composition of Li4Ti2O6 synthesized by sol–gel method and processed in microwave is presented. The microwave-processed Li4Ti2O6 is characterized by structure and microstructure by X-ray powder diffraction and scanning electron microscope confirming the single-phase formation and uniform morphology with a particle size varying from 23 nm to 30 nm. AC conductivity confirms that the materials use three different conduction mechanisms. In the high-temperature region, the conduction is purely due to hopping of electrons. The impedance analysis of LT is confirmed by the negative temperature coefficient of resistance because the resistance value is decreased by increasing the temperature. The conductivity, relaxation time, and capacitance values are measured at different temperatures from 300°C to 480°C.