Dipole Moment Values Research Articles

Structure, Frontier Molecular Orbitals, MEP, Charge Analysis, and NLO Study of 2,4-, 2,5-, and 2,6-Dimethylanilines Using DFT

This study includes the evaluation of most stable structure, frontier molecular orbitals, molecular electrostatic potential (MEP), and nonlinear optical (NLO) parameters of 2,4-dimethylaniline (2,4DMA), 2,5-dimethylaniline (2,5DMA), and 2,6-dimethylaniline (2,6DMA) using density functional theory (DFT) employing B3LYP functional with 6-311++G(d,p) basis set. HOMO-LUMO energies, band gap energies, and global reactivity descriptors were obtained from the optimized structures. The band gap energy was determined as 3.7865, 3.9348, and 3.9443 eV for 2,4DMA, 25DMA, and 2,6DMA, respectively. The reactive sites of the molecules were obtained from the molecular electrostatic potential energy. The NLO parameters such as dipole moment, polarizability, and hyperpolarizability have been investigated for the title molecules. The investigated dipole moment and first-order hyperpolarizability values are higher than the prototypical value of urea and show good NLO behavior. The NMR chemical shifts, electronic absorption spectra, and charge distribution of atoms were calculated theoretically. Furthermore, thermodynamic and rotational constants were also calculated.

Proposing anti-counterfeiting pharmacopoeia quality markers for Shenlingbaizhu granule based on UHPLC-Q-orbitrap-MS identification.

Shenlingbaizhu granule, a Traditional Chinese Medicine prescription comprising Renshen, Gancao, and Shanyao, is widely consumed in China nowadays. The study tries to propose pharmacopoeia quality markers (Q-markers) to prevent counterfeiting involving Renshen, Gancao, and Shanyao. A novel strategy, that is, library-based ultra-high-performance liquid chromatography-quadrupole-orbitrap mass spectrometry, was used to analyse the lyophilised aqueous powder of Shenlingbaizhu granule. Subsequently, quantum chemistry calculation and UV-vis spectra scanning were also performed through theoretical or experimental approaches. Thirty-two isomers have been strictly distinguished, especially positional isomeric isochlorogenic acid B versus isochlorogenic acid C, positional isomeric schaftoside versus isoschaftoside, positional isomeric ginsenoside Rg2 versus 20S-ginsenoside Rg3, and stereoisomeric 20S-ginsenoside Rg3 versus 20R-ginsenoside Rg3. Seventeen compounds were unexpectedly observed, particularly scoparone and pectolinarigenin, while a total of 76 bioactive compounds have been putatively identified in the study. The quantum chemistry calculation and UV-vis spectra scanning results revealed that glycyrrhizic acid, ginsenoside Re, ginsenoside Rb1, and diosgenin displayed different dipole moment values and maximum absorption wavelengths from each other. The study recommends glycyrrhizic acid, ginsenoside Re, ginsenoside Rb1, and diosgenin as four anti-counterfeiting Q-markers for the pharmacopoeia. The anti-counterfeiting Q-markers can be detected using conventional HPLC. The observation of 17 unexpected compounds updates our knowledge regarding the bioactives of Shenlingbaizhu granule.

Adsorption films based on indazole derivatives for application to protect Cu in sulfuric acid: Experimental and theoretical approaches

BackgroundFinding more cost-effective, low-toxicity corrosion inhibitors to reduce copper corrosion in acidic environments is critical. MethodsThe anti-corrosion abilities and mechanisms of 5‑bromo-1H-indazole (5-BIA) and 7‑bromo-1H-indazole (7-BIA) on Cu in 0.5 M H2SO4 environment have been explored by a way of combining both experimental and theoretical approaches. Significant findingsElectrochemical experiments have shown that both 5-BIA and 7-BIA are capable of acting as highly effective corrosion inhibitors for copper, and 5-BIA has a more prominent protective ability than 7-BIA, which has also been proved by weight loss experiments, SEM and AFM. The corrosion inhibition efficiency (ηE) of 1.5 mM 5-BIA and 1.5 mM 7-BIA is as high as 97.1 % and 94.0 %, respectively. The adsorption of 5-BIA and 7-BIA on the metal surfaces conforms to the Langmuir monolayer adsorption model, and both chemosorption and physical adsorption exist. In addition, quantum chemical calculations reveal that 5-BIA has smaller energy gap (ΔE) and hardness (η) values, and larger dipole moment (μ), absolute electronegativity (χ), and chemical softness (σ) values, thus exhibiting better anti-corrosion ability. Molecular dynamics simulations display that both 5-BIA and 7-BIA can be adsorbed on the Cu (111) surface in an approximately parallel approach, which is conducive to achieving 5-BIA and 7-BIA to hinder the process of copper corrosion as much as possible.

Extension of Surface Charge Density Studies of Metal Oxide Semiconductor (MOS) Structure to Polarization Studies of Metal Ferroelectric Metal (MFM) Structure in Bulk Form: Experimental and Simulation of Polarization Data

Ba(NdxTi(1-2x)Nbx)O3 and (Na0.5Bi0.5)(NdyTi1-2yNby)O3 relaxor ferroelectric materials were prepared through solid state sintering route. The polarization as a function of electric field (PE loops) were measured with Radiant technologies PE loop tracer. In the present studies we have extended the surface charge density studies of metal oxide semiconductor (MOS) structure to the polarization studies of metal ferroelectric and metal (MFM) structure in bulk form by combining it with the modified Glazounov and Arrhenius equations. The simulation is in good agreement the experimental data. In the case of Ba(NdxTi(1-2x)Nbx)O3 ceramics the value of dipole moment (p) are 2.24x10−26 C.m, 1.80x10−26 C.m, 2.23x10−26 C.m & 2.21x 10−26 C.m for x = 0.025, 0.05, 0.1 & 0.2, respectively. The values of surface potential (Ψp) are 466 meV, 503 meV, 552 meV & 505 meV for x = 0.025, 0.05, 0.1 & 0.2, respectively.

Multiparametric Investigations on Solvation Behaviour and Spectral Shifts of Symmetric Aromatic Diselenides: A case study of Diphenyldiselenide

ABSTRACT Decorating symmetric aromatic diselenide motif such as in diphenyldiselenide (DPDSe) with diverse supra-functionalities provides a plethora of bioactivities for pharmacological applications. Solvent studies of bioactive molecules are vital descriptors for their drug development as these can predict the drug–target interaction. This study aims to evaluate the influence of intermolecular interactional forces on the solvation behaviour and spectral shifts of DPDSe. The solvation behaviour of DPDSe was evaluated primarily via solvent polarity and solvent parameters. The observed solvatochromic shifts were analysed with various solvent study models, of which Kamlet–Taft and Catalan models were found to be most suitable for describing intermolecular interactions of DPDSe. The experimental data suggest an overall red shift with increasing solvent polarity. Moreover, data analysis using solvatochromic models predict negative coefficients for solvent dipolarity (π*) and solvent polarisabilities (SP) and (SdP). The studied dipole moment values indicate the more polar nature of DPDSe in the excited state relative to the ground state, further corroborating the observed bathochromic shift with increasing solvent polarity.

Green Synthesis and Bioactivity of Aliphatic N-Substituted Glycine Derivatives.

Standard amino acids have an asymmetric α-carbon atom to which -COOH, -NH2, -H, and -R groups are bonded. Among them, glycine is the simplest (R = -H) with no asymmetric carbon, and other natural amino acids are C-substituted of glycine. Here, we have designed and made a green synthesis of some new N-substituted glycine derivatives with R-(NH)CH2-COOH formula, where R is flexible and hydrophobic with different chain lengths and benches of the type propyl, butyl, sec-butyl, tert-butyl, pentyl, isopentyl, tert-pentyl, hexyl, 2-aminoheptyl, and octyl. These glycine derivatives were characterized by recording their melting points and FT-IR, mass, 1H NMR, and 13C NMR spectra. DFT studies revealed that 2-aminoheptyl glycine had the highest electronegativity value and can thus act as a good bidentate ligand for the metal centers. ADME comparative results and bioavailability radars indicated that both octyl- and 2-aminoheptyl glycine had the most lipophilicity, making them good agents in cell passing. Furthermore, lipophilicity determination showed that octyl glycine was the best and propylgly was more soluble than others. Based on solubility, lipophilicity, and dipole moment values, propyl- and 2-aminoheptyl-glycine were considered for bio-macromolecular interaction studies. Thus, the interaction of these two agents with DNA and HSA was studied using absorption spectroscopy and circular dichroism techniques. Due to the presence of the R-amine group, they can interact with the DNA by H-binding and hydrophobicity, while electrostatic mode could not be ruled out. Meanwhile, molecular docking studies revealed that octyl- and 2-aminoheptyl glycine had the highest negative docking energy, which reflects their higher tendency to interact with DNA. The DNA binding affinity of two candidate AAs was determined by viscosity measurement and fluorescence emission recording, which confirms that groove binding occurs. Also, the toxicity of these synthesized amino acid derivates was tested against the human foreskin fibroblast (HFF) cell line. They showed IC50 values within the range of 127-344 μM after 48 h with the highest toxicity for 2-aminoheptyl glycine.

Synthesis, Structural, Spectroscopic, Topological, NLO and Docking Analysis on 4-Ethoxy-3-Methoxy Benzaldehyde: experimental and Theoretical Approach

The main objective of the study is to analyze the structural behavior, NLO, and docking analysis of 4-ethoxy-3-methoxy benzaldehyde (EMBA) by experimental and theoretical spectroscopic techniques. Its computational result is compared with experimental results. The optimized structural parameters of the title compound were computationally obtained at B3LYP/6-311++G (d, p) basis set. The fundamental modes of vibration were examined by experimental FT-IR and FT-Raman techniques. The distribution of the vibrational bands were performed with the help of normal coordinate analysis (NCA). The optical nature of the grown crystal was evaluated by using the UV-Vis optical transmittance spectrum. The lower wavelength absorption range and various optical constants, for instance, energy band gap, and Urbach energy values were evaluated. Hirshfeld surface analysis was performed to determine the intermolecular interactions and crystal packing of the title molecule. Natural bond orbital analysis (NBO) has been performed on the title compound in order to elucidate intermolecular hydrogen bonding, intermolecular charge transfer (ICT), and delocalization of electron density. The formation of C–H…O intermolecular interactions was analyzed using reduced density gradient (RDG) analysis. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP), electron localization function (ELF), and localized orbital locator (LOL) analysis were performed. The emission behavior of EMBA was analyzed by fluorescence spectral analysis. Non-linear optical properties (NLO) such as electric dipole moment (μ), polarizability (α), and hyperpolarizability (β) values of the investigated molecules have been computed using B3LYP quantum chemical calculation. The molecular docking studies were performed to investigate the binding affinity of legend with target receptor.

Structure, chemical reactivity, NBO, MEP analysis and thermodynamic parameters of pentamethyl benzene using DFT study

This study explores the structural, molecular and electronic properties of the pentamethyl benzene (PMB) using quantum chemical calculations employing DFT/ B3LYP/6–311++G(d,p) level of theory. Structural parameters, HOMO-LUMO energies, chemical reactivity descriptors and molecular electrostatic potential (MEP) were evaluated from the optimized molecular geometry. The computed small band gap energy, correlated with the UV–visible spectrum, demonstrates that the test molecule has good biological activity. NLO activity of the molecule was also studied by evaluating dipole moment and first order hyperpolarizability values. Intra-molecular charge transfer, donor-acceptor transitions and stabilizations energies were determined from the analyses of natural bond orbital (NBO) and natural population. 1H and 13C chemical shifts were computed from the simulated NMR spectrum following GIAO approach in DMSO‑d6 solvent at the same level of DFT. Furthermore, thermodynamic parameters and rotational constants were also calculated for this molecule.

Synthesis and structural characterization of azine based oligoesteric chemosensors for Fe2+ ion detection

AbstractAzine‐based monomer and its three oligoesters were synthesized, characterized with IR, UV, GC‐MS, GPC, 1H NMR, 13C{1H} NMR, 31P NMR and applied to chemosensor applications. In the chemosensor study, fluorophores show selective and sensitive responses with Fe2+ ions in the DMF/H2O solution (1 : 1, pH: 7.4, fluorophore: 5 μM). The quenching of fluorescence intensity with the addition of Fe2+ ion gives the correlation coefficient (R2) value above 0.99286, exhibiting good binding stoichiometry nature of fluorophores with Fe2+ than the oligoesters. The high detecting capability of oligoesters is further ascertained by its higher LOD than the monomer (5.05×10−7). The binding constant values of fluorophores obtained from the Benesi‐Hildebrand plot show that the oligoesters have a higher binding ability (1.0012–1.0025 M−1) with Fe2+ ion than the monomer (1.0011 M−1). The conductivity nature of the oligoester gradually increased with the contact time of iodine. After 96hr of iodine doping, EMDAP exhibits higher conductivity (1.98×10−3 Scm−1) than the other oligoesters due to higher electron‐density nitrogen atoms in the structure. The EMDOP shows high dielectric constant value because of its π‐π interaction, loosely attached π electrons and high dipole moment values. All these experimental results are validated with the theoretical (DFT) approach by optimizing the structure of the fluorophore with B3LYP/6‐311++G(d,p) level basis set. The DFT approach also explains the mechanism of fluorescence quenching and the exact binding sites of fluorophores with Fe2+ ions.

Tuning nonlinear optical properties of tetracyclopentatetraphenylnene by superhalogens doping: Quantum chemical perspective of novel NLO materials for modern optoelectronic applications

Fabrication of stable NLO materials is highly demanding because of their numerous applications in optoelectronic and optical devices. This research attempts to theoretically design superhalogens (LiF2, BeF3, MgF3, LiCl2, BeCl3, MgCl3) doped tetracyclopentatetraphenylnene (TCPTP) as potential NLO materials for cutting-edge NLO applications. Density functional theory (DFT) computations explore their geometric, thermodynamic, electrical, and nonlinear optical (NLO) properties. NCI analysis, DOS, FMO, MEP, TDM, and NBO analysis are performed to confirm the type of interaction, participation of various fragments, and charge transfer, respectively. The computational findings demonstratedthat the superhalogen-doped isomers of TCPTP have remarkablethermodynamic stabilities, with the highestbinding energy of −81.344 kcalmol−1. The HOMO–LUMO energy gap was significantly decreased from 1.5319 eV (TCPTP) to 1.2807––1.2269 eV by superhalogens doping. The TD-DFT analysis demonstrates that these proposed complexes have sufficient transparency in the UV region, which is necessary to add a high nonlinear optical response for valuable applications in optoelectronics. Magnification in the dipole moment (µ0), polarizability (α0), and hyperpolarizability (β0) values from 0.0 D, 325.00 a.u. and 0.0 a.u to 18.23 D, 463.92 a.u and 4.11 × 104 a.u respectively, is achieved upon superhalogens doping on TCPTP surface. These complexes also had considerably large initial hyperpolarizability (βo) from 1.57 × 103 to 4.11 × 104 au, which was particularly noteworthy. This research with promising initial hyperpolarizability (βo) value will provide new opportunities for experimental and theoretical researchers to develop innovative NLO materials.

Comparison of spectroscopic, structural, and molecular docking studies of 5-nitro-2-fluoroaniline and 2-nitro-5-fluoroaniline: An attempt on fluoroaniline isomers

Density Functional Theory (DFT) and Hartree-Fock (HF) approaches were used to study the spectroscopic, pharmacological and other molecular properties of structural isomers of fluoroaniline such as 5-nitro-2-fluoroaniline (5N2FA) and 2-nitro-5-fluoroaniline (2N5FA). The geometrical properties, vibrational properties, electronic properties, and chemical shifts of fluoroaniline isomers have been thoroughly investigated. In the gas phase, the energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of fluoroaniline isomers is found to be 3.874 / 8.248 eV (DFT/HF) for 5N2FA and 3.979 / 8.176 eV (DFT/HF) for 2N5FA. The current study reveals that the dipole moment values for 5N2FA and 2N5FA were computed (using DFT / HF) to be approximately 4.5318 / 4.2777 D and 3.6551 / 3.5440 D, respectively. Absorption, distribution, metabolism, and excretion (ADME) properties have been predicted to evaluate the toxicity and pharmacokinetic profile of fluoroaniline isomers. Moreover, the Natural Bond Orbital (NBO), Mulliken population, and Molecular Electrostatic Potential Surface (MESP) analyses have been performed to get a crystal clear insight into the bonding characters, and reactive sites of structural isomers of fluoroaniline. Molecular docking simulation is used to investigate the biological activities of fluoroaniline isomers by forming a stable complex with inducible Nitric Oxide Synthase (iNOS) with a binding affinity of -5.6 kcal/mol (5N2FA), and -5.3 kcal/mol (2N5FA), which shows that of an enzyme inhibitor.

Zerovalent Iron/Cu Combined Degradation of Halogenated Disinfection Byproducts and Quantitative Structure-Activity Relationship Modeling.

Previous studies have reported that zerovalent iron (ZVI) can reduce several aliphatic groups of disinfection byproducts (DBPs) (e.g., haloacetic acids and haloacetamides) effectively, and the removal efficiency can be significantly improved by metallic copper. Information regarding ZVI/Cu combined degradation of different types of halogenated DBPs can help understand the fate of overall DBPs in drinking water distribution and storage systems consisting of unlined cast iron/copper pipes and related potential control strategies. In this study, we found that, besides aliphatic DBPs, many groups of new emerging aromatic DBPs formed in chlorinated and chloraminated drinking water can be effectively degraded by ZVI/Cu; meanwhile, total organic halogen and total ion intensity were reduced significantly after treatment. Moreover, a robust quantitative structure-activity relationship model was developed and validated based on the ZVI/Cu combined degradation rate constants of 14 typical aromatic DBPs; it can predict the degradation rate constants of other aromatic DBPs for screening and comparative purposes, and the optimized descriptors indicate that DBPs possessing a lower value of the lowest unoccupied molecular orbital energy and a higher value of dipole moment tend to present higher degradation rate constants. In addition, toxicity data of 47 DBPs (belonging to 18 groups) were predicted by two previously established toxicity models, demonstrating that, although most DBPs exhibit higher toxicity than their dehalogenated products, some DBPs show lower toxicity than their lowly halogenated analogs.

Addition of acceptor moiety toward Quinoxaline-based conjugated framework of chromophores for highly efficient organic solar cells

The quantum contemplation of highly unsaturated D-π-A type renewed chromophores (TQ41-TQ45) constructed on quinoxaline core-based model TQ4 are predicted to suggest novel photovoltaic constituents for the application of organic solar cells. The model TQ4 was amended by the replacement of terminal groups with conjugated acceptors via thiophene to design five novel chromophores and their structural as well as optoelectronic attributes were calculated at selected DFT method PBEPBE/6-31G (d, p) level of theory. FMO study revealed that high charge transfer occurred between HOMO-LUMO by the reduction of energy gap up to 0.59 eV (for TQ44) which is quite low from the model TQ4 (2.04 eV). Absorption profile unveiled that the maximum absorption of all the designed chromophores in dichloromethane was in visible and near IR region exhibiting bathochromic shift up to 916 nm that is higher than the reference TQ4 (505 nm). Higher values of dipole moment by novel chromophores up to 16.85 D than reference (1.66 D) suggested good solvation and better molecular packing. ESP analysis revealed electron distribution on various parts of the molecules by colored maps that is found to be effective for better ICT. TDM plots depicted density of electron transitions on various molecular sites by the absorption of light. RE values of electron and hole for novel molecules proved to be highly efficient that enhanced the charge mobilities and prevented charge recombination. Finally, open circuit voltage of all the studied chromophores was calculated by scaling our designed donors to the well-known acceptor PC71BM that is very effective for the fabrication of elite organic solar cells.

Environmentally-friendly synthesis, structural determination and antimicrobial activity of new class of spiropyrrolidine embedded with indenoquinoxaline and chromanone heterocyclic units

A regio- and stereoselective synthesis of hitherto unexplored novel class of dispiropyrrolidine embedded with indenoquinoxaline and chromanone hybrid heterocycle has been achieved employing an eco-friendly ionic liquid assisted multicomponent 1,3-dipolar cycloaddition cascade protocol. The dipolarophile, 3-(4-methoxybenzylidene)chroman-4-one reacts with non-stabilized 1,3-dipole component derived from indenoquinoxalinone and l-phenylalanine through decarboxylative cascade reaction pathway affording (2′S,4′S)-5′-benzyl-4′-(4-methoxyphenyl)dispiro[chromane-3,3′-pyrrolidine-2′,11′'-indeno[1,2-b]quinoxalin]-4-one (6) as the final product. The structure of 6 was confirmed through NMR and mass spectroscopic analyses. Further, stereochemistry of the spirocompound was undoubtedly determined through single crystal XRD analysis. In the crystal structure, the O…H and N…H interactions are the most common contacts and also have great importance in molecular packing. In addition, the C…H contacts are also important in the studied crystal structure. DFT and NBO calculations were performed on this system in order to discuss its electronic and reactivity parameters. The calculated dipole moment value is 2.9238 Debye indicating a polar compound. Compound 6 was assayed for antimicrobial efficacy and found to have potential activity against eight tested microbial pathogens. Among them, E. coli ML_KSUB22 and C. albicans ML_KSUF05 were found to be highly susceptible than the other pathogens.

Impact of symmetry breaking on the performance of non-fullerene acceptors (NFAs) for photo and thermally stable organic solar cells (OSCs): A DFT-based interrogation and investigation

Simultaneous enhancement in the fill factor (FF) and power conversion efficiency (PCE) is a crucial task for the development of photovoltaic (PV) devices. In addition, symmetrical acceptor molecules lack photo and thermal stability due to low extinction coefficient and dipole moment. Breaking of symmetry in typical fullerene-free acceptors brings high values of dipole moments along with crystalline features. In this regard, a series of new acceptor molecules have been designed by deep end-capped remodeling of the IPC-BEH-IC2F. Newly remodeled systems disclosed high values of electronic charge shifting and perfect molecular packing. The impact of symmetry breaking is examined through density functional theory (DFT) and time-dependent density functional theory (TDDFT) at CAM-B3LYP/6-311G(d,p) level. Photovoltaic and geometric aspects like frontier molecular orbitals (FMOs), excitation energy, open circuit voltage (Voc), FF%, and PCE have been computed theoretically. Reshaped systems expressed high mobilities of the electrons and holes towards the metal electrodes together with easy excitation of the exciton. High Voc enhances the FF% and PCE in the SGS-1 to SGS-4. Results of all analyses showed that SGS-1 to SGS-4 are well-designed systems for the development of the highly efficient active layer for OSCs.

DFT investigation of stability, electronic and optical properties of coordination of C20 corannulene to Fe(CO)4

Four coordination modes of Fe(CO)4 fragment to C20-corannulene were optimized at the mPW1PW91/6-311G(d,p) and B3LYP*/6-311G(d,p) levels of theory. Energetic stability of these isomers were illustrated. The interaction of between C20 and Fe(CO)4 fragments was evaluated with independent gradient model (IGM). Dipole moment values, polarizability parameters and non-linear optical properties of these complexes were investigated at mPW1PW91/6-311G(d,p)//B3LYP*/6-311G(d,p) levels. The incident–frequency (ω) effect was illustrated on the polarizability and first hyperpolarizability at applied frequencies of 694.56 nm with direct current second harmonic generation (DCSHG). Natural bond orbital analysis computations were employed for clarification the characterizations of Fe-C bonds.

Chemical reactivity of 3-substituted-6,8-dimethylchromones towards 1H-benzimidazol-2-ylacetonitrile and 5-amino-2,4-dihydro-3H-pyrazol-3-one: Spectroscopic, theoretical and in silico ADME studies

The reactivity of 1H-benzimidazol-2-ylacetonitrile and 5-amino-2,4-dihydro-3H-pyrazol-3-one, as nucleophilic reagents, was examined towards some 3-substituted-6,8-dimethylchromones 2a-d. A diversity of novel pyrido[1,2-a]benzimidazoles, chromeno[2,3-b]pyridines, pyrazolo[3,4-b]pyridines and chromenopyrazolopyridines was efficiently synthesized through different chemical transformations; depending on the functional group present at C-3 position of the chromone moiety. With B3LYP/6–311 G(d,p) basis set in the ground state, density functional theory (DFT) is used to determine the molecular geometry of synthesized compounds. The reactivity of the current compounds was studied by global reactivity descriptors at the same level of theory. In order to forecast the reactive locations on the starting substrates 2a-d for nucleophilic and electrophilic attacks, Fukui functions (local reactivity descriptors) were computed at the same level of theory. On the other hand, molecular electrostatic potential (MEP) surface maps were used to identify the nucleophilic and electrophilic sites. Moreover, 1H and 13C NMR chemical shift values in the ground state was calculated using the Gauge-Including Atomic Orbital (GIAO) technique, and the predicted values were compared with the experimental results. To interpret the nonlinear optical (NLO) property of the synthesized compounds, the dipole moment, polarizability, and first hyperpolarizability values have been measured (in the range β = 0.38 × 1030 - 3.28 × 10−30 esu). First hyperpolarizabilities of the investigated compounds indicate promising candidates for nonlinear optical applications. Also, using web-based platforms, in silico ADME calculations were performed.

Vapor-liquid equilibria in the 1-methylpyrrolidine + 1-butylimidazole binary system: Experimental measurements and theoretical modelling

In this study, a comprehensive investigation of the 1-methylpyrrolidine + 1-butylimidazole binary system was conducted to establish a valuable foundation for process design. Isobaric binary vapor − liquid equilibrium (VLE) data was measured (80 data points) at 50.0, 20.0, 10.0, and 7.5 kPa using dynamic equilibrium cell (VLE 602) and found that no azeotrope existed throughout the entire operating pressure range. Thermodynamic consistency was validated using the Redlich − Kister area test (9.56801%). The vapor pressure of 1-butylimidazole was determined through direct measurement (12 data points) of the equilibrium temperature at different pressures and the Antoine equation parameters were regressed based on the acquired data. The VLE data were regressed using maximum likelihood (ML) method, and binary interaction parameters (BIP) were estimated for NRTL–HOC, UNIQUAC, Van Laar, and Wilson models. The model validation demonstrated consistency between calculated and experimental values for temperature and mole fraction of the vapor phase. In addition, dipole moment (μ) values were evaluated by quantum chemical calculations using the Hartree–Fock (HF) method through GAMESS package. The density (12 data points), the sound velocity (12 data points), the refractive index (3 data points), and the normal boiling points (3 data points) were also measured for binary mixtures and pure components.

Size-dependent solvatochromism of CdS nanoparticles: Experimental absorption and fluorescence analyses

Owing to the quantum confinement effect, a nanocrystal shows a unique blend of molecular and solid properties: discrete energy levels with large polarizabilities which could respond to solvent environments. In this paper, we used steady-state fluorescence and absorption spectroscopy to study the size-dependent solvatochromism of CdS nanoparticles. The dipolar character of the ground state and the first excited state of the nanoparticle were also investigated with in the framework of Onsager reaction field theory using Ooshika–Mataga–Lippert equation. The results of the present study revealed that the solvatochromic responses were size dependent. Additionally, the responses increased with the particle size up to a certain size beyond which the response started to fall again. Hence, fine-tuning the nanoparticle's solvatochromic response and band gap is possible by appropriate choice of size. Moreover, size-dependent dipole moment values of CdS nanoparticles were determined. Based on the findings of the present study it was noted that steady-state fluorescence and absorption spectroscopy methods can efficiently be used to study the size-dependent solvatochromism of CdS nanoparticles.

The Effects of Conjugated Fused Ring System: An Investigation of Electronic, Nonlinear Optical, X-Ray Structural Properties and Computational Studies on Chalcone Derivatives

The conjugated fused ring system of chalcone with D-A-π-A and A-A-π-D framing has been the subject of a detailed study on intramolecular charge transfer (ICT). The strong donors (Anthracene and Pyrene), strong acceptors (cyano), and large extended conjugation are in charge for the higher third order susceptibility in order of (10−6 esu) and show good optical limiting behavior with a lower optical limiting threshold which is determined by Z-scan analysis. Computational studies reveal that the higher values of dipole moments, polarizability and second hyperpolarizability values provided evidence that the proposed compounds are suitable as an efficient NLO material. The band gap energy generated from the FMOs was shown to be decreasing while μ increased, which is an indication of ICT occurring within molecules. Natural bond orbital (NBO) studies the different ICT interactions occurring and demonstrated a significant push-pull action for both compounds, with donor (pyrene and anthracene) and negative values for acceptors. The study of single-crystal X-ray diffraction shows the packing arrangements positioned side by side enhance the intermolecular charge transfer between the donor and the acceptor group of the molecules. Based on our experimental and theoretical findings, we can conclude that the studied compounds exhibit potential in NLO applications such as optical limiting devices.