First-order Hyperpolarizability Research Articles

Synthesis, Crystal Structure, Intermolecular Interactions, HOMO-LUMO, MEP, NLO Properties, and DFT/TD-DFT Investigation of (Z)-5-(4-Nitrobenzylidene)-3-N(3-Chlorophenyl)-2-Thioxothiazolidin-4-One

A novel heterocyclic compound named (Z)-5-(4-nitrobenzylidene)-3-N(3-chlorophenyl)-2-thioxothiazolidin-4-one (NCTh) was synthesized and analyzed using various techniques, including single crystal X-ray diffraction, FT-IR, UV-Vis, NMR spectroscopy, and mass spectral data methods. NCTh was observed to crystallize in the triclinic crystal system P-1 space group. To validate the experimental findings, density functional theory (DFT) calculations were performed using the B3LYP functional with the 6-311 G(d,p) basis set. The results indicated good agreement in geometrical parameters between the experimental and theoretical outcomes. The study also calculated HOMO-LUMO energies, molecular electrostatic potential (MEP), and global chemical reactivity descriptors to evaluate the compound’s reactivity. Additionally, the study conducted reduced density gradient and Hirshfeld surface analyses to reveal attractive, repulsive, and van der Waals strong and weak interactions. The calculation of thermodynamic parameters was also included. The study focused on investigating the nonlinear optical (NLO) properties of NCTh, which were characterized through key parameters such as the electric dipole moment (µ), polarizability (α), first-order hyperpolarizability (β), and second-order hyperpolarizability (γ). These properties provide insights into the material’s potential applications in optical and photonic technologies. Additionally, a molecular docking study was performed to further explore the structure-activity relationship, particularly in a biological context. The docking results revealed a strong ligand-protein interaction, with a binding energy of −10.3 kcal/mol, indicating significant affinity. Moreover, the inhibition constant (Ki) was calculated to be 0.0281 μM, suggesting a highly potent interaction, which could be relevant for drug design or biochemical applications.

Investigating the acceptor tuned effect on INPOD-based efficient D-π-A organic chromophores for optoelectronic utilization through quantum chemical analysis

In this study, the dye-sensitized solar cells and non-linear optical capabilities of newly designed ((E)-2-amino-5-((5-(4-p-tolyl-1,2,3,3a, 4,8 b-hexahydrocyclopenta [b]indol-7-yl)thiophen-2-yl)methylene)thiazol-4(5H)-one (INPOD)-based A1-A6 organic chromophores were examined. To create a D-π-A structure, the A1-A6 molecules were positioned on the electron donor, spacer, and acceptor, respectively. The use of hybrid functionals including PBEPBE, CAM-B3LYP, and MPW1PW91 was evaluated for the maximum absorption wavelength of INPOD. According to the calculated outcomes, MPW1PW91 exhibited λmax closest to INPOD. Consequently, the optical absorption spectra of A1-A6 were employed by this method to identify the key factors. The photovoltaic characteristics of these compounds in dye-sensitized solar cells were studied theoretically. The acceptor category affected the photovoltaic performance of A1-A6. Through the quantum chemical technique in time-dependent density functional theory methods, the electronic charge distribution and intramolecular charge transfer inside the A1-A6 were found. Time-dependent density functional theory calculations revealed that all A1-A6 had a λmax, that was greater than the INPOD (437 nm) in the range of 564–806 nm. A6 demonstrated an electron reorganization energy of 0.2340 eV, while a hole reorganization energy of 0.1006 eV. These values represent the maximum mobility of holes and electrons among all values. Additionally, the open circuit voltage was calculated after coupling each compound with a PTB7-Th. By the Voc of 2.10, 2.06, 2.22, and 2.08 eV, the A1, A3, A4, and A5 dyes produced the best results, respectively. The A1-A6 sensitizers were used to derive the non-linear optical properties of the dipole moment, polarizability, and first-order hyperpolarizability. It was noticed from the calculated results that the A2 and A6 molecules have the best options for non-linear optical activity. It tested how well the A1-A6 dyes performed in terms of charge transfer, dye regeneration, electron injection driving force, light harvesting efficiency, transition density matrix, molecular electro-potential, and density of states. The computed result showed that A2 and A6 chromophores are excellent candidates for dye-sensitized solar cells. Finally, those dye derivatives would certainly work effectively as tuning-A in optoelectronic applications.

NLOphoric unsymmetrically substituted D-π-A benzodifuranone dyes: Density functional theory, time dependent-density functional theory, and non-linear optical studies

The linear and non-linear optical properties of thirty-five unsymmetrically substituted compounds are studied using density functional theory and time-dependent density functional theory methods (B3LYP/6311++G(d,p), CAM-B3LYP/6311++G(d,p) and M06-2X/6311++G(d,p)). A comparable set of functionals is also used to investigate vertical excitation. It is observed that the inclusion of the nitrogen-substituted electron-donating group along with the electron-withdrawing group led to more red-shifted absorption maxima and exhibited an excellent (non-linear optical) NLO response. The geometrical framework, dipole moment, and other descriptors, HOMO-LUMO energy gaps, linear polarizability, first-order and second-order hyperpolarizability are calculated to investigate the effect of different electron donating and accepting substituents on the NLO properties of benzodifuranone chromophores. In cases where nitrogen substituents are added, the electron density is more widely spread throughout the donor in HOMO and more displaced to the acceptor in LUMO. The computed first-order and second-order hyperpolarizability values and decreasing HOMO-LUMO energy gaps in disubstituted nitrogen-containing compounds show that 1a-1e, 4a-4e, 5a-5e are promising candidates in all functionals for better NLO properties.

Synthesis, photophysical properties, and in-silico nonlinear optics of 3-hydroxy-N-phenyl-2-naphthamide and its acetate, acrylate, and benzoate derivative

In this study, we report the successful growth of single crystals of 3-hydroxynaphthalene-2-carboxanilides (NAS) with a monoclinic structure in the P21/c space group and space group number of 14 for the first time. We have developed a yield and time-effective modified synthetic procedure using a synthetic reactor by replacing the traditional microwave method. Additionally, acylated derivatives of NAS, including novel acryloyl derivative (NAS AC), are synthesized with a modified procedure, replacing pyridine with triethylamine.We investigate the structural, photophysical, and quantum chemical properties of N-(4-acetylphenyl)-2-oxo-2H-chromene-3-carboxamide (NAS) and its acylated derivatives (NAS AC, NAS ACT, NAS BZ). Photophysical studies reveal significant Stokes shifts observed in different solvents, including time-enhanced fluorescence in DMSO, attributed to solvent relaxation processes. Natural bond orbital (NBO) analysis, molecular electrostatic potential (MEP) maps, and frontier molecular orbital (FMO) provide insights into electronic interactions and asymmetric charge distribution. Low-lying LUMO values of these compounds (-2.31 eV to -1.95 eV) support candidature for the electron acceptor applications. Nonlinear optical properties were thoroughly investigated, with NAS displaying the highest static first-order hyperpolarizability (17.89 × 10−30 esu) and NAS BZ exhibiting the highest second-order hyperpolarizability (113.09 × 10−36 esu), indicating significant nonlinear optical responses. Thermal stability (TGA and DTA) highlights the significant range of temperatures for the NLO applications.

Experimental and theoretical vibrational analysis, structural conformations, DFT estimations, antibacterial, antifungal, DPPH,H2O2, Nitric oxide scavenging activity drug, in silico molecular docking, and ADMET studies of N-(2-carboxylphenyl) phthalimide (CPPD)

The title compound N-(2-carboxylphenyl) phthalimide (CPPD)was purchased with a stated purity of 99 % from M/S. Sigma-Aldrich Co. and utilized as such with no additional purification,CPPD is a thalidomide based derivative, which have led to the uses of most important drugs from 1950 and their mechanisms of action is essential for a better understanding of molecular targets with broad spectrum of biological activity. The obtained FTIR spectral data of the compound were compared to harmonic vibrational frequencies calculated using the ab initio DFT (B3LYP) technique with 6–311++G (d,p)basis sets. Furthermore, 13C and 1H NMR, first-order hyperpolarizability (βo) associated parameters (π, αo)of the compound, theSubsequent to recording the molecule’sUV–Visible spectra, DFT was used to analyze its electronic characteristics, including its HOMO and LUMO energies, molecular electrostatic potential (MESP), and Mulliken population studies were using ab initio DFT6-311++G (d,p)basis sets. Pharmacological Screening investigation of the title molecule showed a strong broad-spectrum of antifungal and antibacterial activity against various Gram (+) and Gram (−) bacteria using Ciprofloxacin as a positive control. The headline molecule is subjected toIn-silico molecular docking research with the purpose of improved recognize its biological activities, in addition with the minimal binding energy and hydrogen bond interaction that can view by Discovery Studio 4.0 visualizers. and drug likeness using Swiss ADME predictor (http://www.swissadme.ch/index.php) along with AdmetSAR-2.0 online software analysis tools features were investigated. The compound CPPD’s ability to degrade DPPH increased as a dose-dependent manner, with its maximal DPPH scavenging characteristic spanning from (18.2 ± 1.5 % to 73.2 ± 1.7 %) and maximum H2O2 scavenging trait ranging from (35.5 ± 5.3to 88.8 ± 3.1 %). The NO free radical scavenging property is linearly dependent on CPPD concentration. The interaction between the CPPD ligands and the 1HD2 protein is demonstrated by these data, as the protein displays a reduced binding energy value of −7.3 (Kcal/mol) and an inhibitory constant (ki) value of 4.39 μM. In swiss ADME prediction, CPPD is an evident from the physicochemical data that has an efficient receptor site binding mechanism. The lipophilicity of a drug is determined by its partition coefficient (Log P=log Po/w) between water and N-(2-carboxylphenyl) phthalimide. The paper further explains that the title compound can act as promising antibacterial and antioxidant agent throughin-vitro and molecular docking studies.

Experimental, quantum chemical spectroscopic investigation, topological, molecular docking/dynamics and biological assessment studies of 2,6-Dihydroxy-4-methyl quinoline

The present work is a comprehensive investigation of the spectral, electronic structure, bonding, and reactivity of the 2,6-dihydroxy-4-methylquinoline (26DH4MQ) molecule through a wide range of experimental and quantum chemical spectroscopic calculations techniques, along with its applications as nonlinear optical materials and biological assessments. The study utilized density functional theory (DFT) and time-dependent density functional theory (TD-DFT) with the B3LYP method and the 6-311G++(d,p) basis set to analyze the structural and molecular properties of 26DH4MQ. The findings from UV–Vis, FT-IR, and FT-NMR spectroscopy show a strong agreement between the experimentally obtained vibrational frequencies and chemical shifts and those predicted by computational methods. Local reactivity descriptors, such as the dual descriptor, Fukui functions, and the molecular electrostatic potential (MEP) map, were used to identify the reactive regions of the molecule. Additionally, natural bond orbital (NBO) analysis provided insights into the charge transfer characteristics of 26DH4MQ, which helps to stabilize the molecular system. The study also revealed notable nonlinear optical (NLO) properties, with polarizability (18.52 × 10–24e.s.u.) and first-order hyperpolarizability (2.26 × 10–30e.s.u.) values that surpass those of standard organic compounds, suggesting significant potential for optoelectronic applications. The biological evaluation of 26DH4MQ assessed its drug-likeness, toxicity, enzyme inhibition, and ADME (Absorption, Distribution, Metabolism, and Excretion) parameters, highlighting its pharmaceutical potential. Furthermore, molecular docking and dynamics studies illustrated the compound's interaction with proteins, indicating its potential role as an insulin inhibitor.

Emissively enhanced novel azo compounds featuring with ESIPT core

This study presents the synthesis and detailed characterization of novel azo compounds featuring Excited State Intramolecular Proton Transfer (ESIPT) cores derived from orcinol, resorcinol, and 2-naphthol. Using a comprehensive suite of spectroscopic techniques, including Nuclear Magnetic Resonance (NMR), Liquid Chromatography-Mass Spectrometry (LC-MS), Ultraviolet-Visible (UV–Vis) spectroscopy, and fluorescence spectroscopy, we explored the unique photophysical properties of these compounds. Notably, the synthesized compounds exhibited exceptionally large Stokes shifts, with values recorded at 204 nm, 251 nm, and 168 nm for compounds 1A, 2A, and 3A, respectively. These shifts indicate significant potential for applications in areas such as optical sensing and fluorescent imaging. Furthermore, Density Functional Theory (DFT) calculations were employed to investigate the nonlinear optical (NLO) properties of the enol and keto tautomeric forms of these compounds. The findings revealed that compound 2A, in particular, demonstrated impressive first-order hyperpolarizability, especially in chloroform, underscoring its suitability for advanced nonlinear optical applications. The study highlights the pivotal role of the ESIPT mechanism, where efficient intramolecular hydrogen bonding facilitates proton transfer upon excitation, leading to enhanced fluorescence properties. This phenomenon is particularly pronounced in compound 2A, where dual O—H interactions contribute to its remarkable fluorescence behavior, making it a standout candidate for use in high-performance optical materials. These findings not only advance our understanding of azo compounds and their versatile photophysical characteristics but also open new avenues for their application in cutting-edge technologies such as optical sensors, imaging agents, laser materials, and other fluorescence-based devices. By strategically leveraging the ESIPT process and the unique structural features of these compounds, this research paves the way for future innovations in the field of advanced optical materials and photonic devices.

Novel emissive styryl dyes from 9-methoxy anthracene: Synthesis, photophysical, thermal stability, viscosity, and DFT study

Novel styryl colorants based on anchoring methoxy with anthracene as a donor linked with various active methylene acceptor groups to derive a conjugated π-system along with push-pull geometry were synthesized and well characterized. Photophysical properties were studied in different polarity solvents. The impact of solvent polarizability is delivered in redshifts in absorption and emission spectra, in addition to enhancing the quantum yield. The benzoxazole and benzimidazole moieties in 4c and 4d demonstrated heat stability of more than 300 °C. Fluorescent intensity is directly proportional to the viscosity and 4a demonstrates a notable viscosity sensor through 1.36 fold increase in intensity. In comparison to other styryl dyes, 4c and 4d were shown to have higher values in DMSO for polarizability (53.3496 × 10−24 esu and 53.7459 × 10−24 esu) and first-order hyperpolarizability (86.3467 × 10−30 esu and 89.1941 × 10−30 esu) as well as second-order hyperpolarizability (1768.9121 × 10−36 esu and 1740.6940 × 10−36 esu) due to presence of heterocyclic character. NLO properties of all the styryl dyes 4a-4e are within the fundamental boundary limits. The 4d (benzoxazole) dye exhibited a small HOMO-LUMO energy gap of 2.8825 eV, whereas the 4b and 4e dyes had a larger band gap due to the presence of a carbonyl group.

The effect of metal-to-ligand charge transfer on linear and nonlinear optical properties of hexaphyrin and metallo-hexaphyrins

Charge transfer from metal to ligand has implications in various fields of chemistry, physics and biology. The manipulation of spin properties would be necessary for controlling charge transfer in spintronics and biological applications. Upon binding to the metal atoms (Ni, Cu, Au, etc.), the spin properties would be modulated in organic conjugated molecules of less intrinsic spin–orbit coupling (SOC) due to SOC coming from the heavy elements. Emission spectra calculation is necessary to validate them as suitable fluorescence quenchers. The nonlinear optical properties like first-order hyperpolarisability β and second-order hyperpolarisability γ calculations are important to find out their relation between fluorescence quenching and higher order nonlinear optical (NLO) properties. From the second-order NLO properties, we computed degenerate four-wave mixing (DFWM) component ( γ ( 2 ) ( − ω ; ω , ω , − ω )) and finally quadratic nonlinear refractive indices of the expanded porphyrins (EPs). How the linear and nonlinear optical properties are dependent on the SOC coming from the heavy materials (Ni, Cu, Au), and charge transfer process is the most interesting question to be addressed for their potential uses for various optoelectronic and spintronic applications.

Interdisciplinary insights into (1′R,3S,3′R)-1'-(4-chlorobenzoyl)-5′,6′,7′,7a′-tetrahydro-1′H dispiro[indoline-3,2′-pyrrolizine-3′,3″-indoline]-2,2″-dione: Structural, electronic, and molecular dynamics perspectives

In the field of heterocyclic compounds, the spiro-pyrrolidine and oxindole ring systems are highly esteemed due to their distinctive structural scaffold that is present in numerous pharmacologically significant alkaloids. Interdisciplinary research has been increasingly important in recent years for deciphering the intricate characteristics and behaviors of novel organic compounds. The current work uses quantum chemical computational techniques to study the structural stability and nonlinear optical (NLO) activity of (1′R,3S,3′R)-1'-(4-chlorobenzoyl)-5′,6′,7′,7a′-tetrahydro-1′H dispiro[indoline-3,2′-pyrrolizine-3′,3″-indoline]-2,2″-dione (DSOIP-Cl). The study combines molecular biology, computational chemistry, and theoretical chemistry knowledge to create a comprehensive picture of this fascinating organic compound. This study employed the density functional theory (DFT) B3LYP method to compute the electronic properties and molecular geometry. The basis set for the computations was 6–311++G(d,p). The IEFPCM solvation method is used to investigate the behavior of the head compound in different solvents. Understanding the interaction between organic compounds and the solvent phase is crucial because the majority of interactions in biological systems occur in solution. UV–Vis spectral analysis of the molecule in different solvents is performed using the TD-DFT method. The compound exhibits more excellent absorption in polar solvents such as water, while its absorption is lower in the gaseous phase. Assessing NLO properties revealed optoelectronics applications. DSOIP-Cl has 5.25 times the first-order hyperpolarizability of urea. Different solvents have higher dipole moments and first-order hyperpolarizability than gases. To identify the inter- and intramolecular charge transfer interactions, intermolecular hydrogen bonding, and hyperconjugative interactions that stabilize the structure, natural bond orbital (NBO) analysis is performed. A stabilization energy of 9.99 kcal/mol is obtained for π(C32–C33) → σ*(C33–C34) due to strong intramolecular hyperconjugative interactions. Frontier molecular orbital (FMO) analysis helps determine the global reactivity parameters and the charge transfer interaction. The van der Waals interaction and steric effect within the molecule are identified using RDG analysis. The pharmacokinetic properties, adherence to drug-likeness criteria, and easily controllable synthesis process were evaluated through ADME analysis, establishing it as an up-and-coming candidate for subsequent drug development. Ultimately, to determine the biological activity and the ability of the title compound to inhibit aldose reductase, a series of computational techniques are employed, including molecular docking study, molecular dynamic (MD) simulation, and MM-PBSA binding energy calculations. −7.86 kcal/mol was reported as the docking score. Hydrophobic interactions play an essential role in the efficiency of protein-ligand binding. The remarkable energetic contribution of DSOIP-Cl to the MM-PBSA binding dynamics highlights its unique association with the AR protein, with a binding energy of −79.81 kJ/mol.

The influence of metal-free thiophene spacer chain on optoelectronic analysis by TD-DFT method for efficient dye-sensitized solar cells with enhanced non-linear optical activity

The pyrene group in conjugation with the thiophene moiety was used to design new organic molecules for the dye-sensitized solar cells (DSSCs) along with non-linear optical (NLO) properties. Five new thiophene chain conjugation molecules (PTRA-SPn, n = 1–5) were formed based on the (E)-2-(5-oxo-4-((5-(pyren-1-yl)thiophen-2-yl)methylene)-2-thioxothiazolidin-3-yl)acetic acid (PTRA). To comprehend the function of conjugation in varying the optoelectronic characteristics of these compounds, the π-spacer chain has been screened. The techniques of density functional theory (DFT) and time-dependent DFT (TD-DFT) have been used to study the electronic structures, Ultraviolet–Visible (UV–Vis) absorptions, and NLO activities of donor-spacer-acceptor (D-π-A) structures. According to the computed results, PTRA-SP5 exhibits a smaller energy gap (Eg) of 2.11 eV. The maximum UV–Vis spectrum has been found in PTRA-SP5 with a wavelength (λmax) of 532 nm. The reorganizational energy (RE) and dye regeneration (ΔGreg) of PTRA-SP5 are the smallest (λ- = 0.2340 eV, λ+ = 0.2122 eV, ΔGreg = 0.21 eV) compared to other sensitizers. The lowest exciton binding energies (Eb) of PTRA-SP2 (0.06 eV) and PTRA-SP3 (0.06 eV) are the lowest ones. The open circuit photovoltage (eVoc) for PTRA-SP5 (1.10 eV) is the highest. The NLO activity of the dipole moment (μnormal) and first-order hyperpolarizability (β) values of PTRA-SP5 achieve higher values (9.00 Debye and 34.82 × 10−30 esu, respectively). In summary, this work refined the impact of chain π-linkers on the photophysical characteristics of D-π-A spacer derivatives and offered some helpful suggestions to create new organic materials for optoelectronic uses.

Quantum Computational and Spectroscopic Investigation of 3-aminosalicylic Acid.

Quantum chemical calculations of3-aminosalicylic acid (3ASA) (monomer and dimer forms) have been performed using DFT and TD-DFT theories with B3LYP/6-311 G(d,p) functional level in the ground and excited states. Using TD-DFT with IEF-PCM model, the electronic spectra of 3ASA in solvents were computed and correlated with the experimental data. The theoretically calculated absorption and emission maxima of 3ASA (monomer) are observed in the range of 343- 347nm (S0 → S1 transition) and 429- 448nm (S1 → S0 transition), respectively. The natural bond orbital (NBO) analysis shows that charge transfer interaction contributes significantly to stabilize the molecular system. In the case of dimer, hydrogen bonding plays a dominant role in stabilizing the molecular framework. Additionally, the obtained nonlinear optical (NLO) properties: polarizability (13.86 × 10-24 e.s.u for monomer and 29.46 × 10-24 e.s.u. for dimer), first-order hyperpolarizability (4.21 × 10-30 e.s.u for monomer and 0.18 × 10-30 e.s.u for dimer) and second-order hyperpolarizability (7.44 × 10-36 e.s.u. for monomer and 14.32 × 10-36 e.s.u. for dimer) were found to be larger than those of standard organic compounds suggesting that 3ASA has a significant NLO character for optoelectronic applications. The NLO properties of dimer may differ from monomer due to dimerization. Further, the radiative lifetime, light harvesting efficiency and band gap energy were calculated, and proposed that 3ASA may be useful in photovoltaics and wide bandgap power devices. HIGHLIGHTS: • DFT and TD-DFT theories were employed to calculate structural and molecular properties of 3ASA (monomer and dimer) in ground and excited states. • HOMO-LUMO study shows monomer and dimer of 3ASA are good reactive. • NBO analysis reflects that charge transfer interactions stabilized the 3ASA molecule. • Electronic absorption/emission spectra in solvents calculated by IEF-PCM/TD-DFT method correlate with experimental results. • Calculated NLO parameters suggested that 3ASA is a potential candidate for NLO material.

Impact of doping with organic dopants and mixed doping with alkali metals and organic dopants on the absorption, electronic, optoelectronic, thermodynamic and nonlinear optical properties of dibenzo[b,def]chrysene in gaseous media: DFT and TD-DFT studies.

In this study, we evaluate the geometrical, absorption, optoelectronic, electronic, nonlinear optical (NLO) and thermodynamic properties of dibenzo[b,def]chrysene molecule derivatives by means of DFT and TD-DFT simulations. In view of the aim of producing new high-performance materials for non-linear optics (NLO) by doping test, two types of doping were used. We obtained six derivatives by doping with organic dopants (Nitro, amide and ticyanoethenyl) and mixed alkali metal (potassium) and organic dopants. Doping with organic dopants produced molecules A, B and C, respectively when substituting one hydrogen with nitro (NO2), amide (CONH2) and tricyanoethenyl (C5N3) groups, while mixed doping involved considering A, B and C and then substituting two hydrogens with two potassiums to obtain compounds D, E and F respectively. The negative values of the various interaction energies calculated for all the doped molecules show that they are all stable, but also that molecules C and F are the most stable in the case of both dopings. The gap energies calculated at the B3LYP level of theory are all below 3eV, which means that all the molecules obtained are semiconductors. Better still, compounds C and F, with gap energies of 1.852eV and 1.204eV, respectively, corresponding to decreases of 35.67% and 58.18% in gap energy compared with the pristine molecule, are more reactive than the other doped molecules. Mixed doping is therefore a highly effective way of narrowing the energy gap and boosting the semiconducting character and reactivity of organic materials. Optoelectronic properties have also been improved, with refractive index values higher than those of the reference material, glass. This shows that our compounds could be used under very high electric field conditions of the order of 4.164 109V.m-1 for C and 7.410 109V.m-1 for F the highest values at the B3LYP level of theory. The maximum first-order hyperpolarizability values for both types of doping are obtained at the CAM-B3LYP level of theory by C: 10-30esu and by F: 10-30esu, and second-order values are also given by these same compounds. These values are higher than the reference value, which is urea, making our compounds potential candidates for high-performance NLO applications. In dynamic mode and at a frequency of 1064nm, at the CAM-B3LYP level of theory, the highest dynamic hyperpolarizability coefficients were obtained by C and F. Hyper-Rayleigh scattering , coefficients of the electro-optical Pockel effect (EOPE), EFISHG, third-order NLO-response degree four-wave mixing , quadratic nonlinear refractive index n2 were also calculated. The maximum values of n2 are obtained by C (6.13 10-20 m2/W) and F (6.60 10-20 m2/W), these values are 2.24 times higher than that of fused silica which is the reference for degenerate four-wave mixing so our molecules could also have applications in optoelectronics as wavelength converters, optical pulse modulators and optical switches. Using the DFT method, we were able to determine the optimized and stable electronic structures of doped dibenzo[b,def]chrysene derivatives in the gas phase. We limited ourselves to using the proven B3LYP and CAMB3LYP levels of theory for calculating electronic properties, and non-linear optics with the 6-311G + + (d,p) basis set, which is a large basis set frequently used for these types of compound. Gaussian 09 software was used to run our calculations, and Gauss View 6.0.16 was used to visualize the output files. TD-DFT was also used to determine absorption properties at the B3LYP level of theory, using the same basis set.

Enhanced nonlinear optical and optical limiting responses of 7-diethylamino-4-methyl coumarin functionalized with silver nanoparticles: A combined experimental and DFT study

The present study accounts for the enhanced nonlinear optical and optical limiting activity of 7-diethylamino-4-methyl coumarin (7DMC) after the addition of silver nanoparticles. The theoretical calculations were done in three different solvents water, methanol, and dimethyl formamide (DMF), and on the basis of the energy gap, DMF was selected as the most suitable solvent. Further, the liquid samples were prepared in DMF. The natural bond orbitals show the active participation of the lone pairs of electrons of 2O and 35Ag as donor and acceptor moieties respectively. The values of first-order hyperpolarizability of the 7DMC+Ag3 combination were raised to 2002.71 × 10−30 esu, 778.72 × 10−30 esu, and 677.12 × 10−30 esu in water, methanol, and DMF. The valley-like structure in the Z-Scan spectra indicated the occurrence of reverse saturable absorption in the prepared samples. The optical limiting threshold of the 7DMC+AgNps was decreased from that of the probe 7DMC and AgNps indicating the early attenuation of the optical limiting nature of the combination. Thus, the overall results validated the enhanced optical nonlinearity of the combination. Moreover, it can be stated that the proposed nanoparticles combination 7DMC+AgNps has potential candidature to be used for the fabrication of laser safety devices and eye aids.

Augmenting the effect of solvents on optical nonlinearity by spectroscopic, DFT, solvatochromism and z-scan studies of push-pull chalcone: (2E)-1-(4-ethoxyphenyl)-3-(4-methoxyphenyl)prop-2-en-1-one

In this article, the structural and nonlinear optical behaviour of a chalcone derivative, (2E)-1-(4-ethoxyphenyl)-3-(4-methoxyphenyl)prop-2-en-1-one have been studied. FT-IR, FT-Raman, and NMR spectroscopy were analyzed to validate the molecular structure. To predict the nonlinear optical characteristics of the chalcone, the DFT approach was used and the experimental results were corroborated by the computations. The bathochromic shift is obtained in linear absorbance spectra and is validated using TD-DFT. Also, the broad emission in the blue region demonstrates the blue light emission property of the sample. Using the finite-field method, the dipole moments, polarizability, first-order and second-order hyperpolarizability parameters have been computed. Ground and excited state dipole moments were quantified by solvatochromism. The third-order nonlinear optical characteristics of chalcone in polar and non-polar solvent media were examined using the open/closed-aperture z-scan technique. The chalcone displayed considerable two-photon absorption with a positive nonlinear absorption coefficient and a positive index of refraction due to the self-focussing effect. Furthermore, the optical limiting study manifests that the investigated chalcone might well be favourable for NLO applications.

Structural, spectroscopic (FTIR, FT-Raman and UV–Vis) investigations, Fukui function analysis and thermodynamic properties of diethyl 3,3′-(ethane-1,2-diylbis(azanediyl))(2Z,2′Z)-bis(but-2-enoate)

Diethyl 3,3′-(ethane-1,2-diylbis(azanediyl))(2Z,2′Z)-bis(but‑2-enoate) (DBE) molecule is characterized by infrared, Raman and UV–visible spectroscopic techniques. The structural parameters obtained using density functional theory (DFT) with B3LYP/6-311++G(d,p) level of theory closely match the experimental data. The molecule's characteristic functional groups were identified through vibrational spectra analysis. The IR and Raman spectra vibrational peaks were assigned based on Potential Energy Distribution (PED) analysis. Excitation wavelengths, oscillator strengths and excitation energies were determined through time dependent density functional theory (TD-DFT) calculations and compared to experimental data. Nonlinear optical (NLO) properties were calculated to predict the electric dipole moment and first-order hyperpolarizability of the molecule. The significant nonlinear optical properties values indicated that these materials possess excellent nonlinear optical properties, making them suitable for applications in telecommunication and signal processing. The Mulliken atomic charge, chemical activity analysis and Fukui functions were utilized to investigate the electron-poor, rich and reactive sites in conjunction with the optimized structures using the DFT method with B3LYP function and 6-311++G(d,p) basis set. Thermodynamic investigations have shown that key molecular parameters such as entropy, heat capacity and enthalpy increase as temperature rises.

The impact of the nitrogen atom on the optoelectronic, nonlinear optical, and thermodynamic properties of graphene quantum dots derived from dibenzocoronene: A DFT investigation

Because of their potential applications in electricity and photonics, graphene quantum dots (GQDs) with intriguing physical characteristics have attracted a lot of attention. Here we use density functional theory (DFT) with the B3LYP functional associated with the 6–31++G(d,p) basis to explore the effect of the nitrogen atom on the optoelectronic, nonlinear optical, and thermodynamic properties of dibenzocoronene (DBC) isomers. The pristine molecules of the DBC isomers have HOMO-LUMO energy gaps of 3.39 eV (DBCa), 3.39 eV (DBCb) and 3.65 eV (DBCc). Inserting a nitrogen atom into the DBC molecular structure considerably reduces the energy gap between these two orbitals. The materials thus obtained after nitrogen doping are DBCa-N, DBCb-N, and DBCc-N and have respective gap energies of 2.05, 1.80, and 1.65 eV (in other words, less than 3 eV). It can therefore be deduced that the compounds studied will be used as semiconductors in electronics. The static polarizabilities α of the N-doped DBC isomers obtained are 442.960, 443.523, and 455.657 au, respectively, each of these values being 4 times higher than that of the organic reference molecule for non-linear optical properties (para-nitroaniline pNA α = 114.7 au), while the first-order hyperpolarizabilities β obtained are 2689.838, 5572.137, and 12717.472 au, respectively. These values are approximately 2.5, 5, and 12 times higher than those of para-nitroaniline (β = 1072.44 au). Our results confirm that the investigated DBC nitrogen derivatives are good non-linear optical materials for photonics, data storage, dynamic imaging, optical signal processing, and computer systems. All the calculated thermodynamic properties show that the proposed molecules can be easily produced. This manuscript thus stands out as a good compass in the rational design of organic semiconductors for efficient electronic devices.

Molecular structure, optical, first-order hyper polarizability, electronic properties, reactivity (ELF and LOL) − computational analysis using DFT and Multiwfn for 2, 3-diaminopyridinium selenate

A detailed study on the first principle calculations of 2,3-diaminopyridinium selenite (2,3-DAPS) – an organometallic salt has been performed using B3LYP/6–311++G(d,p). Single crystal X-ray diffraction (XRD) analysis confirms that the crystal formed exhibits a monoclinic crystal structure, specifically belonging to the centrosymmetric space group P21/c. The obtained primitives and interfacial angles are as follows: a = 7.4978(15)Å, b = 7.6681(15) Å, c = 14.314(3) Å, α = γ = 90°, β = 93.75(3)°, and the volume of the unit cell V = 821.2(3) (Å)3. The structure was optimized with a global minimum. The natural bonding orbital charge transfer studies between the cation and anion was performed to gain insights into their electronic interactions. Energy gap and other global chemical reactivity descriptors have been computed with the aid of molecular orbital studies. The influence of solvent on the absorption spectra provided the evidence of solvent–solute interactions and their impact on the electronic transitions within the molecule. The presence of electrophilic and nucleophilic reactivity in the chemical is indicated by the molecular electrostatic potential (MEP) map. From the nonlinear optical (NLO) studies, it has been found that the first-order hyperpolarizability value is 30.771 × 10−31 esu, which is 8.252 times that of urea. This suggests that the compound may be a better non-linear optical material and suitable for laser applications. To calculate the proportion of intermolecular interactions and examine the distribution compound's electrostatic potential, a Hirshfeld surface analysis was conducted. The analysis provided insights into the spatial arrangement of molecules and their interactions. Additionally, topology path calculations elucidated the intrinsic connectivity between critical points, shedding light on the bonding characteristics within the compound. The likelihood of electron density at bonding and anti-bonding sites was also determined using the Electron Localization Function (ELF) and Localised Orbital Locator (LOL) plots. These analyses aided in understanding the electron distribution and the nature of chemical bonding within the compound, providing valuable information about its electronic structure and reactivity.

Theoretical Insights into the Structural and Optical Properties of D-π-A-based Cyanostilbene Systems of α and β Variants.

The π-conjugated organic molecules containing cyanostilbene motifs have been extensively investigated due to their great potential applications in several optoelectronic and biological fields. Developing efficient molecules in this respect requires strategic structural engineering and a deep understanding of the structure-property relationship at the molecular level. In this context, understanding the impact of positional isomerism in cyanostilbene systems is a fundamental aspect of designing desired materials with improved photophysical properties. Herein, we designed ten donor-π-acceptor (D-π-A) type cyanostilbene derivatives (P1 - P10) with different π linkers and compared their structural and optoelectronic properties arising from the positional variations of the -CN group (α and β- variations) through the utilization of density functional theory (DFT) and time-dependent DFT (TDDFT) methods. The topological analyses of the electron density are used to explain the relatively high stability of α isomer compared to that of β. Frontier molecular orbital analysis reveals that 17 molecules tend to show a reduced highest occupied molecular orbital-lowest unoccupied molecular orbital gap, and most of them showed a greater nonlinear optical (NLO) character compared to the parent molecule. TDDFT calculations indicate that β isomers show higher absorption maxima compared to their α counterparts. Among all the scrutinized molecules, the absorption maximum extended up to 602 nm for P9 and it possesses the highest first-order hyperpolarizability. This study sheds light on positional isomers and their reactivity, absorption spectra, and NLO properties of D-π-A type architecture that can be suitably tuned by appropriating the π-bridge for practical applications.

Experimental and theoretical investigation on the SR method grown semi-organic Piperazinium Tetrachlorozincate Monohydrate (PTZM) single crystal for optoelectronic applications

Efficient semi organic nonlinear optical (NLO) Piperazinium Tetrachlorozincate monohydrate (PTZM) [C4H12N2][ZnCL4]·H2O single crystals have been grown by slow evaporation solution technique (SEST) and Sankaranarayanan-Ramasamy (SR) method using water as solvent. Single crystal X-ray diffraction (SXRD) analysis reveals the unit cell parameters of the grown crystal. The morphology of the grown crystal was identified by the single crystal XRD analysis. The electrical properties, dielectric constant, dielectric loss and piezoelectric (d33) coefficient were determined. The etch pit density of PTZM crystal has been calculated by using the chemical etching analysis. The laser damage threshold (LDT) analysis was investigated by Nd: YAG laser and the wavelength of laser is 1064 nm. The mechanical stability of the grown PTZM crystal was studied using Vickers microhardness measurement. Utilizing quantum chemical calculations, the PTZM compound is analyzed for vibrational properties, HOMO and LUMO characteristics, NBO interactions, and the determination of first-order hyperpolarizability. The nonlinear susceptibility and first-order hyperpolarizability results provide compelling evidence and affirm the PTZM molecule’s potential as a strong candidate for nonlinear optical (NLO) applications.