Nonlinear Optical Behavior Research Articles

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.

Unveiling nonlinear optical behavior in benzophenone and benzophenone hydrazone derivatives

Unveiling nonlinear optical behavior in benzophenone and benzophenone hydrazone derivatives

Enhanced nonlinear optical properties and optical limiting performance of graphene modified polyaniline composite under pulsed laser regime

Polyaniline (PANI) and its graphene-doped composite (PANI-GNP) were subjected to open-aperture (OA) z-scan studies to investigate their nonlinear optical (NLO) properties and optical limiting (OL) behavior. The z-scan experiments were carried out using a nanosecond pulsed Nd:YAG laser at a wavelength of 532 nm. The z-scan studies revealed that PANI and PANI-GNP composites exhibited a reverse saturable absorption (RSA), and graphene doping modified the NLO behaviour and improved the OL property. The nonlinear absorption coefficient (β), OL threshold, and imaginary part of nonlinear susceptibility ( χi(3) ) of PANI and PANI-GNP were calculated for three different laser input pulse energies and found to be in the order of 10−9 cm W−1, 106 W cm−2, and 10−10 esu, respectively. These results qualify the PANI-GNP composite as having potential applications in OL and optoelectronic devices. The successful incorporation of graphene into PANI in PANI-GNP composite was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Linear optical properties were analysed using UV–visible absorption spectroscopy. To the best of our knowledge, the present work is the first attempt to explore the intensity-dependent NLO properties, OL behaviour and the calculation of their related NLO parameters of PANI-GNP composites.

Quasi-Van der Waals Epitaxial Growth of γ'-GaSe Nanometer-Thick Films on GaAs(111)B Substrates.

GaSe is an important member of the post-transition-metal chalcogenide family and is an emerging two-dimensional (2D) semiconductor material. Because it is a van der Waals material, it can be fabricated into atomic-scale ultrathin films, making it suitable for the preparation of compact, heterostructure devices. In addition, GaSe possesses unusual optical and electronic properties, such as a shift from an indirect-bandgap single-layer film to a direct-bandgap bulk material, rare intrinsic p-type conduction, and nonlinear optical behaviors. These properties make GaSe an appealing candidate for the fabrication of field-effect transistors, photodetectors, and photovoltaics. However, the wafer-scale production of pure GaSe single-crystal thin films remains challenging. This study develops an approach for the direct growth of nanometer-thick GaSe films on GaAs substrates by using molecular beam epitaxy. It yields smooth thin GaSe films with a rare γ'-polymorph. We analyze the formation mechanism of γ'-GaSe using density-functional theory and speculate that it is stabilized by Ga vacancies since the formation enthalpy of γ'-GaSe tends to become lower than that of other polymorphs when the Ga vacancy concentration increases. Finally, we investigate the growth conditions of GaSe, providing valuable insights for exploring 2D/three-dimensional (3D) quasi-van der Waals epitaxial growth.

Flexible nonlinear photonics of heterostructured MXene-derived quantum dots

High-quality V2C–VO2-heterostructured MXene-derived quantum dots (MQDs) were hydrothermally fabricated and characterized using microscopic, crystallographic, and spectroscopic methods. Open-aperture Z-scans were employed to investigate the nonlinear optical absorption of the MQDs irradiated using picosecond pulses at 532 nm. The results showed that the heterostructure converted the nonlinear optical behavior from saturable absorption to reverse saturable absorption. In individual V2C MQDs, saturable absorption was ascribed to the bleaching of ground-state free electrons, while in heterostructured V2C–VO2 MQDs, reverse saturable absorption was derived from two-photon-induced free-carrier absorption. The nonlinear absorption coefficient of the V2C–VO2 heterostructured MQDs was comparable to those of previously reported MQDs. This research could provide insight into the integration of heterostructured MQDs and promote the advanced photonics of MQDs and their applications in optoelectronic devices.

Novel schiff base-azide metal complexes: Synthesis, spectral, nonlinear optics, and DFT studies

In order to enhance nonlinear optics (NLO)-based technologies, current research focuses on the design and synthesis of coordination materials. In this context, to investigate spectral and theoretical linear optical (LO)/nonlinear optical (NLO) behaviors, novel metal complexes including azide {[Mn (L1)2(N3)2], (9), [Ni(L1)2(N3)], (10), [Co2(L1)2(N3)2]⋅2H2O, (11); L1: N-(pyridin-2-ylmethylene)methanamine} were synthesized. The vibrational and electronic spectral features of complexes 9–11 were investigated by UV–Vis and FT–IR spectra. Depending on the central metal ion and coordination geometries of complexes, the microscopic static nonlinear behaviors were examined by using the CAM-B3LYP/and ωB97XD/6–311 + G (d,p)//LanL2DZ levels of density functional theory (DFT). Furthermore, the vibrational and electronic properties of complexes 9–11 based on the same levels of time-dependent/density functional theory (TD-DFT/DFT) were surveyed. Additionally, the theoretical χ(1), χ(2), and χ(3) parameters, known as linear optical, second-, and third-order nonlinear optical susceptibility tensors, as well as linear, second-, and third-order polarization parameters (P(1), P(2), and P(3)) for complexes 9–11 were examined. The greatest <β(0; 0,0)> value for complex 10 found to be 262.55 × 10−30 esu using CAM-B3LYP level is 820.5 and 2019.6 times higher than the urea findings (0.32 × 10−30 esu and 0.130 × 10−30 esu). The <γ(0; 0,0,0)> results indicate that complex 9 having the highest value obtained at 2216.40 × 10−36 esu using CAM-B3LYP level is 47.76 and 316.63 times greater than those of pNA (15 × 10−36 esu) and urea (7 × 10−36 esu), respectively. Complexes 10 and 9 demonstrated promising microscopic second-order and third-order NLO features, respectively. Our research is anticipated to provide insight into NLO materials that may have applications in optoelectronics and telecommunication field.

Computational Evaluation of the Structural, Topological, and Solvent Effects on the Nonlinear Optical Properties of 1-Methylurea Butanedioic Acid Crystal

In silico investigation of the effects of a molecule’s framework and surroundings on its nonlinear optical (NLO) response is still an active topic of study in the fields of photonics and optoelectronics. NLO materials play a crucial role in modern photonics and optoelectronic technologies. Presented here is a comprehensive theoretical analysis of the structural, topological, and NLO features of 1-methylurea butanedioic acid (MUBA) alongside solvent effects (water, DMSO, and benzene) using the DFT method at the B3LYP(D4)/6–311++G(d,p) level. Geometric and infrared parameters were calculated and compared with experimental values. The analysis using atoms in molecules (AIM) and the independent gradient model (IGM) reveals the presence of two noncovalent intermolecular interactions: N4–H16⋯O12 and O6–H25⋯O3, which stabilize the crystal structure. The natural bond orbital (NBO) analysis reveals that the LP(1)N4 ⟶ π∗(C2-O3) interaction is the most stabilizing and is enhanced in solvent environments. NLO data show that the first (βtot) and second (γ) hyperpolarizability values of MUBA are approximately 0.6–1.1 and 8.3–17.0 times higher than those of urea. In addition, the quadratic and cubic responses of MUBA are significantly reduced and increased, respectively, in solvent environments. Based on its NLO susceptibilities, MUBA exhibits SHG, EOPE, OKE, and EFISHG properties, suggesting its potential application in the production of optoelectronic devices and optical limiting. This study enhances our understanding of the factors influencing the NLO behaviour of organic crystals, providing valuable insights for designing materials with enhanced NLO characteristics. The implications extend to industries such as telecommunications and computing, where faster data transmission rates are in high demand.

Luminescence and two-photon absorption assisted optical limiting properties of Ag-doped CdWO4 nanorods

The emerging demand for the fabrication of nonlinear optical materials with high limits of optical power is obvious in nonlinear optics due to their wide application in photonic devices. We report the linear and third-order nonlinear optical properties of Ag-doped CdWO4 nanorods and their dependence on Ag-doping concentration. CdWO4 nanorods with different Ag concentrations were synthesized by the chemical precipitation method and characterized by UV–Vis absorption, X-ray diffraction (XRD), Raman, Photoluminescence and its lifetime studies, X-ray Photoelectron spectroscopy and Transmission Electron Microscopy (TEM). The introduction of Ag ions has led to an increased redshift in the CdWO4 absorption spectra extended into longer wavelength bands, thus enhancing optical absorption within the visible range. The XRD pattern showed that the nanorods crystallized in a monoclinic wolframite structure. The incorporation of Ag in CdWO4 decreases the luminescence emission intensity due to surface quenching effect. Luminescence lifetime measurement reveals the longer decay lifetime for Ag-doped CdWO4 nanorods due to the reduction of density of defects and deep trap state. The nonlinear optical behaviour of the nanorods was investigated by an Open aperture Z-scan technique at 532 nm using pulsed wave Nd: YAG laser. Experimental results showed that reverse saturable absorption is responsible for the observed nonlinearity in the nanorods. The addition of Ag can significantly improve the nonlinear absorption coefficient and optical limiting effects of CdWO4 which can be used as a potential material in nonlinear optical devices.

Computational method on highly efficient D-π-A-π-D-based different molecular acceptors for organic solar cells applications and non-linear optical behaviour

Eight molecular structures (BT-A1 to BT-A8) with high-performance non-fullerene acceptor (NFA) were selected for organic solar cells (OSCs) and non-linear optical (NLO) applications. Their electronic, photovoltaic (PV) and optoelectronic properties were tuned by adding powerful electron-withdrawing groups to the acceptor (A) of the D-π-A-π-D structure. Using time-dependent density functional theory (TD-DFT) techniques, based on the laws of quantum chemical calculations, the absorption spectra, stability of the highest and lowest-energy molecular orbitals (HOMO/LUMOs), electron density, intramolecular charge transfer (ICT), transition density matrix (TDM), were examined. The binding energy (Eb) and density of states (DOS) were probed to realize the optoelectronic analysis of the structures BT-A1 to BT-A8. Noncovalent interactions (NCIs) based on a reduced density gradient (RDG) were used to describe the nature and strength of D-A interactions in the molecules BT-A1 to BT-A8. The new refined molecules BT-A1 to BT-A8 exhibited strong absorbance bands between 408–721 nm and high electron transfer contribution (ETC) ranges between 87–96 %, along with the smallest excitation energies (Ex) between 1.71–3.55 eV in the solvent dichloromethane. Dipolar moment strengths ranging from 0.38 to 4.72 Debye in both the excited and ground states have determined with good solubility properties of BT-A1 to BT-A8 in polar solvent. Highly effective charge mobilities and prevention of charge recombination have been demonstrated by the electron (0.18–0.41 eV) and hole RE values (0.13–0.89 eV) for the new compounds. Power conversion efficiencies (PCE) of BT-A1 to BT-A8 were nearly the same because of better outcomes compared to the molecules in the BT. Compared to poly[4.8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b: 4,5-b']dithiophene-2,6- diyl-alt-(4–2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2–6-diyl)] (PTB7-Th), the open circuit voltages (Voc) of compounds BT-A1 to BT-A8 were ranged from 1.52 to 2.13 eV. The polarizability (α) and hyperpolarizability (β) of the molecules BT-A1 to BT-A8 were used to determine the non-linear optical (NLO) properties. The results showed that BT-A2, BT-A6 and BT-A7 have good NLO activity. This computational analysis demonstrates the superiority of the molecules with NFA. Hence the compounds are advised for the use in production of high-performance OSCs and NLO activity.

Density Functional, Dielectric Studies and Anticancer Activity of (2e)-1-(3-Bromothiophen-2-yl)-3-(2, 3, 5-Trimethoxyphenyl) Prop-2-en-1-One

In this work, the optimized structure parameters, and vibrational wavenumbers of (2E)-1-(3-Bromothiophen-2-yl)-3-(2, 3, 5-trimethoxyphenyl) prop-2-en-1-one (BTTP) molecule have been predicted by Density Functional Theory (DFT) method with B3LYP/6–311++G (d,p) basis set. The calculated vibrational wavenumbers have been compared with observed FT-IR (4000 − 400 cm−1) and FT-Raman (3500 − 100 cm−1) wavenumbers. The difference between the observed and the scaled wavenumber values of most of the fundamentals is very small. Using the aid of VEDA 4 software, the vibrational assignments were made using potential energy distributions. The calculated HOMO, LUMO energies and energy differences demonstrate that charge transfers take place within the molecule. The stability of the molecule arising from hyperconjugative interactions, and charge delocalization have been analyzed using natural bond orbitals (NBO) analysis. The results provide that charge in electron density (ED) in the bonding, and antibonding orbital and second order delocalization energies E(2) confirms the occurrence of intramolecular charge transfer (ICT) within the molecule. Thermodynamic parameters such as entropy (S), enthalpy changes (ΔH) and heat capacity at constant pressure (Cp) are calculated in the temperature range from 100 to 700 K. The first hyperpolarizability (β), dipole moment (μ), and polarizability (α) values are being used to confirm the nonlinear optical behavior of the molecule. In addition, the dielectric properties explain the interactions between the sample and solvent at high frequencies. Finally, the compound is taken for the docking studies and molecular docking was performed against the potential target protein tankyrase and the results are compared with the drug Warfarin. The anticancer activity of BTTP confirms that it can be treated as antineoplastic against the two tested cell lines.

Tailoring the optical performance of sprayed NiO nanostructured films through cobalt doping for optoelectronic device applications

The current study aims to tailor the structural and nonlinear/linear optical characteristics of NiO nanostructures for optoelectronic applications. The spray pyrolysis procedure was applied to synthesize Ni1-xCoxO nanostructured films (x; 0, 0.04, 0.08, 0.12, 0.16 and 0.20). The functional groups and morphological investigation were performed by the FT-IR and SEM techniques. The structural and optical properties were investigated based on XRD and UV–vis measurements. The XRD investigations reveal that all samples have a cubic crystalline structure. The UV–vis analysis shows that the optical absorption of NiO nanostructures increased, and the energy bandgap decreased from 3.85 eV to 3.40 eV through cobalt doping. The Herve-Vandamme model was applied to investigate the linear refractive index for all samples. The nonlinear optical (NLO) behavior of all samples has been investigated. A significant improvement was accomplished through cobalt doping in the linear refractive index, optical conductivity, dielectric constants, NLO susceptibility and NLO refractive index of NiO. The achieved results suggest that cobalt-doped NiO nanostructured films have potential applications in linear/nonlinear optical devices and data storage.

Centrosymmetry-Breaking Morphotropic Phase Boundary: A Pathway to Highly Sensitive and Strong Pressure-Responsive Nonlinear Optical Switches.

The quest for high-performance piezoelectric materials has been synonymous with the pursuit of the morphotropic phase boundary (MPB), yet the full potential of MPBs remains largely untapped outside of the realm of ferroelectrics. In this study, we reveal a new class of MPB by creating continuous molecular-based solid solutions between centro- and noncentrosymmetric compounds, exemplified by (tert-butylammonium)1-x(tert-amylammonium)xFeCl4 (0 ≤ x ≤ 1), where the MPB is formed due to disorder of molecular cations. Near the MPB, we discovered an exceptionally sensitive nonlinear optical material in the centrosymmetric phase, capable of activation at pressures as low as 0.12-0.27 GPa, and producing tunable second-harmonic generation (SHG) signals from zero to 18.8 times that of KH2PO4 (KDP). Meanwhile, synchrotron diffraction experiments have unveiled a third competing phase (P212121) appearing at low pressure, forming a triple-phase point near the MPB, thereby providing insight into the mechanism underpinning the nonlinear optical (NLO) switch behavior. These findings highlight the opportunity to harness exceptional physical properties in symmetry-breaking solid solution systems by strategically designing novel MPBs.

Synthesis, crystal structure, DFT calculations, NBO, Fukui function, NCI-RDG, Hirshfeld surface analysis, NLO properties and molecular docking analysis on (E)-N'-(3-methoxybenzylidene)-2-(quinolin-8-yloxy) acetohydrazide

In this study, we present the synthesis and characterization of a novel organic compound, (E)-N'-(3-methoxybenzylidene)-2-(quinolin-8-yloxy) acetohydrazide. Our characterization includes single crystal X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and UV–visible spectroscopy. We also conducted Hirshfeld surface (HS) analysis to investigate intermolecular interactions. The compound crystallizes in the triclinic system with space group P−1. We employed density functional theory (DFT) with the B3LYP function and the 6–311 G (d, p) basis set to calculate its electronic properties. Additionally, we explored its nonlinear optical (NLO) behavior, determining the electric dipole moment (μ), polarizability (α), and hyperpolarizability (β), second-order hyperpolarizabilities (γ) using the same basis set. To evaluate the NLO properties of MBQA, we conducted frontier molecular orbitals (FMO) analysis, examined HOMO-LUMO energies, determined the energy band gap, studied the density of states (DOS), and assessed global chemical reactivity descriptors. We also performed a molecular electrostatic potential (MEP) simulation to identify optimal sites for both electrophilic and nucleophilic attacks. Our analysis further included a reduced density gradient (RDG) analysis to investigate various types of intermolecular interactions in MBQA, such as repulsive, attractive, and Van der Waals interactions while also distinguishing between strong and weak interactions. To understand the molecular stability and interactions, we conducted natural bond orbital (NBO) analysis, which provided insights into hyperconjugative interactions, charge delocalization and electron density ED among the molecular components. Finally, we assessed the biological activity of the MBQA molecule by predicting its potential pharmacological activities using the prediction of activity spectra for substances (PASS) and conducting molecular docking analyses. This comprehensive study provides valuable insights into the structural, electronic, and biological properties of (E)-N'-(3-methoxybenzylidene)-2-(quinolin-8-yloxy) acetohydrazide (MBQA).

Role of SiO2 in tailoring stability and nonlinear optical behaviour of gold nanoparticles in glass

In the present work, a new approach is introduced to mitigate the loss of gold nanoparticles while preparing the glass through the traditional melt-quench technique. The role of refractory material i.e. SiO2 in loss reduction is studied by comparing the results obtained for bismuth borate (40Bi2O3:60B2O3) and borosilicate (40Bi2O3:40B2O3:20SiO2) glasses containing gold nanoparticles of different sizes (10 nm, 40 nm and 100 nm). The particle density and thermal stability obtained from FESEM and DTA, respectively, increase considerably with the presence of SiO2 as one of the components of glass composition. The nonlinear optical behaviour of both systems in non-resonant regions has been obtained using the Z-scan technique. In addition, the suitability of the prepared glasses for optical limiting and switching applications has been analysed.

Phthalocyanine Covalent Organic Frameworks: Dimensionality Effect on Third‐Order Nonlinear Optical Properties

AbstractDimensionality of covalent organic frameworks (COFs), in terms of 2D and 3D, must greatly influence their properties and functionalities due to the different electronic and porous structures, but still less investigated in the 20 years history. Herein, on the basis of the imidization reaction of phthalocyanine‐based tetraanhydride monomers with either 1,4‐phenylenediamine or 1,3,5,7‐tetra(4‐aminophenyl)adamantine, 2D and 3D imide‐bonded COFs with sql and pts topology have been prepared to explore their third‐order nonlinear optical (NLO) properties. In contrast to metal‐free analogues, both 2D and 3D copper‐phthalocyanine COFs have the enhanced NLO behaviors according to the open aperture Z‐scan and optical limiting (OL) results recorded under a nanosecond laser at 532 nm. In particular, 2D COFs with strong π–π staking phthalocyanine units show the NLO property with bigger third‐order nonlinear susceptibility (Imχ(3)) and unique reverse saturation absorption response at 1064 nm than that of 3D species with dispersed conjugated modules. Furthermore, femtosecond transient absorption spectra disclose the longer excited lifetimes of copper COFs than metal free samples, helpful in their NLO property. These findings clearly disclose the materials advantages of 2D phthalocyanine COFs toward the NLO characteristics and provide new candidates for OL application.

Impact of extended π-conjugated acceptor moieties on non-linear optical behavior in polar medium for designed 4,4-dimethyl-4H-indeno[1,2-b] thiophene based materials

In the current study, the organic compounds (D2-D9) with D1–π–D2–π–A configuration were designed by structural modeling with various end-capped acceptor moieties for nonlinear optical (NLO) study. TD-DFT/DFT approaches at CAM-B3LYP/6-311G(d,p) level were accomplished to investigate the NLO behavior of these compounds. For this, various analyses: frontier molecular orbitals (FMOs), density of states (DOS), UV–Vis absorption, natural bond orbitals (NBOs), transition density matrix (TDMs) and non-linear optical (NLO) investigations were performed. These findings revealed that all designed chromophores exhibited comparable band gaps (3.962–4.182 eV) and absorption spectra (λmax = 441.6–460.7 nm) with reference chromophore (band gap = 4.008 eV). An efficient charge transfer from central core in HOMO was transferred towards terminal acceptors in LUMO that was also supported by DOS and TDM maps. Among all studied chromophores, the significant linear and nonlinear polarizability properties were examined in D5 (<α>=2.213 × 10-22esu), D6 (βtot = 3.339 × 10-28esu) and D4 (γtot = 3.068 × 10-33esu) chromophores. The NLO results indicated that the designed compounds (D5, D6 and D4) possess promising NLO behavior via effective charge delocalization. It is inferred that the current computational work might be helpful for further developments in non-linear optic field.

Study of Metal Chalcogenide Material for Optical and Electrical Properties

Abstract: Metal chalcogenide materials offer a complex tapestry of optical and electrical properties that engage researchers from a variety of disciplines, making their study an important area of study in materials science. This abstract light up the dual nature of these materials and their possible uses by exploring the complex interactions that exist between structure, composition, and functioning. The search for new materials with customised optical responses has focused attention on the optical characteristics of metal chalcogenides recently. Optoelectronic device improvements are made possible by the versatile platform provided by the bandgap engineering in these compounds for altering light-matter interactions. A thorough understanding of metal chalcogenides' optical properties is provided by examining their absorption and emission spectra, quantum yield, and nonlinear optical behaviours. This knowledge is essential for the creation of sensors, photodetectors, and light-emitting gadgets of the future.

Third-Order Nonlinear Optical Modulation Behavior of Photoresponsive Bimetallic MOFs.

Bimetallic metal-organic frameworks (MOFs) capable of sensing external stimuli will provide more possibilities for further regulating third-order nonlinear optical (NLO) properties. In this work, we synthesized bimetallic MOFs (ZnCu-MOF and ZnCd-MOF) through central metal exchange using a photoresponsive Zn-MOF as a precursor. Compared with Zn-MOF, both ZnCu-MOF and ZnCd-MOF exhibit significantly enhanced third-order NLO absorption properties. This is mainly attributed to the introduction of metal ions with different electron configurations that can adjust the bandgap of MOFs and enhance electron delocalization, thus promoting electron transfer. Interestingly, the bimetallic MOFs show a transition from reverse saturation absorption (RSA) to saturation absorption (SA) after exposure to ultraviolet irradiation, as they retain the properties of directional photogenerated electron transfer. Photoresponsive bimetallic MOFs not only have the effect of bimetallic modulation of electronic structures but also have the characteristics of photoinduced electron transfer, exhibiting diversified optical properties. These findings provide a novel method for the development of multifunctional NLO materials.

A noncentrosymmetric polymorph of second harmonic generation 2,4 dinitrophenyl hydrazine for nonlinear optical applications: An experimental and theoretical investigation

Potent ocular materials with noncentrosymmetric frameworks seek the attention of researchers throughout the globe. A polymorph of 2,4-dinitrophenylhydrazine single crystals with such framework was grown by slow cooling mechanism with 1,4-dioxane as the solvent. The noncentrosymmetric characteristics of the grown material were confirmed by using X-ray diffraction analysis. The presence of functional groups of the title meld was identified with the aid of Fourier transform infrared spectroscopy analysis. The ability of the material to withstand temperature with weight loss and decomposition peak was determined by using TG/DTA analysis. The transmission window and optical bandgap of the materials were determined by using UV–Vis analysis. The nonlinear optical behavior of the grown crystals was determined with the aid of SHG and Z-scan analysis. The computational analysis was performed using Gaussian 09 software package to investigate various parameters of title meld. Hirshfeld surface analysis was performed using Crystal explorer 17 to quantify the intermolecular interactions of the grown material.

Synthesis of a new hydrazone-based schiff base: Spectroscopy, single crystal, DNA binding and theoretical studies

A new thiosemicarbazide-based Schiff base (TSDHB) was synthesized from thiosemicarbazide and 2,3-dihydroxybenzaldehyde. The prepared thiosemicarbazone was characterized by elemental (CHN), FT-IR, 1H and 13C NMR techniques. Furthermore, the molecular structure was probed using the single-crystal X-ray diffraction (SC-XRD) technique, which confirmed the enol tautomeric form with two independent molecules in asymmetric unit. The dissimilarity between the molecular units was determined by molecular overlay plots. The various intermolecular interactions and solid-state assembly stabilization were explored by Hirshfeld surface analysis. Void analysis was executed to examine the mechanical stability of crystalline units. The bioactivity of thiosemicarbazone was probed with the help of its binding capacity with salmon sperm DNA (SS-DNA) by means of the absorption interaction method. Accompanied by biological activity, optoelectronic properties such as nonlinear optical properties of yielded crystal were also explored through the DFT approach at M06/6–311 G (d,p). For this, various kinds of investigations such as frontier molecular orbital (FMO), UV–Vis, global reactivity parameters (GRPs), transition density matrix (TDM), density of states (DOS), natural population analysis (NPA), and natural bond orbital analysis (NBO) were executed at M06 functional. A good agreement was examined between XRD and DFT findings of molecular geometric parameters. Notably, in comparison with urea, TSDHB demonstrated enhanced nonlinear optical properties (linear polarizability=4.766 × 10−23esu and third-order hyperpolarizability=5.939 × 10−35esu). These findings position TSDHB as a promising candidate for DNA binding as well as for photonic materials due to its unique molecular characteristics and enhanced nonlinear optical behavior.