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Benzothiazole pyrazole containing emissive azo dyes decorated with ESIPT core: Linear and non linear optical properties, Z scan, optical limiting, laser damage threshold with comparative DFT studies
摘要： Positional isomers of "benzothiazoles-pyrazole based azo dyes containing separate with ESIPT core" are analyzed for their "linear and non-linear optical (NLO)" properties. Dyes are emissive in ACN having Stokes shift in the range of 75 nm. Spectroscopic properties are further utilized to calculate band gap by CV. Band gap obtained by DFT and cyclic voltammetry (CV) are in good agreement with each other. Vertical excitation in six different functionals is compared with experimental absorption maxima. Non-linear absorptive coef?cient (b), nonlinear refractive index (?2), third-order non-linear optical suscep- tibility (c3) and optical limiting (OL) in acetone, ethanol and DMSO are obtained using Z-scan technique and results are appreciable than previously reported dyes. Satisfactory laser damage threshold (LDT) values are in the range of 7.9e9.7 (cid:1) 1013 W/m2. TGA study indicates that these compounds are useful in several high-temperature processes in the construction of electronic and optical devices. The geometry of the dyes are optimized at "B3LYP/6-311 t G (d,p) level". "Molecular Electrostatic Potential" (MEP), "Frontier Molecular Orbitals" (FMO) are presented using "Density Functional Theory (DFT)" to gain structural insights. Relatively new electrophilicity descriptor- "Hyperhardness" for both the molecules are calculated which suggests the stability of molecules. Global hybrid (GH) functional (B3LYP, BHandHLYP) and range separated hybrid (RSH) (CAM-B3LYP, uB97, uB97X, and uB97XD) functional are used to calculate linear and NLO properties. uB97 is a more suitable functional observed for determining bo and g. Direct relation in-between "dipole moment" (m) and "linear polarizability" (a) is also presented. These dyes can emerge as attractive NLOphores in optoelectronic applications.
关键词： ESIPT,NLO,Z-scan,LDT,DFT,Emissive azo dyes,Benzothiazole-pyrazole
更新于2025-09-11 14:15:04
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Synthesis and electro-optic properties of novel Y-type polyimide containing nitrothiazolylazodioxyphenyl group
摘要： New Y-type polyimide (5) containing nitrothiazolylazodioxyphenyl groups as nonlinear optical (NLO) chromophores, which are components of the polymer backbone, was prepared and characterized. Polyimide 5 is soluble in common organic solvents such as N,N-dimethylformamide and dimethylsulfoxide. Polyimide 5 shows a thermal stability up to 300 °C in thermogravimetric analysis with glass-transition temperature (Tg) obtained from differential scanning calorimetry near 130 °C. The second harmonic generation (SHG) coefficient (d33) of poled polymer film at the 1064 nm fundamental wavelength is around 2.32 pm/V. The dipole alignment of polymer 5 exhibits a thermal stability even at 5 °C higher than Tg, and there is no SHG decay below 135 °C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.
关键词： thermogravimetric analysis (TGA),NLO,dipole alignment,SHG coefficient,differential scanning calorimetry (DSC),polyimide
更新于2025-09-11 14:15:04
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Ultraviolet Absorption Spectra, Solvent Effect and Non-Linear Optical Properties of Tetrahydroxy-1,4-quinone Hydrate by Hartee-Fock and Density Functional Theory
摘要： In present work, the ultraviolet absorption spectrum of tetrahydroxy-1,4-quinone hydrate (TH,1,4-QH) has been carried out experimentally (in water, methanol dimethyl sulfoxide, acetonitrile and chloroform) and theoretically in the range 3500-2300 cm-1 in the solution phase. Predicted electronic absorption spectra from time dependent density functional theory (TD-DFT) calculation have been analyzed and compared with the experimental UV-visible spectrum. The effects of hydroxy group substituent in benzoquinone ring have been analyzed. The electronic properties such as excitation energy, wavelength corresponding to absorption maxima (λmax), oscillator strength (f), HOMO and LUMO energies are calculated by time-dependent density functional theory (TD-DFT) using HF/6-311++G(d,p) and B3LYP/6-311++G(d,p) as basis sets. The electric dipole moment (μ), α (polarizability) and β (first hyperpolarizability) have been computed to evaluate the NLO (non-linear optical) response of the investigated compound by Hartree-Fock (HF) and density functional theory (DFT) with B3LYP basis sets. Mulliken atomic charges of the atoms are calculated by DFT (B3LYP). In addition natural bond orbital (NBO) analysis has been done using TD-DFT with B3LYP/6-311++G(d,p) basis sets.
关键词： Tetrahydroxy-1,4-quinone hydrate,Density Functional Theory,NLO properties,Hartee-Fock,Ultraviolet spectrum
更新于2025-09-11 14:15:04
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Red emitting coumarin based 4, 6-disubstituted-3-cyano-2-pyridones dyes – Synthesis, solvatochromism, linear and non-linear optical properties
摘要： New coumarin fluorescent based D-π-A-π-D dyes are synthesized and studied for their optical properties. Their show absorption and emission respectively are in the range of 471-504 nm and 506-550 nm. Viscosity induced emission intensity increase is examined with 0-100% PEG-400 in ethanol MLK 4 is good FMR as compared to the MLK 1-3 due to the presence of extra-π-conjugation. FMO analysis and Generalised Mulliken Hush analysis show a strong interaction of molecular charge transfer characteristics. The first (α), second (β) and third (γ) order polarizability of MLK 1-4 are calculated by the solvatochromic technique and corroborated by DFT calculations using CAM-B3LYP/6-31G(d) method. The outcomes found by solvatochromic technique are compared theoretically with DFT using B3LYP/6-31G(d) and CAM-B3LYP/6-31G(d) methods. These methods reveal that, CAM-B3LYP/6-31G(d) carry out for calculating α, β, γ. Photophysical data was also applied to establish the ground and excited state dipole moment ratio using Bakhshiev, Bilot-Kawski, and Liptay functions. Liptay function shows better correlations than the other two functions for all dyes.
关键词： Viscosity sensor,TD-DFT,Coumarin,NLO properties,Carbazole,Intramolecular charge transfer
更新于2025-09-10 09:29:36
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A systematic study of the effects of thionation in naphthalene dimide derivatives to tune their nonlinear optical properties
摘要： In the present study, the number and position of sulfur atoms on naphthalene diimide (NDI) is systematically investigated to tune its nonlinear optical (NLO) response properties. Our DFT calculations for third-order polarizability (γ) show that the thionation significantly influences the nonlinear optical property of NDI as it is seen among its several designed derivatives (NDI-1 to NDI-10). The smallest and the largest γzzzz amplitudes are 503.49×10?36 and 1299.5×10?36 esu for NDI-1 (having tetraone group) and NDI-10 (having tetrathione group), respectively. The increase in γzzzz amplitude for NDI-10 is 796×10?36 esu, which is ~150% from the γzzzz amplitude of NDI-1. A comparison of the γzzzz amplitudes of our designed derivatives are made with para-nitroaniline i.e. a prototype NLO molecule. The γzzzz amplitude of pNA is found to be 42.64×10?36 esu at the same B3LYP/DZVP2 level of theory. Using two-level model, the origin of larger γzzzz amplitudes is traced in lower transition energy of NDI-10. Furthermore, the calculation of vertical ionization potentials (VIPs) shows that the thionation does not affect the stability of designed derivatives, where a slight difference of 0.06 eV is seen between the VIPs of NDI-1 (6.63 eV) and NDI-10 (6.57 eV). Thus, a systematic comparison of the third-order polarizability and other electro-optical properties of our designed derivatives shows that our derivative systems possess good potential for their practical realization in the field of optical and NLO materials.
关键词： Naphthalene Diimide,Nonlinear Optical Properties,Third order-NLO polarizability,Polarizability,Frontier Molecular Orbitals
更新于2025-09-09 09:28:46
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Investigation on Physical Properties of Semiorganic Nonlinear Optical Glycine Zinc Sulfate Single Crystal
摘要： Nonlinear optical single crystals of Glycine Zinc Sulfate (GZS) were grown by slow evaporation technique. Single crystal X-ray diffraction analysis revealed the crystal system and lattice parameter values. Powder X-ray diffraction analyses have been carried out and the diffraction patterns have been indexed. The optical properties of the crystals were determined using UV-Visible spectroscopy. Optical constants such as band gap, refractive index, extinction coefficient and electric susceptibility were determined from UV-Visible spectroscopy. The refractive index was determined using Brewster’s angle method. Hardness of the GZS crystal was estimated by Vicker’s hardness studies. Second Harmonic Generation (SHG) of GZS crystal was investigated by Kurtz powder technique. The dielectric constant and dielectric loss measurements were carried out for different temperatures and frequencies. The photoconductivity studies confirm that the grown crystal has negative photoconductivity nature. In order to investigate the growth mechanism and surface features, etching studies are carried out for the crystal.
关键词： NLO,single X-ray diffraction,SHG,UV-Vis-NIR spectrophotometer,dielectric loss studies,dielectric constant
更新于2025-09-09 09:28:46
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Reverse saturable absorption behaviour of Disodium 8-Hydroxy-5,7-Dinitro-2-Naphthalenesulfonate Hydrate for nonlinear optical applications
摘要： Nonlinear optical properties, vibrational features, optical and electronic properties of organic dye Disodium 8-Hydroxy-5,7-Dinitro-2-Naphthalenesulfonate Hydrate have been studied. Spectral and electronic properties were studied by FT-IR, FT-Raman and UV-visible spectroscopic technique combined with density functional theory (DFT) and time dependent density functional theory (TD-DFT) methods respectively. The intramolecular charge transfer interactions leading to nonlinear optical response have been analyzed by natural bond orbital analysis. The kinetic stability, chemical reactivity and electrophilicity index were studied by frontier molecular orbital analysis. The first- and second hyperpolarizabilities were calculated at DFT level using B3LYP and CAM-B3LYP hybrid functional. The third-order nonlinear optical performance of the compound have been investigated experimentally by open and closed aperture Z-scan techniques. Z-scan measurements were performed using Q-switched Nd: YAG laser with 5 ns pulses at 532 nm with different dye concentrations and intensities. The Z-scan results confirm the sign of nonlinear absorption and refraction is positive. The optical limiting threshold and laser damage threshold were measured. The obtained results promote the title compound can be considered as a promising candidate for developing future optoelectronic and photonic devices.
关键词： RSA,Third-order NLO,Optical limiting,Z-Scan,DFT
更新于2025-09-09 09:28:46
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Spectroscopic Investigation of the Stimulus of NLO Property on Acetone Thiosemicarbazone Using Computational [HF and DFT] Confinement
摘要： In this attempt of research work, the inducement of NLO property on the compound Acetone thiosemicarbazone has been analyzed using computational calculations. The FT-IR, FT-Raman, FT-NMR and UV-Visible spectra have been recorded in specified region. The optimized inducement of NLO activity by the molecular structural deformation due to the addition of acetone compound has been investigated. The supportive analyses such as Mulliken charge levels, first order and second order polarization, vibrational confirmation, frontier molecular interactions, thermodynamic function (Gibbs energy) and VCD profile for proving NLO mechanism in the compound have been carried out. The chemical environment of the compound was simultaneously monitored by simulating and recording 1H and 13C NMR spectra. The isotropic and anisotropic chemical shift related to carbons and hydrogens after the formation of target compound have been carefully interpreted. The stabilization of orbitals by interchanging of energy between donor and acceptor was observed by NBO perturbation calculations.
关键词： NLO activity,Acetone thiosemicarbazone,Isotropic,NBO perturbation,VCD
更新于2025-09-04 15:30:14