- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Structural, optical and nonlinear optical properties and TD-DFT analysis of heteroleptic bis-cyclometalated iridium(III) complex containing 2-phenylpyridine and picolinate ligands
摘要： In this work, we studied the structural, optical and nonlinear optical properties and UV–visible absorption spectrum of the heteroleptic bis-cyclometalated iridium(III) complex (tfmppy)2Ir(pic) recently synthesized with tfmppy = 5-trifluoromethyl-2-phenylpyridine and pic = picolinate. The calculations were performed by means of density functional theory (DFT) and time-dependent density functional (TD-DFT) methods using four functionals B3LYP, PBE0, CAM-B3LYP and M06-2X. Calculated geometric parameters agree with the experimental data. CAM-B3LYP and M06-2X lower the HOMO energy level and give a large energy gaps compared with B3LYP and PBE0. The four functionals show that LUMO is delocalized over ??? ppy and dIr orbitals. The studied complex gets a remarkably large first-order NLO response. B3LYP would provide good estimates of the energy gap and shows the strongest values of the first hyperpolarizabilities βHRS; M06-2X and CAM-B3LYP functionals overestimate the gaps and lower βHRS values. PBE0 and B3LYP spectra agree better with the experimental spectrum in the visible region, while CAM-B3LYP and M06-2X are more accurate in UV-C region. Natural transition orbital analysis shows that the weak band observed at 468 nm corresponds to MLCT/LLCT charge transfer transitions and the intense band observed at 270 nm is mainly assigned to intra-ligand state.
关键词： Excited states,Wiberg indices,Absorption spectrum,Hyperpolarizability,Complexes,Iridium,NTO,TD-DFT,Optical, nonlinear optical,Picolinate
更新于2025-09-10 09:29:36
-
Preparation, Characterization, Spectroscopic (FT-IR, FT-Raman, UV and Visible) Investigation, Optical and Physico Chemical Property Analysis on In2O3 Thin Films
摘要： In this work, Indium oxide (In2O3) thin film is successfully deposited on microscopic glass substrate at different temperatures by spray pyrolysis technique using InCl3 as precursor. The physical properties of these films are characterized by XRD, SEM, AFM, FT-IR, FT-Raman, UV-visible and AFM measurements. XRD analysis exposed that the structural transformation of films from stoichiometric to non-stoichiometric orientation of the plane vice versa and also found that, the film is polycrystalline in nature having cubic crystal structure with a preferred grain orientation along (222) plane. SEM and AFM studies revealed that, the film with 0.1M at 500?C has spherical grains with uniform dimension. The complete vibrational analysis has been carried out and the optimized parameters are calculated using HF and DFT (CAM-B3LYP, B3LYP and B3PW91) methods with 3-21G (d,p) basis set. Furthermore, NMR chemical shifts are calculated by using the gauge independent atomic orbital (GIAO) technique. The molecular electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, molecular electrostatic potential energy (MEP) analysis and Polarizability first order hyperpolarizability calculations are performed by time dependent DFT (TD-DFT) approach. The energy excitation on electronic structure was investigated and the assignment of the absorption bands in the electronic spectra of steady compound is discussed. The calculated HOMO and LUMO energies showed the enhancement of energy gap by the addition of substitutions with the base molecule. The thermodynamic properties (heat capacity, entropy, and enthalpy) at different temperatures are calculated and interpreted in gas phase.
关键词： Gauge independent atomic orbital,Spherical grains,Hyperpolarizability,MEP,Indium Oxide,Frontier molecular orbital energy
更新于2025-09-09 09:28:46
-
Non-linear Optical Response of Triphenylamine Dyes with D-A-π-A Structure
摘要： In this study, we have designed new triphenylamine dyes with D-A-π-A structure and calculated their electro-optical and non-linear properties. Computational techniques were used to study the effect of additional acceptor in π-conjugated systems on absorption spectra and non-linear properties. All the dyes show absorbance in visible region. During theoretical examination polarizability (α), hyperpolarizability (β) and electronic transitions were calculated. Results indicated that the selection of appropriate lengths of conjugated bridges in dye is very important to design high efficiency dyes. This theoretical frame work would be useful to design other organic dyes.
关键词： Hyperpolarizability,Organic dyes,DFT,Polarizability
更新于2025-09-09 09:28:46
-
All-optical field-free three-dimensional orientation of asymmetric-top molecules
摘要： Orientation and alignment of molecules by ultrashort laser pulses is crucial for a variety of applications and has long been of interest in physics and chemistry, with the special emphasis on stereodynamics in chemical reactions and molecular orbitals imaging. As compared to the laser-induced molecular alignment, which has been extensively studied and demonstrated, achieving molecular orientation is a much more challenging task, especially in the case of asymmetric-top molecules. Here, we report the experimental demonstration of all-optical field-free three-dimensional orientation of asymmetric-top molecules by means of phase-locked cross-polarized two-color laser pulse. This approach is based on nonlinear optical mixing process caused by the off-diagonal elements of the molecular hyperpolarizability tensor. It is demonstrated on SO2 molecules and is applicable to a variety of complex nonlinear molecules.
关键词： ultrashort laser pulses,nonlinear optical mixing,hyperpolarizability tensor,molecular orientation,asymmetric-top molecules
更新于2025-09-09 09:28:46
-
Synthesis, physicochemical and quantum chemical studies on a new organic NLO crystal: Cinnamoylproline
摘要： Cinnamoylproline was synthesized and the crystal was grown from solution by the slow evaporation method. The crystal belongs to the trigonal crystal system with non-centrosymmetric space group P31. The calculated geometry and experimental geometry from single crystal X-ray data were compared. Intermolecular interactions were studied using Hirshfeld surface analysis and its real space functions were calculated using Atoms In Molecules (AIM) and its isosurfaces were visualized using Non-covalent interaction analysis. Optical transparency of the crystal was analyzed by UV-Vis analysis and it was found that the crystal has good optical transparency in the visible range and the lower cut-off wavelength was found to be 326 nm. In the photoluminescence spectrum, a broad emission peak at 369 nm was observed. The functional groups were analyzed using FTIR techniques and the vibrational frequencies from experimental and theoretical values were compared. It was inferred from the TG-DTA studies that the crystal was thermally stable up to 375°C. Kurtz-Perry powder SHG analysis was also carried out with KDP as a reference. It showed that the crystal has 1.08 times greater efficiency than KDP. The first hyperpolarizability tensor of the molecule was calculated theoretically and theoretical second order susceptibility was obtained and compared with the experimental susceptibility.
关键词： Non Covalent Interaction (NCI),Crystal growth,Hirshfeld surface analysis,cinnamic acid,QTAIM,First hyperpolarizability
更新于2025-09-04 15:30:14
-
First Hyperpolarizability of 1,3-Thiazolium-5-Thiolates Mesoionic Compounds
摘要： The first hyperpolarizabilities of the mesoionic compounds (MICs) 2-(4-chlorophenyl)-3-methyl-4-phenyl-1,3-thiazole-5-thiolate (MIC-1), 2-(4-chlorophenyl)-3-methyl-4-(4-methylphenyl)-1,3-thiazole-5-thiolate (MIC-2), and (2-(4-chlorophenyl)-3-methyl-4-(4-methoxyphenyl)-1,3-thiazole-5-thiolate) (MIC-3), dissolved in dimethyl sulfoxide (DMSO), are reported here for the first time to our knowledge. Hyper-Rayleigh scattering experiments were performed with an excitation source operating at ?? =1180 nm (?? = 8475 cm?1). The measured hyperpolarizability, ??(2??), was used to calculate the static hyperpolarizability, ??(0), by applying the classical two-level model. The values obtained for ??(0) were 10.1 × 10?30 esu (MIC-1), 8.7 × 10?30 esu (MIC-2) and 10.4 × 10?30 esu (MIC-3) which are smaller than previous theoretical predictions that did not consider features related to the liquid phase.
关键词： nonlinear optics,Hyper-Rayleigh scattering,mesoionic compounds,hyperpolarizability,DMSO
更新于2025-09-04 15:30:14
-
Stark shift of excitons and trions in two-dimensional materials
摘要： The effect of an external in-plane electric ?eld on neutral and charged exciton states in two-dimensional (2D) materials is theoretically investigated. These states are argued to be strongly bound, so that electron-hole dissociation is not observed up to high electric ?eld intensities. Trions in the anisotropic case of monolayer phosphorene are demonstrated to be especially robust under electric ?elds, so that ?elds as high as 100 kV/cm yield no signi?cant effect on the trion binding energy or probability density distribution. Polarizabilities of excitons are obtained from the parabolicity of numerically calculated Stark shifts. For trions, a fourth order Stark shift is observed, which enables the experimental veri?cation of hyperpolarizability in 2D materials, as observed in the highly excited states of the Rydberg series of atoms and ions.
关键词： Stark shift,polarizability,two-dimensional materials,electric field,excitons,trions,hyperpolarizability
更新于2025-09-04 15:30:14