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Synthesis, crystal structure analysis, spectral characterization and nonlinear optical exploration of potent thiosemicarbazones based compounds: A DFT refine experimental study
摘要： The thiosemicarbazones have exciting biological and nonlinear optical (NLO) applications. The present study reports detail experimental and computational studies of three novel ferrocene-substituted thiosemicarbazones: (E/Z)-4-(4-chlorobenzyl)-1-(1-ferrocenyl-ethyl)thiosemicarbazone (2) and (E/Z)-4-benzyl-1-(1-ferrocenylethyl)thiosemicarbazones (1) and (E/Z)-4-(2-bromo benzyl)-1-(1-ferrocenylethyl)thiosemicarbazone (3). These compounds were synthesized and resolved into their single crystal structures for the estimation of unit cells, space groups, bond angles and bond lengths. Chemical structures of 1–3 were further characterized spectroscopically employing nuclear magnetic resonance technique (1H NMR), infrared (FT-IR), mass and UV–Visible studies. Computational studies of 1–3 were performed using density functional theory (DFT) tools at M06 level of theory and 6–31 + G(d,p) basis set combination to gain the optimized geometry. A good correlation was found between experimental SC-XRD structures and DFT optimized geometries. Electronic properties including natural bond orbital (NBO) analysis, frontier molecular orbitals (FMOs) analysis, spectroscopic FT-IR data and NLO properties were calculated using same M06/6–31 + G(d,p) level of theory. NBO analysis confirmed the formation of charge separation state due to successful migration of electrons from donor to acceptor unit through π-bridge. Global reactivity parameters were estimated using energies of FMOs which described that 1–3 are chemically hard and stable molecules. Vertical electronic transition states were calculated using time-dependent DFT (TDDFT) at same level of theory. NLO properties of 1–3 were computed 5.77, 3.48 and 8.93 times greater than the standard urea molecule respectively. Two-state model confirmed the potential of synthesized molecules as NLO candidates.
关键词： Frontier molecular orbital,Ferrocene-substituted thiosemicarbazones,Spectroscopic data,Crystal structures,Non-linear optical properties,Density functional theory
更新于2025-09-23 15:21:01
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Preparation, Structural, Spectroscopic, Thermal, Linear and Nonlinear Optical Characteristics of Semi-Organic Material: Samarium Chloride-Thiourea-L-Tartaric acid
摘要： Samarium chloride-thiourea-l-tartaric acid (SCTuT): a semi-organic material was prepared in the form of a single crystal with an orthorhombic crystal structure and a space group Pnma. The crystallinity and purity of the single crystals were tested by powder X-ray diffraction. The scanning electron microscopy (SEM) analysis shows the rod-like microstructure. Energy dispersive X-ray analysis has confirmed the elemental composition. Fourier transform infrared and Raman spectroscopy analysis established the mode of coordination and functional groups. The thermal effects such as dehydration, melting and decomposition, etc. were observed by the thermogravimetric and differential thermoanalytical (TGA/DTA) analysis. Linear and non-linear characteristics of the compound were studied in detail. The optical band transitions due to C=O and C=S chromophores remain active in grown crystals and thus are recorded in the UV-Vis optical spectrum. The crystals possess finite values of non-linear absorption, non-linear refraction and third order nonlinearity as confirmed by Z-scan experiments.
关键词： Spectroscopic Analysis,Semi-organic Material,Non-Linear Optical Properties
更新于2025-09-19 17:15:36
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AIP Conference Proceedings [AIP Publishing RECENT TRENDS IN PURE AND APPLIED MATHEMATICS - Vellore, India (13–15 December 2018)] RECENT TRENDS IN PURE AND APPLIED MATHEMATICS - Non-linear optical properties of carbazole based dyes modified with diverse spacer units for dye-sensitized solar cells: A first principle study
摘要： Density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations were performed for evaluating the photophysical and photochemical properties of a sequence of carbazole based metal-free organic dyes modified using different π-conjugation spacer units, such as thiopine, pyrrole, furan, thiazole and isoxazole. Moreover, the modified dyes were subjected to investigation towards their non-linear optical (NLO) features. The results revealed that dipole moment (μ), static polarizability (α), anisotropic polarizability (?α) and hyperpolarizability (first order (β) and second order (γ)) of modified dyes are considerably enhanced as a consequence of changing the spacer unit. Likewise, light harvesting efficiency and oscillator strength of the modified dyes are enhanced upon wavelength of absorption is red-shifted by influence of spacer moieties. We believe that our calculations provide a more profound physical perception on structural property relationship for carbazole based dyes and give a hint to create potential sensitizers for opto-electronic and dye-sensitized solar cell applications.
关键词： dyes,DFT,carbazole,TDDFT,non-linear optical properties,dye-sensitized solar cells
更新于2025-09-12 10:27:22
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High Optical Energy Storage and Two-Photon Luminescence from Solution-Processed Perovskite-Polystyrene Composite Microresonators
摘要： Optical green emitting microresonators with high values of nonlinearity are desired for high optical up-conversion energy storage and lasing applications. Here we report on the synthesis of benzylammonium lead iodide (BALI) perovskite microcrystals made via anti-solvent diffusion method. The use of polystyrene (PS) matrix helps the growth of environmentally stable BALI nanocrystals as a result of polymer capping. Optimization of the ratio of BALI-PS during the self-assembly process leads to the formation of defect-free composite microspheres. Further, these BALI crystals act as an active material within the microsphere resonators that display whispering gallery modes (WGM). These WGMs are responsible for high optical storage energy of resonators evidenced by their Q-factor as high as ~1180. Two-dimensional finite difference time-domain calculation shows the concentration of the electric field near the microspheres boundary within a small mode volume of 1.83 μm3. Remarkably, BALI-PS composite microresonators and their neat crystals exhibit brilliant two-photon luminescence upon excitation by the infrared fundamental radiation. This simplistic microresonators fabrication technique provides a route towards low-cost non-linear optical microlasers and other optical energy devices useful for various applications.
关键词： non-linear optical properties,perovskite,optical microresonators,polymer microspheres,two-photon emission
更新于2025-09-10 09:29:36