Nonlinear Optical Behavior Research Articles

Unleashing the nonlinear optical response of layered vanadium diselenide towards the deep mid-infrared regime

Broadband nonlinear optical materials towards the deep mid-infrared regime are highly required in medical diagnostics, environmental pollution monitoring, etc. Here, we report the ultra-broadband nonlinear optical absorption behavior of the layered vanadium diselenide (VSe2) towards deep mid-infrared regime experimentally. The layered VSe2 prepared by the liquid-phase exfoliation method exhibits broadband and wavelength-dependent nonlinear saturable absorption and a large modulation depth of over 8% in the 3-10 µm spectral range. By utilizing the layered VSe2 for optical modulation, stable nanosecond pulse with a low Q-switched threshold has been delivered successfully from an erbium-doped ZBLAN fiber laser. The experimental findings can deepen the understanding of the nonlinear optical response of the transition metal dichalcogenides towards the deep mid-infrared regime, and may make inroads for the advancement of mid-IR optoelectronic devices.

Surface enhanced Raman scattering-based sensing and ultrafast nonlinear optical properties of silver-hexagonal boron nitride nanocomposites achieved by femtosecond laser ablation

This study investigated the surface-enhanced Raman spectroscopy (SERS) properties and nonlinear optical (NLO) behavior of silver nanoparticles (Ag NPs) decorated hexagonal boron nitride (hBN) nanocomposites. Although Ag NPs are known for their excellent plasmonic properties, their susceptibility to oxidation in ambient conditions significantly reduces SERS activity. To overcome this, a femtosecond laser-assisted single-step novel approach is developed for synthesizing hybrid Ag-hBN nanocomposites via ablating Ag target in a solution of exfoliated hBN nanosheets, forming uniformly embedded Ag NPs on hBN nanosheets. The morphological characteristics and elemental compositions were validated by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). TEM analysis revealed that Ag NPs averaged 15 nm in size, while hBN nanosheets had lateral dimensions of approximately 250 nm. The SERS activity of the prepared nanocomposites was investigated using dye and explosive molecules, achieving detection sensitivities of 1 μM and 100 μM, respectively, with high reproducibility. These detection sensitivities are significant as they demonstrate the potential of the Ag-hBN nanocomposites for sensitive and reliable detection of trace amounts of analytes. Notably, the Ag-hBN nanocomposites showed enhanced SERS activity compared to pure Ag NPs, with a 2.5-fold improvement for Nile blue, 3.6-fold for methylene blue, and 2.4-fold for RDX. The current study also demonstrates that hBN prevents Ag NPs’ oxidation and preserves the SERS functionality even at elevated temperatures. Furthermore, the NLO properties of the nanocomposites were investigated using the standard Z-scan technique, revealing two-photon and three-photon absorption coefficients of 3 × 10−4 cm/GW and 6.5 × 10−5 cm3/GW2, respectively. The findings highlight the potential of Ag-hBN nanocomposites to enhance SERS and NLO devices, enabling future applications in sensing and photonics.

Enhanced optical nonlinearity in suspensions of dual-resonance gold–copper chalcogenide core–shell nanoparticles

Plasmonic copper chalcogenide (Cu2−xE, E = S, Se, Te) nanoparticles (NPs) possess high potentials in photothermal therapy and photoacoustic tomography for their unique localized surface plasmon resonant absorption in the second near-infrared biologically transparent window. In this study, strong thermal-induced nonlinear negative-lens effect in aqueous suspensions containing Cu2−xSe NPs was observed. Furthermore, the nonlinear absorption was notably enhanced in aqueous suspensions containing Au@Cu2−xSe core–shell NPs, as the positive nonlinear absorption coefficient increased by 20-fold, attributed to the strong plasmonic coupling in Au@Cu2−xSe core–shell NPs. This finding underscores the importance of the nonlinear optical behaviors of plasmonic NPs in biomedical applications, as they offer extra strategy for optimizing systems and incorporating additional functionalities.

Optoelectronic and Nonlinear Optical Behavior of Corner‐Functionalized Borophene Derivatives and Composites Doped with Polyaniline

Optoelectronic and Nonlinear Optical Behavior of Corner‐Functionalized Borophene Derivatives and Composites Doped with Polyaniline

Elucidation of structural, optical, mechanical, thermal, DFT, and nonlinear optical behavior of 4-chloro-anilinium 4-methyl-benzene-sulfonate single crystals

Elucidation of structural, optical, mechanical, thermal, DFT, and nonlinear optical behavior of 4-chloro-anilinium 4-methyl-benzene-sulfonate single crystals

New Class of Ionic Liquid Crystal Proposed by Using Quantum Chemical Calculation

AbstractThe current investigation conducts a thorough analysis of the nonlinear optical properties, binding characteristics, and electronic features of 1‐proplene‐3‐methylimidazolium (PMIM)‐X ionic liquid (IL) crystal. These findings reveal that the dissociation energy of PMIM‐X indicates a preference for ionic dissociation over neutral dissociation. Notably, the ionic dissociation energy shows an increasing trend with both the electron affinity (EA) and the size of X. In the process of forming the IL crystal PMIM‐X, this study observes a charge transfer from PMIM to X species. It is noteworthy that the extent of charge transfer intensifies with the increasing size of X. Additionally, the calculated energy gap exhibits a positive correlation with both EA and the size of X. Although these results suggest promising nonlinear optical behavior for PMIM‐X, it is crucial to acknowledge the limitations of the study. All calculations are conducted on single atoms in the gas phase, overlooking potential effects that may arise in the liquid phase or bulk conditions. Therefore, future investigations should consider these factors for a more comprehensive understanding of the behavior of PMIM‐X in practical applications.

Exploring nonlinear optical properties of RbPbI3 nanorods using SSPM technique: Implications for all-optical switching applications

Nowadays, nanomaterials' nonlinear optical (NLO) properties are a fascinating topic for developing a novel all-optical switching application. Spatial self-phase modulation (SSPM) is an important technique to determine the laser-induced coherent light-matter interaction to determine the NLO properties of nanomaterials. This study successfully synthesized RbPbI3 nanorods (NRs) via a low-cost, less complicated chemical route with all the basic characterizations to confirm its structural and compositional analysis. For the first time, we conducted a comprehensive analysis of the nonlinear refractive index (n2) and third-order susceptibility (χ(3)) for RbPbI3 NRs dissolved in two different solvents, namely N-Methyl-2-pyrrolidone (NMP) and 2-propanol, utilizing the SSPM technique. Our investigation revealed significant nonlinear optical (NLO) responses with n2 = 6.19 × 10−5 cm2 W−1 and χmonolaer(3) = 2.38 × 10−8 esu for RbPbI3. We elucidated the factors contributing to this pronounced NLO behaviour, including variations in parameters such as solvent type, viscosity, wavelength, and cuvette length. Additionally, we successfully demonstrated optical information transfer through an all-optical switching application. This research sheds light on the NLO properties of Perovskite materials and holds promise for the development of advanced all-optical device applications.

Tuning the photophysical and NLO properties of β-diketonates derived from coumarin-triphenylamine-chalcones: effect of the BF2 group.

Herein the synthesis of three difluoroboron β-diketonate complexes (7a-c) and one chalcone (7d) with coumarin and triphenylamine fragments is described. The effect of the inclusion of the difluoroboron (BF2) group and a phenyl linker on the photophysical properties, intramolecular charge transfer (ICT) and nonlinear optical (NLO) properties was studied. These dyes exhibited excellent ICT properties due to their A-π-D and D-π-A-π-D type push-pull configuration. Thus, all compounds presented a strong solvatochromism, given the absorption and emission maxima shifted to red because of the increase in the polarity of the medium. In addition to this, 7a-d showed the formation of a twisted intramolecular charge transfer (TICT) state, which quenched fluorescence in polar solvents. Compounds 7a, 7b and 7d exhibited aggregation-induced emission (AIE) in MeCN/H2O mixtures, while 7c did not have this behavior. In addition, all compounds showed emission in the solid state. Using DFT and TD-DFT calculations, the molecular geometries of the ground state S0 and the first excited state S1 were elucidated, which confirmed the formation of a TICT state. Furthermore, the theoretical and experimental absorption electronic transitions were correlated by testing different functionals: B3LYP, CAM-B3LYP, PBE0, wB97XD, HSEH1PBE and M062X. Frontier molecular orbitals (FOMs) and molecular electrostatic potentials (MEPs) supported the ICT from the donor to the acceptor group. The global reactivity descriptors were studied and the NLO properties were predicted by calculating first (βtot) and second-order (γave) hyperpolarizabilities, revealing that 7a-d would present promising NLO behavior.

Evaluating non-linear optical behavior in ionic liquids: Combining ab-initio polarizability with additivity rule

In the field of non-linear Optics, the additivity rule, which both experimental and theoretical researchers utilize, provides a simple and reliable method for calculating polarizability. However, this model neglects crucial factors, such as the solvent, the interaction distance, and external optical fields, leading to inaccurate results. In this study, the role of these parameters on the non-linear optical behavior of the ionic liquid BMIM+⋯BF4−, a system extensively studied for its intriguing non-linear optical properties, is investigated. To do that, first-principles calculations based on the density functional theory are developed; the Lennard-Jones potential is used as the reference model. The results of this study reveal the significant influence of the solvent on the second- and third-order non-linear optical responses, which are strongly affected by ion interactions, underscoring the limitations of the additivity rule in terms of molecular polarizability. The EFISHG values for each solvent are inversely proportional to the dielectric constant; for all considered solvents, it observed a clear dependence of polarizability values on the external field, ranging from 1.675 to 1.638× 10−23 esu. It was also found high sensitivity of the static polarizability to changes in the interaction distance and the solvent choice, ranging from 1.57 to 2.05× 10−30 esu, while considering the additivity rule, this parameter changed to 1.59× 10−30 esu. This information can serve as a reference for both theoretical and experimental researchers.

Phase-Matching Second-Harmonic Generation and Enhanced Laser-Induced Damage Threshold Induced by Cs Substitution: Cu3PSe4 vs Cs2CuP3S9.

Chalcophosphates are an important type of infrared nonlinear optical (NLO) candidates in view of their rich anionic motifs. Here, two copper chalcophosphates Cu3PSe4 (CPSe) and Cs2CuP3S9 (CCPS) were synthesized and studied as IR NLO materials. They both feature three-dimensional polyanionic frameworks constructed by similar T2-supertetrahedra, and the structure of CCPS can be derived from CPSe via introducing Cs and substituting Se with S. This structural evolution results in phase-matchable NLO behavior, enlarged optical band gap, and enhanced laser-induced damage threshold for CCPS. These results are elucidated by structure analysis and theoretical calculations, and the increased structural anisotropy contributes to the phase matchable behavior of CCPS. This work presents a case on how to adjust NLO properties via certain structure considerations, which may be extended to more systems for obtaining high-performance NLO materials.

Effect of SiO2 on structural, magnetic, and nonlinear optical behavior of cobalt ferrite nanoparticles

CoFe2O4 and CoFe2O4/SiO2 were synthesized by sol-gel method. The studies carried out using XRD, FT-IR, SEM, TEM, VSM, UV–Vis DRS, and Z-scan techniques. The CoFe2O4 has the inverse cubic spinal structure. TEM and SEM confirmed the less crystallite size of CoFe2O4/SiO2 nanocomposite than CoFe2O4. The results show that two samples have a pure single phase cobalt ferrite with face-centred cubic spinel phase. SiO2 matrix in CoFe2O4 nanocomposite results in reduction particle size and magnetic properties as well as enhancement band gap. The band-gap energy of CoFe2O4 and CoFe2O4/SiO2 calculated 1.76 and 1.92 eV, respectively. Our findings in nonlinear optical aspects suggest that the distinctive characteristics of CoFe2O4/SiO2 present opportunities for advancements in telecommunications and other related fields.

Nonlinear optical studies of Bismuth-doped Titanium di-oxide colloids achieved by femtosecond Z-Scan technique

In this paper, we explored the nonlinear optical (NLO) properties of Bismuth (Bi) doped titanium dioxide (TiO2) nanoparticle (NP) colloids in ethanol, with laser pulses of duration ∼ 150 femtoseconds (fs). The Bi-doped TiO2 NPs were synthesized via the chemical route, sol-gel method. The increased photo response of TiO2 upon doping it with metals has become a burning issue to extend the applications of metal-doped TiO2 NPs as integral parts in solar cells, catalysts, phototherapy, etc. The bandgap of anatase TiO2 NPs was observed to be reduced to 2.89 eV upon doping Bi. The modified band structure of the Bi-doped TiO2 NPs demonstrates novel chemical, mechanical, and optical properties. NLO studies were conducted on Bismuth-doped TiO2 NPs submerged in ethanol employing femtosecond laser input pulses with incoming wavelengths 700, 750, 800, 850, 900, and 950 nm. It has been detected that open aperture (OA) studies performed at an input peak intensity of 100 MW/cm2 on Bi-doped TiO2 NPs in ethanol were exhibiting complex NLO behavior, i.e., reverse saturable absorption (RSA) in saturable absorption (SA) and SA in RSA with mostly effective two-photon absorption (1 + 1) coefficients. Particularly, at ∼800 nm, the behavior observed was so complex, i.e., RSA in SA in RSA in SA, with an effective 3 PA (2 + 1) co-efficient (γ) ∼6.5 × 10−24 m3/W2. The closed aperture (CA) studies at ∼37 MW/cm2 exhibited self-defocusing effects, i.e., an intensity-dependent refractive index (n2) with a negative signature.

Exploration of deep UV-NLO responses of non-conjugated crystal systems by harnessing aprotic solvents: DFT vs experimental

This study introduces a newly found form of a non-conjugated crystal called 1,3,5-triazine-2,4,6-triamine polymorph (TT), which demonstrates a well-rounded UV nonlinear optical (NLO) behavior. By employing solvent-assisted Tauc bandgap adjustment, the crystal's structure was altered, leading to improved optical characteristics. The material's monoclinic polymorph displays adjustable bandgaps that are impacted by the choice of solvent during the crystallization process. When evaluated against a chemical potential of −2.61 eV, its characteristics were forecasted. Charge displacement across the aromatic ring is observed in the solvent stage, while molecular electrostatic potential (MEP) surfaces highlighted the nitrogen atoms as nucleophilic. The comparative examination of its energy gaps (Egaps) offers significant perspectives on their prospective uses. Understanding these energy differences is crucial for choosing materials for specific applications like electronic devices, sensors, or catalysis. Moreover, comprehending charge distributions and nucleophilic tendencies can influence the creation of new materials with customized attributes for diverse uses in fields such as chemistry, materials science, and beyond.

Synthesis, spectroscopic analysis, molecular docking and DFT study of some new heterocyclic compounds tethered 4‑hydroxy-1-methylquinoline-2(1H)one

A diversity of heterocyclic compounds (3, 6–8, 9, 11 and 12) linked 4‑hydroxy-1-methylquinoline-2(1H)one moiety have been synthesized from ring opening ring closure reaction (RORC) of 4‑hydroxy-6-methyl-3-nitro-2H-pyrano[3,2-c]quinoline-2,5(6H)‑dione (2) with various nucleophilic reagents namely hydrazine hydrate, phenylhydrazine, 3-hydrazino-5,6-diphenyl-1,2,4-triazine (4), 7‑chloro-4-hydrazino quinoline (5), 3-amino-1,2,4-triazole, 2-aminobenzimidazole and 3-amino-4,6-dimethyl-1H-pyrazolo[3,4-b]pyridine (10). The biological efficiency of the synthesized compounds against hepatocellular carcinoma cell lines (HepG-2) was analyzed both experimentally and theoretically (topoisomerase IIβ protein). Compound 12 (IC50=4.36 µM/L) has the highest anticancer activity against HepG-2 cell lines in comparison with the positive control (Cis-platin). The synthesized compounds were optimized by DFT/B3LYP functionality using the 6–311G++(d,p) basis set. Frontier molecular orbital analysis using global reactivity parameters indicated that compounds 1 and 12 have the largest) ∆E = 4.268 eV) and smallest) ∆E = 3.344 eV) energy gap, respectively. Thus, compound 1 (η= 2.134 eV) is harder than other compounds and has high stability. While compound 12 (S = 0.598eV-1) is softer than other compounds and more reactive. MEP surface and Fukui function were used to show charge distribution and show reactive zones within the molecules. For further validate of the NMR results, GIAO method was utilized to evaluation the 1HNMR and 13CNMR chemical shifts which were then correlate with the experimental spectra. Non-linear optical (NLO) behavior was further studied and compared to urea, which is a prototype substrate, and found to be greater than that of urea. Swiss-ADME (absorption, distribution, metabolism and excretion) analysis was performed to examine the drug-likeness properties of the current compounds. Finally, using the topoisomerase IIβ protein (PDB ID: 4G0U) receptor, molecular docking studies were used to examine the binding interactions of the synthesized compounds and correlated with anticancer activity.

Synthesis, structure, spectra, NLO behavior, and in-silico study on anti-tumor and anti-tuberculosis efficacy of (Z)-3-((Z)-3-phenylallylidene)benzo[4,5]imidazo[1,2-c]thiazole-1(3H)-thione

In this study, we report the synthesis of (Z)-3-((Z)-3-phenylallylidene)benzo[4,5]imidazo[1,2-c]thiazole-1(3H)-thione (ThBMT). This compound belongs to an important group of molecules containing two or more heterocyclic moieties. ThBMT was experimentally characterized using IR and NMR spectroscopy. The absolute 3D structure of ThBMT was determined by single-crystal X-ray diffraction, revealing crystallization in the monoclinic space group P21/c with four molecules in the unit cell. First principle theoretical calculations were carried out via the Density Functional Theory (DFT) method with B3LYP and B3LYP-GD3(BJ) functionals using the 6–311++G(d, p) basis set. The geometrical parameters of ThBMT were analyzed and compared to those of optimization, which were found to be consistent. The crystal packing and their intermolecular interactions were studied by Hirshfeld surface analysis, revealing that the most common interactions were C-H⋅⋅⋅N and C-H⋅⋅⋅S. Furthermore, theoretical vibrational wavenumbers were computed, assigned, and compared to the experimental ones. The (1H, 13C) NMR chemical shifts were calculated and compared with experimental values. The compound's nonlinear optical (NLO) properties were also investigated to understand its potential applications in optoelectronics, and compared to those of the benzimidazole fragment. The results showed promising NLO characteristics. Molecular docking and in silico ADMET studies were reported to highlight the biological behavior of ThBMT, indicating anti-tuberculosis properties, and anti-tumor activities against HeLa and HepG2 cancer cell lines.

Research on the molecular structure, solvent effects, quantum computing, topology, and biological aspects of 4-phenylcoumarin-7-yl-methacrylate as an anticancer agent

The objective of this research is to conduct both experimental and theoretical analyses on the synthesis and characterization of a new coumarin derivative known as 4-phenylcoumarin-7-yl-methacrylate (PCMA). To accomplish this, several methods including 1H-NMR, FT-IR, and UV-visible spectroscopy were employed, and atomic charges and bond parameters were calculated using the DFT-B3LYP/6-311G++(d,p) basis set. Additionally, topological properties such as Electron Localized Function, Localized Orbital Locator and Non-Covalent interactions (RDG-NCI) were thoroughly examined. The TD-DFT approach was used to calculate the UV-Vis absorption technique in various solvent media, and the Light Harvesting Efficiency was also investigated. An analysis of Frontier Molecular Orbitals (FMO), Molecular Electrostatic Potential (MEP), and Average Local Ionization Energy (ALIE) simulations were conducted to identify the optimal sites for both electrophilic and nucleophilic attacks. Nonlinear Optical (NLO) behavior was also examined by determining the dipole moment (μ), the linear polarizability (α), first hyperpolarizability (β) and second hyperpolarizability (γ) through the use of the same basis set. To better understand molecular stability and interactions, Natural Bond Orbital (NBO) analysis was performed, providing insights into hyperconjugative interactions, charge delocalization, and electron density (ED) among the molecular components. Electron-hole and TDM analysis were also conducted to investigate the various types of electron-excited states. This research will additionally explore the drug-likeness and docking potential of PCMA, with the goal of determining its suitability as a potential candidate for cancer treatment. This comprehensive study offers valuable insights into the structural, electronic, and biological properties of 4-phenylcoumarin-7-yl-methacrylate (PCMA).

Remarkable enhancement of the nonlinear optical behavior towards asymmetric substituted D-π-A dithiophene-based compounds.

Nonlinear optics (NLO) is an interesting field that discloses the interaction between intense light and matter, leading to a deeper understanding of NLO phenomena. Organic chromophores are considered as promising materials for NLO due to their exceptional structural versatility, ease of processing, and rapid response to NLO effects. Functional materials based on thiophene have been indispensable in advancing organic optoelectronics. Specifically, dithiophene-based compounds display weaker aromaticity, reduced steric hindrance, and additional sulfur-sulfur interactions. Hence, by utilizing dithieno[2,3-d:2',3'-d']benzo[1,2-b:4,5-b']dithiophene (DTBDT) as the core structure, designing of a set of organic compounds with D1-π-D2-π-A-type framework, namely ZR1D1-ZR1D8, was carried out in this study. The analysis of frontier molecular orbitals (FMOs) revealed that compound ZR1D2 has the lowest band gap of 1.922eV among all the investigated chromophores. The correlation of global reactivity parameters (GRPs) with the band gap values indicates that ZR1D2 displays a hardness of 0.961eV and a softness of 0.520eV-1. Among the studied compounds, ZR1D2 demonstrated a broad absorption spectrum that extended across the visible region. The maximum absorption wavelengths were observed at 766.470nm for ZR1D2 and 749.783nm for ZR1D5. These DTBDT-based dyes exhibit a remarkable NLO response with exceptionally high first hyperpolarizability (βtot) values. Among them, compound ZR1D2 stands out with the highest average linear polarizability (⟨α⟩ = 3.0 × 10-22 esu), first hyperpolarizability (βtot = 4.1 × 10-27 esu), and second hyperpolarizability (γtot = 7.5 × 10-32 esu) values. In summary, this investigation offers valuable insights into the potential use of DTBDT-based organic chromophores, particularly ZR1D2, for advanced applications in NLO. These findings suggest promising opportunities for researchers to synthesize these molecules and utilize these compounds in hi-tech NLO-based applications. The density functional theory computations were performed at the M06/6-311G(d,p) functional to explore their structural effects on electronic and NLO findings. Various analyses like highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps, absorption maxima, density of states, open circuit voltage, binding energies of electrons and holes, and transition density matrix are employed to investigate photovoltaic efficiencies of the derivatives. Different software packages like Avogadro, Multiwfn, Origin, GaussSum, PyMOlyze, and Chemcraft were used to deduce conclusions from the output files.

Second harmonic generation and reverse saturable absorption in electrospun picric Acid-PMMA nanofibers

Picric acid (PA) – polymethyl methacrylate (PMMA) nanofibers were synthesised using electrospinning technique by optimising all the required parameters. The nonlinear optical behaviour of the synthesised nanofibers was investigated along with their preliminary characterisations like morphological, structural, thermal, mechanical, dielectric and linear optical studies. The nanofibers with average diameter around ∼800 nm, were found to crystallise in Pca21 space group under the orthorhombic crystal system. The incorporation of Picric acid nanocrystals inside the PMMA nanofibers enhanced their tensile strength. Second harmonic generation imaging of picric acid embedded PMMA nanofibers was done by nonlinear microscopy and the emission was confirmed by power dependence as well as Kurtz – Perry powder technique. Nonlinear absorption studies by Z – scan technique were conducted with a Q – switched Nd: YAG laser and the nanofibers exhibited reverse saturable absorption nature at all the input intensities (0.616 × 1012 W/m2, 1.23 × 1012 W/m2 and 2.46 × 1012 W/m2) and the value of the nonlinear absorption coefficient increased corresponding to an increase in input intensity (0.98 × 10−10 m/W, 1.39 × 10−10 m/W and 1.61 × 10−10 m/W) owing to a sequential two photon absorption. Using the transmittance data optical limiting properties of the nanofibers were also analysed and the limiting threshold values (1.92 × 1012 W/m2, 1.80 × 1012 W/m2 and 1.54 × 1012 W/m2) at respective intensities were extracted. The low optical limiting threshold obtained in the present case confirms that picric acid – PMMA nanofibers can be an assured contender as optical limiters in laser safety devices.

Smart design of highly luminescent octupolar mesogenic tetra styryl-alkynyl bipyrimidine-based chromophores presenting non-linear optical properties

The research investigations reported in this paper focuses on the influence of rational design on the photophysical properties of new all-organic multifunctional chromophores. Nonlinear optical (NLO) behavior, optical properties and mesogenicity of several new π-conjugated octupolar chromophores, presenting alkoxy styryl-alkynyl donor groups carrying aliphatic achiral and chiral chains in the 3,4/3,5/2,4 position, connected to electron-accepting 2,2-bipyrimidine cores are investigated by various techniques (light-transmission measurements, polarized-light optical microscopy, differential scanning calorimetry measurements, two-photon excited fluorescence and Hyper Rayleigh Scattering). The mesogenic properties were investigated depending on the position of the alkoxy chain and the 3,4 derivatives were found to exhibit liquid-crystal properties with the formation columnar phases over large temperature ranges which were confirmed by small-angle X-ray scattering analysis. All the molecules exhibit exceptional high fluorescence quantum yields values around 80 % and excellent nonlinear optical properties.

Quantum mechanical, spectroscopic, docking studies (Dementia & breast cancer) and in-vitro assays of phytochemical compound Dehydrozingerone by DFT

Density functional theory (DFT) based quantum computing techniques were used to study the phytochemical compound Dehydrozingerone (DHZ), which originated from the ginger plant Zingiber officinale. Structural analyses, of the title compound such as FTIR, FTR, and Ultraviolet-Visible (UV-Vis) are performed both theoretically and experimentally. DHZ was optimized for the most stable molecular structure. Vibrational frequencies were scaled using a scaling factor, and prominent peaks were identified. Potential energy distribution (%PED) assignments were also examined to determine the percentage of vibrational transitions. Four different solvents were quantitatively analyzed using TD-DFT from UV-Vis spectra. HOMO-LUMO calculations were performed to forecast Dehydrozingerone's stability and non-toxicity. The Natural Bond Orbital (NBO) method was used to study inter- and intra-molecular interactions. DOS spectra were convoluted to analyse the overlapping interactions of the various bonds present in DHZ. Population analysis, such as Mulliken and Natural, was conducted to determine the charge distribution within the compound. Topological analyses such as ELF, LOL and reactive site of DHZ were identified using MEP. Non-linear optical (NLO) behaviour was further studied and compared to urea, a prototype substrate. Drug likeness and Ramachandran plot were determined. Using the Autodock tools for molecular docking studies, the pharmaceutical importance of DHZ was analysed for targeted proteins 4MS4 (anticonvulsant), 7AIX (dementia syndrome), 7E9B (anti-brain cancer) and 7C00 (anti-breast cancer). The biological activity of breast cancer was analysed both theoretically (protein) and experimentally (MCF7). The standard drug was theoretically studied for the four proteins, and binding energies are comparable, implying that DHZ could be a suitable drug for the control and treatment of anti-convulsant, dementia, brain tumours and breast cancer. To better understand the toxicity and bioavailability of the title compound, cytotoxicity assays were also performed.