Spectroscopic Approach Research Articles

Fluorine Labeling and 19F NMR Spectroscopy to Study Biological Molecules and Molecular Complexes

High‐resolution nuclear magnetic resonance (NMR) spectroscopy represents a key methodology for studying biomolecules and their interplay with other molecules. Recent developments in labeling strategies have made it possible to incorporate fluorine into proteins and peptides reliably, with manageable efforts and, importantly, in a highly site‐specific manner. Paired with its excellent NMR spectroscopic properties and absence in most biological systems, fluorine has enabled scientists to investigate a rather wide range of scientific objectives, including protein folding, protein dynamics and drug discovery. Furthermore, NMR spectroscopic experiments can be conducted in complex environments, such as cell lysate or directly inside living cells. This review presents selected studies demonstrating how 19F NMR spectroscopic approaches enable to contribute to the understanding of biomolecular processes. Thereby the focus has been set to labeling strategies available and specific NMR experiments performed to answer the underlying scientific objective.

Mechanistic insights into the interaction of anxiolytic drugs with human serum albumin in a ternary system utilizing spectroscopic and molecular modeling approaches

In recent years, buspirone has been co-administered with sertraline to resolve sexual disorders caused by sertraline. Therefore, the present study was conducted to investigate the interaction effect of two antidepressants and anxiolytic drugs, sertraline and buspirone, on human serum albumin (HSA) using spectroscopic and molecular docking techniques. Fluorescence emission spectroscopy and molecular docking were used to calculate the binding affinity and determine the best binding sites for these two drugs. Additionally, UV-visible and circular dichroism spectroscopy were performed to investigate the effect of these drugs on the conformational changes of HSA. The results showed that both drugs have a strong ability to quench the fluorescence of HSA through a static mechanism, and cause structural changes in HSA. It was also found that binding of sertraline and buspirone to HSA is spontaneous (ΔG° <) and hydrophobic interactions, van der Waals forces and hydrogen bonds play a significant role in these interactions in the ternary system. In addition, molecular docking data showed that both drugs bind with high affinity to the Trp residue in subdomain IIA. The binding constants (Kb) for (HSA-SRH)-BSH and (HSA-BSH)-SRH were equal to 6.30 and 3.99, respectively, at 298 K. This study demonstrates that the presence of the second drug (buspirone/sertraline) affects the interaction and binding affinity of the first drug (sertraline/buspirone) to human serum albumin.

Greenness and Whiteness Assessed Mathematically Filtered UV Spectroscopic Approaches for Quality Control of Amlodipine, Telmisartan and Metoprolol from Ternary Formulation

Greenness and Whiteness Assessed Mathematically Filtered UV Spectroscopic Approaches for Quality Control of Amlodipine, Telmisartan and Metoprolol from Ternary Formulation

Elucidating structure and metabolism of insect biomaterials by solid-state NMR

Among the many natural biomaterials for which information on atomic-level structure and reorientational motion can offer essential clues to function, insoluble multi-component composites with limited degrees of order are among the most challenging to study. Despite its limited sensitivity, solid-state NMR (ssNMR) is often the technique of choice to ferret out these details in carbon- and nitrogen-rich materials: this spectroscopic approach can probe many biomaterials in their native or near-native states, either with or without the introduction of stable NMR-active isotopes, or with the assistance of dynamic nuclear polarization technology. During a span of close to four decades, such research targets and ssNMR approaches have been exemplified by insects, a diverse and evolutionarily agile group of organisms with global impacts that include ecology, agriculture, and human disease. In this short review, we present case studies on insect cuticles that range from protective exoskeletons and egg capsules to the wing structures that enable flight and showcase nature's awe-inspiring beauty, highlighting the use of ssNMR spectroscopy to profile chemical composition, elucidate macromolecular architecture, and monitor metabolic development in these fascinating biological assemblies.

Smart mathematically filtered UV spectroscopic methods for quality assurance of rosuvastatin and valsartan from formulation

Abstract Valsartan and rosuvastatin together in a binary form have been utilized to reduce hypertension and hyperlipidemia to control cardiovascular complications. This study depicts the simple three mathematically manipulated UV spectroscopic techniques for the estimation of rosuvastatin and valsartan in the formulation. The first method is simple UV absorption at 310 nm by RST and the first derivatization method for VTN. Determining the magnitude difference of a ratio spectrum at two identified wavelengths is the second approach, and determination of the magnitude of the first derivatives of the ratio spectra of RST and VTN constitute the third technique. The selection of wavelengths, divisor concentrations, and peak amplitudes were optimized and validated. The straight line was constructed in the range of 1–30 and 2–25 µg/ml for RST and VST by the normal and first derivatization method. By using the magnitude difference and magnitude of first derivative ratio spectra approaches, the concentrations of 1–12 and 2–25 µg/ml for RST and VTN, respectively, displayed a straight line. The limit of quantification was less than 1 µg/ml for RST and less than 2 µg/ml for VTN. It was eventually found that the accuracy, expressed as a percentage recovery, ranged between 98.94 and 99.55% for RST and 100.36 and 101.08% for VTN. The % RSD did not exceed 1.82 and 1.91 for RST and VTN, respectively. The three techniques were used to accurately measure RST and VTN in their binary formulations and physically mixed solutions, and the results were statistically compared to the previously published HPLC technique. The outstanding recovery achieved by using the authentic standard addition approach validated the methods’ supplemental accurateness. The Analytical Greenness and Red Green Blue procedures verified the eco-friendliness of the suggested UV spectroscopic approaches, which were also found to be superior to the documented HPLC methods.

Analysis of molecular interactions of an aqueous benzoates with glycolic and lactic acid: spectroscopic, acoustic, and volumetric approach

Volumetric as well as Acoustic properties for the ternary liquid combination (water + sodium methyl p-hydroxybenzoate + glycolic acid/lactic acid) are evaluated at several temperatures using a Densimeter (DSA 5000 M) over the range of concentrations (0.000, 0.015, 0.025, 0.035) mol.kg−1. Several thermo-acoustical properties were computed utilizing the experimental data. These values were then used to derive several parameters, including the apparent molar volume( V∅ ); partial molar volume (V∅0); apparent molar isentropic compression (K∅,S); transfer properties(Δ V∅0, Δ K∅,s0 ); partial molar isentropic compression (K∅,s0); apparent molar expansibility ( E∅0 ) as well as its first derivative ( ∂Eϕ0/∂T ) P; and coefficient of thermal expansivity( αp ). The obtained results are explained by analyzing the several interactions that take place inside the liquid system by implementing the theory of co-sphere overlap. Utilizing these thermodynamical parameters, the interaction coefficients are computed to evaluate the ternary mixture corresponding to the interactions between solutes and solvents. FTIR spectrum analysis revealed the presence of H-bonds along with the other molecular interactions in the analyzed systems, as shown by the shifting of the O-H stretching band.

Valence-band hybridization in sulphides.

The hybridization state in solids often defines the critical chemical and physical properties of a compound. However, it is difficult to spectroscopically detect and evaluate hybridization beyond just general fingerprint signatures. Here, the valence-band hybridization of metal d-derived bands (short: "metal d bands") in selected metal sulphides is studied with a combined spectroscopic and theoretical approach to derive deeper insights into the fundamental nature of such compounds. The valence bands of the studied sulphides are comprised of hybrid bands derived from the metal d, S 3s, and S 3p states. Employing S K and L2,3 X-ray emission spectroscopy and spectra calculations based on density functional theory, the degree of hybridization (i.e., the covalency) of these bands can be directly probed as a function of their relative energies. We find that the relative intensity of the "metal d band" features in the spectra scales with the inverse square of the energy separation to the respective sulfur-derived bands, which can be analytically derived from a simple two-orbital model. This study demonstrates that soft X-ray emission spectroscopy is a powerful tool to study valence state hybridization, in particular in combination with hard X-ray emission spectroscopy, promising a broad impact in many research fields.

Influence of albumin concentration on surface characteristics and cellular responses in the pre-incubation of multi-walled carbon nanotubes.

Reliable characterization of protein coronas (PCs) that form when nanomaterials are introduced into biological fluids is a critical step in the development of safe and efficient nanomedicine. We observed that bovine serum albumin (BSA)-coated multi-walled carbon nanotubes (MWCNTs) do not induce cytotoxicity, but have different cellular uptake rates depending on the BSA pretreatment concentration. To determine how these slight differences affect A549 cell responses and intracellular changes, we conducted spectroscopic (circular dichroism and Fourier-transform infrared) and spectrometric (nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry) analyses. The various characterization techniques conducted in this study reveal the following. (i) The composition ratio of PCs on MWCNTs differs depending on the BSA concentration. (ii) Analysis of the secondary structure of the proteins revealed that the α-helix structure increased with increasing BSA concentration. (iii) Proteomic analysis showed that different biological pathways were activated at levels higher and lower than 5 mg mL-1. Such combined spectroscopic and spectrometric approaches provide an integrated understanding of PC composition as well as how nano/bio-interface states are linked to cellular-level responses. Our results can support reliable and practical applications of nanomedicine development.

Combustion characteristics of a boron/ethanol nanofuel droplet: Optical and spectroscopic approach

Combustion characteristics of a boron/ethanol nanofuel droplet: Optical and spectroscopic approach

Picoplatin (II)-loaded chitosan nanocomposites as effective drug delivery systems: Preparation, mechanistic investigation of BSA/5-GMP/GSH binding and biological evaluations

The goal of the current study is to improve the characteristics and bioavailability of the drug picoplatin (PPt) by encapsulating it in chitosan nanoparticles (CS NPs) which allows for the targeted delivery of cytotoxic cargo to cancerous tissue, reducing toxic side effects and raising the therapeutic index. When picoplatin was delivered into the CS, it was able to produce an complex with CS (PPt@CS NPs) that had an appropriate particle size of 275 ± 10 nm, a reasonably low PDI of 0.15 ± 0.05, and high stability (ζ = −22.1 ± 0.3 mV). Since almost all pharmaceuticals work by binding to specific proteins or DNA, the in vitro binding mechanism and affinity of bovine serum albumin (BSA), low molecular building units of nucleic acids (5−GMP), and Glutathione (GSH) (considering that cisplatin resistance could be due to a reaction between cisplatin and GSH) to PPt and PPt@CS NPs were examined using stopped-flow and other spectroscopic approaches. Through two reversible processes, a rapid second-order binding followed by a slower first-order isomerization reaction, and a static quenching mechanism, PPt and PPt@CS NPs bind to BSA with relative reactivity of around (PPt)/(PPt@CS NPs) = 1/2.5. The 5−GMP interaction studies demonstrated that, in addition to changing the binding mechanism, PPt's encapsulation in CS increases its rate of reaction through coordination affinity. PPt interacted with 5-GMP via two reversible processes, a rapid second-order binding to phosphate followed by a slower first−order migration to the N7 of pyrimidine moiety. PPt@CS NPs showed weaker binding to GSH compared to PPt and hence PPt@CS NPs exhibits a lower resistance factor. It was also found that the in vitro drug release of PPt@CS NPs in PBS at pH 7.4 was steady, releasing 30% of the PPt in just 5 hours. Nonetheless, 75% of the release in a pH 5.4 solution containing 10 mM GSH—a solution that mimics the tumor microenvironment—shows that the PPt@CS NPs system is sensitive to GSH and specifically targets malignant tissue. The encapsulation of PPt in CS complex maintained its anticancer activity, as shown by an in vitro cell-survival assay on HepG2 cancer cell lines and also cleavage efficiency toward the minor groove of pBR322 DNA via the hydrolytic way. These findings collectively suggested that inclusion PPt in CS would be an effective strategy to formulate a novel picoplatin formulation intended for use as targeted anticancer treatment.

Spectroscopic approach to chlorine local environment in aluminoborosilicate glasses

Chlorine local environment has been investigated using spectroscopic approach (XAS and XPS) for Na- and Ca-bearing aluminoborosilicate glasses synthesised at 1.0 GPa. Based on Cl K-edge EXAFS results, Cl appears to show two local environments in glasses: one at long distance ∼2.7 Å assigned to Cl- species charge compensated by Na+ and/or Ca2+ and one at short distance ∼1.8 Å assigned to Cl-Cl and Si-Cl species. The Cl 2p XPS results cannot unambiguously confirm the presence of Si-Cl overlapped with Na+/Ca2+…Cl- species.

Detailed Abundances of the Planet-hosting TOI-1173 A/B System: Possible Evidence of Planet Engulfment in a Very Wide Binary

Over the last decade, studies of large samples of binary systems have identified chemical anomalies and shown that they might be attributed to planet formation or planet engulfment. However, both scenarios have primarily been tested in pairs without known exoplanets. In this work, we explore these scenarios in the newly detected planet-hosting wide binary TOI-1173 A/B (projected separation ∼11,400 au), using high-resolution MAROON-X and ARCES spectra. We determined photospheric stellar parameters both by fitting stellar models and via the spectroscopic equilibrium approach. Both analyses agree and suggest that they are cool main-sequence stars located in the thin disk. A line-by-line differential analysis between the components (B−A) displays an abundance pattern in the condensation temperature plane, where the planet-hosting star TOI-1173 A is enhanced in refractory elements such as iron by more than 0.05 dex. This suggests the engulfment of ∼18 M ⊕ of rocky material in star A. Our hypothesis is supported by the dynamics of the system (detailed in our companion paper), which suggest that the super-Neptune TOI-1173 A b might have been delivered to its current short period (∼7 days) through circularization and von Zeipel–Lidov–Kozai mechanisms, thereby triggering the engulfment of inner rocky exoplanets.

Fabrication of Cu-doped iron oxyhydroxide for phosphate removal: A comprehensive spectroscopic, equilibrium, and thermodynamic approach

Fabrication of Cu-doped iron oxyhydroxide for phosphate removal: A comprehensive spectroscopic, equilibrium, and thermodynamic approach

A Simple Dispersive Liquid-Liquid Microextraction for the Determination of Copper II in the Water Samples of the Halfaya Oil Field in Maysan

Background: Copper, an important trace element for life on Earth, is crucial to many metabolic processes. This includes its role in the production and breakdown of nucleic acids and the metabolism of proteins, lipids, and carbohydrates. Objective: We aim to integrate DLLME with a spectrophotometric method to establish a novel approach for quantifying trace amounts of copper in water samples. Methods: In this study, a new ligand known as a 2-(4 aminophenol) benzimidazole azo derivative was successfully synthesized. This ligand was created by converting 2-(4-aminophenyl) benzimidazole into a diazonium salt and coupling it with 8-hydroxyquinoline in an alkaline environment. The resulting product was a brown azo dye, which served as the ligand for detecting copper (II) in aqueous samples. Results: To analyze copper (II) in both pure and aqueous samples, we developed and validated micro-extraction techniques combined with UV-Vis measurement. Specifically, we used the DLLME (dispersive liquid-liquid microextraction) method to separate, enrich, and assess copper (II) in both its pure form and in aqueous samples. UV-Vis spectroscopy at a wavelength of 503 nm was used for this purpose. We considered several variables during the experiment, including the type and volume of the dispersive solvent, the extraction solvents, the temperature, the reaction duration, and the centrifuging time. By optimizing these conditions, we achieved linear procedures within the concentration range of (1.0–25.0) and (2.0–25.0) μg/mL for spectroscopy and DLLME methods, respectively. For the spectroscopic and DLLME approaches, the coefficient of determination (R2) was found to be 0.9963 and 0.9979 for the spectrophotometric and DLLME methods, respectively. The limit of detection (LOD) for copper (II) was found to be 0.23 and 0.04 μg/mL, respectively. Moreover, the recovery of the target analyte in aqueous samples was found to be between 95.6% and 101% for the spectroscopy method and between 102.4% and 108.2% for the DLLME method. Conclusions: These results demonstrate the effectiveness and accuracy of both methods in analyzing copper (II) in aqueous samples.

Assessing Mechanochemical Properties of Acrylonitrile Butadiene Styrene (ABS) Items in Cultural Heritage Through a Multimodal Spectroscopic Approach.

A multimodal spectroscopic approach is proposed to correlate the mechanical and chemical properties of plastic materials in art and design objects, at both surface and subsurface levels, to obtain information about their conservation state and to monitor their degradation. The approach was used to investigate the photo-oxidation of acrylonitrile butadiene styrene (ABS), a plastic commonly found in many artistic and design applications, using ABS-based LEGO bricks as model samples. The modifications of the chemical and viscoelastic properties of ABS during photoaging were monitored by correlative Brillouin and Raman microspectroscopy (BRaMS), combined with portable and noninvasive broad-range external reflection infrared (IR) spectroscopy and nuclear magnetic resonance (NMR) relaxometry, directly applicable in museums. BRaMS enabled combined measurements of Brillouin light scattering and Raman spectroscopy in a microspectroscopic setup, providing for the coincident probe of the chemical and mechanical changes of ABS at the sample surface. NMR relaxometry allowed for noninvasive measurements of relaxation times and depth profiles which are directly related to the molecular mobility of the material. Complementary chemical information was acquired by external reflection IR spectroscopy. The simultaneous probe of the chemical and mechanical properties by this multimodal spectroscopic approach enabled us to define a decay model of ABS in terms of compositional changes and variation of stiffness and rigidity occurring with photodegradation. The knowledge acquired on LEGO samples has been used to rate the conservation state of ABS design objects noninvasively investigated by external reflection Fourier transform IR spectroscopy and NMR relaxometry offered by the MObile LABoratory (MOLAB) platform of the European Research Infrastructure of Heritage Science.

A potent Bioorganic azapodophyllotoxin derivative Suppresses tumor Progression in Triple negative breast Cancer: An Insight into its Inhibitory effect on tubulin polymerization and Disruptive effect on microtubule assembly

Triple negative breast cancer (TNBC) has long been a challenging disease owing to its high aggressive behaviour, poor prognosis and its limited treatment options. The growing demand of new therapeutics against TNBC enables us to examine the therapeutic efficiency of an emerging class of anticancer compounds, azapodophyllotoxin derivative (HTDQ), a nitrogen analogue of podophyllotoxin, using different biochemical, spectroscopic and computational approaches. The anticancer activities of HTDQ are studied by performing MTT assay in a dose depended manner on Triple negative breast cancer cells using MDA–MB-468 and MDA-MB-231 cell lines with IC50 value 937 nM and 1.13 µM respectively while demonstrating minimal effect on normal epithelial cells. The efficacy of HTDQ was further tested in 3D tumour spheroids formed by the human TNBC cell line MDA-MB468 and also the murine MMTV positive TNBC cell line 4 T1. The shrinkage that observed in the tumor spheroid clearly indicates that HTDQ remarkably decreases the growth of tumor spheroid thereby affirming its cytotoxicity. The 2D cell viability assay shows significant morphological alteration that possibly caused by the cytoskeleton disturbances. Hence the binding interaction of HTDQ with cytoskeleton protein tubulin, its effect on tubulin polymerisation as well as depolymerisation of preformed microtubules along with the conformational alternation in the protein itself have been investigated in detail. Moreover, the apoptotic effects of HTDQ have been examined using a range of apoptotic markers. HTDQ-treated cancer cells showed increased expression of cleaved PARP-1 and pro-caspase-3, suggesting activation of the apoptosis process. HTDQ also upregulated pro-apoptotic Bax expression while inhibiting anti-apoptotic Bcl2 expression, supporting its ability to induce apoptosis in cancer cells. Hence the consolidated biochemical and spectroscopic research described herein may provide enormous information to use azapodophyllotoxin as promising anticancer therapeutics for TNBC cells.

Designing of some VO(II), Co(II) and Hg(II) Schiff base complexes: Synthesis, structure elucidation, anticancer and biopesticidal activities, DFT and docking approaches

New VO(II), Co(II) and Hg(II) chelates of bi- or tetradentate isatin based ligand i.e.:-2-(((E)-2-oxo-1,4-dihydrocyclohepta [b]pyrrol-3(2H)-ylidene)amino)-N-(8-((1-(2-((E)-2-oxoindolin-3-phenyl)vinyl) amino) naphthalen-1-yl) benzamide (H2L) were synthesized and well characterized. The reaction between N,N′-(naphthalene-1,8-diyl)bis(2-aminobenzamide) and di-oxazine-2,4 dione (isatin) yielded the Schiff base (H2L). The compounds have been identified by different physicochemical and spectroscopic approaches and DFT as well. From all measurements square pyramidal, distorted octahedral or square planar configurations have been suggested for the chelates 1, 2 and 3, respectively. The Coats-Redfern equations were used to calculate and define the dynamics properties of decomposition stages from TGA (Ea, A, ΔH*, ΔS*, and ΔG*). The in vitro anticancer property of the obtained compounds towards human hepato (HepG2) and human breast (MCF-7) carcinoma cell lines has been screened. Also, the biopesticidal effect of these compounds against spodoptera littoralis has been examined. Data showed that, the tested [Hg(H2L)(L)] complex (3) possesses the most anticancer efficacy against both HepG2 and MCF-7 cells, with half inhibitory concentration (IC50) = 5.78 ± 0.029, 11.24 ± 0.58 μg/mL, respectively also, this complex considered as good an insecticide with the concentration lethal to 50 percent of test organisms (LC50) = 27585.45 ppm after 72 h. The insecticide and tumor inhibition properties were compared with the theoretical molecular docking findings with the specification of the active species in the designated proteins.

Multiple Enol-Keto Isomerization and Excited-State Unidirectional Intramolecular Proton Transfer Generate Intense, Narrowband Red OLEDs.

A novel series of excited-state intramolecular proton transfer (ESIPT) emitters, namely, DPNA, DPNA-F, and DPNA-tBu, endowed with dual intramolecular hydrogen bonds, were designed and synthesized. In the condensed phase, DPNAs exhibit unmatched absorption and emission spectral features, where the minor 0-0 absorption peak becomes a major one in the emission. Detailed spectroscopic and dynamic approaches conclude fast ground-state equilibrium among enol-enol (EE), enol-keto (EK), and keto-keto (KK) isomers. The equilibrium ratio can be fine-tuned by varying the substitutions in DPNAs. Independent of isomers and excitation wavelength, ultrafast ESIPT takes place for all DPNAs, giving solely KK tautomer emission maximized at >650 nm. The spectral temporal evolution of ESIPT was resolved by a state-of-the-art technique, namely, the transient grating photoluminescence (TGPL), where the rate of EK* → KK* is measured to be (157 fs)-1 for DPNA-tBu, while a stepwise process is resolved for EE* → EK* → KK*, with a rate of EE* → EK* of (72 fs)-1. For all DPNAs, the KK tautomer emission shows a narrowband emission with high photoluminescence quantum yields (PLQY, ∼62% for DPNA in toluene) in the red, offering advantages to fabricate deep-red organic light-emitting diodes (OLED). The resulting OLEDs give high external quantum efficiency with a spectral full width at half-maximum (FWHM) as narrow as ∼40 nm centered at 666-670 nm for DPNAs, fully satisfying the BT. 2020 standard. The unique ESIPT properties and highly intense tautomer emission with a small fwhm thus establish a benchmark for reaching red narrowband organic electroluminescence.

New BDNF and NT-3 Cyclic Mimetics Concur with Copper to Activate Trophic Signaling Pathways as Potential Molecular Entities to Protect Old Brains from Neurodegeneration.

A low level of Neurotrophins (NTs), their Tyrosine Kinase Receptors (Trks), Vascular Endothelial Growth Factors (VEGFs) and their receptors, mainly VEGFR1 and VEGFR2, characterizes AD brains. The use of NTs and VEGFs as drugs presents different issues due to their low permeability of the blood-brain barrier, the poor pharmacokinetic profile, and the relevant side effects. To overcome these issues, different functional and structural NT mimics have been employed. Being aware that the N-terminus domain as the key domain of NTs for the binding selectivity and activation of Trks and the need to avoid or delay proteolysis, we herein report on the mimicking ability of two cyclic peptide encompassing the N-terminus of Brain Derived Growth Factor (BDNF), (c-[HSDPARRGELSV-]), cBDNF(1-12) and of Neurotrophin3 (NT3), (c-[YAEHKSHRGEYSV-]), cNT3(1-13). The two cyclic peptide features were characterized by a combined thermodynamic and spectroscopic approach (potentiometry, NMR, UV-vis and CD) that was extended to their copper(II) ion complexes. SH-SY5Y cell assays show that the Cu2+ present at the sub-micromolar level in the complete culture media affects the treatments with the two peptides. cBDNF(1-12) and cNT3(1-13) act as ionophores, induce neuronal differentiation and promote Trks and CREB phosphorylation in a copper dependent manner. Consistently, both peptide and Cu2+ stimulate BDNF and VEGF expression as well as VEGF release; cBDNF(1-12) and cNT3(1-13) induce the expression of Trks and VEGFRs.

N-(1H-Benzo[d]imidazol-2-yl)-1-(3-substituted phenyl) methanimines as optoelectronic and nonlinear optical materials: spectroscopic and computational approaches

N-(1H-Benzo[d]imidazol-2-yl)-1-(3-substituted phenyl) methanimines as optoelectronic and nonlinear optical materials: spectroscopic and computational approaches