6-31G Basis Set Research Articles

Theoretical studies of electronic and optical characteristics in donor-π-Acceptor (D-π-A) dyes: DFT and TD-DFT methods

Abstract This research focused on enhancing D-π-A organic dyes derived from coumarin and its derivatives, collectively referred to as D-CM-A dyes. The study aimed to improve these dyes by introducing various donors and acceptors to the coumarin structure. Six new coumarin dyes were evaluated, primarily for their potential application in dye-sensitized solar cells (DSSCs) to enhance energy efficiency. The analysis involved calculating the geometry, electronic properties, and optoelectronic characteristics of the dye molecules using DFT and TD-DFT methods with the B3LYP functional and the 6-311G basis set in both gas and solvent phases. The primary focus was to understand how modifications to the π-conjugated D-π-A organic dyes influenced their optoelectronic properties, including key factors such as maximum absorption wavelength (λmax), highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), and energy gap (Egap). Additionally, the study explored the photovoltaic properties of these dyes. The findings highlighted D4-CM-A4 as a promising candidate with the narrowest energy gap, while D1-CM-A1 and D2-CM-A2 showed superior light-harvesting efficiencies (LHE) compared to other derivatives. In conclusion, this study suggests that D1-CM-A1 and D2-CM-A2 are favourable choices for enhancing the performance of DSSCs due to their promising optoelectronic properties.

Chemical reaction and strength of tricalcium phosphate nano-coating application on dental implants by atomistic calculations

The success of dental titanium implants depends on the interaction of the implant with the surrounding bone, including the type of coating that promotes osseointegration. The most popular are calcium phosphate coatings, in particular tricalcium phosphate (TCP). Since cases of delamination of coatings from titanium have been observed in practice, it is important to be able to evaluate and predict the adhesion strength of coatings of different compositions to titanium.The work involves ab initio quantum chemical modeling of the interaction of TCP with titanium oxide and calculation of their binding energy. Considering that titanium instantly oxidizes in air, calculations were carried out with titanium dioxide. The Gaussian09 DFT B3LYP package with the 6-31G basis set was used. We synthesized tricalcium phosphate stepwise by assessing the binding energies between its constituents and titanium dioxide, as well as other structural characteristics including bond lengths, bond angles, dihedral angles, and charges. A method for assessing adhesion strength at the macro level using binding energy values calculated at the nano level is proposed. The values obtained are in reasonable agreement with experimental data and other numerical calculations. Using the methods of micromechanics of inhomogeneous media for the polycrystalline/amorphous structures of hydroxyapatite (HA) and β-TCP coatings, their anisotropic elastic characteristics were averaged and the degree of their closeness to the characteristics of the Ti substrate was compared.A comparison of two CFs showed that HA has an advantage over TCP both in terms of greater chemical affinity with the titanium substrate (higher adhesive bond energy) and in terms of proximity to the substrate in terms of mechanical characteristics (lower stress concentration at the bond boundary).

Structural tailoring via end-capped acceptors of thiophene-based C-shaped non-fullerene compounds with A-π-A backbone for the exploration of photovoltaic response

In the current era, non-fullerene based electron acceptors show remarkable contribution to develop organic solar cells (OSCs) with maximum possible efficiency via improving their optoelectronic properties. Thus, in current report, eight novel A-π-A type dithieno[3,2-b:2′,3′-d]thiophene (DTh) core-based C-shaped non-fullerene acceptors (ETMM1–ETMM8) were designed theoretically by taking ETMMR as reference to achieve highly proficient photovoltaic materials. Hence, a comprehensive density functional theory (DFT) analysis was accomplished by employing B3LYP level in conjunction with 6-311G(d,p) basis set to determine the enhancement of optical as well as photochemical response. Whereas time-dependent density functional theory (TD-DFT) approach was used for excited state calculations of all the investigated chromophores (ETMMR and ETMM1–ETMM8). So, the influence of structural tailoring via end-capped acceptors modifications was explored by utilizing various quantum chemical analyses such as: transition density matrix (TDM), HOMO–LUMO band gap, density of states (DOS), UV–Vis, binding energy (Eb), global reactivity parameters (GRPs), molecular electrostatic potential (MEP) and open circuit voltage (Voc). Remarkably, all the derivatives (ETMM1–ETMM8) exhibited comparable results with that of the reference chromophore (ETMMR). The results of UV–Vis analysis in chloroform solvent fall in the following order for all the modified chromophores: ETMM5 > ETMM3 > ETMM8 > ETMM4 > ETMM7 > ETMM2 > ETMM6 > ETMM1, which demonstrated maximum red shift in ETMM5 (785.257 eV). Fascinatingly, lowest excitation energy (1.579 eV) as well as binding energy (0.319 eV) along with minimum HOMO/LUMO band gap (1.898 eV) suggested ETMM5 as an excellent candidate for high performance OSCs. Concludingly, all the results indicated that modification of end-capped acceptors is an effective alternative approach to obtain desirable optoelectronic properties.

Kinetics, thermodynamics, and DFT studies of phenols oxidative coupling reactions with 4-amino-N, N-dimethylaniline

A spectrophotometric method has been established for the reaction kinetics of phenol oxidative coupling with 4-amino-N, N-dimethylaniline in the presence of potassium dichromate as an oxidant to form C14H14N2O, known as phenol blue. Optimum conditions for the reaction were investigated: maximum wavelength (λ max), linear range, molar absorptivity, and stability constant. The kinetic models were applied to the reaction, indicating that it is a first-order reaction. The activation energy (Ea) and Arrhenius constant (A) were calculated from the Arrhenius equation as 14.89 kJ·mol−1 and 3.75 × 105 s-1 respectively. Thermodynamic parameters were ΔH* 12.37 Kj·mol−1, ΔG* 5.47 kJ·mol−1 and ΔS* 22.77 J·mol−1·K−1 at 30oC.. Results indicate that the formation of the product phenol blue is non-spontaneous and endothermic in nature. Density function theory (DFT) has been done for the comparison between experimental and theoretical results using the common 6-311G(d,p) basis set. The results are in good agreement with each other, proving the reliability of the method. Finally, some preliminary test has been performed to check possibility of the product as dye.

Two new cyclohexenone derivatives: Synthesis, DFT estimation, biological activities and molecular docking study

Two new cyclohexenone carboxylate derivatives (6a-b) were synthesized through an additional ring-forming chalcone. FT-IR, 1H, 13C NMR, and Mass spectroscopy techniques confirmed the skeletons. The antibacterial, antioxidant, and colon cancer HT-29 cell activity of synthetic substances were assessed. Compound 6a's IC50 is 23.95 and 60.28 for its antioxidant and anticancer activities, whereas Compound 6b's IC50 is 27.56 and 62.72, respectively. MIC values for compound 6a are 15.75 ± 1.12, 10.25 ± 1.27, and 65.61 ± 1.72 against Staphylococcus aureus, Escherichia coli bacterial strains, and Candida albicans, respectively, whereas for compound 6b is equal to 18.32 ± 1.53, 12.63 ± 1.36, and 78.91 ± 1.94. Based on the extent of (B3LYP) and a 6-31G (d, p) basis set, the HOMO and LUMO of synthesized compounds were computed using the density functional theory (DFT) method. Energy gaps for products 6a and 6b are 2.8272 and 2.3360, respectively. Docked products had binding affinities of −9.5 and −9.1 for compounds 6a and 6b, respectively, with the crystal structure of recombinant human acetylcholinesterase in complex with donepezil (PDB ID: 4ey7). Consequently, according to experimental and computational studies, compound 6a is more active than compound 6b.

Quantum Chemical and Biological Properties of Coumarin Derivative Compound

This work presents the characterization of 8-t-buthyl-4-methyl-2H- chromen 2-one by quantum chemical calculations and spectral techniques. The molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO) 1H and 13C NMR chemical shift values of title compound in the ground state have been calculated using the density functional method (B3LYP) with the 6-31G(d) basis set. The theoretical vibrational frequencies and chemical shift values show good agreement with experimental values. In addition, DFT calculations of molecular electrostatic potentials and frontier molecular orbitals of the title were carried out at the B3LYP/6-31G(d) level of theory. The title compound was screened for antibacterial, antifungal and antioxidant activities.

Investigation of thermoelectric properties of cadmium selenide CdnSen (n= 7, 11, 13) molecular junctions: a DFT study.

The thermoelectric properties of cadmium selenide (CdnSen) molecular junctions (n = 7, 11, 13) were investigated before and after adding hydrogen atoms. The effects of hydrogen passivation on the transmission and thermopower curves were analyzed. CdSe-diamantane (Cd7Se7) and CdSe-tetramantane (Cd11Se11) junctions exhibited the best thermoelectric performance due to their low surface reconstruction energy, which is attributed to the number of dangling and unsaturated bonds. This study guides the design of new molecular junctions with desired thermoelectric properties. The electrical and thermal properties of cadmium selenide (CdnSen) molecular junctions (n = 7, 11, 13) were investigated using a ballistic quantum transport method based on the non-equilibrium Green's function (NEGF) approach. Thermoelectric properties were calculated for the molecular junctions with different structures before and after hydrogen passivation. Density functional theory (DFT) calculations were performed at the B3LYP level with the 3-21G basis set for the Cd atoms and the 6-31G** basis set for the Se atoms. The SIESTA and GOLLUM codes were used to study the effect of changing the shape and size of each structure on its electrical and thermal characteristics.

Spectroscopic and theoretical study of novel copper(II) complexes based on phenothiazine ligands: UV–Visible absorption and photoinduced electron transfer

This study presents three novel copper (II) complexes based on phenothiazine ligands that were synthesized and revealed their structures by spectral and analytical measurements. The synthesized complexes offered potential opportunities to explore their UV–visible absorption properties and photoinduced electron transfer with triethylamine. We performed density functional theory (DFT) calculations for Cu(II) (HL1)2 compounds and studied their frontier molecular orbitals in different environments. The calculations were done by using PBE1PBE functional and 6-31G(d)/Lanl2dz basis sets. We applied the LANL2DZ basis set for Cu. The treatment of all the other atoms was done by a 6-31G(d) basis set. For the calculation of the electronic structure, the basis set 6–31 + G(d)/Lanl2dz and SMD solvation model with MeCN and DMF were employed. We computed the frequencies to confirm the stability of the structures. Theoretical calculations can help explain the experimental findings, provide insights into the electronic transitions responsible for UV–visible absorption, and elucidate the photoinduced electron transfer processes involved.

Exploring the dual capabilities of BNQDs: a comprehensive study on enhancing photoelectric performance and photoluminescence via ligand functionalization.

Boron nitride quantum dots (BNQDs) are emerging as promising multifunctional nanomaterials for renewable energy and optoelectronics owing to their versatile properties. However, rational design principles to tailor their photoelectric and photoluminescent capabilities remain scarce. This study employs density functional theory (DFT) to provide fundamental insights into using urea, thiourea, and PPD ligands to modulate the bandgap, charge transfer dynamics, and recombination processes of BNQDs. Modeling explains that incorporating specific ligands enables visible light absorption, spatial charge separation, continuous photocatalytic cycling, and high quantum yields in BNQDs. The structure-property relationships established pave the way for targeted synthesis of high-performance BNQD photocatalysts and light emitters. This investigation utilized density functional theory (DFT) with the B3LYP functional and 6-31G(d,p) basis set to optimize the geometries of pristine and ligand-functionalized boron nitride quantum dots (BNQDs). The absorption spectra were generated using time-dependent DFT (TDDFT). A Ti38O76 cluster modeled the TiO2 substrate. The cpcm solvation model in Gaussian 09 defined the toluene solvent. Cohesive energies, charge transfer lengths, recombination rates, and conversion efficiencies were calculated to establish structure-property relationships. Multiwfn analyzed the charge densities. The modeling provides insights into tuning BNQD photocatalytic and photoluminescent properties using specific ligands.

Effect of the Electronic Structure of Para-Substituted Benzaldehyde Benzohydrazone on Its Antimicrobial Activity: A DFT Analysis

Bacillus subtilis is a bacterium that has demonstrated its efficacy across various domains, including industry, agriculture, and commerce, owing to its protective, inhibitory, and biological mechanisms against specific microbes. However, at high concentrations, it can lead to food poisoning and severe infections, resulting in symptoms such as diarrhea and vomiting. Bacterial spores produced by Bacillus subtilis can induce conditions like gas gangrene and tetanus. In this context, benzohydrazones are recognized for their antimicrobial activity, particularly against Bacillus subtilis. This study aims to elucidate the relationship between the electronic structure of para-substituted benzaldehyde benzohydrazone derivatives and their antimicrobial activity. This leads to the proposal of a 2D pharmacophore for predicting the antibacterial activity of these derivatives. The quantitative structure-activity relationship (QSAR) approach employed is the KPG method. The electronic structures were optimized using the density functional theory (DFT) method with the B3LYP functional and the 6-31G (d,p) basis set. Charge and local molecular orbitals were considered in the optimization process. The resulting prediction equation (R=98.95%, R²=97.91%, Adjusted R²=96.76%, F(5,9)=84.52) derived from multiple linear regression provides the basis for the proposed 2D pharmacophore. This equation shows that antimicrobial activity of benzohydrazone derivative is on charge and orbital controlled. This pharmacophore holds potential utility in designing new molecular structures with enhanced activity against Bacillus subtilis.

A selective and sensitive probes of chalcone derivative as a fluorescent chemosensor for the detection of Cr3+ ion

A new chalcone based chemosensor like 6-cinnamoylthiochroman-4-one (AZAN), has been designed and synthesized from 6-chlorothiochroman-4-one and cinnamaldehyde via keto ethylenic linkage. Its amino derivatives were synthesized by using urea (AZANU), thiourea (AZANTU) and 2,6-diamino pyridine (AZANPy) respectively and its metal ion sensing properties were investigated. The sensors can selectively recognize and sense the metal cations by showing different fluorescent characteristics at different concentrations. The fluorescence intensity shows remarkable enhancement by Cr3+ over other common metal ions (Cd2+, Hg2+ and Pb2+). The proposed mechanism can be confirmed by UV–Vis and emission titration. The newly synthesized receptor can sense the metal ions even in nano molar level. The binding or association constant and detection limit of chemosensor to Cr3+ are 1.684 × 105 M−1 and 0.2245 × 10−9 M respectively. A computation using the density functional theory was done to gain detailed insights into the electronic structures of the ligand and its derivatives. B3LYP function and 6-31G(d,p) basis set were used to optimize the ground-state geometry of the chemical and its derivatives.

Theoretical and experimental investigations on 5,12-di(methyl)-quinacridin-ylidene)-7,14-di(rhodanineimine) for optoelectronic applications

In searching for novel organic semiconductors, 5,12-di(methyl)-quinacridin-ylidene)-7,14-di(rhodanineimine) (DQAR) is designed and chemically synthesized by using condensation reaction. The molecular structure of DQAR is supported with spectral measurements. Electronic and geometrical properties of DQAR are investigated be means of combined computational and experimental analyses. Density function theory (DFT/B3LYP) utilizing 6-311G(d,p) basis set are used to optimize DQAR molecular structure and its related geometrical parameters. The intermolecular interactions are calculated using reduced density gradient (RDG) planes. The highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO) of DQAR are experimentally estimated by using the optical absorbance and cyclic voltammetry techniques. DQAR is used as a third component in the active layer of bulk heterojunction (BHJ) solar cells. The BHJ solar cells based on P3HT:DQAR:PC61BM (P3HT = poly(3-hexylthiophene and PC61BM = [6,6]-phenyl-C61-butyric acid methyl ester) active layers are found to be to be better that those based on only P3HT:PC61BM mainly due to the contribution of DQAR to the photocurrent. The obtained results are analyzed in terms of the computational and experimental data. Our initial results indicate that DQAR can be used in BHJ solar cells fabrications.

Computational investigation of pyrazinamide drugs and its transition metal complexes using a DFT approach.

Pyrazinamide, an antituberculosis but documented toxic drug, is subjected to computational investigation along with the metal complexes via a DFT approach to predict the structure-activity and structure-toxicity relationship. 6-31G(d,p) basis set was used for Zn, Ni, Mn, Fe, and Co, while the SDD basis set was applied to Cu, Cr, Cd, and Hg. Several reactivity parameters and charge distribution were calculated and the reactivity profile was estimated. The complexes were found to be soft and polarizable which could be responsible for their binding with bacterial targets to inhibit their growth. In contrast, pyrazinamide which is found to be hard among all is susceptible to being toxic. Moreover, the electronegative nature of the complexes can endow them with a better antibacterial effect. Since metal complexes have been found to be less toxic and more biologically interactive by computational methods, they can be employed as potent drugs for the cure of tuberculosis.

Theoretical determination of electronic, geometric and spectroscopic properties of some 1,2,4-triazol derivatives

In this study, molecular geometric optimization of five 4,5-dihydro-1H-1,2,4-triazol-5-one derivative compounds was obtained using Density Functional Theory, (DFT, B3LYP)/ Hartree Fock, (HF, B3LYP) methods on the basis set of 6-311G (d,p) in order to find the most stable geometric shape of the studied compounds. FT-IR and UV-vis spectral values were performed by using gauge independent atomic orbital (GIAO) methods with Gaussian G09W package program. IR frequency datas of investigated five compounds were calculated in gas phases and are multiplied with appropriate scala factors. The identification of the calculated IR data was performed in the veda4f program. Additionally, bond angles, bond lengths, dipole moments, highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy and total energy, mulliken charges and molecular electrostatic potential (MEP) of five compounds were calculated using same methods and set.

Vibrational Spectroscopic, 13C NMR, DFT Studies on Chlorofullerene (C60Cl6): A Potential Bioactive Agent

Abstract. The present work comprises the systematic computational chemical findings on Chlorofullerene (C60Cl6). The molecular structure of C60Cl6 was optimized by density function theory (DFT)/B3LYP model of 6-31G(d,p) basis set using Gaussian 09 program. The infrared and Raman spectra were simulated and assigned for C60Cl6 molecule. Carbon – chlorine stretching vibrations are found to be in the range 150-900 cm-1 and the chains are strongly affected with the radial vibrations of the carbon sphere. The optimized geometries at ground-state of the molecules are calculated without any geometrical restriction, except those enforced by symmetry and the molecules are found to be minima on their respective potential energy surfaces. The optimized structures have been subjected to Gauge including atomic orbital (GIAO), the chemical shielding tensors using B3LYP/6-31G(d,p) in solvent phase with the aim of calculating 13C chemical shift values with respect to trimethylsilane (TMS) as computational reference. Molecular acuteness and stability were investigated using the Frontier molecular orbitals (FMO) analysis. The molecular electrostatic potential (MEP) mapping provides a valuable information regarding the net electrostatic effect produced by net charge distribution of the molecule. Chlorofullerenes are considered to be promising compounds for the investigation of biological action which show pronounced anti-HIV action and low toxicity. Hence, these results set goal in scheming the biocompatible molecules which will be useful in the field of carbon nano medicine and drug delivery application.

Investigation of structure-property relationships for triazine-based star-shaped monomers consisting of different carbazole units: A theoretical and experimental study

Combined experimental and theoretical studies in the elucidation of the structure-property relationships of molecules are very guiding for advanced material designs. In this work, a comprehensive investigation of the structural, spectroscopic, and electronic properties of triazine-based star-shaped monomers composed of different carbazole constituents by theoretical and experimental methods has been presented. For this purpose, firstly, triazine-based star-shaped monomers consisting of different carbazole constituents in donor-acceptor configurations have been synthesized. The structural and spectroscopic characterizations of monomers obtained have been elucidated by means of 1H NMR, 13C NMR, FT-IR, FT-Raman, and UV–vis analysis. Theoretical calculations have been carried out by ab-initio methods based on Density Functional Theory (DFT) with the basis set of 6-31G(d,p). Additionally, electronic properties, molecular electrostatic potential (MEP) surface and vibrational modes have been calculated for the star-shaped monomers. It is seen that all the data obtained theoretically and experimentally are consistent with each other.

Benchmarking Basis Sets for Density Functional Theory Thermochemistry Calculations: Why Unpolarized Basis Sets and the Polarized 6-311G Family Should Be Avoided.

Basis sets are a crucial but often largely overlooked choice in setting up quantum chemistry calculations. The choice of the basis set can be critical in determining the accuracy and calculation time of your quantum chemistry calculations. Clear recommendations based on thorough benchmarking are essential but not readily available currently. This study investigates the relative quality of basis sets for general properties by benchmarking basis set performance for a diverse set of 139 reactions (from the diet-150-GMTKN55 data set). In our analysis, we find the distributions of errors are often significantly non-Gaussian, meaning that the joint consideration of median errors, mean absolute errors, and outlier statistics is helpful to provide a holistic understanding of basis set performance. Our direct comparison of performance between most modern basis sets provides quantitative evidence for basis set recommendations that broadly align with the established understanding of basis set experts and is evident in the design of modern basis sets. For example, while zeta is a good measure of quality, it is not the only determining factor for an accurate calculation with unpolarized double- and triple-ζ basis sets (like 6-31G and 6-311G) having very poor performance. Appropriate use of polarization functions (e.g., 6-31G*) is essential to obtain the accuracy offered by double- or triple-ζ basis sets. In our study, the best performances for double- and triple-ζ basis sets are 6-31++G** and pcseg-2, respectively. However, the performances of singly polarized double-ζ and doubly polarized triple-ζ basis sets are quite similar with one key exception: the polarized 6-311G basis set family has poor parametrization, which means its performance is more like a double-ζ than a triple-ζ basis set. All versions of the 6-311G basis set family should be avoided entirely for valence chemistry calculations moving forward.

Linear and Nonlinear Optical Responses of Nitrobenzofurazan-Sulfide Derivatives: DFT-QTAIM Investigation on Twisted Intramolecular Charge Transfer.

In this study, we report on the green fluorescence exhibited by nitrobenzofurazan-sulfide derivatives (NBD-Si, i = 1-4). The optical responses of these studied compounds in a polar methanol solvent were simulated by the use of time-dependent density functional theory (TD-DFT) employing the Becke-3-Parameter-Lee-Yang-Parr (B3LYP) functional along with the 6-31G(d,p) basis set. The computed energy and oscillator strength (f) results complement the experimental results. The band gap was calculated as the difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO). Additionally, the density of states (DOS) was computed, providing a comprehensive understanding of the fundamental properties of these materials and further corroborating the experimental data. When the experimental data derived from ultraviolet/visible (UV/visible) and fluorescence spectroscopic techniques and those from simulated spectra are analyzed, the extracted values match up adequately. In addition, the NBD-sulfide compounds exhibit a large Stokes shift up to 85 nm in a polar methanol solvent. They are hypothesized to represent a novel paradigm of excited-state intramolecular charge transfer (ICT). To understand the intrinsic optical properties of NBD-Si materials, an ICT was identified, and its direction within the molecule was evaluated using the ratio of βvect and βtotal, values extracted from the computed nonlinear optical (NLO) properties. Moreover, the reduced density gradient (RDG)-based noncovalent interactions (NCIs) were employed to characterize the strength and type of NBD-Si interactions. Furthermore, noncovalent interactions were identified and categorized using the Quantum Theory of Atoms in Molecules (QTAIM) analysis. Ultimately, the combination of Hirshfeld surface analysis and DFT calculations was utilized to enhance the characterization and rationalization of these NCIs.

Comparing brightness of nanocrystalline nickel coating with traditional bright nickel coating and investigation of stereochemistry of brightener molecules

ABSTRACT Nanocrystalline nickel coatings can be electrodeposited by using grain refiners like saccharin which consequently increase the gloss of the coating. Also, brighteners can produce bright coatings. The aim of this research was to compare the brightness of electroplated nanocrystalline nickel coating with traditional electroplated bright nickel coating. The coatings prepared from the bath containing saccharin and a bath with para-toluene sulphonamide had virtually the same gloss. Thus, instead of expensive brightening agents, saccharin can be used to achieve the same gloss in nickel plating. To investigate the stereochemistry of brightener molecules, the density functional theory (DFT) method was used at the computational level of B3LYP with the basis set 6-311G (d,p) ++ in a Gaussian software. The results of computational chemistry showed that the most probable state of adsorption of brightening additives is when the aromatic ring or a double bond or a triple bond of the brightener molecule approaches the cathode surface during the adsorption process.

Enhanced Method for the Synthesis and Comprehensive Characterization of 1-(4-Phenylquinolin-2-yl)propan-1-one.

We present an enhanced method for synthesizing a novel compound, 1-(4-phenylquinolin-2-yl)propan-1-one (3), through the solvent-free Friedländer quinoline synthesis using poly(phosphoric acid) as an assisting agent. The crystal structure of compound 3 is analyzed using FT-IR, and the chemical shifts of its 1H- and 13C NMR spectra are measured and calculated using B3LYP/6-311G(d,p), CAM-B3LYP/6-311G(d,p), and M06-2X/6-311G(d,p) basis sets in the gas phase. Additionally, the optimized geometry of quinoline 3 is compared with experimental X-ray diffraction values. Through density functional theory calculations, we explore various aspects of the compound's properties, including noncovalent interactions, Hirshfeld surface analysis, nonlinear optical properties, thermodynamic properties, molecular electrostatic potential, and frontier molecular orbitals. These investigations reveal chemically active sites within this quinoline derivative that contribute to its chemical reactivity.