GIAO Method Research Articles

Experimental Spectroscopic and Theoretical Studies of New Synthesized Sulfonamide Derivatives

In this paper, two new Schiff bases (L1 and L2) derived from substituted salicylaldehyde and sulfamethoxazole/sulfisoxazole were synthesized. The synthesized structures were elucidated by experimental spectroscopic methods such as FT-IR, 1H-13C NMR, 1H, and 13C shielding tensors, and elemental analysis. The theoretical vibrational modes and nonlinear optical (NLO) properties have been computed by DFT/B3LYP/6-311G(d,p) method. Theoretical 1H and 13C shielding tensors were calculated with GIAO methods in CDCl3 with same level of theory. The results have shown that there is perfect harmony between the calculated parameters and recorded experimental data. The first order hyperpolarizabilities of the new synthesized compounds are 201.79 and 113.14 times larger than that of urea (0.3728 × 10–30 esu), respectively. According to evaluated results, the L1 and L2 present large nonlinear optical activity and are candidate molecules for nonlinear optical applications.

Investigation on Molecular Structure, Vibrational Analysis and Thermodynamic Properties of 1-(2,6-dimethylmorpholine-4-yl-methyl)-3-methyl-4-[3-ethoxy-(4-benzenesulfonyloxy)- benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-one

In this article, 1-(2,6-dimethylmorpholine-4-yl-methyl)-3-methyl-4-[3-ethoxy-(4-benzenesulfonyloxy)-benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-one has been theoretically studied. All quantum chemical calculations were carried out by using Gaussian 09W program package and GaussView molecular visualization program. The 1H and 13C NMR chemical shifts of the title molecule were calculated by the GIAO method and compared with experimental results. Theoretical and experimental values were plotted according to dexp=a+b. d calc. The standard error values were found via the Sigma plot with regression coefficient of a and b constants. The vibrational frequency values of this compound have been calculated by using 6-31G(d,p) basis set with DFT and HF methods and these values are multiplied with appropriate adjustment factors. The veda4f program was used in defining IR data. The polarizability (α), hyperpolarizability (β), dipole moment along with molecular electrostatic potential surface have been calculated. The molecular electrostatic potential (MEP) map was calculated to assign reactive site on the surface of the molecule. The calculated electronic, structural (bond lengths and bond angles) and several thermodynamic parameters of title molecule were performed using the Hartree-Fock (HF) and density functional methods (DFT/B3LYP) with 6-31G(d,p) basis set.

A new series of sulfa drugs containing pyrazolyl acylthiourea moiety: Synthesis, experimental and theoretical spectral characterization and molecular docking studies

Ten new molecules of sulfa drugs including pyrazolyl acylthiourea groups (3a-3j) were synthesized and characterized with the help of elemental analysis, HRMS, FT-IR, 1H NMR, 13C NMR and UV measurements. Theoretical calculations were carried out by DFT method using B3LYP functional and 6-311 + G(d,p) basis set. For theoretical IR, NMR (with GIAO method), UV, NLO, MEP, HOMO-LUMO energies analysis of 3a-3j compounds were performed over the optimized structures. Additionally, molecular docking studies were performed to explain the interaction between title molecules and four receptors such as 1UY6, 1YET, 5AML and 3HS4.

Structural (PES), AIM, spectroscopic profiling (FT-IR, FT-Raman, NMR and UV), HOMO-LUMO and docking studies of 2,2-dimethyl-N-(2-pyridinyl)propanamide – a DFT approach

Abstract The conformational study (PES) has been performed and a minimum energy conformer structure has been chosen for DFT exploration on 2,2-dimethyl-N-(2-pyridinyl)propanamide. AIM topological analysis, FT-IR and FT-Raman investigation have been implemented by emerging DFT calculations based on the B3LYP level with 6-311++G(d,p) basis set, which also helps to provide useful information about the structure of the title compound. NMR has been carried through the same method along with the GIAO method for assigning 1H and 13C chemical shifts. The results were compared and discussed with experimental data. UV–Visible analysis has been done by taking DMSO as a solvent to obtain maximum absorption wavelength. HOMO-LUMO diagram for different energies has been illustrated and compared with UV–Visible data to know the maximum filled and empty frontier orbitals. Charge density distribution and chemical activity region of the molecule have been shown by molecular electrostatic potential (MEP) and contour map. Mulliken atomic charges to know electronegative and electropositive atoms in a molecule, thermodynamic variables at various temperatures were estimated. The molecular docking studies revealed that the title molecule plays an important role in binding proteins to exhibit Glutathione thiolesterase inhibition. Thus, this present study reports the structural, electrical, chemical and biological activities of 2,2-dimethyl-N-(2-pyridinyl)propanamide.

A detailed computational investigation on the structural and spectroscopic properties of propolisbenzofuran B

This investigation deals with some structural and spectroscopic aspects of propolisbenzofuran B molecule as one of the most important bioactive molecules which exists in the bee propolis composition. FT-IR vibrational analysis carried-out at B3LYP/6–311++G(d,p) level of the theory. 1H and 13C NMR chemical shift have been predicted with GIAO method. TD- DFT calculations have been established to predict the UV- Vis spectral analysis for propolisbenzofuran B molecule. The detailed structural analysis such as electronic characterization, HOMO and LUMO, DOS plot, Molecular Electronic Potential (MEP), Natural Bond Orbital (NBO) are performed and discussed for studied molecule.

Investigations of Structural Properties, Spectroscopic Aspects, Electronic and Thermodynamic Properties of 3-Benzyl-4-[3-(3-methoxybenzoxy)-benzylidenamino]-4,5-Dihydro-1H-1,2,4-Triazol-5-one with DFT/HF Basis Sets

In this paper, firstly the synthesis, FT-IR, NMR chemical shifts, UV–Vis spectral values of 3-benzyl-4-[3-(3-methoxybenzoxy)-benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-one (1) have been investigated. Later, this molecule was optimized by using B3LYP and HF methods with 6-311G(d)/3-21G basis sets. Electronic and thermodynamic parameters, geometric and structural properties, HOMO-LUMO energy values, the molecular electrostatic potential (MEP) and Mulliken atomic charges of titled molecule have been carried out. 1H-NMR and 13C-NMR isotropic shift values of this molecule (in DMSO solvent and in the ground state) were performed by GIAO method. The geometric and spectroscopic parameters of titled molecule were performed by using density functional (DFT/B3LYP) and Hartree–Fock methods (HF) with the 6-311G(d) and 3-21G basis sets. Also, the determination of FT-IR values was used the veda4f software program. The UV-vis data (ethanol) were calculated and all spectral parameters were compared with experimental data.

Theoretical calculations of 1H NMR chemical shifts for nitrogenated compounds in chloroform solution

In this work we report DFT and MP2 1H NMR calculations using the GIAO method and TMS as reference, for a series of nitrogenated compounds in chloroform solution to assess the ability of available theoretical models to reproduce experimental 1H NMR spectra measured in CDCl3 solution, focusing on CHn and N-H proton signals which are relevant in conformational analysis studies. The Polarizable Continuum Model (PCM) may not work successfully to predict N-H chemical shifts in solution. Only when a few explicit solvent molecules are used in DFT-PCM-CHCl3 geometry optimizations a good agreement with experimental N-H chemical shifts measured in solution is reached, indicating that this is a reliable computational procedure for the prediction of the full NMR spectra of organic molecules containing N-H group. However, finding adequate DFT optimized solvated solute structures which reproduce well both N-H and CHn proton NMR signals can become a hard-computational task.

Vibrational spectroscopic characterization, electronic absorption, optical nonlinearity computation and terahertz investigation of (2E) 3-(4-ethoxyphenyl)-1-(3-bromophenyl) prop-2-en-1-one for NLO device fabrication

The present study spotlights the key structure-property features of a chalcone derivative (2E) 3-(4-ethoxyphenyl)-1-(3-bromophenyl) prop-2-en-1-one (E3BC) for future applications in nonlinear optical devices through dual approach involving experimental and theoretical techniques. The sample has been characterized by 1H NMR, FT-IR, FT-Raman and terahertz spectroscopies. The experimental results are supported by computational studies using density functional theory. To analyse the 1H NMR spectra, theoretical calculations on chemical shifts were done by GIAO method. Complete vibrational assignments of the vibrational modes have been made on the basis of the potential energy distribution in terms of internal coordinates. The low frequency vibrational modes between 0.2 and 1.8 THz were examined via terahertz time domain spectroscopy. The UV–vis spectrum was recorded in methanol solution. The energies, absorption wavelengths and oscillator strengths of electronic singlet-singlet transitions were determined by time dependent density functional theory. The calculated HOMO-LUMO energy gap is small which reveals that the charge transfer takes place within the molecule and it can be exploited for the nonlinear optical applications. Information about the charge density distribution and the sites of chemical reactivity of the molecule has been obtained by mapping electron density with molecular electrostatic potential. The MEP surface around the bromine atom exhibited the dual nature. Along the C-Br axis the positive electrostatic potential (the σ-hole) is present while the remainder of the surface is negative. Hence bromine atom can interact electrostatically with both nucleophiles and electrophiles. For other atoms no atom-specific effects are found. The stability of the molecule arising from hyper conjugative interactions and charge delocalization has been interpreted using natural bond orbital analysis. The study indicates that the intramolecular charge transfer (n → σ∗, n → π∗ and π → π∗) can induce nonlinearity in the molecule and validates E3BC's candidature to be used as a nonlinear optical active material. In order to understand the nonlinear optical activity of the molecule the calculations of electronic dipole moment, polarizability, anisotropy of polarizability as well as first and second hyperpolarizabilities are performed using finite field approach implemented in the DFT method. The findings suggested that the first order hyperpolarizability of titled molecule is 139 times greater than the value of urea. The high value of first order hyperpolarizability shows that E3BC can be a potential candidate in the nonlinear optical applications. The vibrational contribution to the above properties has also been computed using the self-consistent field wave functions within the double harmonic oscillator approximation.

Investigation of theoretical properties of 1-Acetyl-3-(p-methylbenzyl)-4-(3-methyl-2- thienylmethyleneamino)-4,5-dihydro-1H-1,2,4-triazol-5-one molecule

In this study, firstly, 1-acetyl-3-(p-methylbenzyl)-4-(3-methyl-2-thienylmethyleneamino)-4,5-dihydro-1H-1,2,4-triazol -5-one molecule was optimized by using the B3LYP/DFT631G (d) and HF/631G (d) basis sets. Then, the veda4f program was used in defining of IR data theoretically. IR (infrared) vibrational frequencie values with two different basis sets of molecule was calculated in gas phase and multiplied by adjustment scale factors. Infrared spectra of molecule according to these values obtained were formed. Furthermore, 1H-NMR and 13C-NMR isotropic shift values were calculated by GIAO method. Experimental and theoretical values of analyzed molecule were inserted into the graphic according to equation of δ exp =a + b. δ calc. The standard error values were found via SigmaPlot program with regression coefficient of a and b constants. Finally, bond angles, bond lengths, mulliken atomic charges, HOMO-LUMO energy, ELUMO-EHOMO energy gap (ΔE), electronegativity (χ), electron affinity (A), global hardness (η), softness (σ), ionization potential (I), total energy of the molecule, dipole moment and thermodynamic properties were calculated with Gaussian 09W program.

Spectral, DFT and molecular docking investigations on Etodolac

The title compound (RS) -2- (1, 8-Diethyl- 4, 9-dihydro-3H- pyrano [3, 4-b] indol-1-yl) acetic acid (Etodolac) was characterized by experimental FTIR, FT-Raman, NMR and UV-Visible spectral analysis. The optimized molecular geometry and vibrational wave numbers were calculated by employing the method of DFT and B3LYP/6-311++G(d, p) basis set. The vibrational assignments were calculated using VEDA program. Carbon and Proton NMR chemical shifts were calculated in different solvents by GIAO method. Theoretical UV-Visible spectrum was obtained in DMSO and in gas phase using TD-DFT method. For the title compound, HOMO-LUMO and Donor- Acceptor (NBO) interactions were studied. In addition, MEP map was traced to find the reactive sites of Etodolac. Further, NLO properties such as dipole moment, linear and first order hyperpolarizabilities have been studied to reveal NLO nature of the title compound. Also the thermodynamic properties with respect to temperature were calculated. All the theoretical predictions were carried out by using DFT-B3LYP method at the level of 6–311++G(d, p). Finally to find its biological importance, the molecular docking interaction was studied to reveal that Etodolac is a selective inhibitor of COX (cyclooxygenase) enzyme.

Yeni 5-Merkapto-2-(5-metil-furan-2-il-metilidenamino)-1,3,4-tiyadiazol Molekülün Sentezi ve Teorik Analizi

In this study, the novel 5 Mercapto 2--(5 methyl furan 2 yl 1,3,4 thiadiazole molecule was synthesized from the reaction of 2 amino 5 mercapto 1,3,4 thiadiazole with 5 methyl furan 2 carbaldehyde. The 5 Mercapto 2--(5 methyl furan 2 yl 1,3,4 thiadiazole was optimized by using DFT( HF methods. The mulliken charges, HOMO LUMO energy, ELUMO EHOMO energy gap (ΔEg), dipole moments, electron affinity (A), ionization potential (I), chemical softness (σ), chemical hardness (η), electronegativity (χ), bond angles, total energy and bond lengths of the molecule were calculated by using 6 31G(d,p) basis set with DFT (B3LYP) and HF methods. Otherwise, the 1H NMR and 13C NMR isotropic shift values were calculated by using GIAO methods with GaussianG09W package program. The experimental/theoretical values were compared and the regression analysis were found. Defining IR values were used the veda4f program. The theoretical infrared spectrums are visualised.

Structural characterization of kaempferol: a spectroscopic and computational study

Calculations based on the density functional theory, with the B3LYP functional and the 6-311++G(d,p) basis set, were performed with the aim of confirming the molecular structure and spectroscopic characteristics of kaempferol, a naturally occurring flavonoid molecule. The electronic structure of kaempferol was examined using NBO analysis. The assigning of the experimentally obtained IR and Raman spectra was performed after the best-fit-based comparison with theoretical spectra. The 13C and 1H NMR experimental spectra were related to the theoretically obtained values of the chemical shifts determined by the GIAO method. The correlation coefficient and the average absolute error values proved B3LYP-D3 to be an adequate method in describing the NMR parameters of kaempferol. Molecular docking analysis was carried out in order to identify the potency of inhibition of the title molecule against human procalcitonin. The inhibition activity was obtained for 10 conformations of ligand inside the protein.

Synthesis of new cyano-substituted analogues of Tröger's bases from bromo-derivatives. A stereochemical dependence of long-range (n JHH , n=4, 5, and 6) proton-proton and proton-carbon (n JCH , n=1, 2, 3, 4, and 5) coupling constants of these compounds.

A free-catalyst microwave-assisted cyanation of brominated Tröger's base derivatives (2a-f) is reported. The procedure is simple, efficient, and clean affording the nitrile compounds (3a-e, I) in very good yields. Complete assignment of 1 H and 13 C chemical shifts of 2a-f, I and 3a-d, I was achieved using gradient selected 1D nuclear magnetic resonance (NMR) techniques (1D zTOCSY, PSYCHE, DPFGSE NOE, and DEPT), homonuclear 2D NMR techniques (gCOSY and zTOCSY), and heteronuclear 2D NMR techniques (gHSQCAD/or pure-shift gHSQCAD, gHMBCAD, bsHSQCNOESY, and gHSQCAD-TOCSY) with adiabatic pulses. Determination of the long-range proton-proton coupling constants n JHH (n=4, 5, 6) was accomplished by simultaneous irradiation of two protons at appropriate power levels. In turn, determined coupling constants were tested by an iterative simulation program by calculating the 1 H NMR spectrum and comparing it to the experimental spectrum. The excitation-sculptured indirect-detection experiment (EXSIDE) and 1 H-15 N CIGARAD-HMBC (constant time inverse-detection gradient accordion rescaled heteronuclear multiple bond correlation) were applied for determination of long-range carbon-proton coupling constants n JCH (n=2, 3, and 4) and for assignment of 15 N chemical shift at natural abundance, respectively. DFT/B3LYP optimization studies were performed in order to determine the geometry of 2c using 6-31G(d,p), 6-311G(d,p), and 6-311+G(d,p) basis sets. For calculation of 1 H and 13 C chemical shifts, n JHH (n=2, 3, 4, 5, and 6), and n JCH (n=1, 2, 3, and 4) coupling constants, the GIAO method was employed at the B3LYP/6-31G(d,p), B3LYP/6-31+G(d,p), B3LYP/6-311+G(d,p), B3LYP/6-311++G(2d,2p), B3LYP/cc-pVTZ), and B3LYP/aug-cc-pVTZ) levels of theory. For the first time, a stereochemical dependence magnitude of the long-range n JHH (n=4, 5, and 6) and n JCH (n=1, 2, 3, 4, and 5) have been found in bromo-substituted analogues of Tröger's bases.

Conformational, structural, electronic, and vibrational investigations on 5-methyl-4-(2-thiazolylazo)resorcinol by FT-IR, FT–Raman, NMR, and DFT

The all conformers of 5-methyl-4-(2-thizolylazo)resorcinol have been identified by Spartan 13 software. All conformers have been optimized B3LYP/6-311G (d, p) level of theory in Gaussian 09 software. According to potential energy surface search, 5-methyl-4-(2-thizolylazo)resorcinol has eight conformers. All the structural parameters of the most stable conformer of 5-methyl-4-(2-thizolylazo)resorcinol are predicted using DFT (B3LYP) method with the same basis set given above. The vibrational frequencies are recorded by the Fourier transform infrared (FT-IR 4000–550 cm−1) and Fourier transform Raman (FT–Raman; 4000–100 cm−1) spectra in the powder form. The vibrational frequencies are predicted and compared with experimental FT-IR and FT–Raman ones. The experimental 1H and 13C NMR spectra have been recorded and compared with the theoretical chemical shifts determined by the GIAO method. The results of UV–Vis spectra of molecule are also presented. Theoretical results compared with the experimental results for the identification and characterization of 5-methyl-4-(2-thizolylazo)resorcinol molecule.

DFT analysis on spectral and NLO properties of (2E)-3-[4-(dimethylamino) phenyl]-1-(naphthalen-2-yl) prop-2-en-1-one; a d-π-A chalcone derivative and its docking studies as a potent hepatoprotective agent

Abstract The optimization and spectral (IR, 1H and 13C NMR) analysis of the synthesized chalcone derivative (2E)-3-[4-(dimethylamino) phenyl]-1-(naphthalen-2-yl) prop-2-en-1-one was carried out using DFT B3LYP/6-311G (d,p) method and compared with experimental results. The GIAO method was used to calculate 1H and 13C chemical shift. The βtot value was calculated by CAM-B3LYP method. Experimental SHG efficiency of DANP was analysed. TD-DFT method was used for absorption spectral analysis and compared with experimental result. The experimental and theoretical band gap was analysed. NBO analysis explains the molecular interactions; MEP plot was also performed. Molecular docking on hepatoprotective ability of title molecule with four different proteins was conducted and compared with most commonly used hepatoprotective drug silymarin.

A theoretical study on 1H/13C/31P NMR chemical shifts, and the correlation between 2JP–H and the electronic structure of different phosphoryl benzamide derivatives

A comprehensive study was performed on 1H/13C/31P NMR chemical shifts (CSs) of some phosphoryl benzamide derivatives (R1C6H5C(O)NHP(O)R2R3), [R1 = CH3, OCH3, NO2, F, Cl, Br and R1, R2 = NHC(CH3)3 or NC4H8O] by the GIAO method to find the most correlated level of theory with experimental values. All the structures (C1C12) were firstly optimized at B3LYP, BP86, PBE1PBE, M06-2X, MPWB1K and MP2 methods with 6–31 + G* basis set. Computed structural parameters demonstrate that BP86 has the best agreement to experimental values. The def2-TZVP and aug-cc-pVDZ basis sets were also employed to inspect the effect of different basis sets. The correlation between experimental and computational values prove that 6–31 + G* basis set is the optimum case regarding minimization of the costs and results. Chemical shifts were calculated at all mentioned combinations and compared with experimental data, which demonstrate that in accordance with structural parameters, BP86/6−31 + G* gives the best results. Calculating 2JPH values of studied compounds, focusing on the comparison between experimental and theoretical results was another aim of this study. Computed values of 2JPH at the optimum level of theory reveal an acceptable agreement with experimental data. Eventually, the dependency between 2JPH values and the bonding structures was inspected. NBO analysis at BP86/6−311++G** explicates the relationship between the electronic properties of studied compounds and 2JPH values.

Theoretical study via DFT for prediction of 13C and 1H NMR data of two diterpenoids derived from the root of salvia grandifolia

The DFT method has become a promising alternative in the support of traditional NMR experimental techniques, comparing experimental data with theoretical data, thereby achieving accurate and satisfactory results. In the present study, the experimental data of two diterpenes were compared to the theoretical data obtained by the GIAO method, applying DFT at the B3LYP/cc-pVDZ and B3PW91/DGDZVP levels to verify the degree of correlation, significance and predictability of the models obtained with the purpose of proving which of the computational methods is the most efficient for this class of substances. The theoretical NMR values obtained at B3LYP/cc-pVDZ were the more satisfactory, showing better linear correlations, presenting greater degrees of adjustments, significance and predictability compared to the B3PW91/DGDZVP method. Thus, these values were used to define H? and H? 1, 2, 3, 6 and 7 for diterpene 1 and 1, 2, 3, 6 and 7 for diterpene 2, which was not possible using experimental data. This showed that the quantum method used could help in the structural elucidation of natural products.

Molecular Structure, Spectroscopic (FT-IR, FT-Raman, 13C and 1H NMR) Analysis, HOMO-LUMO Energies, Mulliken, MEP and Thermal Properties of New Chalcone Derivative by DFT Calculation

Quantum chemical calculations of (E)-3-(4-Hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one[HMHP-I] were carried out with DFT calculation using B3LYP/6-311++G(d,p) basis set by Gaussian 09W. Geometrical parameters, vibrational analysis (FT-IR and Raman), 13C NMR and 1H NMR (GIAO method) have been done for conforming the molecular structure. The molecular orbital calculations such as HOMO-LUMO energy gap, Mulliken population analysis and molecular electrostatic potential (MEP) surfaces have been calculated. The thermodynamic parameters such as heat capacity, entropy and enthalpy at different temperatures were calculated.

Detailed theoretical characterization of azo chromophores containing dicyanomethylene acceptor and various coupling components by DFT

The structural, electronic and nonlinear optical (NLO) properties of a new series of donor-π-acceptor (D-π-A) type azo dyes bearing strong electron-accepting dicyanomethylene unit and various coupling components having different properties and conjugated through an azo linker have been investigated theoretically using Density Functional Theory (DFT) at B3LYP/631g(d). The 1H NMR chemical shifts of the dyes were calculated using GIAO method at B3LYP/6311 + g (d,p). The theoretical values of absorption maxima of the dyes were obtained by time dependent DFT using various solvents. The calculated data for 1H NMR and UV–vis were compared with the experimental ones, and the results were consistent with each other. The stabilities of the possible tautomeric forms of the compounds (I, IV, V and VI) were determined by comparison with their energies in the used solvents. The frontier molecular orbitals and the global reactivity descriptors were also computed. The computed HOMO and LUMO proved the charge transfer from the donor to the acceptor units. In addition, the NLO properties of the molecules were determined. The molecules, including strong donor and acceptor units, have a very high NLO response and may be a strong candidate as an NLO material.

Synthesis, spectroscopic characterization, and computational studies of 2-cyano-6-hydroxybenzothiazole: a key synthetic intermediate of firefly luciferin

Firefly luciferin is widely applied as a biotechnological tool for visualizing various biological processes in vitro and in vivo. Chemically, 2-cyano-6-hydroxybenzothiazole, as a key synthetic intermediate of firefly luciferin, is obtained from 2-cyano-6-methoxybenzothiazole by changing the methoxy with a hydroxy group. However, this approach is costly and not suited for large-scale synthesis. Here we report cost-effective and efficient syntheses of 2-cyano-6-hydroxybenzothiazole through the catalytic Sandmeyer-type cyanation reaction. Our approach employs diazonium tetrafluoroborate salt of 2-amino-6-hydroxybenzothiazole as a cyanation substrate. The cyanation reaction proceeds efficiently under mild conditions by using Cu(I)/Cu(II)/N,N,N\textquotesingle,N\textquotesingle-tetramethylethylenediamine as a catalyst. In addition, computational studies of the 2-cyano-6-hydroxybenzothiazole structure were performed based on the density functional theory method. The theoretical parameters of the optimized geometry were derived from the B3LYP/6-311$++$G(d, p) method. Time-dependent density functional theory was applied to assign the electronic absorption bands observed experimentally and the $^{1}$H NMR chemical shifts were computed using the GIAO method. There was a significant relationship between computational studies and experimental results.