Molecular structure, spectroscopic and quantum chemical studies on benzoic acid and succinic acid co-crystals of 2-aminopyrimidine

2018 ◽  
Vol 17 (04) ◽  
pp. 1850021 ◽  
Author(s):  
S. Thangarasu ◽  
V. Siva ◽  
S. Athimoolam ◽  
S. Asath Bahadur
Keyword(s):  
Benzoic Acid ◽  
Succinic Acid ◽  
Molecular Orbital ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Basis Sets ◽  
Experimental Result ◽  
Chemical Hardness ◽  
Geometrical Parameters ◽  
Computational Calculations

Organic nonlinear optical co-crystals 2-aminopyrimidine benzoic acid (2APB) and 2-aminopyrimidine succinic acid (2APS) have been successfully grown by slow solvent evaporation method at room temperature. The structural characterization of the grown crystals was carried out by single crystal X-ray diffraction. Fourier transform infrared spectroscopy (FT-IR) and FT-Raman spectra of the grown crystals are recorded and the observed vibrational frequencies are assigned. The hybrid computational calculations are carried out by Hartree–Fock (HF) and density functional theory (DFT) (3-parameter, Lee-Yang-Parr (B3LYP)) methods with 6-311[Formula: see text]G(d,p) basis sets and the corresponding results are tabulated. The geometrical parameters of the molecules also have been analyzed. The computed vibrational spectra were compared with experimental result which shows appreciable agreement. The chemical hardness, electronegativity, chemical potential and electrophilicity index were determined by highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) plot. The grown crystals were subjected to population analysis, thermal, linear and nonlinear optical studies of materials. The calculated second-order hyperpolarizability values of these materials are nearly two to four times that of urea.

scholarly journals Synthesis, Spectroscopic Studies, Antimicrobial Activity and Computational Calculations on 3-Nitroanilinium Dihydrogen Phosphate

2021 ◽  
Vol 33 (5) ◽  
pp. 1099-1106
Author(s):  
Subramanian Thangarasu ◽  
Vadivel Siva ◽  
Shunmuganarayanan Athimoolam ◽  
Sultan Asath Bahadur
Keyword(s):  
Antimicrobial Activity ◽  
Density Functional ◽  
Chemical Potential ◽  
Basis Set ◽  
Experimental Result ◽  
Frontier Molecular Orbital ◽  
Chemical Hardness ◽  
Geometrical Parameters ◽  
Dihydrogen Phosphate ◽  
Computational Calculations

3-Nitroanilinium dihydrogen phosphate (3NADP) has been synthesized and crystallized successfully using the method of solvent evaporation solution growth. The molecular structure has been optimized and geometrical parameters of 3NADP also have been analyzed using B3LYP function with density functional theory (DFT) and Hartree-Fock (HF) methods with a 6-311++G(d,p) basis set. The comparison between computed vibrational spectra and experimental result shows an appreciable agreement. The thermal stability of 3NADP crystal was analyzed using TG/DTA and the melting point was identified at 209 ºC. The properties like electronegativity, chemical hardness, electrophilicity index and chemical potential of the crystal were determined through HOMO-LUMO study. Lower band gap value obtained in frontier molecular orbital analysis and favours the possible biological activity of 3NADP. The grown crystals was also screened for the antimicrobial activity against some specific potentially threatening microbes.

Fluorescent styryl chromophores with rigid (pyrazole) donor and rigid (benzothiophenedioxide) acceptor – complete density functional theory (DFT), TDDFT and nonlinear optical study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sulochana Bhalekar ◽  
Archana Bhagwat ◽  
Nagaiyan Sekar
Keyword(s):  
Density Functional Theory ◽  
Dipole Moment ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Absolute Error ◽  
Basis Sets ◽  
Chemical Hardness ◽  
Styryl Dyes ◽  
Functional Theory ◽  
Hybrid Functionals

Abstract Density functional theory (DFT) and time-dependent DFT computations were employed to examine linear and nonlinear optical (NLO) characteristics of (E)-4-((1,1-dioxido-3-oxobenzo[b]thiophen-2(3H)-ylidene) ethyl)-1-phenyl-1H-pyrazol-5(4H)-one derived styryl dyes. NLO properties were computed using the two different global hybrid functionals B3LYP, BHandHLYP and three range separated hybrid functionals CAM B3LYP, wB97, wB97X and wB97XD with the basis sets 6–311++G(d,p), cc-pVDZ and cc-pVTZ. The compounds shows higher values of dipole moment around 8–9 Debye than the other compounds. They show higher values of α 0, ß 0 and γ 0 values. The values of γ 0 are around 204–544 × 10−36 e.s.u. with the method, B3LYP/6–311++G(d, p). We have calculated the mean absolute error (MAE) for dipole moment, α 0, ß 0 and γ 0 values. It is observed that MAE is less (0.89) for wB97/6–311++G(d,p) which indicates that wB97 is the most suited functional for all three compounds. Chemical stability and reactivity of these dyes were studied using electrophilicity index and chemical hardness and hyperhardness.

Molecular Structure, Vibrational Assignments and Nonlinear Optical Properties of Borazine by DFT Calculations

2021 ◽  
pp. 102-107
Author(s):  
Vinayak P. Deshmukh
Keyword(s):  
Molecular Structure ◽  
Finite Field ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Field Method ◽  
Vibrational Frequencies ◽  
Basis Sets ◽  
Geometrical Parameters ◽  
Nlo Properties ◽  
Vibrational Assignments

In this work, density functional theory (DFT) combined with the finite field (FF) method has been adopted to study the molecular structure, vibrational assignments and nonlinear optical (NLO) properties of borazine. The geometrical parameters, vibrational frequencies and NLO properties have been obtained at B3LYP/6-311++G** level of theory. The optimized geometries and vibrational frequencies for borazine are in excellent agreement with the available experimental determinations. The B-N stretching mode observed is the most intense vibrational mode for borazine. The NLO properties of borazine have been investigated by using finite field method. The β and γ values are calculated at field strength of 0.006 a.u. for borazine using different methods and different basis sets.

scholarly journals DFT investigations on arylsulphonyl pyrazole derivatives as potential ligands of selected kinases

2020 ◽  
Vol 18 (1) ◽  
pp. 857-873
Author(s):  
Kornelia Czaja ◽  
Jacek Kujawski ◽  
Radosław Kujawski ◽  
Marek K. Bernard
Keyword(s):  
Free Energy ◽  
Molecular Orbital ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Chemical Hardness ◽  
Free Energy Of Solvation ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Condensed Fukui Functions ◽  
Charge Partitioning

AbstractUsing the density functional theory (DFT) formalism, we have investigated the properties of some arylsulphonyl indazole derivatives that we studied previously for their biological activity and susceptibility to interactions of azoles. This study includes the following physicochemical properties of these derivatives: electronegativity and polarisability (Mulliken charges, adjusted charge partitioning, and iterative-adjusted charge partitioning approaches); free energy of solvation (solvation model based on density model and M062X functional); highest occupied molecular orbital (HOMO)–lowest occupied molecular orbital (LUMO) gap together with the corresponding condensed Fukui functions, time-dependent DFT along with the UV spectra simulations using B3LYP, CAM-B3LYP, MPW1PW91, and WB97XD functionals, as well as linear response polarisable continuum model; and estimation of global chemical reactivity descriptors, particularly the chemical hardness factor. The charges on pyrrolic and pyridinic nitrogen (the latter one in the quinolone ring of compound 8, as well as condensed Fukui functions) reveal a significant role of these atoms in potential interactions of azole ligand–protein binding pocket. The lowest negative value of free energy of solvation can be attributed to carbazole 6, whereas pyrazole 7 has the least negative value of this energy. Moreover, the HOMO–LUMO gap and chemical hardness show that carbazole 6 and indole 5 exist as soft molecules, while fused pyrazole 7 has hard character.

scholarly journals Theoretical Study of Solvent Effects on the Electronic and Thermodynamic Properties of Tetrathiafulvalene (TTF) Molecule Based on DFT

2021 ◽  
pp. 42-54
Author(s):  
Rabiu Nuhu Muhammad ◽  
N. M. Mahraz ◽  
A. S Gidado ◽  
A. Musa
Keyword(s):  
Thermodynamic Properties ◽  
Bond Length ◽  
Density Functional ◽  
Theoretical Study ◽  
Energy Gap ◽  
Basis Set ◽  
Basis Sets ◽  
Frontier Molecular Orbital ◽  
Orbital Energy ◽  
Chemical Hardness

Tetrathiafulvalene () is an organosulfur compound used in the production of molecular devices such as switches, sensors, nonlinear optical devices and rectifiers. In this work, a theoretical study on the effects of solvent on TTF molecule was investigated and reported based on Density Functional Theory (DFT) as implemented in Gaussian 03 package using B3LYP/6-31++G(d,p) basis set. Different solvents were introduced as a bridge to investigate their effects on the electronic structure. The HUMO, LUMO, energy gap, global chemical index, thermodynamic properties, NLO and DOS analysis of the TTF molecule in order to determine the reactivity and stability of the molecule were obtained. The results obtained showed that the solvents have effects on the electronic and non-linear-optical properties of the molecule. The optimized bond length revealed that the molecule has strong bond in gas phase with smallest bond length of about 1.0834Å than in the rest of the solvents. It was observed that the molecule is more stable in acetonitrile with HOMO-LUMO gap and chemical hardness of 3.6373eV and 1.8187eV respectively. This indicates that the energy gap and chemical hardness of TTF molecule increases with the increase in polarity and dielectric constant of the solvents. The computed results agreed with the results in the literature. The thermodynamics and NLO properties calculation also indicated that TTF molecule has highest value of specific heat capacity (Cv), total dipole moment () and first order hyperpolarizability () in acetonitrile, while acetone has the highest value of entropy and toluene has a slightly higher value of zero point vibrational energy (ZPVE) than the rest of the solvents. The results show that careful selection of the solvents and basis sets can tune the frontier molecular orbital energy gap of the molecule and can be used for molecular device applications.

DFT STUDIES ON ELECTRONIC STRUCTURES AND THIRD-ORDER NONLINEAR OPTICAL PROPERTIES OF A SERIES OF Pt–Pt BOND-CONTAINING METAL COMPLEXES

2012 ◽  
Vol 11 (02) ◽  
pp. 403-419 ◽  
Author(s):  
CHUN-GUANG LIU ◽  
XIAO-HUI GUAN ◽  
ZHONG-MIN SU
Keyword(s):  
Metal Complexes ◽  
Electronic Structures ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Thiophene Ring ◽  
Basis Sets ◽  
Third Order ◽  
Strong Electron ◽  
Nlo Response ◽  
Ct Transitions

In this paper, electronic structures and third-order nonlinear optical (NLO) properties of a series of Pt–Pt bond-containing metal complexes have been calculated by using the density functional theory (DFT) combining with the sum-over-states (SOS) method. In order to check the reliability of this method, the electron correlations and basis sets have been compared. Our calculated results show that introduction of electron donor, thiophene ring and lengthing of organic conjugated ligand can enhance third-order NLO responses. The electronic structure analysis shows that the [Pt–Pt(H2P(CH2)PH2)2] fragment displays strong electron-withdrawing character in these systems. Meanwhile, the third-order NLO response of Pt–Pt bond also has been estimated by using TDDFT–SOS method. An enhancement of third-order NLO response has been observed because of the introduction of the Pt–Pt bond. This is mainly due to the intense and low-lying metal-to-ligand charge transfer (MLCT) and intraligand (IL) CT transitions.

Non Linear Optical, Thermodynamic Analysis and Spectroscopic Investigation of GPA Optical Materials

2017 ◽  
Vol 730 ◽  
pp. 106-111
Author(s):  
Xiao Jing Liu ◽  
Xin Sun ◽  
Jing Hua Guo
Keyword(s):  
Optical Materials ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Chemical Reactivity ◽  
Nbo Analysis ◽  
Basis Sets ◽  
Nucleophilic Attack ◽  
Charge Delocalization ◽  
Different Temperatures

In this work, density functional theory (DFT) calculations with B3LYP/6-311++G(d,p) basis sets was used to explore the electronic, structural, nonlinear optical and thermal properties aspects of glycine-phthalic acid (GPA) optical materials. Dipole moment, static polarizability and first hyperpolarizability analysis of the molecule have been performed. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. MEP study confirms GPA as an electron rich species and explains its electrophilic nature. MEP shows that this molecule has several possible sites for electrophilic/nucleophilic attack in which V(r) calculations provide insights into the order of preference. The low value of HOMO-LUMO energy gap reflects the high chemical reactivity, low chemical stability and hardness of GPA molecule. Thermodynamic properties of the title compound have been calculated at different temperatures and the results reveal that the standard heat capacities (Cp), standard entropies (S) and standard enthalpy (H) increase with rise in temperature. These results discussed in this study will upsurge the knowledge to design and synthesize new type nonlinear optical materials with exceptional chemical and physical properties.

Static- and frequency-dependent NLO properties of dithienothiophene and thienothiophene bridges — A computational investigation

2020 ◽  
Vol 19 (05) ◽  
pp. 2050018
Author(s):  
Sagar B. Yadav ◽  
Nagaiyan Sekar
Keyword(s):  
Density Functional ◽  
Nonlinear Optical ◽  
Chemical Reactivity ◽  
Second Order ◽  
Basis Sets ◽  
Frequency Dependent ◽  
Nlo Properties ◽  
Reactivity Descriptors ◽  
Hartree Fock ◽  
Perturbation Potential

We have explored detailed linear and nonlinear optical properties of push-pull systems bearing thienothiophene and dithienothiophene spacers. By using density functional theory (DFT), frequency-dependent strategies were applied to examine the polarizability ([Formula: see text] and hyperpolarizability ([Formula: see text] and [Formula: see text]. The set of global and range-separated hybrid functionals with different Hartree–Fock (HF) exchange percentage at two basis sets cc-pVDZ and cc-pVTZ were used to evaluate the nonlinear optical (NLO) properties. The observed trends in the absorption maxima supported by perturbation potential analysis; as the absorption maxima increases, the respective amplitude potential decreases. For the investigated compounds, [Formula: see text]-conjugation along with the type of substituted acceptor plays a crucial role in the enhancement of NLO properties. The presence of acceptor group and length of conjugation increase between the D and A group; the first- and second-order intrinsic hyperpolarizability increases, leads to enhanced first- as well as second-order hyperpolarizability. Bond length alternation (BLA)/bond order alteration (BOA) exploration suggested that compounds attain cyanine limit. The trends in NLO properties for investigated compounds are supported by chemical reactivity descriptors, hardness and hyperhardness analysis. The polarizability is linearly correlated with the hyperpolarizability parameters ([Formula: see text] and [Formula: see text] and shows a good regression coefficient by figures of merit analysis.

scholarly journals Computational studies of the thermodynamic properties, and global and reactivity descriptors of fluorescein dye derivatives in acetonitrile using density functional theory

2021 ◽  
pp. 174751982199451
Author(s):  
Juma Mzume Juma ◽  
Said AH Vuai
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Properties ◽  
Ionization Potential ◽  
Molecular Orbital ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Sets ◽  
Hybrid Functional ◽  
Functional Theory ◽  
Reactivity Descriptors

This work reports density functional theory calculations of the optimized geometries, molecular reactivity, energy gap, and thermodynamic properties of molecular dyes fluorescein (FS), fluorescein attached with methoxy (FSO), fluorescein attached with amine (FSA), fluorescein attached with methane (FSM), fluorescein attached with ethene (FSE), and fluorescein attached with thiophene (FST) using the hybrid functional B3LYP and 6-311G basis sets. When donating groups are attached to the molecular dye, the bond lengths are slightly decreased which is important for easy transfer of electron from donating to the accepting group. For all dyes, highest occupied molecular orbital/lowest occupied molecular orbital analysis results in positive outcomes upon electron injection to semiconductors and subsequent dye regeneration by the electrolyte. The ionization potential increases with increasing conjugation; therefore, the molecular dye attached to thiophene has the highest ionization potential. Meanwhile, a donating group with increased conjugation results in low electron affinity.

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