Quantum chemical calculations of a novel Specie – Boron Nano Bucket (B16) and the interaction of its complex (B15-Li) with drug Resorcinol

2020 ◽  
Vol 20 (3) ◽  
pp. 1017-1028
Author(s):  
Anoop Kumar Pandey ◽  
Vijay Singh ◽  
Apoorva Dwivedi
Keyword(s):  
Density Functional ◽  
Drug Carrier ◽  
Chemical Properties ◽  
Ionic Species ◽  
Basis Set ◽  
Cell Manipulation ◽  
Chemical Hardness ◽  
Equilibrium Geometry ◽  
Aim Analysis ◽  
The Stability

At Nano-scale level, innovative biomedical techniques are developed in advanced drug delivery systems and targeted Nano-therapy. Ultrathin needles provide a low invasive and highly selective means for molecular delivery and cell manipulation. This article studies the geometry and the stability of Boron Nano-Bucket (B16 Cluster of Bucket Shape) and B15-Li complex by using computational modeling methods. The equilibrium geometry of Boron Nano-Bucket and BNB-Li complex in the ground state have been determined and analyzed by Density functional theory (DFT) employing 6-311 G (d, p) as the basis set. The frontier orbital HOMO-LUMO gap, Chemical Softness, Chemical Hardness have also been calculated to understand its complete Chemical Properties. In this study, we have also performed BNB-Li complex interaction with drug Resorcinol. The binding character interactive species have been determined by NBO and AIM analysis. From these studies, we can say that BNB and BNB-Li complex may also potentially able to stabilize ions around their structure like Carbon Nano Niddle (CNN) in future. The polar characteristics of CNN and their ability to carry ionic species, Li doped Boron Nano-Bucket might be suitable to act as drug carrier through nonpolar biologic media.

scholarly journals Synthesis and DFT study of novel pyrazole, thiophene, 1,3-thiazole and 1,3,4-thiadiazole derivatives

2018 ◽  
Vol 9 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Asmaa Mahmoud Fahim ◽  
Ahmad Mahmoud Farag ◽  
Mohamed Rabie Shaaban ◽  
Eman Ali Ragab
Keyword(s):  
Potassium Salt ◽  
Density Functional ◽  
Basis Set ◽  
Equilibrium Geometry ◽  
Thiophene Derivative ◽  
Pyrazole Derivative ◽  
Facile Synthesis ◽  
Functional Theory ◽  
The Stability ◽  
Homo Lumo

Regioselective facile synthesis of innovative heterocycles from the reaction of 2-cyano-N-cyclohexylacetamide (3) with hydrazonoyl chloride (4) in basic condition afforded amino pyrazole derivative 6. The behavior of acetamide 3 with phenylisothiocyanate in DMF/KOH surveyed by addition of the α-halo ketones to yeild the corresponding thiophene derivative 13a, 13b, 16, 18 and 1,3-thiazoles 21. Reaction of intermediate potassium salt 9 with hydrazonoyl chloride 22a-e furnished the corresponding 1,2,4-thiadiazoles 24a-e. Density functional theory (DFT) calculations at the B3LYP and HF techniques combined with 6-31G(d) basis set to investigate the equilibrium geometry of the innovative compound pyrazoles 6 and the stability affording of HOMO/LUMO molecular orbitals.

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.

Theoretical investigation of the stability, reactivity, and the interaction of methyl-substituted peridinium-based ionic liquids

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Emmanuel A. Bisong ◽  
Hitler Louis ◽  
Tomsmith O. Unimuke ◽  
Victoria M. Bassey ◽  
John A. Agwupuye ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Electron Density ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Stabilization Energy ◽  
Basis Set ◽  
Bond Critical Point ◽  
Electronic Interaction ◽  
Donor And Acceptor ◽  
The Stability

Abstract This research work focuses on the reactivity, stability, and electronic interaction of pyridinium hydrogen nitrate (PHN)-based ionic liquids and the influence of methyl substituent on this class of ionic liquids: Ortho- (O-MPHN), meta- (M-MPHN), and para- (P-MPHN) substitution. Natural bond orbital (NBO) calculations were performed at the density functional theory (DFT) with Becke’s Lee Yang and Parr functional (B3LYP) methods and DFT/B3LYP/6-311++G(d,p) as basis set using GAUSSIAN 09W and GAUSSVIEW 6.0 software and the most important interaction between donor (Filled Lewis-type NBO’s) and the acceptor (vacant non-Lewis NBOs) were observed. From our natural bond orbital (NBO) result, it could be deduced that the higher the stabilization energy value, the greater the interaction between the donor and acceptor NBOs. The stability of the studied compounds is said to follow the order from O-MPHN > PHN > P-MPHN > M-MPHN based on the hyperconjugative interaction (stabilization energy) of the most significant interaction. The result of the highest occupied molecular orbital (HOMO), shows that PHN has the highest HOMO while the substituted derivatives have similar HOMO values between −7.70 and −7.98 eV thus PHN complex is the best electron donor while the substituted derivatives act as electron acceptors due to the presence of methyl group substituent which is observed to be electron deficient as a result of its withdrawal effect from the aromatic ring. Furthermore, the electron density, real space functions such as energy density and Laplacian of electron density at bond critical point (BCP) of the hydrogen bond interaction of the studied compounds were analyzed using Multifunctional Wavefunction analyzer software version 3.7 and it was observed that the hydrogen at position 6 and oxygen at position 11 (H6–O11) of M-methyl pyridinium nitrate with bond distance of 4.59 (Å) gave binding energy with the strongest electrostatic interaction between the cation and anion of the compounds under investigation. We also observed from our results that, substitution at the ortho position enhances the stability and strengthen the extent of charge transfer. This therefore implies that substitution at ortho position is more favorable for inter- and intramolecular interactions resulting to stabilization of the studied molecules.

scholarly journals The Spectroscopic and Conductive Properties of Ru(II) Complexes with Potential Anticancer Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Adebayo A. Adeniyi ◽  
Peter A. Ajibade
Keyword(s):  
Density Functional ◽  
Spectroscopic Properties ◽  
Spin Coupling ◽  
Basis Set ◽  
Polarizability Tensor ◽  
Chemical Hardness ◽  
Anticancer Properties ◽  
Shielding Tensor ◽  
Spin Spin Coupling ◽  
Conductive Properties

Different density functional methods (DFT) have been used to optimize and study the chemistry of five potential anticancer complexes in terms of their electronic, conductive, and spectroscopic properties. Many of the computed properties in addition to the IR and QTAIM analysis of the NMR are dipole moment vector (μi), linear polarizability tensor (αij), first hyperpolarizability tensors (βijk), polarizability exaltation index (Γ), and chemical hardness (η) of the complexes. Stable low energy geometries are obtained using basis set with effective core potential (ECP) approximation but, in the computation of atomic or molecular properties, the metal Ru atom is better treated with higher all electron basis set like DGDZVP. The spectroscopic features like the IR of the metal-ligand bonds and the isotropic NMR shielding tensor of the coordinated atoms are significantly influenced by the chemical environment of the participating atoms. The carboxylic and pyrazole units are found to significantly enhance the polarizabilities and hyperpolarizabilities of the complexes while the chloride only improves the polarity of the complexes. Fermi contacts (FC) have the highest effect followed by the PSO among all the four Ramsey terms which defined the total spin-spin coupling constant J (HZ) of these complexes.

scholarly journals Density functional theory study on the molecular structure of loganin

2011 ◽  
Vol 25 (6) ◽  
pp. 287-302 ◽  
Author(s):  
Anoop Kumar Pandey ◽  
Shamoon Ahmad Siddiqui ◽  
Apoorva Dwivedi ◽  
Kanwal Raj ◽  
Neeraj Misra
Keyword(s):  
Molecular Structure ◽  
Density Functional ◽  
Solid Phase ◽  
Density Functional Method ◽  
Functional Method ◽  
Basis Set ◽  
Equilibrium Geometry ◽  
B3lyp Method ◽  
Ft Ir ◽  
Detailed Interpretation

The computational Quantum Chemistry (QC) has been used for different types of problems, for example: structural biology, surface phenomena and liquid phase. In this paper we have employed the density functional method for the study of molecular structure of loganin. The equilibrium geometry, harmonic vibrational frequencies and infrared intensities were calculated by B3LYP/6-311G (d, p) method and basis set combinations. It was found that the optimized parameters obtained by the DFT/B3LYP method are very near to the experimental ones. A detailed conformational analysis was carried out. A detailed interpretation of the infrared spectra of loganin is also reported in the present work. The FT-IR spectra of loganin were recorded in solid phase. The thermodynamic calculations related to the title compound were also performed at B3LYP/6-311G (d, p) level of theory.

scholarly journals The difference in stability between 5′R and 5′S diastereomers of 5′,8-cyclopurine-2′-deoxynucleosides. DFT study in gaseous and aqueous phase

2010 ◽  
Vol 8 (1) ◽  
pp. 134-141 ◽  
Author(s):  
Boleslaw Karwowski
Keyword(s):  
Density Functional ◽  
Bond Cleavage ◽  
Basis Set ◽  
Small Range ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Formic Acid Hydrolysis ◽  
The Difference ◽  
The Stability ◽  
First Time

AbstractOxidatively generated damage to DNA frequently appears in the human genome as an effect of aerobic metabolism or as the result of exposure to exogenous oxidizing agents. Due to these facts it has been decided to calculate the stability of 5′,8-cyclo-2′-deoxyadenosine/guanosine (cdA, cdG) in their 5′R and 5′S diastereomeric forms. For all points of quantum mechanics studies presented, the density functional theory (DFT) with B3LYP parameters on 6-311++G** basis set level was used. The calculations showed a significant negative enthalpy for glycosidic bond cleavage reaction for cationic forms and slightly negative for neutral ones. The preliminary study of the discussed process has shown the nature of stepwise nucleophilic substitution DN*AD type mechanism. Surprisingly, the different values in free energy, between short-lived oxacarbenium ion intermediates, have been found to lie over a relatively small range, around 1 and 2.8 kcal mol−1. For anions, the decomposition enthalpies were found as positive in aqueous phases. These theoretical results are supported by the formic acid hydrolysis experiments of both diastereomers of cdA, for the first time. (5′S)cdA exhibited higher stability than (5′R)cdA.

scholarly journals Study on the chemical potential of apigenin, luteolin, quercetin, and myricetin using the molecular modeling

2021 ◽  
Vol 44 (1) ◽  
pp. 63-66
Author(s):  
Steluta Gosav ◽  
Adriana Hodorogea ◽  
Dan Maftei
Keyword(s):  
Gas Phase ◽  
Chemical Potential ◽  
Chemical Compounds ◽  
Molecular Structures ◽  
Basis Set ◽  
Chemical Hardness ◽  
Equilibrium Geometry ◽  
Hybrid Functional ◽  
Electrophilicity Index ◽  
Quantum Molecular Descriptors

In the present paper, the chemical potential of four flavonoids i.e. apigenin, luteolin, quercetin, and myricetin, of interest in the pharmaceutical industry was investigated using molecular modelling. The equilibrium geometry of molecular structures was calculated in the gas phase and ground state by using B3LYP hybrid functional in conjunction with a 6-311G(d,p) basis set. In order to assess the chemical potential of investigated flavonoids, the main quantum molecular descriptors, such as the dipole moment, the energy of the highest/lowest occupied/unoccupied molecular orbital, the gap energy, the electronegativity, the chemical hardness/softness, and the electrophilicity index have been computed. Also, the influence of the hydroxylation degree of chemical compounds on the chemical potential is discussed.

scholarly journals How Accurate Are Static Polarizability Predictions from Density Functional Theory? An Assessment over 132 Species at Equilibrium Geometry

2018 ◽  
Author(s):  
Diptarka Hait ◽  
Martin Head-Gordon
Keyword(s):  
Electric Fields ◽  
Density Functional ◽  
Basis Set ◽  
Equilibrium Geometry ◽  
Density Functionals ◽  
Functional Theory ◽  
First Response ◽  
Complete Basis Set ◽  
Complete Basis Set Limit ◽  
Hybrid Functionals

Static polarizabilities are the first response of the electron density to electric fields, and are therefore important for predicting intermolecular and molecule-field interactions. They also offer a global measure of the accuracy of the treatment of excited states by density functionals in a formally exact manner. We have developed a database of benchmark static polarizabilities for 132 small species at equilibrium geometry, using coupled cluster theory through triple excitations (extrapolated to the complete basis set limit), for the purpose of developing and assessing density functionals. The performance of 60 popular and recent functionals are also assessed, which indicates that double hybrid functionals perform the best, having RMS errors in the range of 2.5-3.8% . Many hybrid functionals also give quite reasonable estimates with 4-5% RMSE. A few meta-GGAs like mBEEF and MVS yield performance comparable to hybrids, indicating potential for improved excited state predictions relative to typical local functionals. Some recent functionals however are found to be prone to catastrophic failure (possibly as a consequence of overparameterization), indicating a need for caution in applying these.

scholarly journals Comparing Study of The Stability and spectral properties vibrations for some Tellurium (IV) compounds containing cycloctadienyl group by Quantum Mechanical Calculations

2013 ◽  
Vol 10 (3) ◽  
pp. 1041-1049
Author(s):  
Baghdad Science Journal
Keyword(s):  
Density Functional ◽  
Heat Of Formation ◽  
Basis Set ◽  
Orbital Energy ◽  
Empirical Methods ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Exchange Correlation ◽  
The Stability ◽  
Semi Empirical

Density Functional Theory (DFT) with B3LYP hybrid exchange-correlation functional and 3-21G basis set and semi-empirical methods (PM3) were used to calculate the energies (total energy, binding energy (Eb), molecular orbital energy (EHOMO-ELUMO), heat of formation (?Hf)) and vibrational spectra for some Tellurium (IV) compounds containing cycloctadienyl group which can use as ligands with some transition metals or essential metals of periodic table at optimized geometrical structures.

scholarly journals Therortical Studies and Investagting of Selected Potnet CDK2 Inhibitors as Anticancer Agents

2021 ◽  
Author(s):  
Mohammad J Abunuwar ◽  
Adnan A Dahadha
Keyword(s):  
Anticancer Agents ◽  
Density Functional ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Three Dimensional ◽  
Data Bank ◽  
Basis Set ◽  
Chemical Hardness ◽  
Cyclin Dependent Kinase ◽  
Reactivity Descriptors

Abstract In this study eight selected of the most potent cyclin dependent kinase 2 inhibitors in which targeting adenosine triphosphate -pocket site theoretically investigated to support literature information of frontier molecular orbitals, molecular electrostatic maps, and global chemical reactivity descriptors such as chemical hardness, chemical softness, chemical potential, electronegativity and electrophilicity of cyclin dependent kinase 2 inhibitors. Calculation and three-dimensional plotting were achieved through Gaussian 09W and Gausview 6 software’s utilizing density functional theory quantum modeling applying both hybrids extended and not extended basis set. Crystal structure of CDK2 with inhibitors was obtained from protein data bank and visualized through PyMol Schrödinger software to assign polar and non-polar interactions of inhibitors with enzyme. A promising conclusion trend obtained in this research regarding to molecules that could have an inhibition activity toward the cyclin dependent kinase 2 enzymes. Our theoretical investigation emphasizes that, the anti-cancer activity has directly relationship with value of chemical hardness and chemical softness, where the most potent compounds was the pyrazolopyrimidine and imidazole pyrimidine and they have higher chemical hardness value and at the same time lower value of chemical softness compared with the rest of compounds.

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