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Journal articles on the topic 'Natural bond Orbitals (NBO)'

Author: Grafiati

Published: 3 June 2025

Last updated: 31 July 2025

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1

Li, Xiao-Hong, Rui-Zhou Zhang, and Xian-Zhou Zhang. "Theoretical investigation of some N-nitrosodiphenylamine biological molecules — A natural bond orbital (NBO) study." Canadian Journal of Chemistry 89, no. 10 (2011): 1230–35. http://dx.doi.org/10.1139/v11-084.

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Theoretical study of several N-nitrosodiphenylamine biological molecules has been performed using quantum computational ab initio RHF and density functional B3LYP and B3PW91 methods with 6–311G++(d,p) basis set. Geometries obtained from density functional theory (DFT) calculations were used to perform Natural bond orbital (NBO) analysis. The p characters of two nitrogen natural hybrid orbitals (NHOs) σN3−N2 increase with increasing σp values of the substituents on the benzene, which results in a lengthening of the N3–N2 bond. The p characters of oxygen NHO σO1−N2 and nitrogen NHO σO1−N2 bond o

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2

Monajjemi, Majid, Halleh H. Haeri, and Malihe T. Azad. "Theoritical ab initio study of Internal Rotation Barriers, Structures Stabilities and Population of Formamide." Journal of Chemical Research 2002, no. 8 (2002): 403–6. http://dx.doi.org/10.3184/030823402103172473.

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The internal rotational barriers for formamide are calculated in gas and solution phases (acetonitrile) at the HF/6-31G* (16.64 and 16.18 kcal/mol, respectively) and MP2/6-31G* (16.86 and 16.71 kcal/ mol, respectively) level of theory. Calculated parameters are compared with experimental data and there is a good agreement between them. Orbital populations are obtained by MPA (mulliken population analysis) and NPA (natural population analysis) methods and bond energies are calculated by the NBO method (natural bond orbitals). The distribution of atomic charges are also given. These calculation

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3

Joshi, Bhawani Datt, Poonam Tandon, and Sudha Jain. "Differential Scanning Calorimetry, NBO and Hyperpolarizability Analysis of Yohimbine Hydrochloride." Himalayan Physics 3 (December 26, 2012): 44–49. http://dx.doi.org/10.3126/hj.v3i0.7276.

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Yohimbine (C21H27N2O3) is one of the most important indole alkaloid. Differential scanning calorimetry, natural bond orbital (NBO) analysis and dipole moment with hyperpolarizability have been performed for molecular characterization. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using NBO analysis. The results show that charge in electron density (ED) in the ?* and ?* anti bonding orbitals and E(2) energies confirms the occurrence of intra molecular charge transfer (ICT) within the molecule.The Himalayan PhysicsVol. 3, No. 32012

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4

Kazeminejad, Zahra, Abolfazl Shiroudi, Khalil Pourshamsian, Farhad Hatamjafari, and Ahmad Oliaey. "Understanding the isomerization kinetics in the gas phase of a triazole-3-thione derivative: A theoretical approach." Journal of the Serbian Chemical Society 84, no. 9 (2019): 975–89. http://dx.doi.org/10.2298/jsc181208013k.

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The isomerization reactions of the 4-amino-5-methyl-2,4-dihydro- -3H-1,2,4-triazole-3-thione were studied using the B3LYP and M06-2x, as well as the CBS-QB3 theoretical methods. The measured energy profiles were complemented with kinetic rate constants using the transition state theory (TST). Based on the isomers geometries optimized using the CBS-QB3 method, a natural bond orbital (NBO) analysis shows that the stabilization energies of non-bonding lone-pair orbitals [LP(e)S7] to the ?*N2?C3 antibonding orbital increase from isomers 1 to 2. Moreover, the LP(e)S7 ? ?*N2?C3 delocalizations could

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5

Safonova, Liubov P., Michail G. Kiselev, and Irina V. Fedorova. "Complexes of sulfuric acid with N,N-dimethylformamide: An ab initio investigation." Pure and Applied Chemistry 85, no. 1 (2012): 225–36. http://dx.doi.org/10.1351/pac-con-12-01-04.

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The (H2SO4)2, H2SO4-DMF, and (H2SO4)2-DMF complexes have been investigated, using the B3LYP functional with cc-pVQZ basis set. The characteristics of structure and energetics for binary complexes of sulfuric acid with dimethylformamide (DMF) have been obtained for the first time. The H-bond formation both between molecules of sulfuric acid as well as sulfuric acid-DMF were studied, on the basis of Weinhold’s natural bond orbital (NBO) analysis. It was shown that the H-bond formation between sulfuric acid and DMF molecules is stronger than ones for the acids dimer. The value of charge transfer

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6

Gourlaouen, Christophe, and Jean-Philip Piquemal. "On the Quantum Chemical Nature of Lead(II) “Lone Pair”." Molecules 27, no. 1 (2021): 27. http://dx.doi.org/10.3390/molecules27010027.

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We study the quantum chemical nature of the Lead(II) valence basins, sometimes called the lead “lone pair”. Using various chemical interpretation tools, such as molecular orbital analysis, natural bond orbitals (NBO), natural population analysis (NPA) and electron localization function (ELF) topological analysis, we study a variety of Lead(II) complexes. A careful analysis of the results shows that the optimal structures of the lead complexes are only governed by the 6s and 6p subshells, whereas no involvement of the 5d orbitals is found. Similarly, we do not find any significant contribution

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7

Aracena, Andrés, and Moisés Domínguez. "Computational Quantification of the Zwitterionic/Quinoid Ratio of Phenolate Dyes for Their Solvatochromic Prediction." Molecules 27, no. 24 (2022): 9023. http://dx.doi.org/10.3390/molecules27249023.

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Solvatochromic dyes are utilized in various chemical and biological media as chemical sensors. Unfortunately, there is no simple way to predict the type of solvatochromism based on the structure of the dye alone, which restricts their design and synthesis. The most important family of solvatochromic sensors, pyridinium phenolate dyes, has the strongest solvatochromism. Using a natural population analysis (NPA) of the natural bond orbitals (NBO) of the phenolate group in the frontier molecular orbitals, it is possible to calculate the relative polarity of the ground state and excited state and,

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8

Matin, Mohammad A., Mohammad Alauddin, Tapas Debnath, M. Saiful Islam, and Mohammed A. Aziz. "DFT and TD-DFT Study of [Tris(dithiolato)M]3- Complexes[M= Cr, Mn and Fe]: Electronic Structures, Properties and Analyses." Dhaka University Journal of Science 67, no. 1 (2019): 63–68. http://dx.doi.org/10.3329/dujs.v67i1.54576.

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Using Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) methods, transition metal complexes of benzene-1, 2-dithiolate (L2-) ligand from Cr to Fe have been studied theoretically. The ground state geometries, binding energies, UV-Visible spectra (UV-Vis), frontier molecular orbitals (FMOs) analysis, charge analysis and natural bond orbital (NBO) have been calculated. The structural parameters are in good accord with the experimental data. The metal-ligand binding energies are one (1) order of magnitude higher than the physisorption energy of a benzene-1, 2-dt

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9

Danaie, Elmira, Shiva Masoudi, and Nasrin Masnabadi. "A Computational Study of the Conformational Behavior of 2,5-Dimethyl- 1,4-dithiane-2,5-diol and Analogous S and Se: DFT and NBO Study." Letters in Organic Chemistry 17, no. 10 (2020): 749–59. http://dx.doi.org/10.2174/1570178617666200129144750.

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Conformational behaviors of 2,5-dimethyl-1,4-dithiane-2,5-diol (compound 1), 2,5- dimethyl-1,4-dithiane-2,5-dithiol (compound 2) and 2,5-dimethyl-1,4-dithiane-2,5-diselenol (compound 3) were investigated by the B3LYP/6-311+G **, the M06-2X/aug-ccpvdz levels of theory and natural bond orbital NBO analysis. The structures and the structural parameters of the mentioned molecules were optimized by the B3LYP and the M06-2X methods. We assessed the roles and contributions of the effective factors in the conformational properties of the mentioned compounds by means of the B3LYP and M06-2X levels of t

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10

Tetteh, Samuel. "Coordination Behavior of Ni2+, Cu2+, and Zn2+ in Tetrahedral 1-Methylimidazole Complexes: A DFT/CSD Study." Bioinorganic Chemistry and Applications 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/3157969.

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The interaction between nickel (Ni2+), copper (Cu2+), and zinc (Zn2+) ions and 1-methylimidazole has been studied by exploring the geometries of eleven crystal structures in the Cambridge Structural Database (CSD). The coordination behavior of the respective ions was further investigated by means of density functional theory (DFT) methods. The gas-phase complexes were fully optimized using B3LYP/GENECP functionals with 6-31G∗ and LANL2DZ basis sets. The Ni2+ and Cu2+ complexes show distorted tetrahedral geometries around the central ions, with Zn2+ being a perfect tetrahedron. Natural bond orb

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11

Chandra, Asit K., and Thérèse Zeegers-Huyskens. "Theoretical Investigation of the Cooperativity in CH3CHO·2H2O, CH2FCHO·2H2O, and CH3CFO·2H2O Systems." Journal of Atomic, Molecular, and Optical Physics 2012 (July 29, 2012): 1–8. http://dx.doi.org/10.1155/2012/754879.

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The hydrogen bond interaction between CH3CHO, CH2FCHO, and CH3CFO and two water molecules is investigated at the B3LYP/6-311++G(d,p) level. The results are compared with the complexes involving the same carbonyl derivatives and one water molecule. The calculations involve the optimization of the structure, the harmonic vibrational frequencies, and relevant NBO (natural bond orbital) parameters such as the NBO charges, the occupation of antibonding orbitals, and intra- and intermolecular hyperconjugation energies. Two stable cyclic structures are predicted. The two structures are stabilized by

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12

Singh, Naorem Shubhaschandra, and Sagolsem Manimukta Devi. "Computational Exploration of 1-Amidino-O-(n-butyl) Urea (ABnUH) with Natural Atomic Orbitals, Natural Bond Orbital, Vibrational Analysis and Simulated UV-Visible Spectra." Asian Journal of Chemistry 33, no. 12 (2021): 3089–98. http://dx.doi.org/10.14233/ajchem.2021.23438.

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Theoretical treatment of 1-amidino-O-(n-butyl)urea (ABnUH) have been performed by DFT/B3LYP with 6-311++ G (d,p) basis set using Gaussian 09W. The compound has been analyzed on the basis of electronic structure, hybridization of the atoms, charge delocalization, hyper-conjugative interactions, vibrational modes, etc. NBO analysis was performed to figure out any charge transfer among the localized bond and lone pair of the proposed compound.

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13

PARVEEN, SALMA, SUBOJIT DAS, ASIT K. CHANDRA, and THERESE ZEEGERS-HUYSKENS. "THEORETICAL STUDIES OF HYDROGEN BONDING INTERACTION BETWEEN TRIMETHYLAMINE AND SUBSTITUTED PHENOLS, INFLUENCE OF THE SUBSTITUENTS ON THE HYDROGEN BOND PROPERTIES AND THE VIBRATIONAL SPECTRUM." Journal of Theoretical and Computational Chemistry 07, no. 06 (2008): 1171–86. http://dx.doi.org/10.1142/s0219633608004507.

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Hydrogen bonding interactions between trimethylamine (TMA) and a series of para substituted phenols (X– C 6 H 4 OH , X = H , CH 3, NH 2, Cl , CN , and NO 2) are studied by using density functional theory with the hybrid B3LYP functional and the 6-31++G(d,p) basis set. Both electron donor and acceptor substituents (X) are chosen to study systematically the relation between the proton donor ability of the phenols and the strength of the OH … N hydrogen bond. The effect of hydrogen bonding on spectral and structural parameters and their inter relation are discussed. The natural bond orbital (NBO)

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14

Abbaz, Tahar, Amel Bendjeddou, and Didier Villemin. "Molecular structure, HOMO, LUMO, MEP, natural bond orbital analysis of benzo and anthraquinodimethane derivatives." Pharmaceutical and Biological Evaluations 5, no. 2 (2018): 27. http://dx.doi.org/10.26510/2394-0859.pbe.2018.04.

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Objective: Optimized molecular structures have been investigated by DFT/B3LYP method with 6-31G (d,p) basis set. Stability of Benzo and anthraquinodimethane derivatives 1-4, hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed by using natural bond orbital (NBO) analysis. Electronic structures were discussed and the relocation of the electron density was determined. Molecular electrostatic potential (MEP), local density functional descriptors has been studied. Nonlinear optical (NLO) properties were also investigated. In addition, frontier mol

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15

Glendening, Eric D., Clark R. Landis, and Frank Weinhold. "NBO 6.0: Natural bond orbital analysis program." Journal of Computational Chemistry 34, no. 16 (2013): 1429–37. http://dx.doi.org/10.1002/jcc.23266.

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16

David, Emem, Chinyere Ayi Anyama, Ayi A. Ayi, Hitler Louis, and Charles O. Oseghale. "Intercalation of metal–aluminum layered double hydroxides with anionic surfactants: Experimental and density functional theory studies." AIP Advances 12, no. 4 (2022): 045217. http://dx.doi.org/10.1063/5.0081639.

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Metal–aluminum layered double hydroxides (LDHs) intercalated with bis(2-ethylhexyl)sulfosuccinate (EHS) and dodecyl sulfate (SDS) anions, formulated as EHS-MgAl-LDH 1, SDS-MgAl-LDH 2, EHS-CaAl-LDH 3, and SDS-CaAl-LDH 4, were synthesized using the co-precipitation method. The compounds were characterized using Fourier transform infrared spectroscopy, x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and thermogravimetric analysis. The textural properties were studied using the Brunauer–Emmett–Teller method. The density functional theory method was used to perfor

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17

Tetteh, Samuel, and Ruphino Zugle. "Theoretical Study of Terminal Vanadium(V) Chalcogenido Complexes Bearing Chlorido and Methoxido Ligands." Journal of Chemistry 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/6796321.

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Solvent (methanol) coordinated vanadium(V) chalcogenido complexes bearing chlorido and methoxido ligands have been studied computationally by means of density functional (DFT) methods. The gas phase complexes were fully optimized using B3LYP/GEN functionals with 6-31+G⁎⁎ and LANL2DZ basis sets. The optimized complexes show distorted octahedral geometries around the central vanadium atom. The ligand pπ-vanadium dπ interactions were analyzed by natural bond order (NBO) and natural population analyses (NPA). These results show strong stabilization of the V=O bond as was further confirmed by the a

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18

Kavousi, Hossein, Abdolreza Rezaeifard, Heidar Raissi, and Maasoumeh Jafarpour. "A DFT investigation of axial N-donor ligands effects on the high valent manganese-oxo meso-tetraphenyl porphyrin." Journal of Porphyrins and Phthalocyanines 19, no. 05 (2015): 651–62. http://dx.doi.org/10.1142/s1088424615500029.

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The effect of different electronic and structural nitrogen donors (L) on the N ( ax )- Mn - O properties in the high valent manganese-oxo meso-tetraphenylporphyrin intermediate is investigated by the density functional B3LYP method with 6-31g* basis set. The geometric structures, frontier molecular orbitals, thermodynamic parameters and physical properties such as chemical potential and chemical hardness of [( TPP )( L ) MnO ]+ complexes in the gas phase as well as water solution are calculated. Our theoretical results confirm that the Mn - O distances in [( TPP )( L ) MnO ]+ species decrease

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19

Subramaniyan, Vasudevan, Ashok Kumar, Anbarasu Govindaraj, and Ganesan Mani. "Crystal structure and DFT analyses of a pentacoordinated PCP pincer nickel(II) complex." Acta Crystallographica Section C Structural Chemistry 75, no. 6 (2019): 734–39. http://dx.doi.org/10.1107/s2053229619006211.

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The reaction of NiCl2 with 1,3-bis[(diphenylphosphanyl)methyl]hexahydropyrimidine in the presence of 2,6-dimethylphenyl isocyanide and KPF6 afforded a new pentacoordinated PCP pincer NiII complex, namely {1,3-bis[(diphenylphosphanyl)methyl]hexahydropyrimidin-2-yl-κN 2}(2,6-dimethylphenyl isocyanide-κC)nickel(II) hexafluoridophosphate 0.70-hydrate, [Ni(C9H9N)(C30H30ClN2P2)]PF6·0.7H2O or [NiCl{C(NCH2PPh2)2(CH2)3-κ3 P,C,P′}(Xylyl-NC)]PF6·0.7H2O, in very good yield. Its X-ray structure showed a distorted square-pyramidal geometry and the compound does not undergo dissociation in solution, as shown

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20

Momeni, Mohammad R., Lisa Shulman, Eric Rivard, and Alex Brown. "Interplay of donor–acceptor interactions in stabilizing boron nitride compounds: insights from theory." Physical Chemistry Chemical Physics 17, no. 25 (2015): 16525–35. http://dx.doi.org/10.1039/c5cp01993a.

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The chemical bonds in donor–acceptor stabilized linear and cyclic (BN)<sub>n</sub> (n = 1–3) adducts are examined using natural bond orbital (NBO), atoms-in-molecules (AIM), and energy decomposition (EDA-NOCV) analyses.

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21

Glendening, Eric D., Clark R. Landis, and Frank Weinhold. "Erratum: NBO 6.0: Natural bond orbital analysis program." Journal of Computational Chemistry 34, no. 24 (2013): 2134. http://dx.doi.org/10.1002/jcc.23366.

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22

Kalaiarasi, N., and S. Manivarman. "Structural, vibrational (FTIR and FT-Raman), NMR, UV–vis spectral analysis, and DFT study of 2-(6-oxo-2-thioxotetrahydropyrimidin-4(1H)-ylidene) hydrazine carboxamide." Canadian Journal of Chemistry 95, no. 5 (2017): 580–89. http://dx.doi.org/10.1139/cjc-2016-0655.

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Vibrational and spectral characterizations of 2-(6-oxo-2-thioxo tetrahydro pyrimidin-4(1h)-ylidene) hydrazine carboxamide (OTHHPYHC) were experimentally presented for the ground state using FTIR and FT-Raman and theoretically presented by density functional theory (DFT) using B3LYP correlation function with the basis set 6-31G(d,p). The geometrical parameters, energies, and wavenumbers have been obtained. The fundamental assignments were performed on the basis of total energy distribution. The first order hyperpolarizability (β0) and relative properties (β, α0, and Δα) were calculated using B3

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23

Zeng, Wulan, Xia Wang, Tao Zhou, and Yunju Zhang. "Crystal Structure, Photophysical Study, Hirshfeld Surface Analysis, and Nonlinear Optical Properties of a New Hydroxyphenylamino Meldrum’s Acid Derivative." Molecules 28, no. 5 (2023): 2181. http://dx.doi.org/10.3390/molecules28052181.

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The structural, photophysical, and vibrational properties of a new hydroxyphenylamino Meldrum’s acid derivative, 3-((2-hydroxyphenylamino)methylene)-1,5-dioxaspiro[5.5]undecane-2,4-dione (HMD), were studied. The comparison of experimental and theoretical vibrational spectra can help understand basic vibration patterns and provides a better interpretation of IR spectra. The UV–Vis spectrum of HMD was computed using density functional theory (DFT)/B3LYP/6-311 G(d,p) basis set in the gas state, and the maximum wavelength was in accord with the experimental data. The molecular electrostatic potent

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24

Bihain, Murielly Fernanda Ribeiro, Raissa Santos Sousa, Sílvio Quintino de Aguiar Filho, and Douglas Henrique Pereira. "Cálculos teóricos para elucidação eletrônica de barreiras rotacionais: teoria e aplicações." Journal of Biotechnology and Biodiversity 8, no. 2 (2020): 136–47. http://dx.doi.org/10.20873/jbb.uft.cemaf.v8n2.bihain.

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Cálculos teóricos de estrutura eletrônica são ferramentas da química teórica. Sua importância se estende desde a análises de rotação, hiperconjugação, efeitos estéricos a cálculos de localização de orbitais, nível de energia e interação entre orbitais ligantes e antiligantes. As teorias como Natural Bond Orbital (NBO), Quantum Theory of Atoms in Molecules (QTAIM), e Energetic Decomposition Analysis (EDA), são exemplos de ferramentas teóricas que descrevem a estrutura eletrônica de moléculas e sólidos. Neste contexto o objetivo do artigo foi descrever as abordagens teóricas do NBO, EDA e QTAIM

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25

Pinheiro, Renata Batista dos Santos, Anilton Coelho da Costa Junior, Claudio Andrés Téllez Zepeda, et al. "Vibrational Spectra of the thioglycolate complexes of Zn(II) and Cd(II), structure and natural bond orbitals." Research, Society and Development 12, no. 7 (2023): e18712742678. http://dx.doi.org/10.33448/rsd-v12i7.42678.

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The objective of this research was to characterize the vibrational spectrum of the Zn(II) and Cd(II) thioglycolate complexes, as well as their structures, vibrational analysis and the natural orbitals of bonds, through the infrared spectrum with Fourier transform (FT -IR) and Raman. The thioglycolate complexes of Zn(II) and Cd(II) were synthesized following procedures given by the graphical method, and structural analysis was performed through a theoretical-experimental method using both, the hybrid RHF/MP2:STO-3G and the experimental FT-IR and FT-Raman spectra. Calculations were performed on

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26

Takagi, Nozomi, Andreas Krapp, and Gernot Frenking. "On the nature of homo- and hetero-dinuclear metal–metal quadruple bonds — Analysis of the bonding situation and benchmarking DFT against wave function methods." Canadian Journal of Chemistry 88, no. 11 (2010): 1079–93. http://dx.doi.org/10.1139/v10-078.

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Homo- and hetero-dimetallic (d–d)8 analogues of the formally quadruply bonded [Re2Cl8]2– system with the general formula [MM′Cl8]x (M, M′ = Tc, Re, Ru, Os, Rh, Ir and x = –2, –1, 0, +1, +2) have been calculated with the density functional theory (DFT) functionals SVWN, BLYP, BP86, PBE, OLYP, OPBE, HCTH, B3LYP, O3LYP, X3LYP, BH&HLYP, TPSS, VSXC, TPPSh, and ab initio methods (CASPT2, CCSD(T)) using basis sets of triple-ζ quality. The performance of the functionals for the description of the metal–metal bond distance and the bond dissociation energy as well as the singlet–triplet gap was eval

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Nihal, Kus. "MOLECULAR STRUCTURE, NBO AND TD-DFT ANALYSIS OF 4-METHYL-3-FURALDEHYDE BASED ON DFT CALCULATIONS." Journal of Natural Science and Technologies 1, no. 1 (2022): 113–23. https://doi.org/10.5281/zenodo.7319331.

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In this study, molecular structure of 4-methyl-3-furaldehyde (4M3F) was analyzed using density functional theory (DFT) with level of B3LYP/6-311G++(d,p). As a result of the scanning of the CCC=O dihedral angle, two conformers (trans and cis) were found at minimum energy and the <em>trans</em> was more stable than the <em>cis</em> at ca. 6.4 kJ mol-1. Time dependent DFT (TD-DFT) calculations have been used to calculate the low-energy excited states energies and oscillator strengths. As a result of calculations, it was found that the highest transition probability and most effective oscillator s

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28

Rivera, Augusto, Juan Manuel Uribe, Jaime Ríos-Motta, Hector Jairo Osorio, and Michael Bolte. "Evidence for stereoelectronic effects in the N—C—N group of 8,10,12-triaza-1-azoniatetracyclo[8.3.1.18,12.02,7]pentadecane 4-nitrophenolate 4-nitrophenol monosolvate from the protonation of aminal (2R,7R)-1,8,10,12-tetraazatetracyclo[8.3.1.18,12.02,7]pentadecane: X-ray and natural bond orbital analysis." Acta Crystallographica Section C Structural Chemistry 71, no. 4 (2015): 284–88. http://dx.doi.org/10.1107/s2053229615004829.

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The title molecular salt, C11H21N4+·C6H4NO3−·C6H5NO3, (II), crystallizes with two independent three-component aggregates in the asymmetric unit. In the cations, the cyclohexane rings fused to the cage azaadamantane systems both adopt a chair conformation. In the crystal structure, the aggregates are connected by C—H...O hydrogen bonds, forming a supramolecular unit enclosing anR44(24) ring motif. These units are linkedviaC—H...O and C—H...N hydrogen bonds, forming a three-dimensional network. Even hydrogen-bond formation to one of the N atoms is enough to induce structural stereoelectronic eff

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TAFERGUENNIT, Manel, Noura KICHOU, and Zakia HANK. "Comparative Experimental and Theoretical Study on the Structure of Potassium 2,4-Hexadienoate: Structure-Activity Relationship." Eurasia Proceedings of Science Technology Engineering and Mathematics 23 (October 16, 2023): 69–84. http://dx.doi.org/10.55549/epstem.1361714.

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For the first time, a density functional theory (DFT) study was conducted on the structure of a well-known antibacterial agent namely potassium 2,4-Hexadienoate, in order to elucidate its vibrational, electronic and reactivity proprieties. Structure optimization was performed using three common hybrid functionals (DFT/ B3LYP-D3; DFT/ M05-2X and DFT/M06-2X) to identify the suitable functional. Geometric parameters, IR and UV-vis spectra were well reproduced when using DFT/M06-2X with 6-311(d)G+ basis set (R2 = 0.99913). The assimilation of IR frequencies has been achieved using potential energy

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El-Shishtawy, Reda M., Shaaban A. Elroby, Abdullah M. Asiri, and Rifaat H. Hilal. "Pyran-Squaraine as Photosensitizers for Dye-Sensitized Solar Cells: DFT/TDDFT Study of the Electronic Structures and Absorption Properties." International Journal of Photoenergy 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/136893.

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In an effort to provide, assess, and evaluate a theoretical approach which enables designing efficient donor-acceptor dye systems, the electronic structure and optical properties of pyran-squaraine as donor-acceptor dyes used in dye-sensitized solar cells were investigated. Ground state properties have been computed at the B3LYP/6-31+G**level of theory. The long-range corrected density functionals CAM-B3LYP, PBEPBE, PBE1PBE (PBE0), and TPSSH with 6-311++G**were employed to examine absorption properties of the studied dyes. In an extensive comparison between experimental results and ab initio b

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Gnanasekar, Sharon Priya, and Elangannan Arunan. "A Detailed Classification of Three-Centre Two-Electron Bonds." Australian Journal of Chemistry 73, no. 8 (2020): 767. http://dx.doi.org/10.1071/ch19557.

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We evaluate the three-centre two-electron (3c-2e) bonds using atoms in molecules (AIM) and natural bond orbital (NBO) theoretical analyses. They have been classified as ‘open (V)’ or ‘closed (Δ)’, depending on how the three centres were bonded. Herein, we show that they could be classified as V, L, Δ, Y, T and I (linear) arrangements depending on the way the three centres are bonded. These different structures are found in B2H6 (V), CH5+ (V), Me-C2H2+ (L), B3+ (Δ), C3H3+ (Δ), H3+ (Y), 2-norbornyl+ (T), SiH5+ (T), and Al2H7− (I). Our results suggest that CH3Li2+ does not contain a 3c-2e bond ac

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32

More, S., O. Patil, S. Chillargikar, D. Lalasangi, and S. M. Hanagodimath. "DFT-Based Quantum Chemical Analysis of Coumarin Derivatives." Nucleus 62, no. 1 (2025): 37–46. https://doi.org/10.71330/thenucleus.2025.1445.

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The goal of the current work is to use density functional theory (DFT) at the B3LYP level of theory, using a basis set of 6-311++G (d, p), to comprehend the physical and chemical characteristics of 6-Methoxy-4-(4-nitro-phenoxy methyl)-chromen-2-one (6MNPM) and 1-(4-nitro-phenoxy methyl)-benzo[f]-chromen-3-one (4NPMB) of coumarin derivatives. Bond lengths and bond angles, two geometrical parameters, are calculated for coumarin derivatives. We have estimated the frontier molecular orbitals (FMO). Furthermore, to shed light on the stability and chemical reactivity of coumarin derivatives, the glo

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33

Ferreira, V. A. V., V. G. do Nascimento, and M. B. de Amorim. "Conjugation and Hyperconjugation Effects: Comparative Studies Through Localized Molecular Orbitals Energy Decomposition Analysis (LMO-EDA) and Natural Bond Orbitals (NBO)." Revista Processos Químicos 9, no. 18 (2015): 234–39. http://dx.doi.org/10.19142/rpq.v9i18.308.

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34

Beyramabadi, S. Ali, Tina Khadivjam, Atoosa Gonabadi, et al. "A DFT study on the geometry, tautomerism and noncovalent interactions of the Mepivacaine drug with the pristine SWCNT and –COOH functionalized SWCNT." Journal of Theoretical and Computational Chemistry 16, no. 01 (2017): 1750008. http://dx.doi.org/10.1142/s0219633617500080.

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The Mepivacaine drug is used as a local anesthetic in dentistry, which could exist as three different tautomers. Herein, geometry, energy behavior as well as tautomerization of these tautomers have been investigated by employing density functional theory (DFT) and considering the solvent effects with the polarizable continuum model (PCM) model. The most stable tautomer of the Mepivacaine has a carbonyl and an –NH amine groups in its structure. The frontier orbitals and the energy gap of the molecule have been computed using the natural bond orbital analysis (NBO). Also, the armchair (5,5) sing

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35

Kouassi, Koffi Alexis Respect, Anoubilé Benié, Kouakou Nobel N’guessan, et al. "Orbital Analysis of Natural Bonds, Calculations of the Functional Theory of Density Time-Dependent and Absorption Spectral of a Series of Rhodanine Derivatives." Mediterranean Journal of Chemistry 10, no. 5 (2020): 453. http://dx.doi.org/10.13171/mjc10502005131374mgrk.

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<p>In this work, the density functional theory (DFT) method at the B3LYP/6-31 + G (d, p) level has used to determine the optimization of five rhodanine derivatives. The stability of the derivatives (7a-7e) of 5-arylidene rhodanine, the hyperconjugative interactions, the delocalization of the atomic charges was analyzed with the analysis of the Natural Bond Orbital (NBO). The electronic structures were discussed and the relocation of electronic density was determined. Molecular Electrostatic Potential (MEP), local density functional descriptors, border molecular orbitals and absorption sp

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36

Laconsay, Croix J., Ka Yi Tsui, and Dean J. Tantillo. "Tipping the balance: theoretical interrogation of divergent extended heterolytic fragmentations." Chemical Science 11, no. 8 (2020): 2231–42. http://dx.doi.org/10.1039/c9sc05161a.

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We interrogate a type of heterolytic fragmentation called a ‘divergent fragmentation’ using density functional theory (DFT), natural bond orbital (NBO) analysis, ab initio molecular dynamics (AIMD), and external electric field (EEF) calculations.

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37

Othman, Khdir Ahmed, Yousif Hussein Azeez, Rebaz Anwar Omer, and Rebaz Obaid Kareem. "Theoretical exploration of halogenated anthracene derivatives: unraveling electronic and molecular insights." Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 26, no. 2 (2024): 280–94. http://dx.doi.org/10.17308/kcmf.2024.26/12043.

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This research article delves into the profound ramifications of halogenation on anthracene within the captivating domain of polycyclic aromatic hydrocarbons (PAHs). By employing Density Functional Theory (DFT) calculations, the study comprehensively explores the intricate interplay between halogen atoms and the molecular framework of anthracene. The entwining of halogens such as fluorine, chlorine, and bromine with aromatic rings orchestrates a symphony of changes, reshaping electronic structures, reactivity, and optical behaviors. This investigation traverses diverse analytical landscapes, en

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Brenner, Valérie, Eric Gloaguen, and Michel Mons. "Rationalizing the diversity of amide–amide H-bonding in peptides using the natural bond orbital method." Physical Chemistry Chemical Physics 21, no. 44 (2019): 24601–19. http://dx.doi.org/10.1039/c9cp03825f.

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Natural bond orbital (NBO) analysis of electron delocalization in a series of capped isolated peptides is used to diagnose amide–amide H-bonding and backbone-induced hyperconjugative interactions, and to rationalize their spectral effects.

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39

Dineshkumar, J., S. Subashchandrabose, S. Niaz, and P. Parthiban. "Electronic Transitions, Inter- and Intra-Bond Interactions of an Azabicycle Single Crystal using DFT." Asian Journal of Chemistry 33, no. 10 (2021): 2365–72. http://dx.doi.org/10.14233/ajchem.2021.23334.

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2,4-Diphenyl-3-azabicyclo[3.3.1]nonan-9-one O-benzyloxime (ABN-OBn) was synthesized by modified Mannich condensation, purified by recrystallization and single crystals were grown by slow evaporation from ethanol. The empirical formula of the molecule is C27H28N2O as witnessed by HRMS, elemental analysis and the X-ray diffraction. The crystal belongs to triclinic system (α = 73.640, β = 78.505, γ = 87.078) with P-1 space group. The electronic excited states of ABN-OBn have been calculated using TD-DFT/B3LYP/6-31G(d,p) level of theory, in order to investigate the electronic transitions within th

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Li, Xiao-Hong, Geng-Xin Yin, and Xian-Zhou Zhang. "Natural bond orbital (NBO) population analysis of some benzyl nitrites." Journal of Molecular Structure: THEOCHEM 957, no. 1-3 (2010): 61–65. http://dx.doi.org/10.1016/j.theochem.2010.07.005.

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41

Glendening, Eric D., and Frank Weinhold. "Pauling’s Conceptions of Hybridization and Resonance in Modern Quantum Chemistry." Molecules 26, no. 14 (2021): 4110. http://dx.doi.org/10.3390/molecules26144110.

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We employ the tools of natural bond orbital (NBO) and natural resonance theory (NRT) analysis to demonstrate the robustness, consistency, and accuracy with which Linus Pauling’s qualitative conceptions of directional hybridization and resonance delocalization are manifested in all known variants of modern computational quantum chemistry methodology.

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Jiao, Yinchun, and Frank Weinhold. "NBO/NRT Two-State Theory of Bond-Shift Spectral Excitation." Molecules 25, no. 18 (2020): 4052. http://dx.doi.org/10.3390/molecules25184052.

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We show that natural bond orbital (NBO) and natural resonance theory (NRT) analysis methods provide both optimized Lewis-structural bonding descriptors for ground-state electronic properties as well as suitable building blocks for idealized “diabatic” two-state models of the associated spectroscopic excitations. Specifically, in the framework of single-determinant Hartree-Fock or density functional methods for a resonance-stabilized molecule or supramolecular complex, we employ NBO/NRT descriptors of the ground-state determinant to develop a qualitative picture of the associated charge-transfe

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43

Suresh, Lakshmi, Ralte Lalrempuia, Jonas B. Ekeli, et al. "Unsaturated and Benzannulated N-Heterocyclic Carbene Complexes of Titanium and Hafnium: Impact on Catalysts Structure and Performance in Copolymerization of Cyclohexene Oxide with CO2." Molecules 25, no. 19 (2020): 4364. http://dx.doi.org/10.3390/molecules25194364.

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Tridentate, bis-phenolate N-heterocyclic carbenes (NHCs) are among the ligands giving the most selective and active group 4-based catalysts for the copolymerization of cyclohexene oxide (CHO) with CO2. In particular, ligands based on imidazolidin-2-ylidene (saturated NHC) moieties have given catalysts which exclusively form polycarbonate in moderate-to-high yields even under low CO2 pressure and at low copolymerization temperatures. Here, to evaluate the influence of the NHC moiety on the molecular structure of the catalyst and its performance in copolymerization, we extend this chemistry by s

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44

Sekhar, M. Chandra, Dereje Wakgari, Dunkana Negussa Kenie, and K. Chandrasekhar Reddy. "Study of Intermolecular Interactions between 2-Chloroaniline Isomeric Butanol Complexes in Gas Phase by Using DFT, NBO, QTAIM and RDG Analysis." Asian Journal of Chemistry 31, no. 3 (2019): 538–44. http://dx.doi.org/10.14233/ajchem.2019.21651.

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Density functional theoretical (DFT) studies on intermolecular hydrogen bond interactions between self and cross-associated molecular complexes of 2-chloroaniline and isomeric butanols (e.g., 2-methyl-2-propanol, 2-methyl-1-propanol, 2-butanol and1-butanol) have been analyzed in gas phase. Thirteen 2-chloroaniline isomeric butanol complexes are analyzed at B3LYP/6-311++G(d,p) level regarding their geometries, bond characteristics and interaction energies. The second-order perturbation stabilization energy has been calculated by natural bond orbitals analysis. Barder's quantum theory of atoms i

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45

Xu, Hui-Ying, Wei Wang, Jian-Wei Zou та Xiao-Lu Xu. "Theoretical calculations of π-type pnicogen bonds in the triad intermolecular complexes". Journal of Theoretical and Computational Chemistry 13, № 08 (2014): 1450068. http://dx.doi.org/10.1142/s0219633614500680.

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The pnicogen bonding interactions of PCl3and π-electron systems (acetylene, ethylene, benzene) were calculated by using MP2/aug-cc-pVDZ method and the effect of hydrogen bond on pnicogen bond systems were investigated. It has been indicated that the hydrogen bonding and the pnicogen bonding interactions have influence on each other and the positively cooperative effect has been detected. The interaction energies of pnicogen bonded supramolecular system were also calculated by using DFT method (M06-2X) and some simple comparisons with those by using MP2 method were made. It has been disclosed f

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46

Lessard, Olivier, Mathilde Grosset-Magagne, Paul A. Johnson та Denis Giguère. "Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose". Beilstein Journal of Organic Chemistry 20 (27 вересня 2024): 2442–54. http://dx.doi.org/10.3762/bjoc.20.208.

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In this work, we describe the synthesis of halogenated pyran analogues of ᴅ-talose using a halo-divergent strategy from known 1,6-anhydro-2,3-dideoxy-2,3-difluoro-β-ᴅ-mannopyranose. In solution and in the solid-state, all analogues adopt standard 4C1-like conformations despite 1,3-diaxial repulsion between the F2 and the C4 halogen. Moreover, the solid-state conformational analysis of halogenated pyrans reveals deviation in the intra-annular torsion angles arising from repulsion between the axial fluorine at C2 and the axial halogen at C4, which increases with the size of the halogen at C4 (F

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47

Ramuthai, M., S. Jeyavijayan, R. Premkumar, M. Uma Priya, and Naidu Dhanpal Jayram. "Structure, Spectroscopic Investigation, Molecular Docking and In vitro Cytotoxicity Studies on 4,7-dihydroxycoumarin: A Breast Cancer Drug." Journal of Computational Biophysics and Chemistry 21, no. 02 (2022): 219–36. http://dx.doi.org/10.1142/s2737416522500119.

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Coumarin derivatives are broadly used as anti-inflammatory, antioxidants, anticancer, and antiviral drugs in recent years. In particular, hydroxy coumarins have great importance because of their various biological and pharmacological purposes. The quantum chemical studies of 4,7-dihydroxycoumarin (DHC) have been performed using the cc-pVTZ level of basis set. The DHC molecular structure has been optimized and the computed frequency assignments have been correlated well with the experimental results. The experimental [Formula: see text]C NMR shifts of DHC have been compared with the computed [F

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48

Yuan, Chengqian, Haiming Wu, Meiye Jia, Peifeng Su, Zhixun Luo, and Jiannian Yao. "A theoretical study of weak interactions in phenylenediamine homodimer clusters." Physical Chemistry Chemical Physics 18, no. 42 (2016): 29249–57. http://dx.doi.org/10.1039/c6cp04922b.

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Utilizing dispersion-corrected density functional theory (DFT) calculations, we demonstrate the weak intermolecular interactions of phenylenediamine dimer (pdd) clusters, emphasizing the local lowest energy structures and decomposition of interaction energies by natural bond orbital (NBO) and atoms in molecule (AIM) analyses.

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49

Zhabanov, Yuriy A., Natalya V. Tverdova, Nina I. Giricheva, Georgiy V. Girichev, and Pavel A. Stuzhin. "DFT Study of molecular and electronic structure of magnesium (II) tetra(1,2,5-chalcogenadiazolo) porphyrazines, [TXDPzMg] (X = O, S, Se, Te)." Journal of Porphyrins and Phthalocyanines 21, no. 04-06 (2017): 439–52. http://dx.doi.org/10.1142/s1088424617500444.

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The influence of the chalcogen atom (X) on the molecular and electronic structures for the series of Mg[Formula: see text] tetra(1,2,5-chalcogenadiazolo)porphyrazines [TXDPzMg] (X [Formula: see text] O, S, Se, Te) and their monoaqua complexes [TXDPzMg(OH[Formula: see text]] was studied using DFT methods (B3LYP and PBE0 functionals) with cc-pVTZ basis sets. The chalcogen atom X changes strongly the geometry of the fused 1,2,5-chalcogenadiazole rings, but has only a weak influence on the dimensions of the coordination cavity of the porphyrazine macrocycle in [TXDPzMg] leading to its slight expan

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50

Günay, N., H. Pir, D. Avcı, and Y. Atalay. "NLO and NBO Analysis of Sarcosine-Maleic Acid by Using HF and B3LYP Calculations." Journal of Chemistry 2013 (2013): 1–16. http://dx.doi.org/10.1155/2013/712130.

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We report a theoretical study on molecular structure, vibrational spectra, nonlinear optical (NLO), and natural bond orbital (NBO) analysis of sarcosine-maleic acid (C7H11NO6) in the ground state calculated by using the Hartree-Fock (HF) and density functional method (DFT/B3LYP) with 6–31++G(d,p) basis set. We repeat NBO calculations with 6–31G(d,p) basis set so as to see the diffuse function impact on NBO analysis. Stability of the molecule arising from hyper conjugative interactions and charge delocalization has been analyzed using NBO analysis. NBO analysis shows that there is a O–H⋯O and N

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