Relevant bibliographies by topics / Natural bond orbital (NBO)

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  2. Dissertations / Theses
  3. Books
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  5. Conference papers

Academic literature on the topic 'Natural bond orbital (NBO)'

Author: Grafiati
Published: 4 June 2021
Last updated: 2 February 2022

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Journal articles on the topic "Natural bond orbital (NBO)"

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Glendening, Eric D., Clark R. Landis, and Frank Weinhold. "NBO 6.0: Natural bond orbital analysis program." Journal of Computational Chemistry 34, no. 16 (March 9, 2013): 1429–37. http://dx.doi.org/10.1002/jcc.23266.

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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 (October 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 orbitals decrease with increasing σp values of the substituents on the benzene, which results in a shortening of the N2=O1 bond. It is also noted that decreased occupancy of the localized σN3−N2 orbital in the idealized Lewis structure, or increased occupancy of [Formula: see text]of the non-Lewis orbital, and their subsequent impact on molecular stability and geometry (bond lengths) are also related to the resulting p character of the corresponding nitrogen NHO of σN3−N2 bond orbital.
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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 (June 26, 2013): 2134. http://dx.doi.org/10.1002/jcc.23366.

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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)n (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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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 (August 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 indicate that the internal rotational barrier is produced because of change in the distribution of orbital populations of 2p y, 2p z, d yz, d y2 and dz2 orbitals of the nitrogen atom.
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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. 32012Page : 44-49
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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 (October 2010): 61–65. http://dx.doi.org/10.1016/j.theochem.2010.07.005.

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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 (January 30, 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-dthiolate molecule on a metallic surface. In accordance with experiment the calculated electronic spectra of these tris complexes show bands at 565, 559 and 546 nm for Cr3+, Mn3+, and Fe3+ respectively which are mainly qualified to ligand-to metal charge transfer (LMCT) transitions. The electronic properties analysis demonstrate that the highest occupied molecular orbital (HOMO) is mostly centered on metal coordinated sulfur atoms whereas the lowest unoccupied molecular orbital (LUMO) is mainly located on the metal surface. By calculating natural bond orbital (NBO), the intramolecular interactions and electron delocalization was obtained. The results of NBO analysis illustrated the significant charge transfer from sulfur to central metal ions, as well as to the benzene of the complex. The calculated charges on metal ions are also reported at various charge schemes. The calculations show encouraging agreement with the available experimental data. Dhaka Univ. J. Sci. 67(1): 63-68, 2019 (January)
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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 (July 23, 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 from lone pair (LP) orbitals of DMF oxygen to the antibonding orbital of acid OH-bond significantly exceeds the criterion of H-bond existance (0.01 e). As follows from energy, among the complexes under investigation the most preferable one was found to be (H2SO4)2-DMF in which sulfuric acid molecules are linked with each other by three H-bonds.
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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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Dissertations / Theses on the topic "Natural bond orbital (NBO)"

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Santana, Rafael Germano [UNIFESP]. "Análise conformacional e das interações eletrônicas de algumas 2-acetamido-3-metil-3-nitrososulfanil-N-arilbutanamidas: S-nitrosotióis com potencial atividade biológica." Universidade Federal de São Paulo (UNIFESP), 2012. http://repositorio.unifesp.br/handle/11600/8899.

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O presente trabalho trata do estudo conformacional de S-nitrosotióis com potencial atividade biológica, 2–acetamido-3-metil-3-nitrosossulfanil-N-arilbutanamidas, e de seus tióis precursores, 2–acetamido-3-mercapto-3-metil-N-arilbutanamidas. As conformações de menor energia dos S-nitrosotióis e tióis em estudo são estabilizadas por ligações de hidrogênio intramoleculares que promovem uma maior estabilidade dos confôrmeros. A análise geométrica do grupo R-SNO mostra que esses compostos preferem a conformação trans. O cálculo das interações orbitalares pelo método NBO (Natural Bond Orbital) para as 2–acetamido-3-mercapto-3-metil-N-arilbutanamidas mostrou que as mesmas são estabilizadas pelas seguintes interações: no (N2) →  (C3-O4) e no(N10) → (C11-O12). Os resultados de NBO para os S-nitrosotíois mostraram que a interação hiperconjugativa é bastante efetiva nas conformações estáveis desses compostos, enfraquecendo a ligação que resulta no aumento do comprimento da ligação S-N em S-Nitrosotióis. A forte delocalização , induz caráter parcial a ligação S-N. A fraca ligação S-N indica uma forte delocalização do par de elétrons do O(NO) devido a interação, que é responsável pelo alongamento da ligação S-N, aumentando e a potencial capacidade do óxido nítrico ser liberado.
We carried out a conformational study on the S-nitrosothiols (R-SNO), 2-acetamido-3-methyl-3-(nitrososulfanyl)-N-arylbutanamides and their thiol precursors 2-acetamido-3-mercapto-3-methyl-N-arylbutanamides. The lowest energy conformation for both compounds is stabilized by intramolecular hydrogen bonds. Trans conformation was determined as the predominant conformation after geometrical analysis of R-SNO. Orbital interactions for 2-acetamido-3-mercapto-3-methyl-N-arylbutanamides were calculated using Natural Bond Orbital (NBO) methodology. Calculations indicated that orbital interactions for these compounds are stabilized by the following interactions: no (N2) →  (C3-O4) and no(N10) → (C11-O12). NBO results showed that the hyperconjugative interaction is very effective, weakening the σ bond and resulting in increasing length of the S-N bond in R-SNO. The strong delocalization induces partial character to the S-N bond. The bond S-N indicates a strong delocalization of the electron pair of O(NO) due to interaction. This interaction is responsible for the elongation of the S-N bond which increases the ability of the compound to release nitric oxide (NO). Based on the enhanced capacity to release NO by these compounds, our findings suggest that both compounds may display biological activity.
TEDE
BV UNIFESP: Teses e dissertações
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Nguyen, Thi Ai Nhung. "Transition metal complexes of NHE ligands [(CO)4W-{NHE}] with E = C – Pb as tracers in environmental study: structures, energies, and natural bond orbital of molecular interaction." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-190482.

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Quantum chemical calculations at BP86/TZVPP//BP86/SVP have been carried out for the Nheterocylic carbene and analogues complexes (tetrylene) [(CO)4W-NHE] (W4-NHE) with E = C – Pb. The tetrylene complexes W4-NHE possess end-on-bonded NHE ligands (E = C, Si), while for E = Ge and Sn, they possess slightly side-on-bonded ligands. The strongest side-on-bonded ligand when E = Pb has a bending angle of 102.9°. The trend of the bond dissociations energies (BDEs) for the W-E bond is W4-NHC > W4-NHSi > W4-NHGe > W4-NHSn > W4-NHPb. Analysis of the bonding situation suggests that the NHE ligands in W4-NHE are strong σ-donors and weak π-donors. This is because the tetrylenes have only one lone-pair orbital available for donation. The polarization of the W-E bond and the hybridization at atom E explain the trend in the bond strength of the tetrylene complexes W4-NHE. The W-E bonds of the heavier systems W4-NHE are strongly polarized toward atom E giving rise to rather weak electrostatic attraction with the tungsten atom which is the main source for the decreasing trend of the bond energies. The theoretical calculations suggest that transition-metal complexes tetrylenes [(CO)4W-{NHE}] (E = C – Pb) should be synthetically accessible compounds with tetrylenes NHE act as two-electron-donor ligands in complexes
Phân tích cấu trúc và bản chất liên kết hóa học của hợp chất với kim loại chuyển tiếp chứa phối tử N-heterocyclic carbene và các đồng đẳng (tetrylene) [(CO)4W–NHE] (W4-NHE) với E = C – Pb sử dụng tính toán hóa lượng tử ở mức BP86/TZVPP//BP86/SVP. Cấu trúc của phức W4-NHE cho thấy các phối tử NHE với E = C, Si tạo với phân tử W(CO)4 một góc thẳng α = 180,0°, trong khi đó các phức W4-NHE thì phối tử NHE với E = Ge – Pb tạo liên kết với nhóm W(CO)4 một góc cong α < 180,0° và góc cong càng trở nên nhọn hơn khi E = Pb (α = 102.9°). Năng lượng phân ly liên kết của liên kết W-E giảm dần: W4-NHC > W4-NHSi > W4-NHGe > W4-NHSn > W4-NHPb. Tính toán hóa lượng tử trong phức [(CO)4W-{NHE}] (E = C – Pb) cho thấy phối tử tetrylene là chất cho electron. Điều này có thể do phối tử tetrylene chỉ giữ lại một cặp electron tại nguyên tử E để đóng vai trò là chất cho điện tử. Độ bền liên kết của phức W4-NHE được giải thích nhờ vào độ phân cực của liên kết W-E và sự lai hóa của nguyên tử trung tâm E. Nguyên nhân chính làm giảm dần năng lượng liên kết là do liên kết W-E của các phức nặng hơn W4-NHE bị phân cực mạnh về phía nguyên tử E dẫn đến lực hút tĩnh điện với nguyên tử W yếu dần. Hệ phức nghiên cứu được coi là hợp chất điển hình cho các nghiên cứu thực nghiệm
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Nguyen, Thi Ai Nhung. "Transition metal complexes of NHE ligands [(CO)4W-{NHE}] with E = C – Pb as tracers in environmental study: structures, energies, and natural bond orbital of molecular interaction: Research article." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A29086.

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Quantum chemical calculations at BP86/TZVPP//BP86/SVP have been carried out for the Nheterocylic carbene and analogues complexes (tetrylene) [(CO)4W-NHE] (W4-NHE) with E = C – Pb. The tetrylene complexes W4-NHE possess end-on-bonded NHE ligands (E = C, Si), while for E = Ge and Sn, they possess slightly side-on-bonded ligands. The strongest side-on-bonded ligand when E = Pb has a bending angle of 102.9°. The trend of the bond dissociations energies (BDEs) for the W-E bond is W4-NHC > W4-NHSi > W4-NHGe > W4-NHSn > W4-NHPb. Analysis of the bonding situation suggests that the NHE ligands in W4-NHE are strong σ-donors and weak π-donors. This is because the tetrylenes have only one lone-pair orbital available for donation. The polarization of the W-E bond and the hybridization at atom E explain the trend in the bond strength of the tetrylene complexes W4-NHE. The W-E bonds of the heavier systems W4-NHE are strongly polarized toward atom E giving rise to rather weak electrostatic attraction with the tungsten atom which is the main source for the decreasing trend of the bond energies. The theoretical calculations suggest that transition-metal complexes tetrylenes [(CO)4W-{NHE}] (E = C – Pb) should be synthetically accessible compounds with tetrylenes NHE act as two-electron-donor ligands in complexes.
Phân tích cấu trúc và bản chất liên kết hóa học của hợp chất với kim loại chuyển tiếp chứa phối tử N-heterocyclic carbene và các đồng đẳng (tetrylene) [(CO)4W–NHE] (W4-NHE) với E = C – Pb sử dụng tính toán hóa lượng tử ở mức BP86/TZVPP//BP86/SVP. Cấu trúc của phức W4-NHE cho thấy các phối tử NHE với E = C, Si tạo với phân tử W(CO)4 một góc thẳng α = 180,0°, trong khi đó các phức W4-NHE thì phối tử NHE với E = Ge – Pb tạo liên kết với nhóm W(CO)4 một góc cong α < 180,0° và góc cong càng trở nên nhọn hơn khi E = Pb (α = 102.9°). Năng lượng phân ly liên kết của liên kết W-E giảm dần: W4-NHC > W4-NHSi > W4-NHGe > W4-NHSn > W4-NHPb. Tính toán hóa lượng tử trong phức [(CO)4W-{NHE}] (E = C – Pb) cho thấy phối tử tetrylene là chất cho electron. Điều này có thể do phối tử tetrylene chỉ giữ lại một cặp electron tại nguyên tử E để đóng vai trò là chất cho điện tử. Độ bền liên kết của phức W4-NHE được giải thích nhờ vào độ phân cực của liên kết W-E và sự lai hóa của nguyên tử trung tâm E. Nguyên nhân chính làm giảm dần năng lượng liên kết là do liên kết W-E của các phức nặng hơn W4-NHE bị phân cực mạnh về phía nguyên tử E dẫn đến lực hút tĩnh điện với nguyên tử W yếu dần. Hệ phức nghiên cứu được coi là hợp chất điển hình cho các nghiên cứu thực nghiệm.
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Viana, Marco Antonio de Abreu. "Ligações de hidrogênio usuais e não usuais: um estudo comparativo das propriedades moleculares e topológicas da densidade eletrônica em HCCH --- HX e HCN --- HX com X = F, CI, CN e CCH." Universidade Federal da Paraí­ba, 2013. http://tede.biblioteca.ufpb.br:8080/handle/tede/7117.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The aim of this work was to study two kinds of intermolecular hydrogen bonding, the non-usual that is represented by the interaction between acetylene and the HX species (C2H2 --- HX) and the usual that is represented by the interaction between hydrogen cyanide and HX species, with X = F, Cl, CN, and HCCH. This interaction promotes changes in the structural, electronic and vibrational properties of the species involved. In this work, we employe d not onlycomputational-quantum methods MP2/6-311 + + G (d, p) and DFT/B3LYP/6-311 + + G (d, p) in order to study the structural, electronic and vibrational properties of those two types of intermolecular hydrogen bonding, but also we employed QTAIM and NBO methods to complement our research. The results have shown no significant differences between the two correlated methods employed for both types of hydrogen bonded complexes, leading us to suggest the use of the DFT/B3LYP method for studies of similar systems to those studied here, due to the lower computational demand. The increase in bond length of the HX species are enhanced due to formation of more linear complexes than T-complexes, in both calculation levels. The intermolecular bond length values in the complex HCN --- HX are smaller than in the complexes HCCH --- HX, and the values from MP2 and DFT/B3LYP are very close in each individual type of hydrogen complex, suggesting that the linear complexes are more stabilized by the formation of hydrogen bonding than the T-complexes, which can be proved by the values of the binding energy of hydrogen in HCN --- HX. Concerning the redshift effect in the harmonic vibrational mode of species HX, due to the formation of intermolecular bond, the values obtained for linear complexes hydrogen are higher than for the corresponding T-complexes, considering both calculation levels. Values were evaluated from the increase in the intensity values of the stretch mode HX bond formation due to intermolecular and, according to the model CCFOM, the term load flow is responsible for the effect on the increase of HX intensity. We also highlight the new vibrational modes, emphasizing the stretch mode of the intermolecular bond. From studies employing QTAIM, it was possible to obtain the values of electron density and the Laplacian electron density and evaluate these parameters in critical points in HX and intermolecular hydrogen bonding, thus confirming the formation of hydrogen bonded complexes. We evaluated the energy difference between π orbitals and lone pair of nitrogen (in HCN), for the species receiving proton and sigma antibonding for the hydrogen of HX, using the method of natural bond orbital variation.
O objeto de estudo deste trabalho foi a ligação de hidrogênio intermolecular de dois tipos, a não-usual representada pela interação entre o acetileno e espécies HX (C2H2---HX) e a usual representada pela interação entre o ácido cianídrico e espécies HX, com X=F, Cl, CN e HCCH. Esta interação provoca mudanças nas propriedades estruturais, eletrônicas e vibracionais das espécies envolvidas. Neste trabalho empregamos os métodos quântico-computacionais MP2/6-311++G(d,p) e DFT/B3LYP/6-311++G(d,p) para estudar as propriedades estruturais, eletrônicas e vibracionais dos dois tipos de ligação de hidrogênio intermolecular, além de complementar nossa investigação empregando os métodos QTAIM e NBO. Os resultados não mostraram diferenças significativas entre os dois métodos correlacionados empregados para ambos os tipos de complexos de hidrogênio, nos levando a sugerir o emprego do método DFT/B3LYP para estudos de sistemas semelhantes aos aqui estudados, devido a menor demanda computacional. Os valores de incremento no comprimento de ligação das espécies HX são mais acentuados devido à formação dos complexos lineares do que dos complexos-T, em ambos os níveis de cálculo. Os valores de comprimento de ligação intermolecular nos complexos HCN---HX são menores do que nos complexos HCCH---HX, sendo os valores MP2 e DFT/B3LYP bem próximos em cada tipo individual de complexo de hidrogênio, sugerindo que os complexos lineares são mais estabilizados pela formação da ligação de hidrogênio do que os complexos-T, fato que pode ser comprovado pelos valores da energia de ligação de hidrogênio em HCN---HX. Com respeito ao efeito redshift no modo vibracional harmônico das espécies HX, devido à formação da ligação intermolecular, os valores obtidos para os complexos de hidrogênio lineares são maiores do que para os correspondentes complexos-T, considerando ambos os níveis de cálculo. Foram avaliados os valores do incremento nos valores de intensidade do modo de estiramento de HX devido à formação da ligação intermolecular e, de acordo com o modelo CCFOM, o termo de fluxo de carga é o responsável pelo efeito no aumento da intensidade de HX. Foram ainda destacados os novos modos vibracionais, dando ênfase ao modo de estiramento da ligação intermolecular. Dos estudos empregando a QTAIM foi possível obter os valores da densidade eletrônica e do Laplaciano da densidade eletrônica e avaliar os valores desses parâmetros nos pontos críticos de ligação em HX e na ligação de hidrogênio intermolecular, comprovando dessa forma a formação dos complexos de hidrogênio. Com os estudos empregando o método dos orbitais naturais de ligação foi avaliada a diferença de energia entre os orbitais π (no acetileno) e o orbital do par de elétrons livres do nitrogênio (em HCN), para as espécies receptoras de próton, e o orbital sigma antiligante do hidrogênio em HX.
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Hsu, Wen-Yi, and 許文一. "Applications of Natural Bond Orbital (NBO) Analysis: Transition-metal hexacarbonyl and mono-substituted pentacarbonyl complexes." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/97658299658745029363.

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博士
國立成功大學
化學系碩博士班
96
This article includes four units and the first unit contains Ab Initio Molecular Orbital (MO) theory. Here it introduces the Hamiltonian and wavefunctions of the Schrödinger equation, and molecular orbitals obtained from the Schrödinger equation. The related software introduction is Gaussian package in chief. The second unit covers Natural Bond Orbital (NBO) analysis. It could acquire quantized Lewis structures on the basis of the density matrix obtained from MO theory. According to second-order perturbation theory, the donor-acceptor interaction between bonding and antibonding orbitals can stabilize a molecule on the whole, and the orbital energy lowing due to this interaction is called second-order energy lowing [E(2)]. The related software introduction is NBO 5.0 program in chief. The fourth unit involves some calculations about the properties of ionic liquid solutions. The third unit embraces applications for example. Using Linux version of Gaussian 98 and NBO 5.0 program, we can obtain 2pi orbital populations ([2pi]) of transition-metal hexacarbonyl [M(CO)6] and mono-substituted pentacarbonyl [M(CO)5X] complexes. In M(CO)6 (M = Cr, Mo, W), pi-back-donations of the calculated and NMR experiments show the similar trend: 3d ~ 5d > 4d. According to the results of NBO analysis, M(CO)6 contains two donor-acceptor interactions, 3-center, 4-electron hyperbond → pi*CO (3CHB hyperconjugation) and M → pi*CO, for pi-back-donation. The trend of M → pi*CO is 3d < 4d < 5d and that of 3CHB hyperconjugation is 3d > 5d ~ 4d. It could be found that the 3CHB hyperconjugation is the main factor that influences the pi-back-donation. In M(CO)5X complexes (M = Cr, Mo, W), we can arrange the pi-acceptor ability of ligands X in increasing order: X = F– < Cl– < Br– < I– < CN– < Quinuclidine < NMe3 < Pyridine < Pyrazine < N2 < PPh3 < PPh2Me < PPhMe2 < PMe3 < H2 < P(OMe)3 < PI3 < PBr3 < PCl3 < PF3 < CO < SiO < CS < BF < NO+, according to axial [2pi].
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6

Blair, John Thomas. "Natural bond orbital studies of radicals and radical cations." 1987. http://catalog.hathitrust.org/api/volumes/oclc/17215521.html.

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Thesis (Ph. D.)--University of Wisconsin--Madison, 1987.
Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 159-166).
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7

Badenhoop, Jay Kent. "Natural bond orbital analysis of resonance and steric interactions." 1994. http://catalog.hathitrust.org/api/volumes/oclc/32068835.html.

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8

Chen, Erh-Hao, and 陳邇浩. "The Natural Bond Orbital Anaiysis of the Canonical Molecular Orbital for Some Simple Molecules." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/90142115723985060499.

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9

Liu, Ting-Wei, and 劉挺緯. "Studies of the interaction between ionic liquid and solvents by Natural Bond Orbital method." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/69866971398746268306.

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碩士
國立成功大學
化學系碩博士班
94
Bond orbital analysis performed on EMI+ and various Lewis bases reveals that the Weinhold’s “counterbalance effects of rehybridization and hyperconjugation” are valid for the most polar C-H (EMI+) bonding orbitals and are not suitable for the lone-pair bonding orbital of the bases. Only when alkyl C-H BOs are involved in hyperconjugative interactions with the base, chloride or bromide anions under this research, the hyperconjugation effect prevails over rehybridization effect and H-bonding results in a strengthened C(3)-H bond. The self-diffusing BMI-PF6 in neat ionic liquid (IL) state have been found, in the presence of aprotic organic solvent (AOS), associated to different extents, which can be explained by B3LYP/3-21G* calculated binding energies for the adducts of AOS and PF6 anion. These results are consistent with the very recent nitrogen NMR studies performed on ionic liquids, which infer that solvent-anion interactions dominate modified physical properties. The NBO second-order perturbation energy analysis provides orbital-based explanations for the unusually up-field shifts of 19F NMR resonances in propylene carbonate and the relative solvent-IL effects .
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10

Chen, Mei-Hung, and 陳美宏. "Studies of the interaction between ionic liquid and solvents by Natural Bond Orbital method (II)." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/92028099328769138657.

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碩士
國立成功大學
化學系專班
95
Under the neat ionic liquid condition, it is observed that the cation and anion diffused respectively. In recently, there were also papers about cation’s 1H and 19F NMR spectrum pointed out that the HAP (hyper anion preference) is more than the HCP (hyper cation preference) under the different temperature and the different organic solvent ratio. Which reason actually affects the intermolecular relative function in the ionic liquid and the solvent? And which reaslly affects the hyper anion preference, is the major research motive of this paper. We use the B3LYP/6-31G* method to calculate the solvent molecule and binding energy tendency between the cation and anion. And using the computational E(2) value to explaine the NMR experimental T1-19F and T1-1H results (relaxation time). The first part of this paper (adding solvents to the ionic liquid system), the computational results meet the NMR experimental results. In the second part of this paper (hyper ion preference), the theoretical calculation results are unable to explain the results of the NMR experiment. Regarding this unable explained phenomenon, we try to use the following formula to explain that, �� G = H－TS ……… (1) When G = 0, H = TS �� T = H/S ……… (2) Where, H is equal to the theoretical calculated stability energy (SE). In formula 2, the temperature (T) is inverse proportion with entropy change (S) but direct proportion with enthalpy change (H). Thought the calculated H values have not much difference between hyper anion and hyper cation, we explain that regarding the next conclusion: Under the gaseous state ionic liquid, the entropy change (S), in fact, is the most influence.
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Books on the topic "Natural bond orbital (NBO)"

1

Landis, Clark R., and Frank Weinhold. Valency and Bonding: A Natural Bond Orbital Donor-Acceptor Perspective. Cambridge University Press, 2005.

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Book chapters on the topic "Natural bond orbital (NBO)"

1

Weinhold, Frank, and John E. Carpenter. "The Natural Bond Orbital Lewis Structure Concept for Molecules, Radicals, and Radical Ions." In The Structure of Small Molecules and Ions, 227–36. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4684-7424-4_24.

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Glendening, Eric D., Clark R. Landis, and Frank Weinhold. "6 Natural bond orbital theory: Discovering chemistry with NBO7." In Complementary Bonding Analysis, 129–56. De Gruyter, 2021. http://dx.doi.org/10.1515/9783110660074-006.

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"Appendix B: Orbital Graphics: The NBOView Orbital Plotter." In Discovering Chemistry with Natural Bond Orbitals, 300–301. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781118229101.app2.

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Weinhold, F. "Natural Bond Orbital Analysis of Photochemical Excitation, With Illustrative Applications to Vinoxy Radical." In Computational Methods in Photochemistry, 393–476. CRC Press, 2005. http://dx.doi.org/10.1201/9781420030587.ch7.

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Conference papers on the topic "Natural bond orbital (NBO)"

1

Moharana, Maheswata, Satya Narayan Sahu, and Subrat Kumar Pattanayak. "Natural bond orbital analysis of creatinine: A DFT approach study." In ADVANCES IN BASIC SCIENCE (ICABS 2019). AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5122636.

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Rastogi, V. K., M. Amalanathan, I. Hubert Joe, P. M. Champion, and L. D. Ziegler. "Natural Bond Orbital Analysis and Vibrational Spectral Investigation of 3,5-(Dinitro benzoic acid)." In XXII INTERNATIONAL CONFERENCE ON RAMAN SPECTROSCOPY. AIP, 2010. http://dx.doi.org/10.1063/1.3482712.

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Silva, Victor Hugo Malamace da, and Glaucio Braga Ferreira. "Chemical interaction study between xanthate ligand and lead (II) using NBO, EDA and QTAIM analysis." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol2020159.

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As a useful flotation agent, the xanthate ligand, O-alkyldithiocarbonates, has been used by different countries by its easy and inexpensive synthesis. More recently papers explored many different applications using this ligand within a complex of several metals cation. In order to study the proprieties of the lead (II) complex with such ligand, the object of this work is to provide a better understanding of the Pb-S bond using different theoretical approaches as NBO, EDA and QTAIM analysis and the influence caused by the different alkyl groups of the ligand. By an optimized structure, the NBO showed that the Pb-S is mainly composed by p orbital of the lead and by the p lone pair of the sulfur atom. The calculation with different alkyl groups highlights that the presence of a larger hydrocarbon chain provides a higher contribution of the s orbital of the lead atom to the interaction. Through the EDA analysis, the interaction between ligand and metal has the predominance of an electrostatic character. The size of the alkyl group has an impact on the value of both covalent and electrostatic character, making the interaction more covalent, due to a higher presence of an electronic density on sulfur atom. This density can be evaluated by the topological study of the QTAIM analysis, which enhances the fact that the charge over the sulfur atom gets higher when using a larger alkyl group for the xanthate ligand.
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Prabu, K. M., P. Arachimani, M. Anand Sagaya Chinnarani, G. Kalaiyan, and S. Suresh. "Molecular structure, vibrational, non-linear optical and natural bond orbital analysis of 7-amino-4-methylcoumarin: A quantum chemical study." In RECENT TRENDS IN PURE AND APPLIED MATHEMATICS. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5135246.

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