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Marie A, Loos PF. Reference Energies for Valence Ionizations and Satellite Transitions. J Chem Theory Comput 2024; 20:4751-4777. [PMID: 38776293 PMCID: PMC11171335 DOI: 10.1021/acs.jctc.4c00216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 05/24/2024]
Abstract
Upon ionization of an atom or a molecule, another electron (or more) can be simultaneously excited. These concurrently generated states are called "satellites" (or shakeup transitions) as they appear in ionization spectra as higher-energy peaks with weaker intensity and larger width than the main peaks associated with single-particle ionizations. Satellites, which correspond to electronically excited states of the cationic species, are notoriously challenging to model using conventional single-reference methods due to their high excitation degree compared to the neutral reference state. This work reports 42 satellite transition energies and 58 valence ionization potentials (IPs) of full configuration interaction quality computed in small molecular systems. Following the protocol developed for the quest database [Véril, M.; Scemama, A.; Caffarel, M.; Lipparini, F.; Boggio-Pasqua, M.; Jacquemin, D.; and Loos, P.-F. Wiley Interdiscip. Rev.: Comput. Mol. Sci. 2021, 11, e1517], these reference energies are computed using the configuration interaction using a perturbative selection made iteratively (CIPSI) method. In addition, the accuracy of the well-known coupled-cluster (CC) hierarchy (CC2, CCSD, CC3, CCSDT, CC4, and CCSDTQ) is gauged against these new accurate references. The performances of various approximations based on many-body Green's functions (GW, GF2, and T-matrix) for IPs are also analyzed. Their limitations in correctly modeling satellite transitions are discussed.
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Affiliation(s)
- Antoine Marie
- Laboratoire de Chimie et Physique
Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Pierre-François Loos
- Laboratoire de Chimie et Physique
Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
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2
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Tikhonov SA, Sidorin AE, Samoilov IS, Borisenko AV, Vovna VI. Photoelectron spectra and electronic structure of boron diacetate formazanates. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 238:118441. [PMID: 32403076 DOI: 10.1016/j.saa.2020.118441] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
The electronic structure and cationic states of two 1,5-diphenylformazanes and two boron diacetate (B(OAc)2) formazanates were modeled using the outer valence Green's function (OVGF) and density functional theory (DFT) methods. Comparison of data of the OVGF and ultraviolet photoelectron spectroscopy (UPS) methods made it possible to determine an effect of functional groups and complexing agents on energies of cationic states. Addition of NO2-group at the γ-position of the chelate cycle causes stabilization of levels the five upper occupied molecular orbitals (MO) and destabilization of the bonding orbital π3Ph + π3 level. The levels of MOs π3Ph-π3 and n- are stabilized due to influence of the complexing agent B(OAc)2, with a difference in the shift of 0.67 eV. The ionization energies (In) changes for the π-orbitals of benzene rings are within the error of the OVGF method. Under methylation of phenyl groups, the differences between the calculated In, corresponding to the π-orbitals of aromatic substituents, are in good agreement with the experimental In shifts at transition from benzene to toluene. According to the OVGF method, in all the studied complexes the lowest unoccupied molecular orbital (LUMO) is localized mainly on the chelate cycle and has a strong acceptor character, which should contribute the low-lying charge-transfer electronic excitations. Moreover, an application of the DFT analog of the Koopmans' theorem with the BHHLYP and B2PLYP functionals made it possible to determine qualitatively a sequence of cationic states and energy intervals between them in the spectral range up to 10 eV. The DFT/wB97x/cc-pVTZ method data on the energy gap between the highest occupied molecular orbital (HOMO) and LUMO levels correlate with the OVGF/cc-pVTZ calculation results.
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Affiliation(s)
- Sergey A Tikhonov
- Far Eastern Federal University, School of Natural Sciences, Vladivostok 690950, Russian Federation.
| | - Andrey E Sidorin
- Far Eastern Federal University, School of Natural Sciences, Vladivostok 690950, Russian Federation
| | - Ilya S Samoilov
- Saint Petersburg State University, Department of Photonics, St. Petersburg 199034, Russian Federation
| | - Aleksandr V Borisenko
- Vladivostok Branch of Russian Customs Academy, Vladivostok 690034, Russian Federation
| | - Vitaliy I Vovna
- Far Eastern Federal University, School of Natural Sciences, Vladivostok 690950, Russian Federation
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Gao P, Wang X, Huang Z, Yu H. 11B NMR Chemical Shift Predictions via Density Functional Theory and Gauge-Including Atomic Orbital Approach: Applications to Structural Elucidations of Boron-Containing Molecules. ACS OMEGA 2019; 4:12385-12392. [PMID: 31460356 PMCID: PMC6682094 DOI: 10.1021/acsomega.9b01566] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
11B nuclear magnetic resonance (NMR) spectroscopy is a useful tool for studies of boron-containing compounds in terms of structural analysis and reaction kinetics monitoring. A computational protocol, which is aimed at an accurate prediction of 11B NMR chemical shifts via linear regression, was proposed based on the density functional theory and the gauge-including atomic orbital approach. Similar to the procedure used for carbon, hydrogen, and nitrogen chemical shift predictions, a database of boron-containing molecules was first compiled. Scaling factors for the linear regression between calculated isotropic shielding constants and experimental chemical shifts were then fitted using eight different levels of theory with both the solvation model based on density and conductor-like polarizable continuum model solvent models. The best method with the two solvent models yields a root-mean-square deviation of about 3.40 and 3.37 ppm, respectively. To explore the capabilities and potential limitations of the developed protocols, classical boron-hydrogen compounds and molecules with representative boron bonding environments were chosen as test cases, and the consistency between experimental values and theoretical predictions was demonstrated.
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Affiliation(s)
- Peng Gao
- School
of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Xingyong Wang
- School
of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Zhenguo Huang
- School
of Civil and Environmental Engineering, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Haibo Yu
- School
of Chemistry and Molecular Bioscience and Molecular Horizons, University of Wollongong, Wollongong, New South Wales 2500, Australia
- Illawarra
Health and Medical Research Institute, Wollongong 2522, Australia
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Kupka T, Buczek A, Broda MA, Gajda Ł, Ignasiak M. Convergence of nuclear magnetic shieldings and one-bond 1 J( 11 B 1 H) indirect spin-spin coupling constants in small boron molecules. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2018; 56:338-351. [PMID: 29361201 DOI: 10.1002/mrc.4714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/10/2018] [Accepted: 01/13/2018] [Indexed: 06/07/2023]
Abstract
Self-consistent field Hartree-Fock, density functional theory, and coupled-cluster calculations of the nuclear magnetic shielding constants of BH and BH3 molecules have been conducted to characterize the convergence of individual results obtained with correlation-consistent and polarization-consistent basis sets. The individual 11 B and 1 H NMR parameters were estimated in the complete basis set limit and compared with benchmark results. Only the KT3 density functional accurately reproduced 11 B shielding in BH molecule.
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Affiliation(s)
- Teobald Kupka
- Faculty of Chemistry, University of Opole, 48, Oleska Street, 46-052, Opole, Poland
| | - Aneta Buczek
- Faculty of Chemistry, University of Opole, 48, Oleska Street, 46-052, Opole, Poland
| | - Małgorzata A Broda
- Faculty of Chemistry, University of Opole, 48, Oleska Street, 46-052, Opole, Poland
| | - Łukasz Gajda
- Faculty of Chemistry, University of Opole, 48, Oleska Street, 46-052, Opole, Poland
| | - Monika Ignasiak
- Faculty of Chemistry, University of Opole, 48, Oleska Street, 46-052, Opole, Poland
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Loukhovitski BI, Torokhov SA, Loukhovitskaya EE, Sharipov AS. DFT study of small aluminum and boron hydrides: isomeric composition and physical properties. Struct Chem 2018. [DOI: 10.1007/s11224-017-1000-5 https:/doi.org/10.1007/s11224-017-1000-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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6
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DFT study of small aluminum and boron hydrides: isomeric composition and physical properties. Struct Chem 2017. [DOI: 10.1007/s11224-017-1000-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Li DZ, Li SD. B2(BO)6 0/- and B 2(BS) 6 0/- doubly bridged structures containing BO or BS as ligands. J Mol Model 2014; 20:2427. [PMID: 25159274 DOI: 10.1007/s00894-014-2427-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 08/07/2014] [Indexed: 11/27/2022]
Abstract
The investigation on the geometrical and electronic properties of B(2)(BO)(6) (0/-) and B(2)(BS)(6) (0/-) has been performed by density functional theory (DFT) using the B3LYP and BP86 methods. The chemical bonding in B(2)A(6) (A = H, BO, and BS) series is elucidated through the recently developed adaptive natural density partitioning (AdNDP). D(2h) B(2)(BO)(6) and B(2)(BS)(6) were found to possess two bridging η (2)-BO or η (2)-BS groups, as well as four terminal BO or BS groups that are analogs of diborane B(2)H(6). D(2)h B(2)(BO)(6) (-) and B(2)(BS)(6) (-) with two bridging η (2)-BO or η (2)-BS groups which are more stable than their corresponding D(3d) structures. The binding energy of B(2)(BO)(6) and B(2)(BS)(6) with respect to B(2)(BO)(6) (D2h) → 2B(BO)(3) (D(3h)) and B(2)(BS)(6)(D(2h)) → 2B(BS)(3) (D(3h)) are estimated to be (△)E = 19.8 and 40.6 kcal mol(-1) at CCSD(T)//B3LYP level, respectively. This finding advances the boronyl chemistry and helps establish the isolobal analogy between boron-rich oxide clusters and boranes.
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Affiliation(s)
- Da-Zhi Li
- Department of Chemistry and Chemical Engineering, Binzhou University, Binzhou, Shandong, 256603, People's Republic of China,
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Sun B, McKee ML. Evaluating the Role of Triborane(7) As Catalyst in the Pyrolysis of Tetraborane(10). J Phys Chem A 2013; 117:9076-82. [DOI: 10.1021/jp405621u] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Baili Sun
- Department of Chemistry and
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Michael L. McKee
- Department of Chemistry and
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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Abstract
The rate constants for the association of two boranes to form diborane are investigated using several methods. The most sophisticated method is the variable reaction coordinate-variational transition state theory (VRC-VTST) which has been developed to handle reactions with no enthalpic barriers. The calculated rate constant of 8.2 × 10(-11) cm(3)·molecule(-1)·s(-1) at 545 K is in good agreement with experiment. The rate constant was also computed using conventional VTST with the G4 composite method. Two variations of the multistep mechanisms for diborane pyrolysis are presented. One is initiated by the step B2H6 ⇄ 2 BH3 while the other begins with 2 B2H6 ⇄ B3H9 + BH3 as the initial elementary step. Both variations are 3/2 order in diborane and have the same activation energy (G4, 28.65 kcal/mol at 420 K). In contrast, the traditional mechanism involving a B3H9 intermediate with C3v symmetry has a higher activation energy (33.37 kcal/mol). The two variations involve a C2-symmetry penta-coordinate B3H9 structure that, while an electronic minimum, is not a stationary point on the free energy path between B2H6 + BH3 → B3H7 + H2. While the calculated activation barrier is higher than the recently determined experimental barrier, the variation in reported values is large (22.0-29.0 kcal/mol). We discuss possible sources of disagreement between experiment and theory.
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Affiliation(s)
- Baili Sun
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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B30H8, B39H9 2−, B42H10, B48H10, and B72H12: polycyclic aromatic snub hydroboron clusters analogous to polycyclic aromatic hydrocarbons. J Mol Model 2012; 19:1195-204. [DOI: 10.1007/s00894-012-1640-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/07/2012] [Indexed: 10/27/2022]
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Li DZ, Lu HG, Li SD. Planar π-aromatic C3h B6H 3 + and π-antiaromatic C2h B8H2: boron hydride analogues of D3h C3H 3 + and D2h C4H4. J Mol Model 2012; 18:3161-7. [DOI: 10.1007/s00894-011-1322-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Accepted: 11/24/2011] [Indexed: 10/14/2022]
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Li DZ, Chen Q, Wu YB, Lu HG, Li SD. Double-chain planar D2h B4H2, C2h B8H2, and C2h B12H2: conjugated aromatic borenes. Phys Chem Chem Phys 2012; 14:14769-74. [DOI: 10.1039/c2cp40902j] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Lee TB, McKee ML. Dissolution Thermochemistry of Alkali Metal Dianion Salts (M2X1, M = Li+, Na+, and K+ with X = CO32–, SO42–, C8H82–, and B12H122–). Inorg Chem 2011; 50:11412-22. [DOI: 10.1021/ic201176s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tae Bum Lee
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Michael L. McKee
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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Srinivasu K, Chandrakumar KRS, Ghosh SK. Ab Initio Studies on the Electronic Structure and Properties of Aluminum Hydrides that Are Analogues of Boron Hydrides. J Phys Chem A 2010; 114:12244-50. [DOI: 10.1021/jp103088m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- K. Srinivasu
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai 400 085, India
| | | | - Swapan K. Ghosh
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai 400 085, India
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18
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Theoretical study for the molecular structures and spectroscopic properties of various boron hydrides (B nH n, B nH n+1, B nH n+2, n = 3-6). JOURNAL OF THE KOREAN CHEMICAL SOCIETY-DAEHAN HWAHAK HOE JEE 2010. [DOI: 10.5012/jkcs.2010.54.4.387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Olson JK, Boldyrev AI. Ab Initio Search for Global Minimum Structures of the Novel B3Hy (y=4−7) Neutral and Anionic Clusters. Inorg Chem 2009; 48:10060-7. [DOI: 10.1021/ic900905h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Jared K. Olson
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322-0300
| | - Alexander I. Boldyrev
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322-0300
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Förster D, Hübschle CB, Luger P, Hügle T, Lentz D. On the 2-Electron 3-Center B−H−B Bond: Charge Density Determination of Tetraborane(10). Inorg Chem 2008; 47:1874-6. [DOI: 10.1021/ic701924r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Diana Förster
- Institut für Chemie und Biochemie/Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34−36, 14195 Berlin, Germany, and Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin, Fabeckstrasse 36a, 14195 Berlin, Germany
| | - Christian B. Hübschle
- Institut für Chemie und Biochemie/Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34−36, 14195 Berlin, Germany, and Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin, Fabeckstrasse 36a, 14195 Berlin, Germany
| | - Peter Luger
- Institut für Chemie und Biochemie/Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34−36, 14195 Berlin, Germany, and Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin, Fabeckstrasse 36a, 14195 Berlin, Germany
| | - Thomas Hügle
- Institut für Chemie und Biochemie/Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34−36, 14195 Berlin, Germany, and Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin, Fabeckstrasse 36a, 14195 Berlin, Germany
| | - Dieter Lentz
- Institut für Chemie und Biochemie/Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34−36, 14195 Berlin, Germany, and Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin, Fabeckstrasse 36a, 14195 Berlin, Germany
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Nguyen MT, Matus MH, Dixon DA. Heats of Formation of Boron Hydride Anions and Dianions and Their Ammonium Salts [BnHmy-][NH4+]y with y = 1−2. Inorg Chem 2007; 46:7561-70. [PMID: 17691770 DOI: 10.1021/ic700941c] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thermochemical parameters of the closo boron hydride BnHn2- dianions, with n=5-12, the B3H8- and B11H14- anions, and the B5H9 and B10H14 neutral species were predicted by high-level ab initio electronic structure calculations. Total atomization energies obtained from coupled-cluster CCSD(T)/complete basis set (CBS) extrapolated energies, plus additional corrections were used to predict the heats of formation of the simplest BnHmy- species in the gas phase in kcal/mol at 298 K: DeltaHf(B3H8-)=-23.1+/-1.0; DeltaHf(B5H52-)=119.4+/-1.5; DeltaHf(B6H62-)=64.1+/-1.5; and DeltaHf(B5H9)=24.1+/-1.5. The heats of formation of the larger species were evaluated by the G3 method from hydrogenation reactions (values at 298 K, in kcal/mol with estimated error bars of+/-3 kcal/mol): DeltaHf(B7H72-)=51.8; DeltaHf(B8H82-)=46.1; DeltaHf(B9H92-)=24.4; DeltaHf(B10H102-)=-12.5; DeltaHf(B11H112-)=-11.8; DeltaHf(B12H122-)=-86.3; DeltaHf(B11H14-)=-57.3; and DeltaHf(B10H14)=18.7. A linear correlation between atomization energies of the dianions and energies of the BH units was found. The heats of formation of the ammonium salts of the anions and dianions were predicted using lattice energies (UL) calculated from an empirical expression based on ionic volumes. The UL values (0 K) of the BnHn2- dianions range from 319 to 372 kcal/mol. The values of UL for the B3H8- and B11H14- anions are 113 and 135 kcal/mol, respectively. The calculated lattice energies and gas-phase heats of formation of the constituent ions were used to predict the heats of formation of the ammonium crystal salts [BnHmy-][NH4+]y. These results were used to evaluate the thermodynamics of the H2 release reactions from the ammonium hydro-borate salts.
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Affiliation(s)
- Minh Tho Nguyen
- Department of Chemistry, The University of Alabama, Shelby Hall, Tuscaloosa, Alabama 35487-0336, USA
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An investigation of hydrogen bonded neutral B4Hn (n=1–11) and anionic clusters: Density functional study. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.theochem.2006.10.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
Ten low-lying conformers of beta-alanine have been studied by the hybrid density functional B3LYP/aug-cc-pVDZ method. Energetic extrapolation calculations at the MP3 and MP4(SDQ) levels of theory and the theoretical photoelectron spectra simulated with the electron propagation theory demonstrate that there are at least three gauche conformers (G1, G2, and G3) in gas-phase experiments. The calculated ionization potentials are in good agreement with the experimental data available in the literature. Natural bond orbital and atoms-in-molecules analyses exhibit a remarkable influence on the molecular electronic structures by the strong intramolecular hydrogen bonding O-H...N in the neutral conformer G2. Remarkable internal rotations of the COOH group are found in the cationic G1+ and G3+ with respect to the neutral conformers. A distonic [NH3+-(CH2)2-COO*] radical can be formed through the spontaneous intramolecular proton transfer in G2+. A novel intramolecular hydrogen bonding, C-H...O, is found in the anti A1+ cation.
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Affiliation(s)
- Shan Xi Tian
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Bond Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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Pratt LM, Van Nguyên N. Novel diborane-analogue transition structures for borane reactions with alkyl halides. J Phys Chem A 2006; 110:687-90. [PMID: 16405341 DOI: 10.1021/jp054057p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ab initio and DFT calculations were performed to examine the mechanisms of reduction of alkyl halides and formaldehyde by borane. With alkyl halides, the optimized transition structure geometry resembled diborane, with a pair of hydrogen atoms bridging the boron and carbon atoms by three-center-two-electron bonds. A similar transition structure was found for the reduction of formaldehyde, although it was not the lowest-energy transition structure. Solvation by dimethyl ether or dimethyl sulfide disrupted this bridging with chloromethane, while both ligands dissociated from borane during the reduction of formaldehyde. The high calculated activation free energies of alkyl halide reduction are consistent with their observed lack of reactivity with borane.
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Affiliation(s)
- Lawrence M Pratt
- Department of Chemistry, Fisk University, 1000 17th Ave. N., Nashville, Tennessee 37209, USA.
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Tian SX. Theoretical Study of Isoelectronic Molecules: B6H10, 2-CB5H9, 2,3-C2B4H8, 2,3,4-C3B3H7, and 2,3,4,5-C4B2H6. J Phys Chem A 2005; 109:6580-6. [PMID: 16834005 DOI: 10.1021/jp051663b] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Isoelectronic molecules regarding B6H10, 2-CB5H9, 2,3-C2B4H8, 2,3,4-C3B3H7, and 2,3,4,5-C4B2H6 are studied by the density functional B3LYP/6-311G(d,p) method and the electron propagator theory in the partial third-order quasiparticale approximation, as well as the extrapolated calculation with the coupled-cluster CCSD(T) theory. The calculated ionization potentials are in good agreement with the experimental data from photoelectron spectroscopy. Valence structures are characterized with natural orbital bond (NBO) theory, exhibiting the multiple three-center two-electron bonds B-H-B, B-B-B, C-B-B, B-C-B, and C-B-C, and chemical bond rearrangements in the cations.
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Affiliation(s)
- Shan Xi Tian
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Bond Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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