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Nakamura T, Mesuda A, Kudo T. Theoretical Study of the Si/C Mixed Benzenes and Their Major Valence Isomers. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Taiji Nakamura
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, Kiryu 376-8515, Japan
| | - Atsumi Mesuda
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, Kiryu 376-8515, Japan
| | - Takako Kudo
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, Kiryu 376-8515, Japan
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2
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Pino-Rios R, Vásquez-Espinal A, Alvarez-Thon L, Tiznado W. Relativistic effects on the aromaticity of E3M3H3 (E = C–Pb; M = N–Bi) benzene analogues. Phys Chem Chem Phys 2020; 22:22973-22978. [DOI: 10.1039/d0cp04446f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The relativistic effects on the aromaticity of a set of benzene analogues, E3M3H3 (E = C–Pb; M = N–Bi) heterocycles, using magnetically induced current density (MICD) and the NICSzz component of the conventional nucleus independent chemical shift (NICS), is hereby examined.
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Affiliation(s)
- Ricardo Pino-Rios
- Laboratorio de Química Teórica
- Facultad de Química y Biología
- Universidad de Santiago de Chile (USACH)
- Av. Libertador Bernardo O’Higgins
- Santiago
| | - Alejandro Vásquez-Espinal
- Computational and Theoretical Chemistry Group
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
| | | | - William Tiznado
- Computational and Theoretical Chemistry Group
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
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3
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Kudo T, Schmidt MW, Matsunaga N. Ab Initio Molecular Orbital Study of the First Four Si/C Alternately Substituted Annulenes. J Phys Chem A 2019; 123:4588-4598. [DOI: 10.1021/acs.jpca.9b02631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takako Kudo
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, Kiryu 376-8515, Japan
| | - Michael W. Schmidt
- Department of Chemistry, Iowa State University, Ames, Iowa 50011-2030, United States
| | - Nikita Matsunaga
- Department of Chemistry & Biochemistry, Long Island University, Brooklyn, New York 11201, United States
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4
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Nakamura T, Kudo T. The planarity of heteroatom analogues of benzene: Energy component analysis and the planarization of hexasilabenzene. J Comput Chem 2019; 40:581-590. [PMID: 30575087 DOI: 10.1002/jcc.25743] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 10/03/2018] [Accepted: 10/09/2018] [Indexed: 11/07/2022]
Abstract
There are various nonplanar heteroatom analogues of benzene-cyclic 6π electron systems-and among them, hexasilabenzene (Si6 H6 ) is well known as a typical example. To determine the factors that control their planarity, quantum chemical calculations and an energy component analysis were performed. The results show that the energy components mainly controlling the planarity of benzene and hexasilabenzene are different. For hexasilabenzene, electron repulsion energy was found to be significantly important for the planarity. The application of the pseudo Jahn-Teller effect and the Carter-Goddard-Malrieu-Trinquier model for the interpretation of the planarity of the benzene analogues was also investigated. Furthermore, based on the quantitative results, it was revealed that the planarization of hexasilabenzene is realized by introducing substituents with π-accepting ability, such as the boryl group, that bring about a reduction of the π-electron repulsion on the silicon skeleton. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Taiji Nakamura
- Devision of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, Kiryu 376-8515, Japan
| | - Takako Kudo
- Devision of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, Kiryu 376-8515, Japan
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5
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Seitz AE, Eckhardt M, Erlebach A, Peresypkina EV, Sierka M, Scheer M. Pnictogen-Silicon Analogues of Benzene. J Am Chem Soc 2016; 138:10433-6. [PMID: 27513314 DOI: 10.1021/jacs.6b07389] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Since the discovery of the first "inorganic benzene" (borazine, B3N3H6), the synthesis of other noncarbon derivatives is an ongoing challenge in Inorganic Chemistry. Here we report on the synthesis of the first pnictogen-silicon congeners of benzene, the triarsa- and the triphospha-trisilabenzene [(PhC(NtBu)2)3Si3E3] (E = P (1a), As (1b)) by a simple metathesis reaction. These compounds are formed by the reaction of [Cp″2Zr(η(1:1)-E4)] (E = P, As; Cp″ = C5H3tBu2) with [PhC(NtBu)2SiCl] in toluene at room temperature along with the silicon pnictogen congeners of the cyclobutadiene, [(PhC(NtBu)2)2Si2E2] (E = P (2a), As (2b)), which is unprecedented for the arsenic system 2b. All compounds were comprehensively characterized, and density functional theory calculations were performed to verify the stability and the aromatic character of the triarsa- and the triphospha-trisilabenzene.
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Affiliation(s)
- Andreas E Seitz
- Institute of Inorganic Chemistry, University of Regensburg , Universitätsstr. 31, 93040 Regensburg, Germany
| | - Maria Eckhardt
- Institute of Inorganic Chemistry, University of Regensburg , Universitätsstr. 31, 93040 Regensburg, Germany
| | - Andreas Erlebach
- Otto-Schott-Institut für Materialforschung, Friedrich-Schiller-Universität Jena , Löbdergraben 32, 07743 Jena, Germany
| | - Eugenia V Peresypkina
- Institute of Inorganic Chemistry, University of Regensburg , Universitätsstr. 31, 93040 Regensburg, Germany.,Nikolaev Institute of Inorganic Chemistry SB RAS , Ak. Lavrentiev prosp. 3, 630090 Novosibirsk, Russia
| | - Marek Sierka
- Otto-Schott-Institut für Materialforschung, Friedrich-Schiller-Universität Jena , Löbdergraben 32, 07743 Jena, Germany
| | - Manfred Scheer
- Institute of Inorganic Chemistry, University of Regensburg , Universitätsstr. 31, 93040 Regensburg, Germany
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6
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West AC, Schmidt MW, Gordon MS, Ruedenberg K. A comprehensive analysis of molecule-intrinsic quasi-atomic, bonding, and correlating orbitals. I. Hartree-Fock wave functions. J Chem Phys 2014; 139:234107. [PMID: 24359352 DOI: 10.1063/1.4840776] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Through a basis-set-independent web of localizing orbital-transformations, the electronic wave function of a molecule is expressed in terms of a set of orbitals that reveal the atomic structure and the bonding pattern of a molecule. The analysis is based on resolving the valence orbital space in terms of an internal space, which has minimal basis set dimensions, and an external space. In the internal space, oriented quasi-atomic orbitals and split-localized molecular orbitals are determined by new, fast localization methods. The density matrix between the oriented quasi-atomic orbitals as well as the locations of the split-localized orbitals exhibit atomic populations and inter-atomic bonding patterns. A correlation-adapted quasi-atomic basis is determined in the external orbital space. The general formulations are specified in detail for Hartree-Fock wave functions. Applications to specific molecules exemplify the general scheme.
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Affiliation(s)
- Aaron C West
- Department of Chemistry and Ames Laboratory USDOE, Iowa State University, Ames, Iowa 50011, USA
| | - Michael W Schmidt
- Department of Chemistry and Ames Laboratory USDOE, Iowa State University, Ames, Iowa 50011, USA
| | - Mark S Gordon
- Department of Chemistry and Ames Laboratory USDOE, Iowa State University, Ames, Iowa 50011, USA
| | - Klaus Ruedenberg
- Department of Chemistry and Ames Laboratory USDOE, Iowa State University, Ames, Iowa 50011, USA
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7
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Nagase S. Theory and Calculations of Molecules Containing Heavier Main Group Elements and Fullerenes Encaging Transition Metals: Interplay with Experiment. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2014. [DOI: 10.1246/bcsj.20130266] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Shigeru Nagase
- Fukui Institute for Fundamental Chemistry, Kyoto University
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8
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RASEKH MAHTABFATHI. THEORETICAL INVESTIGATION ON THE STRUCTURE AND PROPERTIES OF ALUMAZINE⋯M COMPLEXES ( M = Li+, Na+, K+, Be2+, Mg2+, AND Ca2+). JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s0219633613500338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The nature of alumazine⋯M ( M = Li+ , Na+ , K+ , Be2+ , Mg2+ , AND Ca2+ ) interactions was studied by ab initio calculations. The interaction energies were calculated at MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p) level. The calculations suggest that the size and charge of cation are two important factors that affect the interaction energy, charge transfer values and the variation in aromaticity of alumazine ring upon complexation. The theory of atoms in molecules (AIM) and natural bond orbital (NBO) analyses of complexes indicate that the variation of densities and the extent of charge shifts upon complexation correlate well with the obtained interaction energies. Finally, nucleus independent chemical shift (NICS) method was applied for evaluating the variation in aromaticity of alumazine ring upon complexation.
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Affiliation(s)
- MAHTAB FATHI RASEKH
- Department of Chemistry, Sharif University of Technology, Azadi Avenue, Tehran, Iran
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9
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FEREYDUNI EHSAN, KAMAEE MAHDI, SOLEYMANI REZA, AHMADI ROYA. THE SUBSTITUTION EFFECT ON THE AROMATICITY OF SOME N-PHENYLACETAMIDE DERIVATIVES: A DFT STUDY. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2012. [DOI: 10.1142/s0219633612500903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The relative aromaticity of some N-phenylacetamide (NPA) derivatives were investigated in which the NPA was substituted by NO2, CN, CF3, Br, Cl, F, H, CH3 , and NH2 groups at two meta and para positions. For this purpose, density functional theory calculations were applied at the B3LYP/6-31+G(d,p) level to calculate the aromaticity indices including nucleus independent chemical shift (NICS), harmonic oscillator model of aromaticity (HOMA) and harmonic oscillator model of electron delocalization (HOMED). The obtained results indicated that the aromaticity of derivatives decreased in the order of NO 2 > CN > CF 3 > Br > Cl > F > H > CH 3 > NH 2 for both meta and para positions. Furthermore, the resulting order was directly related to the electron withdrawing and electron releasing strengths of the substituents. Finally, it was found that all the aromaticity indices of have a good correlation with the Hammett constant.
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Affiliation(s)
- EHSAN FEREYDUNI
- Department of Chemistry, Tabriz Branch, Islamic Azad University, Tabriz, Iran
| | - MAHDI KAMAEE
- Department of Chemistry, Shahid Chamran University, Ahvaz, Iran
| | - REZA SOLEYMANI
- Young Researchers Club, Shahre-Rey Branch, Islamic Azad University, Tehran, Iran
| | - ROYA AHMADI
- Department of Chemistry, Shahre-Rey Branch, Islamic Azad University, Tehran, Iran
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10
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Ivanov AS, Boldyrev AI. Si6–nCnH6 (n = 0–6) Series: When Do Silabenzenes Become Planar and Global Minima? J Phys Chem A 2012; 116:9591-8. [DOI: 10.1021/jp307722q] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Alexander S. Ivanov
- Department
of Chemistry and Biochemistry, Utah State University, 0300 Old Main
Hill, Logan, Utah 84322, United States
| | - Alexander I. Boldyrev
- Department
of Chemistry and Biochemistry, Utah State University, 0300 Old Main
Hill, Logan, Utah 84322, United States
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11
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Chakraborty A, Bandaru S, Das R, Duley S, Giri S, Goswami K, Mondal S, Pan S, Sen S, Chattaraj PK. Some novel molecular frameworks involving representative elements. Phys Chem Chem Phys 2012; 14:14784-802. [PMID: 22777087 DOI: 10.1039/c2cp41424d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Several new molecular frameworks with interesting structures, based on clusters of main group elements have been studied at different levels of theory with various basis sets. Conceptual density functional theory based reactivity descriptors and nucleus independent chemical shift provide important insights into their bonding, reactivity, stability and aromaticity.
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Affiliation(s)
- Arindam Chakraborty
- Department of Chemistry and Center for Theoretical Studies, Indian Institute of Technology, Kharagpur-721 302, India
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12
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Mo Y, Hiberty PC, Schleyer PVR. How to properly compute the resonance energy within the ab initio valence bond theory: a response to the ZHJVL paper. Theor Chem Acc 2010. [DOI: 10.1007/s00214-010-0794-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Affiliation(s)
- Yirong Mo
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008
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14
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Lee VY, Sekiguchi A. Cyclic polyenes of heavy group 14 elements: new generation ligands for transition-metal complexes. Chem Soc Rev 2008; 37:1652-65. [DOI: 10.1039/b800580j] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Löbl J, Timoshkin AY, Cong T, Necas M, Roesky HW, Pinkas J. Alumazene Adducts with Pyridines: Synthesis, Structure, and Stability Studies. Inorg Chem 2007; 46:5678-85. [PMID: 17567003 DOI: 10.1021/ic700488p] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lewis acid-base adducts of the alumazene [2,6-(i-Pr)2C6H3NAlMe]3 (1) with pyridine (py) and 4-dimethylaminopyridine (dmap) were synthesized and structurally characterized: 1(py)2 (2), 1(py)3 (3), 1(dmap)2 (4), and 1(py)(dmap) (5). The bisadducts 2, 4, and 5 form the trans isomers. The trisadduct 3 exhibits an unexpected cis-cis isomer and can be prepared only in the presence of excess py. The planarity of the alumazene ring is lost upon coordination of the Lewis base molecules. A comparison of the Al-N(base) bond distances and pyramidality at Al suggests the higher basicity of dmap. NMR spectroscopy confirms stability to dissociation of the bisadducts in solution while the trisadduct 3 is labile and converts to 2. The thermodynamics of the adduct formation has been investigated experimentally and theoretically. Thermodynamic characteristics of the 1(py)n (n=2, 3) dissociation reactions in the temperature range 25-200 degrees C have been derived from the vapor pressure-temperature dependence measurements by the static tensimetric method. In all experiments, excess py was employed. Quantum chemical computations at the B3LYP/6-31G* level of theory have been performed for the 1(py)n and model complexes [HAlNH]3(py)n (n=1-3). Obtained results indicate that for the gas phase adducts upon increasing the number of py ligands the donor-acceptor Al-N(py) distance increases in accord with decreasing donor-acceptor bond dissociation energies.
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Affiliation(s)
- Jiri Löbl
- Department of Chemistry, Masaryk University, Kotlarska 2, CZ-61137 Brno, Czech Republic
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16
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Mo Y, von Ragué Schleyer P. An energetic measure of aromaticity and antiaromaticity based on the Pauling-Wheland resonance energies. Chemistry 2007; 12:2009-20. [PMID: 16342222 DOI: 10.1002/chem.200500376] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Various criteria based on geometric, energetic, magnetic, and electronic properties are employed to delineate aromatic and antiaromatic systems. The recently proposed block-localized wave function (BLW) method evaluates the original Pauling-Wheland adiabatic resonance energy (ARE), defined as the energy difference between the real conjugated system and the corresponding virtual most stable resonance structure. The BLW-derived ARE of benzene is 57.5 kcal mol(-1) with the 6-311+G** basis set. Kistiakowsky's historical experimental evaluation of the stabilization energy of benzene (36 kcal mol(-1)), based on heats of hydrogenation, seriously underestimates this quantity due to the neglect of the partially counterbalancing hyperconjugative stabilization of cyclohexene, employed as the reference olefin (three times) in Kistiakowsky's evaluation. Based instead on the bond-separation-energy reaction involving ethene, which has no hyperconjugation, as well as methane and ethane, the experimental resonance energy of benzene is found to be 65.0 kcal mol(-1). We derived the "extra cyclic resonance energy" (ECRE) to characterize and measure the extra stabilization (aromaticity) of conjugated rings. ECRE is the difference between the AREs of a fully cyclically conjugated compound and an appropriate model with corresponding, but interrupted (acyclic) conjugation. Based on 1,3,5-hexatriene, which also has three double bonds, the ECRE of benzene is 36.7 kcal mol(-1), whereas based on 1,3,5,7-octatetraene, which has three diene conjugations, the ECRE of benzene is 25.7 kcal mol(-1). Computations on a series of aromatic, nonaromatic, and antiaromatic five-membered rings validate the BLW-computed resonance energies (ARE). ECRE data on the five-membered rings (derived from comparisons with acyclic models) correlate well with nucleus-independent chemical shift (NICS) and other quantitative aromaticity criteria. The ARE of cyclobutadiene is almost the same as butadiene but is 10.5 kcal mol(-1) less than 1,3,5-hexatriene, which also has two diene conjugations. The instability and high reactivity of cyclobutadiene thus mainly result from the sigma-frame strain and the pi-pi Pauli repulsion.
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Affiliation(s)
- Yirong Mo
- Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008, USA.
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17
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Fernández I, Frenking G. Direct estimate of conjugation and aromaticity in cyclic compounds with the EDA method. Faraday Discuss 2007; 135:403-21; discussion 489-506. [PMID: 17328439 DOI: 10.1039/b606835a] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The nature of the interatomic interactions in cyclic conjugated molecules has been investigated with the Energy Decomposition Analysis (EDA). The focus of this work is on the strength of the pi bonding and pi conjugation in carbocyclic and heterocyclic molecules. The calculated deltaE(pi) values suggest that the EDA may be used directly for estimating the strength of pi conjugation in aromatic, homoaromatic, homoantiaromatic and antiaromatic compounds. The theoretical data show a pattern which agrees with the 4n + 2 rule. The extra aromatic stabilization energy has been obtained by comparing cyclic conjugation with the strength of pi conjugation in acyclic reference compounds. The deltaE(pi) values indicate that benzene is significantly stabilized by aromatic stabilization, but the total pi bonding contribution to the carbon-carbon bonding becomes even more stabilizing when the geometry is distorted toward a D(3h) form which has three long and three short C-C bonds. The D(6h) equilibrium structure is enforced by the sigma orbital interactions and by the quasiclassical electrostatic attraction. The VRE and ASE values suggest that pyridine is more strongly stabilized by aromatic conjugation than benzene. The EDA data of the six-membered cyclic 6pi species C5H5E (E = CH, N-Bi) and (HB = NH)3 predicts strength of aromatic stabilization in the order N > CH > P > As > Bi >> borazine. The ASE values of the five-membered heterocyclic systems C4H4E (E = NH, O, S) are smaller than for the benzene analogues showing the order NH approximately S > O. The ASE value for Cp is very small which probably comes from the choice of the reference system. The VRE results indicate that Cp is strongly stabilized by cyclic conjugation. The ASE values for the cyclic singlet carbenes indicate weak aromatic stabilization in the 2pi system cyclopropenylidene which is much stronger in the 6pi compound cycloheptatrienylidene while the 4pi molecule cylopentadienylidene is clearly antiaromatic. The triplet states of all three cyclic carbenes are antiaromatic. The strength of the pi conjugation in the homoconjugated cyclic compounds suggests weak aromatic stabilization in the 6pi compounds 1,3-cyclobutene and 1,3-cyclopentadiene but weak antiaromatic destabilization in the 2pi compound cyclopropene and in the 8pi molecules 1,3-cyclohexadiene and 1,3,5-cycloheptatriene. The 4n + 2 rule thus holds also for homoconjugated systems. A large negative value for the ASE is calculated for 1,3-cyclobutadiene.
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Affiliation(s)
- Israel Fernández
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany
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18
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Löbl J, Necas M, Pinkas J. Alumazene adducts with triphenylphosphine oxide. MAIN GROUP CHEMISTRY 2006. [DOI: 10.1080/10241220600923850] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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Chen Z, Wannere CS, Corminboeuf C, Puchta R, Schleyer PVR. Nucleus-independent chemical shifts (NICS) as an aromaticity criterion. Chem Rev 2005; 105:3842-88. [PMID: 16218569 DOI: 10.1021/cr030088+] [Citation(s) in RCA: 2278] [Impact Index Per Article: 119.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhongfang Chen
- Computational Chemistry Annex, The University of Georgia, Athens, GA 30602-2525, USA.
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20
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Cyrański MK. Energetic aspects of cyclic pi-electron delocalization: evaluation of the methods of estimating aromatic stabilization energies. Chem Rev 2005; 105:3773-811. [PMID: 16218567 DOI: 10.1021/cr0300845] [Citation(s) in RCA: 468] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Abstract
The energetic ionic liquids formed by the 1,2,4-triazolium cation family and dinitramide anion are investigated by ab initio quantum chemistry calculations, to address the following questions: How does substitution at the triazolium ring's nitrogen atoms affect its heat of formation, and its charge delocalization? What kind of ion dimer structures might exist? And, do deprotonation reactions occur, as a possible first step in the decomposition of these materials?
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Affiliation(s)
- Michael W Schmidt
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA
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22
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Dworkin A, Naumann R, Seigfred C, Karty JM, Mo Y. Y-Aromaticity: Why Is the Trimethylenemethane Dication More Stable than the Butadienyl Dication? J Org Chem 2005; 70:7605-16. [PMID: 16149789 DOI: 10.1021/jo0508090] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reactions: see text] Resonance energies of the trimethylenemethane dication (1) and the butadienyl dication (4) were evaluated using two independent computational methodologies to provide insight into the validity of Y-aromaticity. One methodology employed density functional theory calculations and examined the resonance contribution of the C=C double bond toward the double hydride abstraction enthalpies of methylpropene (6) and 2-butene (8), yielding 1 and 4, respectively. These resonance contributions by the double bond were determined by calculating the double hydride abstraction enthalpies of both the parallel and perpendicular conformations of vinylogues of 6 and 8, in which n = 1-4 vinyl units were inserted between the central carbon-carbon double bond and each of the reaction centers. Extrapolation of the resonance contribution in each vinylogue to n = 0 yielded the resonance contribution in the respective parent molecules. The second methodology employed an orbital deletion procedure (ODP), which effectively allowed us to examine the energies of individual resonance structures. The resonance energy of each dication is computed as the difference between the most stable resonance structure and that of the delocalized species. The two methodologies are in agreement, suggesting that the resonance energy of the trimethylenemethane dication is substantially greater than that of the butadienyl dication. The origin of this difference in resonance stabilization is discussed.
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Affiliation(s)
- Amy Dworkin
- Department of Chemistry, Elon University, 2625 Campus Box, Elon, North Carolina 27244, USA
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23
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Benker D, Klapötke TM, Kuhn G, Li J, Miller C. An ab initio valence bond (VB) calculation of the π delocalization energy in borazine, B3N3H6. HETEROATOM CHEMISTRY 2005. [DOI: 10.1002/hc.20095] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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24
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Phukan AK, Kalagi RP, Gadre SR, Jemmis ED. Structure, reactivity and aromaticity of acenes and their BN analogues: a density functional and electrostatic investigation. Inorg Chem 2004; 43:5824-32. [PMID: 15360231 DOI: 10.1021/ic049690o] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Density functional calculations have been carried out on a series of linearly annelated acenes and their BN analogues. Even though borazine shows aromatic and reactivity behavior parallel with that of benzene, its condensed derivatives show patterns different from those of their hydrocarbon analogues. Nucleus independent chemical shift (NICS) values in acenes suggest that the aromaticity of the inner rings is more than that of benzene, whereas in BN-acenes there is no substantial change in the aromaticity of the individual rings. Molecular electrostatic potential (MESP) is employed to obtain further insights into the bonding and reactivity trends for these systems. The MESP topography patterns of acenes and BN-acenes are substantially different, with BN-acenes showing more localized pi electron features compared to those of acenes. The MESP values at the critical points (CPs) indicate overall lowering of aromaticity in these annelated systems. However, this change is gradual among the BN-acenes.
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Abstract
The interest over the magnitude of the conjugation effect in the allyl cation (1) and anion (2) has been revived recently by Barbour and Karty (J. Org. Chem. 2004, 69, 648-654), who derived the resonance energies of 20-22 and 17-18 kcal/mol for 1 and 2, respectively, using an empirical extrapolation approximation. This paper revisits the case by explicitly calculating the Pauling-Wheland resonance energy, which measures the stabilization from the most stable resonance structure to the delocalized energy-minimum state of a conjugated system, using our newly developed block-localized wave function (BLW) method. This BLW method has the geometrical optimization capability. The computations result in adiabatic resonance energies of 37 kcal/mol for 1 and 38 kcal/mol for 2. The significant disagreement between these values and Barbour and Karty's results originates from the neglect of structural and electronic variations in their derivation which are energy costing.
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Affiliation(s)
- Yirong Mo
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, USA.
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26
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Cyrański MK, Schleyer PVR, Krygowski TM, Jiao H, Hohlneicher G. Facts and artifacts about aromatic stability estimation. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)00137-6] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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27
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Timoshkin AY, Frenking G. "True" inorganic heterocycles: structures and stability of group 13-15 analogues of benzene and their dimers. Inorg Chem 2003; 42:60-9. [PMID: 12513078 DOI: 10.1021/ic020361a] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Group 13-15 inorganic analogues of benzene, [HMYH](3) (M = B, Al, Ga; Y = N, P, As), mixed heterocycles of the type [BAlGaNPAs]H(6) and their dimers have been theoretically examined at the B3LYP/TZVP level of theory. Six different isomers have been structurally characterized for the mixed compounds [BAlGaNPAs]H(6). B-N bonding strongly (about approximately 90-100 kJ mol(-)(1)) stabilizes the mixed heterocycles, followed by the preference of the Al-N bonded structures over Ga-N bonded ( approximately 30-40 kJ mol(-1)), while B-P bonding is slightly (5-10 kJ mol(-1)) more favorable compared to B-As. Thus, the bonding pattern is predicted to be the most stable, followed by the core. Processes of [HMYH](3) formation from donor-acceptor complexes H(3)MYH(3) are predicted to be thermodynamically favorable for all MY combinations. Dimerization reactions of the coordinationally unsaturated [HMYH](3) heterocycles yielding hexamer clusters [HMYH](6) are found to be exothermic, with the exception of borazine, for which, as for benzene, dimerization is strongly endothermic due to the aromaticity of C(6)H(6) and [HBNH](3). Despite the high endothermicity of [HBNH](3) dimerization, the B-N bond formation is the driving force of the dimerization of mixed species [BAlGaNPAs]H(6). The dimerization enthalpies of [BAlGaNPAs]H(6) may be both exo- and endothermic, depending on the bonding pattern of the isomers. A complete set of mean MY bond energies in four- and six-membered cycles of [HMYH](6) was derived. The MY energies were found to be transferable quantities and may serve for a qualitative prediction of the relative stability of different isomers of mixed cluster compounds. [BAlGaNPAs](2)H(12) clusters are promising synthetic targets, they are expected to serve as single-source precursors for the stoichiometry-controlled CVD processes of the group 13-15 composites. A strategy of their synthesis and the most suitable starting systems have been also predicted.
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Affiliation(s)
- Alexey Y Timoshkin
- Inorganic Chemistry Group, Department of Chemistry, St. Petersburg State University, University Pr. 26, Old Peterhof 198504, Russia.
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28
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Priyakumar UD, Sastry GN. Theoretical Study of Silabenzene and Its Valence Isomers. Organometallics 2002. [DOI: 10.1021/om011001i] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- U. Deva Priyakumar
- Department of Chemistry, Pondicherry University, Pondicherry-605 014, India
| | - G. Narahari Sastry
- Department of Chemistry, Pondicherry University, Pondicherry-605 014, India
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29
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Priyakumar UD, Sastry GN. A theoretical study of the structures, energetics, stabilities, reactivities, and out-of-plane distortive tendencies of skeletally substituted benzenes (CH)(5)XH and (CH)(4)(XH)(2) (X = B(-), N(+), Al(-), Si, P(+), Ga(-), Ge, and As(+)). J Org Chem 2002; 67:271-81. [PMID: 11777471 DOI: 10.1021/jo0161781] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ab initio molecular orbital theory at Hartree-Fock (HF), post-Hartree-Fock (MP2 and CCSD(T)), and the hybrid density functional theory (B3LYP) calculations were done on the mono-(CH)(5)XH and diskeletally substituted (CH)(4)(XH)(2) benzenes (X = B(-), N(+), Al(-), Si, P(+), Ga(-), Ge, and As(+)). The computed relative energies of the disubstituted isomers show interesting trends. While the ortho-isomer is the most stable for X = Ga(-), Ge, and As(+), meta was found to be the most stable for X = B(-), N(+), Al(-) and Si, and para was found to be the most stable for X = P(+). Various intricate factors that govern the relative stabilities, such as the sum of bond strengths in the twin Kekule forms, rule of topological charge stabilization (TCS), and electrostatic repulsion were critically examined. The sum of bond strengths in the twin Kekule forms was proved to be quite a successful measure in predicting the relative stability orders between ortho- and meta-/para-isomers. The rule of TCS breaks down especially in the presence of overwhelming factors such as the differences in the cumulative bond strengths of the two positional isomers; however, the stability ordering between the para- and meta-isomers is successfully predicted in most cases. The tendency for ring puckering increases a great deal especially when the substituents are from 3rd or 4th row. Extension of the popular inverse relationship between the thermodynamic stability and reactivity was found to be inapplicable for this class of compounds. The computed singlet-triplet energy differences and the chemical hardness (eta) values indicate that the skeletal substitution weakens the pi-strength of the benzenoid system and increases their reactivity.
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Affiliation(s)
- U Deva Priyakumar
- Department of Chemistry, Pondicherry University, Pondicherry-605 014, India
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Kiran B, Phukan AK, Jemmis ED. Is borazine aromatic? Unusual parallel behavior between hydrocarbons and corresponding B-N analogues. Inorg Chem 2001; 40:3615-8. [PMID: 11421714 DOI: 10.1021/ic001394y] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- B Kiran
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
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Baldridge KK, Uzan O, Martin JML. The Silabenzenes: Structure, Properties, and Aromaticity. Organometallics 2000. [DOI: 10.1021/om9903745] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kim K. Baldridge
- San Diego Supercomputer Center, 9500 Gilman Drive, Building 109, La Jolla, California 92093-0505
| | - Olivier Uzan
- Department of Organic Chemistry, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Jan M. L. Martin
- Department of Organic Chemistry, Weizmann Institute of Science, 76100 Rehovot, Israel
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Krygowski T, Cyrañski M, Czarnocki Z, Häfelinger G, Katritzky AR. Aromaticity: a Theoretical Concept of Immense Practical Importance. Tetrahedron 2000. [DOI: 10.1016/s0040-4020(99)00979-5] [Citation(s) in RCA: 324] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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McKee ML. Ab Initio Study of BnHn and Bn(NH2)n (n = 3−6) Species. A Comparison of Classical and Nonclassical Structures. Inorg Chem 1998. [DOI: 10.1021/ic981034z] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael L. McKee
- Department of Chemistry, Auburn University, Auburn, Alabama 36849
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Abstract
The multiconfiguration self-consistent field (MCSCF) method offers the most general approach to the computation of chemical reactions and multiple electronic states. This review discusses the design of MCSCF wavefunctions for treating these problems and the interpretation of the resulting orbitals and configurations. In particular, localized orbitals are convenient both for selection of the appropriate active space and for understanding the computed results. The computational procedures for optimizing these wavefunctions and the techniques for recovery of dynamical correlation energy are reviewed.
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Affiliation(s)
- M W Schmidt
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
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36
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Jemmis ED, Kiran B. Aromaticity in X(3)Y(3)H(6) (X = B, Al, Ga; Y = N, P, As), X(3)Z(3)H(3) (Z = O, S, Se), and Phosphazenes. Theoretical Study of the Structures, Energetics, and Magnetic Properties. Inorg Chem 1998; 37:2110-2116. [PMID: 11670363 DOI: 10.1021/ic970737y] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A systematic estimation of aromaticity in X(3)Y(3)H(6), 1, (X = B, Al, Ga; Y = N, P, As), P(3)N(3)H(6), 2, and X(3)Z(3)H(3), 3 (Z = O, S, Se), has been conducted using structural, energetic, and magnetic criteria. Estimates based on aromatic stabilization energy (ASE) calculations predict that 1BN (1; X = B, Y = N) and 1BP are equally aromatic. Contrary to this, we have found, from magnetic susceptibility exaltation (MSE) and from the nucleus independent chemical shift (NICS) data at the B3LYP/6-31G level, that 1BN is not aromatic while 1BP is. This emphasizes the fact that energetic and magnetic criteria need not be parallel. On the basis of MSE and NICS values, all 1XP compounds show strong aromatic character; 1XAs are borderline aromatic while 1XN compounds are nonaromatic. Despite being aromatic, all 1XP and 1XAs compounds are found to prefer nonplanar geometries. MSE and NICS criteria can also diverge quite strongly; this has been observed in the X(3)Z(3)H(3) family. MSE values for 3BS, 3BSe, 3AlO, 3AlS, and 3GaS are more than half of the MSE value for benzene, indicating substantial aromatic character. However, NICS estimates point to the contrary; none of the type 3 compounds are aromatic. The problem with the ASE and MSE is that both depend on the choice of the reference systems while NICS, which avoids the need for reference molecules, is impossible to vary experimentally. In spite of this epistemological deficiency of NICS, we find it complementary to the ASE and MSE criteria. Despite the existence of a large number of well-established structures and substantial aromatic stabilization energy, phosphazenes, 2, are not aromatic according to NICS data.
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Xie Y, Schreiner PR, Schaefer HF, Li XW, Robinson GH. Are Heterocyclic 2π-Electron Aromatic Systems HC−Ga(H)−CH, M[HGa−C(H)−GaH], [HGa−C(H)−GaH]-, HSi−Ga(H)−SiH, M[HGa−Si(H)−GaH] (M = Li, Na, and K), and [HGa−Si(H)−GaH]- Stable? Organometallics 1998. [DOI: 10.1021/om970719o] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yaoming Xie
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602-2556, the Institut für Organische Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany, and the Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - Peter R. Schreiner
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602-2556, the Institut für Organische Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany, and the Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602-2556, the Institut für Organische Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany, and the Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - Xiao-Wang Li
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602-2556, the Institut für Organische Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany, and the Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - Gregory H. Robinson
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602-2556, the Institut für Organische Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany, and the Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
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Schleyer PVR, Jiao H, Hommes NJRVE, Malkin VG, Malkina OL. An Evaluation of the Aromaticity of Inorganic Rings: Refined Evidence from Magnetic Properties. J Am Chem Soc 1997. [DOI: 10.1021/ja9719135] [Citation(s) in RCA: 829] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul von Ragué Schleyer
- Computer Chemistry Center, Institut für Organische Chemie, Universität Erlangen-Nürnberg Henkestrasse 42, D-91054 Erlangen, Germany Institut of Inorganic Chemistry Slovak Academy of Sciences Dubravska Cesta, SK.84236, Bratislava, Slovakia
| | - Haijun Jiao
- Computer Chemistry Center, Institut für Organische Chemie, Universität Erlangen-Nürnberg Henkestrasse 42, D-91054 Erlangen, Germany Institut of Inorganic Chemistry Slovak Academy of Sciences Dubravska Cesta, SK.84236, Bratislava, Slovakia
| | - Nicolaas J. R. van Eikema Hommes
- Computer Chemistry Center, Institut für Organische Chemie, Universität Erlangen-Nürnberg Henkestrasse 42, D-91054 Erlangen, Germany Institut of Inorganic Chemistry Slovak Academy of Sciences Dubravska Cesta, SK.84236, Bratislava, Slovakia
| | - Vladimir G. Malkin
- Computer Chemistry Center, Institut für Organische Chemie, Universität Erlangen-Nürnberg Henkestrasse 42, D-91054 Erlangen, Germany Institut of Inorganic Chemistry Slovak Academy of Sciences Dubravska Cesta, SK.84236, Bratislava, Slovakia
| | - Olga L. Malkina
- Computer Chemistry Center, Institut für Organische Chemie, Universität Erlangen-Nürnberg Henkestrasse 42, D-91054 Erlangen, Germany Institut of Inorganic Chemistry Slovak Academy of Sciences Dubravska Cesta, SK.84236, Bratislava, Slovakia
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40
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Davy RD, Schaefer HF. Structure, Spectra, and Reaction Energies of the Aluminum−Phosphorus Rings (HAl−PH)2 and (H2Al−PH2)2 and the (HAl−PH)4 Cluster. J Phys Chem A 1997. [DOI: 10.1021/jp9705535] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Randall D. Davy
- Department of Chemistry, Liberty University, Lynchburg, Virginia 24502
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
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41
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Davy RD, Schaefer HF. Aluminum−Phosphorus Compounds with Low Coordination Numbers: Structures, Energies, and Vibrational Frequencies of the AlPH2, AlPH3, and AlPH4 Isomers and the H3Al−PH3 Adduct. J Phys Chem A 1997. [DOI: 10.1021/jp962387r] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Randall D. Davy
- Department of Chemistry, Liberty University, Lynchburg, Virginia 24502
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
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42
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Hamilton TP, Shaikh AW. Theoretical Study of the Dimerization of Multiply-Bonded Aluminum−Nitrogen Compounds. Inorg Chem 1997. [DOI: 10.1021/ic961248l] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tracy P. Hamilton
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Adam W. Shaikh
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294
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Matsunaga N, Koseki S, Gordon MS. Relativistic potential energy surfaces of XH2 (X=C, Si, Ge, Sn, and Pb) molecules: Coupling of 1A1 and 3B1 states. J Chem Phys 1996. [DOI: 10.1063/1.471515] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Srinivas G, Kiran B, Jemmis ED. H-bridged alternatives to the homologues of cyclopropane. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/0166-1280(95)04319-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Schmidt MW, Baldridge KK, Boatz JA, Elbert ST, Gordon MS, Jensen JH, Koseki S, Matsunaga N, Nguyen KA, Su S, Windus TL, Dupuis M, Montgomery JA. General atomic and molecular electronic structure system. J Comput Chem 1993. [DOI: 10.1002/jcc.540141112] [Citation(s) in RCA: 17153] [Impact Index Per Article: 553.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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