1
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Karadakov PB. How Different are the Diamagnetic and Paramagnetic Contributions to Off-Nucleus Shielding in Aromatic and Antiaromatic Rings? Chemphyschem 2023; 24:e202300038. [PMID: 36811600 DOI: 10.1002/cphc.202300038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/15/2023] [Accepted: 02/21/2023] [Indexed: 02/24/2023]
Abstract
The spatial variations in the diamagnetic and paramagnetic contributions to the off-nucleus isotropic shielding, σ i s o r = σ i s o d r + σ i s o p r ${\ {{\sigma }_{{\rm i}{\rm s}{\rm o}}\left({\bf r}\right)=\ \sigma }_{{\rm i}{\rm s}{\rm o}}^{{\rm d}}\left({\bf r}\right)+{\sigma }_{{\rm i}{\rm s}{\rm o}}^{{\rm p}}\left({\bf r}\right)}$ , and to the zz component of the off-nucleus shielding tensor, σ z z r = σ z z d r + σ z z p r ${{{\sigma }_{zz}\left({\bf r}\right)=\sigma }_{zz}^{{\rm d}}\left({\bf r}\right)+{\sigma }_{zz}^{{\rm p}}\left({\bf r}\right)}$ , around benzene (C6 H6 ) and cyclobutadiene (C4 H4 ) are investigated using complete-active-space self-consistent field wavefunctions. Despite the substantial differences between σ i s o r ${{\sigma }_{{\rm i}{\rm s}{\rm o}}\left({\bf r}\right)}$ and σ z z r ${{\sigma }_{zz}\left({\bf r}\right)}$ around the aromatic C6 H6 and the antiaromatic C4 H4 , the diamagnetic and paramagnetic contributions to these quantities, σ i s o d r ${{\sigma }_{{\rm i}{\rm s}{\rm o}}^{{\rm d}}\left({\bf r}\right)}$ and σ z z d r ${{\sigma }_{zz}^{{\rm d}}\left({\bf r}\right)}$ , and σ i s o p r ${{\sigma }_{{\rm i}{\rm s}{\rm o}}^{{\rm p}}\left({\bf r}\right)}$ and σ z z P r ${{\sigma }_{zz}^{{\rm P}}\left({\bf r}\right)}$ , are found to behave similarly in the two molecules, shielding and deshielding, respectively, each ring and its surroundings. The different signs of the most popular aromaticity criterion, the nucleus-independent chemical shift (NICS), in C6 H6 and C4 H4 are shown to follow from a change in the balance between the respective diamagnetic and paramagnetic contributions. Thus, the different NICS values for antiaromatic and antiaromatic molecules cannot be attributed to differences in the ease of access to excited states only; differences in the electron density, which determines the overall bonding picture, also play an important role.
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Affiliation(s)
- Peter B Karadakov
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
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2
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Roy T, Thimmakondu VS, Ghosal S. New Carbenes and Cyclic Allenes Energetically Comparable to Experimentally Known 1-Azulenylcarbene. ACS OMEGA 2022; 7:30149-30160. [PMID: 36061723 PMCID: PMC9435053 DOI: 10.1021/acsomega.2c03224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
1-Azulenylcarbene (18; 0 kJ mol-1) is experimentally known as the key reactive intermediate for the rearrangement reactions of aryl carbenes in the laboratory. Here, using coupled-cluster methods up to the fc-CCSD(T)/cc-pVTZ//fc-CCSD(T)/cc-pVDZ level, thirteen new carbenes and one new cyclic allene are theoretically identified within the C11H8 elemental composition that either energetically lie below or very close to 18. While the cyclic allene, bicyclo[5.4.0]undeca-2,3,5,7,9,11-hexene (1; -166 kJ mol-1), is the experimentally known lowest energy isomer, three other cyclic allenes, bicyclo[5.4.0]undeca-1,2,4,6,8,10-hexene (2; -100 kJ mol-1), bicyclo[5.4.0]undeca-1,3,4,6,8,10-hexene (3; -97 kJ mol-1), and bicyclo[6.3.0]undeca-1,2,4,6,8,10-hexene (13; -42 kJ mol-1), demand new experimental studies. In total, thirty-one isomers are studied in this work (within -166 to +15 kJ mol-1 from 18) and all are found to be polar (μ ≠ 0). Among these, 1H-benzo[7]annulen-1-ylidene (17; -4 kJ mol-1; μ = 5.24 D), bicyclo[5.4.0]undeca-2,4,6,8,11-pentaene-10-ylidene (24; 13 kJ mol-1; μ = 7.59 D), 5-methylene-naphthalen-1-ylidene (26; 15 kJ mol-1; μ = 5.32 D), 6-methylene-naphthalen-2-ylidene (27; -43 kJ mol-1; μ = 6.60 D), and 8-methylene-naphthalen-2-ylidene (28; -39 kJ mol-1; μ = 5.55 D) are competitively polar compared to 18 (μ = 5.39 D). Therefore, these carbene molecules are potential targets for rotational spectroscopists and radioastronomers. Considering the importance of naphthyl and azulenylcarbenes in reactive intermediate chemistry, mechanisms of different rearrangement reactions and plausible formation pathways of some of these new carbenes are studied in this work using density functional theory.
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Affiliation(s)
- Tarun Roy
- Department
of Chemistry, National Institute of Technology
Durgapur, M G Avenue, Durgapur 713
209, India
| | - Venkatesan S. Thimmakondu
- Department
of Chemistry and Biochemistry, San Diego
State University, San Diego, California 92182-1030, United States
| | - Subhas Ghosal
- Department
of Chemistry, National Institute of Technology
Durgapur, M G Avenue, Durgapur 713
209, India
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3
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El-Meligy A, El-Demerdash SH, Abdel-Rahman MA, Mahmoud MAM, Taketsugu T, El-Nahas AM. Structures, Energetics, and Spectra of (NH) and (OH) Tautomers of 2-(2-Hydroxyphenyl)-1-azaazulene: A Density Functional Theory/Time-Dependent Density Functional Theory Study. ACS OMEGA 2022; 7:14222-14238. [PMID: 35559155 PMCID: PMC9089341 DOI: 10.1021/acsomega.2c00866] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 04/05/2022] [Indexed: 06/15/2023]
Abstract
Tautomerization of 2-(2-hydroxyphenyl)-1-azaazulene (2OHPhAZ) in the gas phase and ethanol has been studied using B3LYP, M06-2X, and ωB97XD density functional theory (DFT) with different basis sets. For more accurate data, energies were refined at CCSD(T)/6-311++G(2d,2p) in the gas phase. Nuclear magnetic resonance (NMR), aromaticity, Fukui functions, acidity, and basicity were also calculated and compared with experimental data. Time-dependent density functional theory (TDDFT)-solvation model based on density (TDDFT-SMD) calculations in acetonitrile have been utilized for the simulation of UV-vis electronic spectra. In addition, electronic structures of the investigated system have been discussed. The results reveal that the enol form (2OHPhAZ) is thermodynamically and kinetically stable relative to the keto tautomer (2OPhAZ) and different rotamers (2OHPhAZ-R1:R3) in the gas phase and ethanol. A comparison with the experiment illustrates a good agreement and supports the computational findings.
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Affiliation(s)
- Asmaa
B. El-Meligy
- Chemistry
Department, Faculty of Science, Menoufia
University, Shebin
El-Kom 32512, Egypt
| | | | | | - Mohamed A. M. Mahmoud
- Basic
Sciences Department, Tanta Higher Institute
of Engineering and Technology, Tanta 31511, Egypt
| | - Tetsuya Taketsugu
- Department
of Chemistry, Faculty of Science, Hokkaido
University, Sapporo 060-0810, Japan
- Institute
for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido
University, Sapporo 060-0810, Japan
| | - Ahmed M. El-Nahas
- Chemistry
Department, Faculty of Science, Menoufia
University, Shebin
El-Kom 32512, Egypt
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4
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Roy T, Ghosal S, Thimmakondu VS. Six Low-Lying Isomers of C 11H 8 Are Unidentified in the Laboratory-A Theoretical Study. J Phys Chem A 2021; 125:4352-4364. [PMID: 34003652 DOI: 10.1021/acs.jpca.1c02247] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Isomers of C11H8 have been theoretically examined using density functional theory and coupled-cluster methods. The current investigation reveals that 2aH-cyclopenta[cd]indene (2), 7-ethynyl-1H-indene (6), 4-ethynyl-1H-indene (7), 6-ethynyl-1H-indene (8), 5-ethynyl-1H-indene (9), and 7bH-cyclopenta[cd]indene (10) remain elusive till date in the laboratory. The puckered low-lying isomer 2 lies at 9 kJ mol-1 below the experimentally known molecule, cyclobuta[de]naphthalene (3), at the fc-CCSD(T)/cc-pVTZ//fc-CCSD(T)/cc-pVDZ level of theory. 2 lies at 36 kJ mol-1 above the thermodynamically most stable and experimentally known isomer, 1H-cyclopenta[cd]indene (1), at the same level. It is identified that 1,2-H transfer from 1 yields 2H-cyclopenta[cd]indene (14) and subsequent 1,2-H shift from 14 yields 2. Appropriate transition states have been identified, and intrinsic reaction coordinate calculations have been carried out at the B3LYP/6-311+G(d,p) level of theory. Recently, 1-ethynyl-1H-indene (11) has been detected using synchrotron-based vacuum ultraviolet ionization mass spectrometry. 2-Ethynyl-1H-indene (4) and 3-ethynyl-1H-indene (5) have been synthetically characterized in the past. While the derivatives of 7bH-cyclopenta[cd]indene (10) have been isolated elsewhere, the parent compound remains unidentified till date in the laboratory. Although C11H8 is a key elemental composition of astronomical interest for the formation of polycyclic aromatic hydrocarbons in the interstellar medium, none of its low-lying isomers have been characterized by rotational spectroscopy though they are having a permanent dipole moment (μ ≠ 0). Therefore, energetic and spectroscopic properties have been computed, and the present investigation necessitates new synthetic studies on C11H8, in particular 2, 6-10, and also rotational spectroscopic studies on all low-lying isomers.
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Affiliation(s)
- Tarun Roy
- Department of Chemistry, National Institute of Technology Durgapur, M G Avenue, Durgapur 713 209, India
| | - Subhas Ghosal
- Department of Chemistry, National Institute of Technology Durgapur, M G Avenue, Durgapur 713 209, India
| | - Venkatesan S Thimmakondu
- Department of Chemistry and Biochemistry, San Diego State University, San Diego 92182-1030, California, United States
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Abstract
Dissociation pathways of the global minimum geometry of Si2C5H2 with a planar tetracoordinate carbon (ptC) atom, 2,7-disilatricyclo[4.1.0.01,3]hept-2,4,6-trien-2,7-diyl (1), have been theoretically investigated using density functional theory and coupled-cluster (CC) methods. Dissociation of Si-C bond connected to the ptC atom leads to the formation of 4,7-disilabicyclo[4.1.0]hept-1(6),4(5)-dien-2-yn-7-ylidene (4) through a single transition state. Dissociation of C-C bond connected to the ptC atom leads to an intermediate with two identical transition states and leads back to 1 itself. Simultaneous breaking of both Si-C and C-C bonds leads to an acyclic transition state, which forms an acyclic product, cis-1,7-disilahept-1,2,3,5,6-pentaen-1,7-diylidene (19). Overall, two different products, four transition states, and an intermediate have been identified at the B3LYP/6-311++G(2d,2p) level of theory. Intrinsic reaction coordinate calculations have also been done at the latter level to confirm the isomerization pathways. CC calculations have been done at the CCSD(T)/cc-pVTZ level of theory for all minima. Importantly, all reaction profiles for 1 are found be endothermic in Si2C5H2. These results are in stark contrast compared to the structurally similar and isovalent lowest-energy isomer of C7H2 with a ptC atom as the overall reaction profiles there have been found to be exothermic. The activation energies for Si-C, C-C, and Si-C/C-C breaking are found to be 30.51, 64.05, and 61.85 kcal mol−1, respectively. Thus, it is emphasized here that 1 is a kinetically stable molecule. However, it remains elusive in the laboratory to date. Therefore, energetic and spectroscopic parameters have been documented here, which may be of relevance to molecular spectroscopists in identifying this key anti-van’t-Hoff-Le Bel molecule.
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6
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Pandey AP, Padidela UK, Thulasiraman LK, Sethu R, Vairaprakash P, Thimmakondu VS. MgC 6H 2 Isomers: Potential Candidates for Laboratory and Radioastronomical Studies. J Phys Chem A 2020; 124:7518-7525. [PMID: 32804506 DOI: 10.1021/acs.jpca.0c06401] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Eighty three stationary points of MgC6H2 isomers spanning from 0 to 215 kcal mol-1 have been theoretically identified using density functional theory at the B3LYP/6-311++G(2d,2p) level of theory. Among them, four low-lying isomers lying within 23.06 kcal mol-1 (1 eV) have been further characterized in detail using high-level coupled-cluster (CC) methods. The thermodynamically most stable isomer turns out to be 1-magnesacyclohepta-4-en-2,6-diyne (1). The other three isomers, 3-magnesahepta-1,4,6-triyne (2), 1-magnesacyclohepta-2,3,4-trien-6-yne (3), and 1-magnesahepta-2,4,6-triyne (4) lie 8.24, 19.76, and 21.36 kcal mol-1, respectively, above 1 at the ae-CCSD(T)/cc-pCVTZ level of theory. All the four isomers are polar with a permanent electric dipole moment (μ ≠ 0). Hence, they are potential candidates for rotational spectroscopic studies. Considering the recent identification of magnesium-bearing hydrocarbons such as, MgC2H and MgC4H in IRC+10216, it is believed that the current theoretical data may be of relevance to laboratory molecular spectroscopic and radioastronomical studies on MgC6H2 isomers. The energetic and spectroscopic information gathered in this study would aid the detection of low-lying MgC6H2 isomers in the laboratory, which are indispensable for radioastronomical studies. It is also noted here that neither the National Institute of Standards and Technology Chemistry WebBook nor the Kinetic Database for Astrochemistry lists any isomer of MgC6H2 at the moment. Therefore, these isomers are studied here theoretically for the very first time.
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Affiliation(s)
- Aditya P Pandey
- Electrical and Computer Engineering, College of Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States.,Department of Chemistry, Birla Institute of Technology and Science, Pilani, K K Birla Goa Campus, Goa - 403 726, India
| | - Uday Kumar Padidela
- Department of Chemistry, Birla Institute of Technology and Science, Pilani, K K Birla Goa Campus, Goa - 403 726, India
| | - Loganathan Konda Thulasiraman
- Department of Chemistry, Alagappa Chettiar Government College of Engineering and Technology, Karaikudi 630 003, Tamil Nadu, India
| | - Ramakrishnan Sethu
- Department of Microbiology, University of Illinois, 601 South Goodwin Avenue, Urbana, Illinois 61801, United States
| | - Pothiappan Vairaprakash
- Department of Chemistry, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur - 613 401, Tamil Nadu, India
| | - Venkatesan S Thimmakondu
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030, United States
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7
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Job N, Karton A, Thirumoorthy K, Cooksy AL, Thimmakondu VS. Theoretical Studies of SiC 4H 2 Isomers Delineate Three Low-Lying Silylidenes Are Missing in the Laboratory. J Phys Chem A 2020; 124:987-1002. [PMID: 31904236 DOI: 10.1021/acs.jpca.9b11742] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Eleven isomers of SiC4H2 lying within 50 kcal mol-1 have been theoretically investigated using density functional theory and high-level coupled-cluster methods. Among them, four isomers, 1-ethynyl-3-silacycloprop-1(2)-en-3-ylidene (1), diethynylsilylidene (2), 1-sila-1,2,3,4-pentatetraenylidene (4), and 1,3-butadiynylsilylidene (5), have already been identified in the laboratory. The current investigation reports three low-lying (<1 eV) silylidenes [2-methylenesilabicyclo[1.1.0]but-1(3)-en-4-ylidene (3), 4-sila-2-methylenebicyclo[1.1.0]but-1(3)-en-4-ylidene (6), and 3-ethynyl-1-silapropadienylidene (7)] and three high-lying (>1 eV) silylidenes [2-sila-(didehydrovinylidene)cyclopropene (8), an isomer with a planar tetracoordinate carbon (ptC) atom (10), and 1-ethynyl-1-silapropadienylidene (11)], which remain elusive in the laboratory to date. Isomer 9 also contains a ptC atom, which turned out to be a transition state at all levels. Though all isomers are polar (μ ≠ 0), rotational spectrum is available only for 4. Using matrix isolation, three isomers (1, 2, and 5) have been trapped in the laboratory at 10 K. Considering the astrochemical relevance of silicon-carbide clusters in the interstellar medium, the current theoretical data demand new molecular spectroscopic studies on SiC4H2. Surprisingly, unlike the isovalent C5H2 isomers, where the bent carbenes are yet to be identified in the laboratory, the bent silylidenes (2 and 5) have been trapped in the case of SiC4H2. In both the cases, molecules with transannular C-C and/or Si-C bonds remain elusive, though they lie in the low-lying region. Using suitable precursors, whether these peculiar geometries (especially 3 and 6) would be identified or not in the laboratory needs to be addressed by molecular spectroscopists. The present investigation documents structural and spectroscopic information of SiC4H2 isomers, which may compliment future molecular spectroscopic observations including radioastronomical searches.
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Affiliation(s)
- Nisha Job
- Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore 632014 , Tamil Nadu , India
| | - Amir Karton
- School of Molecular Sciences , The University of Western Australia , Perth , Western Australia 6009 , Australia
| | - Krishnan Thirumoorthy
- Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore 632014 , Tamil Nadu , India
| | - Andrew L Cooksy
- Department of Chemistry and Biochemistry , San Diego State University , San Diego , California 92182-1030 , United States
| | - Venkatesan S Thimmakondu
- Department of Chemistry and Biochemistry , San Diego State University , San Diego , California 92182-1030 , United States
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8
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Báez-Grez R, Pino-Rios R. Borataalkene or boratabenzene? Understanding the aromaticity of 9-borataphenanthrene anions and its central ring. NEW J CHEM 2020. [DOI: 10.1039/d0nj03942j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The recently isolated 1 is isoelectronic to 2 and shows reactivity in central ring that resembles both (cyclo)alkene and aromatic ring. Evaluation of local aromaticity reveal that central ring is best described as a non-aromatic following Clar’s rules.
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Affiliation(s)
- Rodrigo Báez-Grez
- Computational and Theoretical Chemistry Group
- Departamento de Ciencias Química
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- República 498
| | - Ricardo Pino-Rios
- Laboratorio de Química teórica
- Facultad de Química y Biología
- Universidad de Santiago de Chile (USACH) Av. Libertador Bernardo O’Higgins 3363
- Estación Central
- Chile
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9
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Thirumoorthy K, Viji M, Pandey AP, Netke TG, Sekar B, Yadav G, Deshpande S, Thimmakondu VS. Many unknowns below or close to the experimentally known cumulene carbene – A case study of C9H2 isomers. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.110496] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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11
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Monaco G, Zanasi R. Analysis of the Nucleus-Independent Chemical Shifts of [10]Cyclophenacene: Is It an Aromatic or Antiaromatic Molecule? J Phys Chem Lett 2017; 8:4673-4678. [PMID: 28892392 DOI: 10.1021/acs.jpclett.7b01937] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
[10]Cyclophenacene is an important synthetic target that shows a pair of nucleus-independent chemical shift (NICS) values for the center of mass and six-membered rings typical of an aromatic species. This is found in contrast with the global paratropic current density induced by a magnetic field parallel to the main symmetry axis. This apparent contradiction has been analyzed by studying the tensor character of the magnetic response. It turns out that the molecule displays two characters, one paratropic (antiaromatic) and another one diatropic (aromatic), depending on the orientation of the inducing magnetic field. The paratropic response, which cannot be recognized from the NICS values, is associated with a well-defined destabilization of the belt closure, as witnessed by homodesmotic reactions. A scalar measure of magnetic aromaticity, the field-independent current strength, has been introduced, which allows us to reach the conclusion that [10]cyclophenacene is indeed an aromatic molecule, although it is significantly affected by the paratropic response.
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Affiliation(s)
- Guglielmo Monaco
- Department of Chemistry and Biology "A. Zambelli", University of Salerno , via Giovanni Paolo II 132, Fisciano (SA) 84084, Italy
| | - Riccardo Zanasi
- Department of Chemistry and Biology "A. Zambelli", University of Salerno , via Giovanni Paolo II 132, Fisciano (SA) 84084, Italy
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12
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Dixit VA, Goundry WRF, Tomasi S. CC/B–N substitution in five membered heterocycles. A computational analysis. NEW J CHEM 2017. [DOI: 10.1039/c7nj00950j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel five-membered azaboroles are aromatic, stable under neutral conditions, isomer stabilization energy is explained using σ-bond and aromatic stabilization energies.
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Affiliation(s)
- Vaibhav A. Dixit
- Department of Pharmaceutical Chemistry
- School of Pharmacy & Technology Management (SPTM)
- Shri Vile Parle Kelavani Mandal's (SVKM's)
- Narsee Monjee Institute of Management Studies (NMIMS)
- Mukesh Patel Technology Park
| | | | - Simone Tomasi
- Global Medicines Development
- Process Research and Development
- Macclesfield
- UK
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13
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Deka BC, Purkayastha SK, Sharma H, Bhattacharyya PK. Ground and excited states of neutral and cationic thieno[3,2-b]thiophene: A DFT study. COMPUT THEOR CHEM 2016. [DOI: 10.1016/j.comptc.2016.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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14
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15
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Bhattacharya D, Shil S, Misra A, Bytautas L, Klein DJ. Borazine: spin blocker or not? Phys Chem Chem Phys 2015; 17:14223-37. [DOI: 10.1039/c5cp00801h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Spin-blocker capacity of borazine is investigated formeta-BB,meta-NN andpara-BN structures highlighting the correlation between magnetic properties and aromaticity.
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Affiliation(s)
| | - Suranjan Shil
- Department of Chemistry
- University of North Bengal
- Darjeeling
- India
| | - Anirban Misra
- Department of Chemistry
- University of North Bengal
- Darjeeling
- India
| | | | - Douglas J. Klein
- Department of Marine Sciences
- Texas A&M University at Galveston
- Texas
- USA
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16
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Pelloni S, Monaco G, Della Porta P, Zanasi R, Lazzeretti P. Delocalized Currents without a Ring of Bonded Atoms: Strong Delocalized Electron Currents Induced by Magnetic Fields in Noncyclic Molecules. J Phys Chem A 2014; 118:3367-75. [DOI: 10.1021/jp502491a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stefano Pelloni
- Dipartimento
di Scienze Chimiche e Geologiche, Universitá degli Studi di Modena, via G. Campi 183, 41100 Modena, Italy
| | - Guglielmo Monaco
- Dipartimento
di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, Fisciano 84084 SA, Italy
| | - Paolo Della Porta
- Dipartimento
di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, Fisciano 84084 SA, Italy
| | - Riccardo Zanasi
- Dipartimento
di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, Fisciano 84084 SA, Italy
| | - Paolo Lazzeretti
- Dipartimento
di Scienze Chimiche e Geologiche, Universitá degli Studi di Modena, via G. Campi 183, 41100 Modena, Italy
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17
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Molecular structure and bonding character of mono and divalent metal cations (Li+, Na+, K+, Be2+, Mg2+, and Ca2+) with substituted benzene derivatives: AIM, NBO, and NMR analyses. Struct Chem 2014. [DOI: 10.1007/s11224-014-0405-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Affiliation(s)
- Guglielmo Monaco
- Dipartimento
di Chimica e
Biologia, Universitá degli Studi di Salerno, Via Giovanni
Paolo II, 132, Fisciano 84084 Salerno, Italy
| | - Riccardo Zanasi
- Dipartimento
di Chimica e
Biologia, Universitá degli Studi di Salerno, Via Giovanni
Paolo II, 132, Fisciano 84084 Salerno, Italy
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19
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Monaco G, Zanasi R. Linearized ring current models for the retrieval of π ring current strength in monocycles. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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20
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21
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Müller M, Maichle-Mössmer C, Sirsch P, Bettinger HF. Is There BN Bond-Length Alternation in 1,2:3,4:5,6-Tris(biphenylylene)borazines? Chempluschem 2013; 78:988-994. [DOI: 10.1002/cplu.201300110] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Indexed: 11/09/2022]
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22
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Foroutan-Nejad C, Shahbazian S, Rashidi-Ranjbar P. The critical re-evaluation of the aromatic/antiaromatic nature of Ti3(CO)3: a missed opportunity? Phys Chem Chem Phys 2011; 13:4576-82. [PMID: 21279217 DOI: 10.1039/c0cp01519a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The nature of bonding and aromaticity of Ti(3)(CO)(3), a mill-shaped metal-carbonyl complex, is studied carefully. A unique bonding mechanism between metal and carbonyl groups is found in this species. Ti(3)(CO)(3) is an example of a metal-carbonyl complex with prominent metal to carbonyl donation. Moreover, it is proven that not only is Ti(3)(CO)(3) not an antiaromatic complex but also it is the first synthesized example of d-block, σ+π aromatic species. A quick survey among the first row of transition metals in the periodic table shows that other local minima with similar structures and aromaticity are present and Ti(3)(CO)(3) is the first synthesized species of an unknown family.
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Affiliation(s)
- Cina Foroutan-Nejad
- School of Chemistry, College of Science, University of Tehran, Tehran, Iran.
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24
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Diagnosis of the σ-, π- and (σ+π)-Aromaticity by the Shape of the NICSzz-Scan Curves and Symmetry-Based Selection Rules. Symmetry (Basel) 2010. [DOI: 10.3390/sym2010284] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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25
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Muñoz-Castro A, Mac-Leod Carey D, Arratia-Pérez R. Inside a Superatom: The M7q (M=Cu, Ag, q=1+, 0, 1−) Case. Chemphyschem 2010; 11:646-50. [DOI: 10.1002/cphc.200900714] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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26
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Foroutan-Nejad C, Shahbazian S, Rashidi-Ranjbar P. The electron density vs. NICS scan: a new approach to assess aromaticity in molecules with different ring sizes. Phys Chem Chem Phys 2010; 12:12630-7. [DOI: 10.1039/c004254d] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Wolf R, Uhl W. Hauptgruppenmetallcluster stabilisiert durch N-heterocyclische Carbene. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200902287] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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29
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Bettinger HF, Kar T, Sánchez-García E. Borazine and Benzene Homo- and Heterodimers. J Phys Chem A 2009; 113:3353-9. [DOI: 10.1021/jp808173h] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Holger F. Bettinger
- Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany, Institut für Organische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany, Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300, and Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr, Germany
| | - Tapas Kar
- Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany, Institut für Organische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany, Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300, and Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr, Germany
| | - Elsa Sánchez-García
- Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany, Institut für Organische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany, Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300, and Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr, Germany
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30
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Is nucleus-independent chemical shift scan a reliable aromaticity index for planar and neutral A2B2 clusters? ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2008.09.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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31
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Stanger A. The Different Aromatic Characters of Some Localized Benzene Derivatives. J Phys Chem A 2008; 112:12849-54. [DOI: 10.1021/jp801634x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amnon Stanger
- Schulich Faculty of Chemistry and The Lise-Meitner-Minerva Center for Computational Quantum Chemistry, Technion—Israel Institute of Technology, Haifa 32000, Israel
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