1
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Leyva-Parra L, Pino-Rios R. Update for Isomerization Stabilization Energies: The Fulvenization Approach. ACS OMEGA 2024; 9:1436-1442. [PMID: 38222592 PMCID: PMC10785285 DOI: 10.1021/acsomega.3c07881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/28/2023] [Accepted: 12/04/2023] [Indexed: 01/16/2024]
Abstract
An alternative approach for calculating aromatic stabilization energies is proposed based on transforming an (anti)aromatic ring into a fulvene isomer. This fulvenization process gives a value of 34.05 kcal·mol-1 for benzene in the singlet state and a value of -17.85 kcal·mol-1 in the triplet state. Additionally, it is possible to use experimental values (as long as they exist) for the calculation as the gas-phase formation enthalpies of benzene and fulvene, whose difference is 33.72 kcal·mol-1. On the other hand, this same approach has been evaluated on several six-membered rings, including those persubstituted, biradicals, azines, and inorganic analogues, giving results in agreement with those reported in the literature using different criteria. Additionally, it is possible to differentiate the aromaticity of the rings in polycyclic aromatic hydrocarbons according to Clar's rules. Assigning the (anti)aromatic character in various nonbenzenoid rings (neutral and charged), except for five- and seven-membered rings, is also possible. The construction of the fulvene isomers in PAHs is set such that nonaromaticity-related effects are not considered. The results show that the fulvenization approach is an effective and efficient approach that can serve as an alternative or complement to existing tools.
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Affiliation(s)
- Luis Leyva-Parra
- Departamento
de Ciencias Químicas, Centro de Química Teórica
& Computacional (CQT&C), Universidad
Andrés Bello, Facultad de Ciencias Exactas, Avenida República 275, 8370146 Santiago de Chile, Chile
| | - Ricardo Pino-Rios
- Instituto
de Estudios de la Salud, Universidad Arturo
Prat, 1100000 Iquique, Chile
- Química
y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat, Casilla 121, 1100000 Iquique, Chile
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2
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Báez-Grez R, Pino-Rios R. Evaluation of Slight Changes in Aromaticity through Electronic and Density Functional Reactivity Theory-Based Descriptors. ACS OMEGA 2022; 7:21939-21945. [PMID: 35785290 PMCID: PMC9245093 DOI: 10.1021/acsomega.2c02291] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Aromaticity is a useful tool to rationalize the structure, stability, and reactivity in several compounds. Although aromaticity is not directly an observable, it is well accepted that electronic delocalization around the molecular ring is a key stabilizing feature of aromatic compounds. This contribution presents a systematic evaluation of the capability of delocalization and reactivity criteria to describe aromaticity in a set of fluorinated benzenes. The aromaticity indices are compared with quantities obtained from the magnetic criteria of aromaticity, i.e., the strength of the ring current induced by an external magnetic field and the popular NICS zz (1) index. In this evaluation, the indices based on delocalization criteria used are aromatic fluctuation index (FLU), para-delocalization index (PDI), PDIπ, and the multicenter delocalization index (MCI). In addition, indices based on the bifurcation values of scalar functions are derived from electron density such as electron localization function (the π contribution, ELFπ) and the π contribution of the localized orbital locator (LOLπ). Furthermore, reactivity indices based on chemical reactivity and the information-theoretic (reactivity) approach are para-linear response (PLR), Shannon entropy, Fisher information, and Ghosh-Berkowitz-Parr (GBP) entropy. The results obtained show that the delocalization-based indicators present a high sensitivity to slight changes in aromaticity and that the reactivity criterion can be considered as a complementary tool for the study of this phenomenon, even when these changes are minimal. These results encourage the use of multiple indicators for a complete understanding of aromaticity in various chemical compounds.
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Affiliation(s)
- Rodrigo Báez-Grez
- Computational
and Theoretical Chemistry Group, Departamento de Ciencias Químicas,
Facultad de Ciencias Exactas, Universidad
Andres Bello, República 275, Santiago 8370146, Chile
| | - Ricardo Pino-Rios
- Instituto
de Ciencias Químicas Aplicadas, Facultad de Ingeniería, Universidad Autónoma de Chile, 7500912 Santiago, Chile
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3
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Fuhrer TJ, Houck M, Iacono ST. Fluoromaticity: The Molecular Orbital Contributions of Fluorine Substituents to the π-Systems of Aromatic Rings. ACS OMEGA 2021; 6:32607-32617. [PMID: 34901609 PMCID: PMC8655763 DOI: 10.1021/acsomega.1c04175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
The addition of fluorine atoms to an aromatic ring brings about an additional set of π-bonding and antibonding orbitals culminating after the addition of the sixth fluorine with a new set of π-aromatic-like orbitals that affect the molecule in a way that we will refer to hereafter as "fluoromaticity". Depending on the number and position of the fluorine atoms, the contributed π-orbitals can even further stabilize the ring leading to smaller bond lengths within the ring and higher resistance to addition reactions. This added ring stability partially explains the high thermostability and chemical resistance found in polymers containing fluorinated aromatics in their architecture. A similar molecular orbital effect is seen with the addition of other halogen atoms to aromatic rings, though to a much smaller degree and not resulting in the additional ring stability.
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Affiliation(s)
- Timothy J. Fuhrer
- Department
of Chemistry, Radford University, Box 6949 Radford, Virginia 24142, United States
| | - Matthew Houck
- Department
of Chemistry & Chemistry Research Center, United States Air Force Academy, Colorado Springs, Colorado 80840, United States
| | - Scott T. Iacono
- Department
of Chemistry & Chemistry Research Center, United States Air Force Academy, Colorado Springs, Colorado 80840, United States
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4
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Erb W, Richy N, Hurvois JP, Low PJ, Mongin F. From ferrocene to 1,2,3,4,5-pentafluoroferrocene: halogen effect on the properties of metallocene. Dalton Trans 2021; 50:16933-16938. [PMID: 34779458 DOI: 10.1039/d1dt03430h] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The sequentially fluorinated ferrocenes (1-, 1,2-di, 1,2,3-tri, 1,2,3,4-tetra and 1,2,3,4,5-pentafluoroferrocene) have been synthesized from ferrocene. Rather than a 'perfluoro' effect, experimental and computational analysis of the complete series robustly demonstrates a linear additive effect of fluorine on the electrochemical and spectroscopic properties of ferrocene.
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Affiliation(s)
- William Erb
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
| | - Nicolas Richy
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
| | - Jean-Pierre Hurvois
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
| | - Paul J Low
- School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley 6009, Western Australia, Australia
| | - Florence Mongin
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
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5
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Báez-Grez R, Arrué L, Pino-Rios R. Quantitative analysis of aromaticity in azines by means of dissected descriptors based on the magnetic criteria. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Manrique-de-la-Cuba MF, Leyva-Parra L, Inostroza D, Gomez B, Vásquez-Espinal A, Garza J, Yañez O, Tiznado W. Li 8 Si 8 , Li 10 Si 9 , and Li 12 Si 10 : Assemblies of Lithium-Silicon Aromatic Units. Chemphyschem 2021; 22:906-910. [PMID: 33779015 DOI: 10.1002/cphc.202001051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/18/2021] [Indexed: 11/12/2022]
Abstract
We report the global minima structures of Li8 Si8 , Li10 Si9 , and Li12 Si10 systems, in which silicon moieties maintain structural and chemical bonding characteristics similar to those of their building blocks: the aromatic clusters Td -Li4 Si4 and C2v -Li6 Si5 . Electron counting rules, chemical bonding analysis, and magnetic response properties verify the silicon unit's aromaticity persistence. This study demonstrates the feasibility of assembling silicon-based nanostructures from aromatics clusters as building blocks.
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Affiliation(s)
- María Fernanda Manrique-de-la-Cuba
- Centro de Investigación en Ingeniería Molecular, Universidad Católica de Santa María, 04013, Urb. San José S/N, Umacollo, Arequipa, Perú
| | - Luis Leyva-Parra
- Computational and Theoretical Chemistry Group Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, 8370251, Santiago, Chile.,Programa de Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas, Universidad Andres Bello, Santiago, Chile
| | - Diego Inostroza
- Computational and Theoretical Chemistry Group Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, 8370251, Santiago, Chile.,Programa de Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas, Universidad Andres Bello, Santiago, Chile
| | - Badhin Gomez
- Centro de Investigación en Ingeniería Molecular, Universidad Católica de Santa María, 04013, Urb. San José S/N, Umacollo, Arequipa, Perú
| | - Alejandro Vásquez-Espinal
- Computational and Theoretical Chemistry Group Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, 8370251, Santiago, Chile
| | - Jorge Garza
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, Iztapalapa, 09340, México City, México
| | - Osvaldo Yañez
- Computational and Theoretical Chemistry Group Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, 8370251, Santiago, Chile.,Center of New Drugs for Hypertension (CENDHY), 8370251, Santiago, Chile
| | - William Tiznado
- Computational and Theoretical Chemistry Group Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, 8370251, Santiago, Chile
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7
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Savage DT, Briot NJ, Hilt JZ, Dziubla TD. On the swelling behavior of poly( N-Isopropylacrylamide) hydrogels exposed to perfluoroalkyl acids. JOURNAL OF POLYMER SCIENCE 2021; 59:289-299. [PMID: 34859243 PMCID: PMC8631585 DOI: 10.1002/pol.20200805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 12/18/2020] [Indexed: 11/06/2022]
Abstract
Per- and polyfluoroalkyl substances (PFAS) have rapidly accumulated in the environment due to their widespread use prior to commercial discussion in the early 21st century, and their slow degradation has magnified concerns of their potential toxicity. Monitoring their distribution is, therefore, necessary to evaluate and control their impact on the health of exposed populations. This investigation evaluates the capability of a simple polymeric detection scheme for PFAS based on crosslinked, thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) hydrogels. Surveying swelling perturbations induced by several hydrotropes and comparable hydrocarbon analogs, tetraethylammonium perfluorooctane sulfonate (TPFOS) showed a significantly higher swelling ratio on a mass basis (65.5 ± 8.8 at 15°C) than any of the other analytes tested. Combining swelling with the fluorimetric response of a solvachromatic dye, nile red, revealed the fluorosurfactant to initiate observable aggregation (i.e., its critical aggregation concentration) at 0.05 mM and reach saturation (i.e., its charge neutralization concentration) at 0.5 mM. The fluorosurfactant was found to homogeneously distribute throughout the polymer matrix with energy dispersive X-ray spectroscopy, marking the swelling response as a peculiar nexus of fluorinated interfacial positioning and delocalized electrostatic repulsion. Results from the current study hold promise for exploiting the physiochemical response of PNIPAM to assess TPFOS's concentration.
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Affiliation(s)
- Dustin T. Savage
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky
| | - Nicolas J. Briot
- Electron Microscopy Center, University of Kentucky, Lexington, Kentucky
| | - J. Zach Hilt
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky
| | - Thomas D. Dziubla
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky
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8
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Pino-Rios R, Cárdenas-Jirón G, Tiznado W. Local and macrocyclic (anti)aromaticity of porphyrinoids revealed by the topology of the induced magnetic field. Phys Chem Chem Phys 2020; 22:21267-21274. [PMID: 32935691 DOI: 10.1039/d0cp03272g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The aromaticity in porphyrinoids results from the π conjugation through two different annular perimeters: the macrocyclic ring and the local heterocyclic rings appended to it. Analyses, based on aromatic stabilization energies (ASE), indicate that the local circuits (6π) are responsible for the significant aromatic stabilization of these systems. This local aromaticity can be coupled with the one from 4n + 2π macrocyclic circuit. It can either compensate for the destabilization due to a 4n π macrocyclic circuit, or be the only source of aromatic stabilization in porphyrinoids with macrocycles without π-conjugated bonds. This "multifaceted" aromatic character of porphyrinoids makes it challenging to analyze their aromaticity using magnetic descriptors because of the intricate interaction of local versus macro-cyclic circulation. In this contribution, we show that the analysis of the bifurcation of the induced magnetic field, Bind, allows clear identification and quantification of both local, and macrocyclic aromaticity, in a representative group of porphyrinioids. In porphyrin, bifurcation values accurately predict the local and macrocyclic contribution rate to overall aromatic stabilization determined by ASE.
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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 3363, Santiago, Estación Central, Región Metropolitana, Chile.
| | - Gloria Cárdenas-Jirón
- Laboratorio de Química teórica, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Av. Libertador Bernardo O'Higgins 3363, Santiago, Estación Central, Región Metropolitana, Chile.
| | - William Tiznado
- Departamento de Química, Facultad de Ciencias Exactas, Universidad Andres Bello (UNAB), Av. República 275, Santiago, Región Metropolitana, Chile.
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9
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Pino-Rios R, Vásquez-Espinal A, Yañez O, Tiznado W. Searching for double σ- and π-aromaticity in borazine derivatives. RSC Adv 2020; 10:29705-29711. [PMID: 35518239 PMCID: PMC9056176 DOI: 10.1039/d0ra05939k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/31/2020] [Indexed: 11/25/2022] Open
Abstract
Inspired by the double-aromatic (σ and π) C6H3 +, C6I6 2+, and C6(SePh)6 2+ ring-shaped compounds, herein we theoretically study their borazine derivative analogues. The systems studied are the cation and dications with formulas B3N3H3 +, B3N3Br6 2+, B3N3I6 2+, B3N3(SeH)6 2+, and B3N3(TeH)6 2+. Our DFT calculations indicate that the ring-shaped planar structures of B3N3H3 +, B3N3I6 2+, and B3N3(TeH)6 2+ are more stable in the singlet state, while those of B3N3Br6 2+ and B3N3(SeH)6 2+ prefer the triplet state. Besides, exploration of the potential energy surface shows that the ring-shaped structure is the putative global minimum only for B3N3I6 2+. According to chemical bonding analysis, B3N3H3 +, B3N3I6 2+, and B3N3(TeH)6 2+ have σ and π delocalized bonds. The number of delocalized σ/π electrons is 2/6 for the first, and 10/6 for the second and third, similar to what their carbon analogs exhibit. Finally, the analysis of the magnetically induced current density allows B3N3H3 +, B3N3I6 2+, and B3N3(TeH)6 2+ to be classified as strongly σ aromatic, and poorly π aromatic compounds.
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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 3363 Santiago Estación Central, Región Metropolitana Chile
| | - Alejandro Vásquez-Espinal
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello República 498 Santiago Chile
| | - Osvaldo Yañez
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello República 498 Santiago Chile
- Center for Bioinformatics and Integrative Biology (CBIB), Facultad de Ciencias de la Vida, Universidad Andres Bello Av. Republica 330 Santiago 8370146 Chile
| | - William Tiznado
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello República 498 Santiago Chile
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10
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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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11
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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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12
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Pino-Rios R, Cárdenas-Jirón G. Effect of the meso/beta halogenation in the photoelectronic properties and aromaticity of expanded porphyrins. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2019.112052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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13
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Narsaria AK, Hamlin TA, Lammertsma K, Bickelhaupt FM. Dual Activation of Aromatic Diels-Alder Reactions. Chemistry 2019; 25:9902-9912. [PMID: 31111976 PMCID: PMC6771859 DOI: 10.1002/chem.201901617] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/20/2019] [Indexed: 11/20/2022]
Abstract
The unusually fast Diels-Alder reactions of [5]cyclophanes were analyzed by DFT at the BLYP-D3(BJ)/TZ2P level of theory. The computations were guided by an integrated activation-strain and Kohn-Sham molecular orbital analysis. It is revealed why both [5]metacyclophane and [5]paracyclophane exhibit a significant rate enhancement compared to their planar benzene analogue. The activation strain analyses revealed that the enhanced reactivity originates from 1) predistortion of the aromatic core resulting in a reduced activation strain of the aromatic diene, and/or 2) enhanced interaction with the dienophile through a distortion-controlled lowering of the HOMO-LUMO gap within the diene. Both of these physical mechanisms and thus the rate of Diels-Alder cycloaddition can be tuned through different modes of geometrical distortion (meta versus para bridging) and by heteroatom substitution in the aromatic ring. Judicious choice of the bridge and heteroatom in the aromatic core enables effective tuning of the aromatic Diels-Alder reactivity to achieve activation barriers as low as 2 kcal mol-1 , which is an impressive 35 kcal mol-1 lower than that of benzene.
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Affiliation(s)
- Ayush K. Narsaria
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
| | - Trevor A. Hamlin
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
| | - Koop Lammertsma
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
- Department of ChemistryUniversity of JohannesburgAuckland ParkJohannesburg2006South Africa
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
- Institute for Molecules and Materials (IMM)Radboud UniversityHeyendaalseweg 1356525AJNijmegenThe Netherlands
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14
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Pino‐Rios R, Cárdenas‐Jirón G, Ruiz L, Tiznado W. Interpreting Aromaticity and Antiaromaticity through Bifurcation Analysis of the Induced Magnetic Field. ChemistryOpen 2019; 8:321-326. [PMID: 30906684 PMCID: PMC6414146 DOI: 10.1002/open.201800238] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/09/2019] [Indexed: 11/29/2022] Open
Abstract
In all molecules, a current density is induced when the molecule is subjected to an external magnetic field. In turn, this current density creates a particular magnetic field. In this work, the bifurcation value of the induced magnetic field is analyzed in a representative set of aromatic, non-aromatic and antiaromatic monocycles, as well as a set of polycyclic hydrocarbons. The results show that the bifurcation value of the ring-shaped domain adequately classifies the studied molecules according to their aromatic character. For aromatic and nonaromatic molecules, it is possible to analyze two ring-shaped domains, one diatropic (inside the molecular ring) and one paratropic (outside the molecular ring). Meanwhile, for antiaromatic rings, only a diatropic ring-shaped domain (outside the molecular ring) is possible to analyze, since the paratropic domain (inside the molecular ring) is irreducible with the maximum value (attractor) at the center of the molecular ring. In some of the studied cases, i. e., in heteroatomic species, bifurcation values do not follow aromaticity trends and present some inconsistencies in comparison to ring currents strengths, showing that this approximation provides only a qualitative estimation about (anti)aromaticity.
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Affiliation(s)
- Ricardo Pino‐Rios
- Laboratorio de Química Teórica, Facultad de Química y BiologíaUniversidad de Santiago de Chile (USACH)Av. Libertador Bernardo O'Higgins 3363Santiago, Estación Central, Región MetropolitanaChile
| | - Gloria Cárdenas‐Jirón
- Laboratorio de Química Teórica, Facultad de Química y BiologíaUniversidad de Santiago de Chile (USACH)Av. Libertador Bernardo O'Higgins 3363Santiago, Estación Central, Región MetropolitanaChile
| | - Lina Ruiz
- Instituto de Ciencias Biomédicas, Facultad Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile
| | - William Tiznado
- Departamento de Química, Facultad de Ciencias Exactas, Computational and Theoretical Chemistry GroupUniversidad Andres Bello (UNAB)Av. República 275Santiago, Región MetropolitanaChile
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15
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Yañez O, Vásquez-Espinal A, Báez-Grez R, Rabanal-León WA, Osorio E, Ruiz L, Tiznado W. Carbon rings decorated with group 14 elements: new aromatic clusters containing planar tetracoordinate carbon. NEW J CHEM 2019. [DOI: 10.1039/c9nj01022j] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple and chemically intuitive approach is used to design ptC-containing E–C clusters (E = Si–Pb).
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Affiliation(s)
- Osvaldo Yañez
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
- Chile
| | - Alejandro Vásquez-Espinal
- Computational and Theoretical Chemistry Group
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
| | - Rodrigo Báez-Grez
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
- Chile
| | - Walter A. Rabanal-León
- Laboratorio de Química Inorgánica y Organometálica
- Departamento de Química Analítica e Inorgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Casilla 160-C
| | - Edison Osorio
- Facultad de Ciencias Naturales y Matemáticas
- Universidad de Ibagué
- Ibagué
- Colombia
| | - Lina Ruiz
- Instituto de Ciencias Biomédicas
- Facultad Ciencias de la Salud
- Universidad Autónoma de Chile
- Santiago
- Chile
| | - William Tiznado
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
- Chile
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16
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Rabanal-León WA, Vásquez-Espinal A, Yañez O, Pino-Rios R, Arratia-Pérez R, Alvarez-Thon L, Torres-Vega JJ, Tiznado W. Aromaticity of [M3(µ-X)3X6]0/2-(M = Re and Tc, X = Cl, Br, I) Clusters Confirmed by Ring Current Analysis and Induced Magnetic Field. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800339] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Walter A. Rabanal-León
- Departamento de Ciencias Químicas; Facultad de Ciencias Exactas; Universidad Andres Bello; Av. República 275, Santiago, Chile República 275 Santiago Chile
| | - Alejandro Vásquez-Espinal
- Departamento de Física Aplicada; Centro de Investigación y de Estudios Avanzados; Unidad Mérida; Km 6 Antigua carretera a Progreso, Apdo. Postal 73 97310 Cordemex México
| | - Osvaldo Yañez
- Departamento de Ciencias Químicas; Facultad de Ciencias Exactas; Universidad Andres Bello; Av. República 275, Santiago, Chile República 275 Santiago Chile
| | - Ricardo Pino-Rios
- Departamento de Ciencias Químicas; Facultad de Ciencias Exactas; Universidad Andres Bello; Av. República 275, Santiago, Chile República 275 Santiago Chile
| | - Ramiro Arratia-Pérez
- Universidad Andrés Bello; Doctorado en Fisicoquímica Molecular; República 275 Santiago Chile
| | - Luis Alvarez-Thon
- Facultad de Ingeniería; Universidad Central de Chile; Toesca 1783 Santiago Chile
| | - Juan J. Torres-Vega
- Facultad de Ciencias Físicas; Universidad Nacional Mayor de San Marcos; P.O. Box 14-0149 Lima Perú
| | - William Tiznado
- Departamento de Ciencias Químicas; Facultad de Ciencias Exactas; Universidad Andres Bello; Av. República 275, Santiago, Chile República 275 Santiago Chile
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17
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Vásquez‐Espinal A, Palacio‐Rodríguez K, Ravell E, Orozco‐Ic M, Barroso J, Pan S, Tiznado W, Merino G. E
5
M
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(E=C–Pb, M=Li–Cs): A Source of Viable Star‐Shaped Clusters. Chem Asian J 2018; 13:1751-1755. [DOI: 10.1002/asia.201800654] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/16/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Alejandro Vásquez‐Espinal
- Departamento de Física AplicadaCentro de Investigación y de Estudios Avanzados, Unidad Mérida Km 6 Antigua carretera a Progreso, Apdo. Postal 73, Cordemex 97310 Mérida Yuc. México
| | - Karen Palacio‐Rodríguez
- Química de Recursos Energéticos y Medio AmbienteInstituto de Química, Facultad de Ciencias Exactas y NaturalesUniversidad de Antioquia Calle 70 No. 52-21 Medellín Colombia
| | - Estefanía Ravell
- Departamento de Física AplicadaCentro de Investigación y de Estudios Avanzados, Unidad Mérida Km 6 Antigua carretera a Progreso, Apdo. Postal 73, Cordemex 97310 Mérida Yuc. México
| | - Mesías Orozco‐Ic
- Departamento de Física AplicadaCentro de Investigación y de Estudios Avanzados, Unidad Mérida Km 6 Antigua carretera a Progreso, Apdo. Postal 73, Cordemex 97310 Mérida Yuc. México
| | - Jorge Barroso
- Departamento de Física AplicadaCentro de Investigación y de Estudios Avanzados, Unidad Mérida Km 6 Antigua carretera a Progreso, Apdo. Postal 73, Cordemex 97310 Mérida Yuc. México
| | - Sudip Pan
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech University Nanjing 211816 China
| | - William Tiznado
- Departamento de Ciencias Químicas, Facultad de Ciencias ExactasUniversidad Andres Bello República 275 Santiago Chile
| | - Gabriel Merino
- Departamento de Física AplicadaCentro de Investigación y de Estudios Avanzados, Unidad Mérida Km 6 Antigua carretera a Progreso, Apdo. Postal 73, Cordemex 97310 Mérida Yuc. México
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18
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Báez-Grez R, Rabanal-León WA, Alvarez-Thon L, Ruiz L, Tiznado W, Pino-Rios R. Aromaticity in heterocyclic analogues of benzene: Dissected NICS and current density analysis. J PHYS ORG CHEM 2018. [DOI: 10.1002/poc.3823] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- R. Báez-Grez
- Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas; Universidad Andres Bello; Santiago Chile
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas; Universidad Andres Bello; Santiago Chile
| | - Walter A. Rabanal-León
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas; Universidad Andres Bello; Santiago Chile
| | - Luis Alvarez-Thon
- Facultad de Ingeniería; Universidad Central de Chile; Santiago Chile
| | - Lina Ruiz
- Centro de Investigación Biomédica; Universidad Autónoma de Chile; Santiago Chile
| | - W. Tiznado
- Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas; Universidad Andres Bello; Santiago Chile
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas; Universidad Andres Bello; Santiago Chile
| | - R. Pino-Rios
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas; Universidad Andres Bello; Santiago Chile
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19
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Báez-Grez R, Ruiz L, Pino-Rios R, Tiznado W. Which NICS method is most consistent with ring current analysis? Assessment in simple monocycles. RSC Adv 2018; 8:13446-13453. [PMID: 35542548 PMCID: PMC9079725 DOI: 10.1039/c8ra01263f] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/05/2018] [Indexed: 02/05/2023] Open
Abstract
A linear relationship between NICSzz,π and NICSπ,σ with their current strength counterparts is shown. The comparative analysis was performed in simple and representative monocycles.
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Affiliation(s)
- R. Báez-Grez
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
- Chile
| | - Lina Ruiz
- Instituto de Ciencias Biomédicas
- Universidad Autónoma de Chile
- Santiago
- Chile
| | - R. Pino-Rios
- Departamento de CienciasQuímicas
- Facultad de Ciencias Exactas Universidad Andres Bello
- Santiago
- Chile
- Laboratorio de Química Teórica
| | - W. Tiznado
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
- Chile
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20
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Li J, Li G, Xie Y, King RB, Schaefer HF. Enhanced Relative Stability of Metallabenzenes versus Metallocenes upon Ring Perfluorination: Nickel, Palladium, and Platinum Systems. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jing Li
- MOE Key Laboratory of Theoretical Chemistry of the Environment Center for Computational Quantum Chemistry South China Normal University 510006 Guangzhou P. R. China
| | - Guoliang Li
- MOE Key Laboratory of Theoretical Chemistry of the Environment Center for Computational Quantum Chemistry South China Normal University 510006 Guangzhou P. R. China
- Guangzhou Key Laboratory of Materials for Energy Conversion and Storage School of Chemistry and Environment South China Normal University 510006 Guangzhou P. R. China
- Department of Chemistry and Center for Computational Chemistry University of Georgia 30602 Athens Georgia USA
| | - Yaoming Xie
- Department of Chemistry and Center for Computational Chemistry University of Georgia 30602 Athens Georgia USA
| | - R. Bruce King
- MOE Key Laboratory of Theoretical Chemistry of the Environment Center for Computational Quantum Chemistry South China Normal University 510006 Guangzhou P. R. China
- Department of Chemistry and Center for Computational Chemistry University of Georgia 30602 Athens Georgia USA
| | - Henry F. Schaefer
- Department of Chemistry and Center for Computational Chemistry University of Georgia 30602 Athens Georgia USA
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21
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Alvarez-Thon L, Mammino L. Information on Gas-Phase Diatomic Molecules from Magnetically Induced Current Densities. J Comput Chem 2017; 39:52-60. [DOI: 10.1002/jcc.25083] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/20/2017] [Accepted: 09/22/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Luis Alvarez-Thon
- Facultad de Ingeniería, Universidad Central de Chile; Toesca 1783 Santiago Chile
| | - Liliana Mammino
- Department of Chemistry; University of Venda, P/bag X5050; Thohoyandou 0950 South Africa
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22
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Esrafili MD, Mousavian P. The Key Role of Orbital Interaction in Cooperativity between B⋅⋅⋅N and Hydrogen/Lithium Bonding: An ab initio Study. ChemistrySelect 2017. [DOI: 10.1002/slct.201701309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Mehdi D. Esrafili
- Laboratory of Theoretical Chemistry; Department of Chemistry; University of Maragheh, P.O. Box: 5513864596; Maragheh Iran
| | - Parisasadat Mousavian
- Laboratory of Theoretical Chemistry; Department of Chemistry; University of Maragheh, P.O. Box: 5513864596; Maragheh Iran
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23
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Rauhalahti M, Taubert S, Sundholm D, Liégeois V. Calculations of current densities for neutral and doubly charged persubstituted benzenes using effective core potentials. Phys Chem Chem Phys 2017; 19:7124-7131. [DOI: 10.1039/c7cp00194k] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Magnetically induced current density of C6I62+ using GIMIC method and effective core potentials.
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Affiliation(s)
- Markus Rauhalahti
- Department of Chemistry
- University of Helsinki
- P.O. Box 55
- FIN-00014 Helsinki
- Finland
| | - Stefan Taubert
- Department of Chemistry
- University of Helsinki
- P.O. Box 55
- FIN-00014 Helsinki
- Finland
| | - Dage Sundholm
- Department of Chemistry
- University of Helsinki
- P.O. Box 55
- FIN-00014 Helsinki
- Finland
| | - Vincent Liégeois
- Laboratoire de Chimie Théorique (LCT)
- Unité de Chimie-Physique Théorique et Structurale (UCPTS)
- University of Namur
- Rue de Bruxelles
- 61
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24
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Ramírez-Tagle R, Alvarado-Soto L, Villavicencio-Wastavino A, Alvarez-Thon L. Relativistic effects on the aromaticity of the halogenated benzenes: C6X6, X = H, F, Cl, Br, I, At. Phys Chem Chem Phys 2016; 18:25751-5. [PMID: 27603224 DOI: 10.1039/c6cp05265g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study we report about the relativistic effects on the aromaticity of the six hexahalogenated compounds (C6H6, C6F6, C6Cl6, C6Br6, C6I6 and C6At6), via a magnetically induced current density method. All-electron density functional theory (DFT) calculations were carried out using the four-component Dirac-Coulomb (DC) Hamiltonian, including scalar and spin-orbit (SO) relativistic effects. Fully relativistic values of the magnetically induced ring currents were obtained by numerical integration over the current flow. These values were compared to the spin-free (SO interaction switched off) and non-relativistic values, in order to assess the corresponding contributions to aromaticity. It was found that in C6I6 and C6At6 there is a strong SO influence, in line with the expected relativistic effects of the heavy elements, iodine and astatine.
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Affiliation(s)
- Rodrigo Ramírez-Tagle
- Facultad de Ingeniería, Universidad Bernardo O'Higgins, Avenida Viel 1497, Santiago, Chile
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25
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Sun H, An K, Zhu J. Triplet State Aromaticity: NICS Criterion, Hyperconjugation, and Charge Effects. Chem Asian J 2015; 11:234-40. [PMID: 26507692 DOI: 10.1002/asia.201500897] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 09/28/2015] [Indexed: 11/06/2022]
Abstract
Aromaticity, one of the most important concepts in organic chemistry, has attracted considerable interest from both experimentalists and theoreticians. It remains unclear which NICS index is best to evaluate the triplet-state aromaticity. Here, we carry out thorough density functional theory (DFT) calculations to examine this issue. Our results indicate that among the various computationally available NICS indices, NICS(1)zz is the best for the triplet state. The correlations can be improved from 0.840 to 0.938 when only neutral species are considered, demonstrating the significant effect of the charge on the triplet-state aromaticity. In addition, calculations suggest that five-membered cyclic species with "hyperconjugative" aromaticity (and antiaromaticity) in the S0 state will become antiaromatic (and aromatic) in the T1 state, indicating an important role of hyperconjugation. Finally, a moderate correlation (r(2) =0.708) is identified between the NICS(1)zz values and spin distributions.
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Affiliation(s)
- Hongchao Sun
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, P. R. China
| | - Ke An
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, P. R. China
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, P. R. China.
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26
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Vásquez-Espinal A, Pino-Rios R, Alvarez-Thon L, Rabanal-León WA, Torres-Vega JJ, Arratia-Perez R, Tiznado W. New Insights into Re3(μ-Cl)3Cl6 Aromaticity. Evidence of σ- and π-Diatropicity. J Phys Chem Lett 2015; 6:4326-4330. [PMID: 26722969 DOI: 10.1021/acs.jpclett.5b01816] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We have theoretically evaluated the behavior of the Re3(μ-Cl)3Cl6 cluster under magnetic perturbation, and it clearly shows that the magnetic response within the Re3(μ-Cl)3 plane is highly diatropic in nature. An analysis of both the magnetically induced current density (MICD) and induced magnetic field (B(ind)) allows us to classify this cluster as doubly σ- and also π-aromatic on the magnetic criterion. These findings contradict the classical Re-Re double bond representation and favor a chemical bonding pattern that involves delocalized bonds.
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Affiliation(s)
| | | | - Luis Alvarez-Thon
- Departamento de Ciencias Fı́sicas, Facultad de Ciencias Exactas, Universidad Andres Bello , República 220, Santiago, Chile
| | | | - Juan J Torres-Vega
- Facultad de Ciencias Fı́sicas, Universidad Nacional Mayor de San Marcos , P.O. Box: 14-0149, Lima, Perú
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27
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Papadopoulos AG, Charistos ND, Kyriakidou K, Sigalas MP. Study of Electron Delocalization in 1,2-, 1,3-, and 1,4-Azaborines Based on the Canonical Molecular Orbital Contributions to the Induced Magnetic Field and Polyelectron Population Analysis. J Phys Chem A 2015; 119:10091-100. [PMID: 26348255 DOI: 10.1021/acs.jpca.5b06027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The electron delocalization in 1,2-azaborine, 1,3-azaborine, and 1,4-azaborine is studied using canonical molecular orbital contributions to the induced magnetic field (CMO-IMF) method and polyelectron population analysis (PEPA). Contour maps of the out-of-plane component of the induced magnetic field (Bz(ind)) of the π system show that the three azaborines, in contrast with borazine, sustain much of benzene's π-aromatic character. Among them, 1,3-azaborine exhibits the strongest π delocalization, while 1,4-azaborine is the weakest. Contour maps of Bz(ind) for individual π orbitals reveal that the differentiation of the magnetic response among the three isomers originates from the π-HOMO orbitals, whose magnetic response is governed by rotational allowed transitions to unoccupied orbitals. The low symmetry of azaborines enables a paratropic response from HOMO to unoccupied orbitals excitations, with their magnitude depending on the shape of interacting orbitals. 1,3-Azaborine presents negligible paratropic contributions to Bz(ind) from HOMO to unoccupied orbitals transitions, where 1,2- and 1,4-azaborine present substantial paratropic contributions, which lead to reduced diatropic response. Natural bond orbital (NBO) analysis employing PEPA shows that only the 1,3-azaborine contains π-electron fully delocalized resonance structures.
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Affiliation(s)
- Anastasios G Papadopoulos
- Aristotle University of Thessaloniki , Department of Chemistry, Laboratory of Applied Quantum Chemistry, Thessaloniki 54124, Greece
| | - Nickolas D Charistos
- Aristotle University of Thessaloniki , Department of Chemistry, Laboratory of Applied Quantum Chemistry, Thessaloniki 54124, Greece
| | - Katerina Kyriakidou
- Aristotle University of Thessaloniki , Department of Chemistry, Laboratory of Applied Quantum Chemistry, Thessaloniki 54124, Greece
| | - Michael P Sigalas
- Aristotle University of Thessaloniki , Department of Chemistry, Laboratory of Applied Quantum Chemistry, Thessaloniki 54124, Greece
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28
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Sánchez-Sanz G, Trujillo C, Rozas I, Alkorta I. Influence of fluoro and cyano substituents in the aromatic and antiaromatic characteristics of cyclooctatetraene. Phys Chem Chem Phys 2015; 17:14961-71. [DOI: 10.1039/c5cp00876j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
An exhaustive and systematic study of the structural and electronic properties of cyclooctatetraene (COT) upon substitution of hydrogen atoms by fluoro and cyano groups has been carried out in order to analyse the influence of both substituents on the aromaticity.
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Affiliation(s)
- Goar Sánchez-Sanz
- School of Physics & Complex and Adaptive Systems Laboratory
- University College Dublin
- Dublin 4
- Ireland
| | - Cristina Trujillo
- School of Chemistry
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Isabel Rozas
- School of Chemistry
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Ibon Alkorta
- Instituto de Química Médica
- CSIC
- E-28006 Madrid
- Spain
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