1
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Prakash M, Rudharachari Maiyelvaganan K, Giri Lakshman N, Gopalakrishnan C, Hochlaf M. Microhydration of small protonated polyaromatic hydrocarbons: a first principles study. Phys Chem Chem Phys 2024; 26:17489-17503. [PMID: 38804893 DOI: 10.1039/d3cp06000d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Using first principles methodology, we investigate the microsolvation of protonated benzene (BzH+), protonated coronene (CorH+) and protonated dodecabenzocoronene (DbcH+). Gas phase complexes of these small protonated polyaromatic hydrocarbons (H+PAHs) with mono-, di-, and tri-hydrated water molecules are considered. Their most stable forms are presented, where we discuss their structural, energetic aromaticity and IR and UV spectral features. In particular, we focus on the analysis of the bonding and various non-bonded interactions between these protonated aromatics and water clusters. The strength of non-bonded interactions is quantified and correlated with their electron density profiles. Furthermore, insights into the interfacial interactions and stability of these complexes were obtained through non-covalent index and symmetry-adapted perturbation theory (SAPT0) analyses. We also discuss the effects of the extension of the π aromatic cloud on the water solvation of these protonated aromatics. In particular, we extended our predictions for the S0 → S1 and S0 → T1 wavelength transitions of micro hydrated H+PAHs to deduce those of these species solvated in aqueous solution. The present findings should be useful for understanding, at the microscopic level, the effects of water interacting with H+PAHs, which are relevant for organic chemistry, astrochemistry, atmospheric chemistry, combustion and materials science.
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Affiliation(s)
- Muthuramalingam Prakash
- Computational Chemistry Research Laboratory (CCRL), Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur-603 203, Chengalpattu, Tamil Nadu, India.
| | - K Rudharachari Maiyelvaganan
- Computational Chemistry Research Laboratory (CCRL), Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur-603 203, Chengalpattu, Tamil Nadu, India.
| | - N Giri Lakshman
- Computational Chemistry Research Laboratory (CCRL), Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur-603 203, Chengalpattu, Tamil Nadu, India.
| | - C Gopalakrishnan
- Computational Chemistry Research Laboratory (CCRL), Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur-603 203, Chengalpattu, Tamil Nadu, India.
| | - Majdi Hochlaf
- Université Gustave Eiffel, COSYS/IMSE, 5 Bd Descartes, 77454, Champs Sur Marne, France.
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2
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Bai LX, Jin YX, Guo JC. D 4h H©K 4H 4-: a planar tetracoordinate hydrogen global minimum. Chem Commun (Camb) 2024; 60:6300-6303. [PMID: 38818579 DOI: 10.1039/d4cc01368a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
Herein we report a square-like D4h H©K4H4- anion with one planar tetracoordinate hydrogen (ptH) center, which is the global minimum (GM) structure and possesses good dynamic stability. The planar structure of the system is preserved by four peripheral K-H-K three-center two-electron (3c-2e) σ bonds together with one 5c-2e σ bond over the HK4 core. The multicenter ionic bonds dominate the stability of ptH, while the contribution of qualitative σ aromaticity is extremely limited.
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Affiliation(s)
- Li-Xia Bai
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China.
| | - Yan-Xia Jin
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China.
| | - Jin-Chang Guo
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China.
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3
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Kenouche S, Bachir N, Bouchal W, Martínez-Araya JI. Aromaticity of six-membered nitro energetic compounds through molecular electrostatic potential, magnetic, electronic delocalization and reactivity-based indices. J Mol Graph Model 2024; 129:108728. [PMID: 38412811 DOI: 10.1016/j.jmgm.2024.108728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 02/29/2024]
Abstract
The electron density depletion associated with π-hole at the ring center typical of energetic compounds was clearly revealed by the molecular electrostatic potential (ESP). In addition, the spatial arrangement of NO2 groups appears to affect the ESP value in the ring center, and therefore sensitivity to detonation. Indeed, for monocyclic nitrobenzene compounds with the same number of NO2 groups, the ESP value in the ring center decreases as the NO2 groups are more closely spaced. As expected, the central rings become less aromatic as NO2 groups are added. The MCI, PDI, PLR, NICSzz(1), FLU indices are all strongly correlated with the ESP values observed in the ring center of the set of nitrobenzenes. Aromaticity indices based on electron delocalization criteria appear to be very sensitive to small variations in aromaticity. Among magnetic-based indices, only NICSzz(1) is capable to predict small changes in aromaticity. The PLR index derived from conceptual DFT is quite relevant for predicting small variations in aromaticity. According to our results, the most suitable aromaticity index is not based on a single criterion, and that selecting it is more subtle. Therefore, it is important to combine information from several criteria to obtain a more complete description of the aromaticity of the studied compounds.
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Affiliation(s)
- Samir Kenouche
- Group of Modeling of Chemical Systems using Quantum Calculations, Applied Chemistry Laboratory (LCA). University M. Khider of Biskra, 07000 Biskra, Algeria
| | - Nassima Bachir
- Group of Modeling of Chemical Systems using Quantum Calculations, Applied Chemistry Laboratory (LCA). University M. Khider of Biskra, 07000 Biskra, Algeria
| | - Wissam Bouchal
- Molecular Chemistry and Environment Laboratory, University of Mohammed Khider of Biskra, BP 145 RP, Biskra 07000, Algeria
| | - Jorge I Martínez-Araya
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello (UNAB), Av. República 275, 8370146 Santiago, Chile; Centro de Química Teórica y Computacional (CQT&C). Facultad de Ciencias Exactas, Santiago, Chile.
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4
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Báez-Grez R, Rios RP. Is azulene's local aromaticity and relative stability driven by the Glidewell-Lloyd rule? Phys Chem Chem Phys 2024; 26:12162-12167. [PMID: 38590242 DOI: 10.1039/d4cp00091a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
The local aromaticity of azulene has been studied to understand their electronic properties. For this purpose, we have used the magnetic criterion through magnetically induced current density maps, ring current strengths, NICSzz(1), and the bifurcation value of three-dimensional surfaces of NICSzz. On the other hand, the delocalization criterion was used by calculating the MCI and ELFπ. The results show that the five-membered ring (5-MR) is more aromatic than the seven-membered ring (7-MR) and more aromatic than the free C5H5- ring. The opposite case is seen for the seven-membered ring, which is less aromatic than the free C7H7+. The local aromatic rings in azulene are formed due to an intramolecular electron transfer from the 7-MR to the 5-MR. In addition, the proposed resonance structures that allow explaining the properties of azulene, such as the dipole moment or the relative stability (in comparison to other isomers), show a preference for the formation of 5-MRs; for this reason, it is possible to conclude that the aromaticity and relative stability of azulene is driven by the Glidewell-Lloyd rule.
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Affiliation(s)
- Rodrigo Báez-Grez
- Facultad de Ciencias, Universidad Arturo Prat, Casilla 121, Iquique 1100000, Chile
| | - Ricardo Pino Rios
- Centro de Investigación Medicina de Altura - CEIMA, Universidad Arturo Prat. Casilla 121, Iquique 1100000, Chile.
- Química y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat, Casilla 121, Iquique 1100000, Chile
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Orozco-Ic M, Soriano-Agueda L, Escayola S, Sundholm D, Merino G, Matito E. Understanding Aromaticity in [5]Helicene-Bridged Cyclophanes: A Comprehensive Study. J Org Chem 2024; 89:2459-2466. [PMID: 38236016 DOI: 10.1021/acs.joc.3c02485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
This study explores the aromaticity of doubly [5]helicene-bridged (1,4)cyclophane and triply [5]helicene-bridged (1,3,5)cyclophane via calculations of the magnetic response and of electronic aromaticity indices. The primary objective is to assess the π-electron delocalization to determine whether they sustain global ring currents associated with π aromaticity. The molecules show local ring currents in the presence of an external magnetic field. The ring currents flow diatropically in the stacked six-membered rings and in the helicene arms. However, these π currents are not interconnected due to the discontinuity of the π delocalization at the C-C single bonds connecting the central six-membered rings to the helicene arms. Electronic indices suggest that the helicene-arm systems have significantly smaller electron delocalization than benzene. The reduction in the delocalization does not compromise their ability to exhibit ring currents in the presence of an external magnetic field. The analysis provides further evidence that the magnetic criteria yield a different degree of aromaticity for the helicene arms than obtained in the calculation of the electronic aromaticity indices. However, both approaches confirm that the studied molecules are not globally aromatic.
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Affiliation(s)
- Mesías Orozco-Ic
- Donostia International Physics Center (DIPC), Donostia, 20018 Euskadi, Spain
| | - Luis Soriano-Agueda
- Donostia International Physics Center (DIPC), Donostia, 20018 Euskadi, Spain
| | - Sílvia Escayola
- Donostia International Physics Center (DIPC), Donostia, 20018 Euskadi, Spain
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany, 69, Girona, 17003 Catalonia, Spain
| | - Dage Sundholm
- Department of Chemistry, Faculty of Science, University of Helsinki, A. I. Virtasen aukio 1, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Gabriel Merino
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida, Km 6 Antigua Carretera a Progreso. Apdo. Postal 73, Cordemex, 97310 Mérida, Yuc., México
| | - Eduard Matito
- Donostia International Physics Center (DIPC), Donostia, 20018 Euskadi, Spain
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Krishnapriya KC, Thayyil A, Kumari M, Parambil PC. Bond-alternated and bond-equalized hexazine derivatives. Phys Chem Chem Phys 2024; 26:3569-3577. [PMID: 38214527 DOI: 10.1039/d3cp05546a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Planar cyclic conjugated molecules satisfying the Hückel rule are generally classified as aromatics and π delocalization is the key feature of aromatic compounds. It was shown that the π system of benzene prefers bond-alternation and that the delocalization observed is a consequence of bond-equalization, which is a σ effect. For systems wherein the π bonds are strong, such as those between N atoms, the π-distortivity may outweigh the σ preference for bond-equalization. Thus, one anticipates a bond-alternated structure for N6; however, neither the bond-equalized structure (D6h) nor the bond-alternated one (D3h) is a minimum as evident from the previous literature; calculations have shown that cyclic N6 is non-planar. Herein we show that a Lewis acid coordination strategy can be employed to stabilize the planar structure of N6. We show that the structure can be bond-alternated or bond-equalized depending on the strength of the Lewis acid. Kinetic stability with respect to concerted decomposition to three N-N triple bonded systems was assessed, and a few bond-equalized N6 systems were found to be potential candidates for synthesis.
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Affiliation(s)
| | - Ashith Thayyil
- Department of Chemistry, Indian Institute of Technology, Palakkad 678 557, India
| | - Mithu Kumari
- Department of Chemistry, Indian Institute of Technology, Palakkad 678 557, India
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7
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Sahu P, Jana NC, Barik S, Kisan HK, Changotra A, Isab AA, Dinda J. Unexpected structural preference with metallophilic Ag-Au contacts in silver(I)-N-heterocyclic carbene cluster; experimental and theoretical approach. Dalton Trans 2024; 53:1099-1104. [PMID: 38099652 DOI: 10.1039/d3dt02551a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
A novel synthetic donor-atom-selective approach has been adopted for the synthesis of a heterobimetallic cluster of a new NCN-pincer, 1,3-bis-(1-methyl-1H-benzo[d]imidazol-2-yl-methyl)-1H-imidazol-3-ium hexafluorophosphate (1·HPF6). The complex [Ag3(1)3][PF6]3 (2) has been prepared via the Ag2O route; which undergoes transmetallation to yield a cluster that seems to be the first example of the heterobimetallic trinuclear system [Au-Ag2(1)2Cl][PF6]2, 3. Finally, the trinuclear cluster geometries of 2 and 3 were confirmed via SCXRD studies. Interestingly, Au(I) binds preferentially with soft donor Ccarbene, which transmetallated from the cluster of 2. In both the cyclic trinuclear clusters, the M-M interactions were further inspected using gauge independent atomic orbital (GIAO) computations. Both 2 and 3 are luminescent and possess σ-aromaticity; the NICS values indicate that 3 is more aromatic than 2.
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Affiliation(s)
- Priyanka Sahu
- Department of Chemistry, Utkal University, Bhubaneswar-751004, Odisha, India.
| | - Narayan Ch Jana
- School of Chemical Sciences, National Institute of Science Education and Research, HBNI, Bhubaneswar, Odisha, 752050, India
| | - Sahadev Barik
- School of Chemical Sciences, National Institute of Science Education and Research, HBNI, Bhubaneswar, Odisha, 752050, India
| | - Hemanta K Kisan
- Department of Chemistry, Indian Institute of Technology Bhilai, GEC Campus, Sejbahar, Raipur-492015, Chhattisgarh, India
| | - Avtar Changotra
- School of Science, Department of Chemistry, Cluster University of Jammu, Jammu-180001, India
| | - Anvarhusein A Isab
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| | - Joydev Dinda
- Department of Chemistry, Utkal University, Bhubaneswar-751004, Odisha, India.
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8
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Báez-Grez R, Pino-Rios R. On the aromaticity and stability of benzynes in the ground and lowest-lying triplet excited states. J Comput Chem 2024; 45:6-12. [PMID: 37671655 DOI: 10.1002/jcc.27214] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/02/2023] [Accepted: 08/09/2023] [Indexed: 09/07/2023]
Abstract
In this work, we have revisited the aromaticity of benzyne isomers at the unrestricted density functional theory level (UDFT) using the energetic, magnetic, and delocalization criteria. In addition, this last criterion has also been analyzed employing complete active space (CASSCF) calculations. The results show conservation of aromaticity in these monocycles. Additionally it is observed that this trend is maintained in polycyclic aromatic hydrocarbon derivatives such as biradical didehydrophenanthrenes. Do these results imply a violation of Baird's rule? The answer is No, because this conservation in aromaticity is due to the loss of hydrogen atoms affects only the electronic σ skeleton and exerts a minor influence on the π cloud. Additionally, we have analyzed the relative stability of benzyne isomers and their relationship with experimental ΔES-T values. According to the literature, the stability of the benzynes in the singlet state is due to an effective interaction between the electrons of the biradical centers; however, this effect is completely reversed in the triplet state, which explains why the para isomer has the lowest ΔES-T gap.
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Affiliation(s)
- Rodrigo Báez-Grez
- Departamento de Química, Facultad de Ciencias Exactas, Universidad Andres Bello, Santiago, Chile
| | - Ricardo Pino-Rios
- Instituto de Estudios de la Salud, Universidad Arturo, Chile
- Química y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat, Chile
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9
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Pino-Rios R, Pino E, Cárdenas-Jirón G. Deciphering the origin of the first steps in the degradation of azo dyes: a computational study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:657-667. [PMID: 38015401 DOI: 10.1007/s11356-023-31172-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/18/2023] [Indexed: 11/29/2023]
Abstract
Azo dyes find applications across various sectors including food, pharmaceuticals, cosmetics, printing, and textiles. The contaminating effects of dyes on aquatic environments arise from toxic effects caused by their long-term presence in the environment, buildup in sediments, particularly in aquatic species, degradation of pollutants into mutagenic or mutagenic compounds, and low aerobic biodegradability. Therefore, we theoretically propose the first steps of the degradation of azo dyes based on the interaction of hydroperoxyl radical (•OOH) with the dye. This interaction is studied by the OC and ON mechanisms in three azo dyes: azobenzene (AB), disperse orange 3 (DO3), and disperse red 1 (DR1). Rate constants calculated at several temperatures show a preference for the OC mechanism in all the dyes with lower activation energies than the ON mechanism. The optical properties were calculated and because the dye-•OOH systems are open shell, to verify the validity of the results, a study of the spin contamination of the ground [Formula: see text] and excited states [Formula: see text] was previously performed. Most of the excited states calculated are acceptable as doublet states. The absorption spectra of the dye-•OOH systems show a decrease in the intensity of the bands compared to the isolated dyes and the appearance of a new band of the type π → π* at a longer wavelength in the visible region, achieving up to 868 nm. This demonstrates that the reaction with the •OOH radical could be a good alternative for the degradation of the azo dyes.
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Affiliation(s)
- Ricardo Pino-Rios
- Laboratory of Theoretical Chemistry, Faculty of Chemistry and Biology, University of Santiago de Chile (USACH), Santiago, Chile
| | - Eduardo Pino
- Laboratory of Kinetics and Photochemistry, Faculty of Chemistry and Biology, University of Santiago de Chile (USACH), Santiago, Chile
| | - Gloria Cárdenas-Jirón
- Laboratory of Theoretical Chemistry, Faculty of Chemistry and Biology, University of Santiago de Chile (USACH), Santiago, Chile.
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10
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Bischof T, Wieprecht N, Fuchs S, Endres L, Krummenacher I, Michel M, Mihm C, Braunschweig H, Finze M. Unlocking Heteroaromatic Ring Systems through Chalcogen Insertion into Boroles. Inorg Chem 2023; 62:21329-21335. [PMID: 38048693 DOI: 10.1021/acs.inorgchem.3c03403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
In this work, we report the reactivity of various annulated borole derivatives toward chalcogen (O, S, and Se) insertion. Among a series of 9-borafluorenes with different boron substituents (Ph, Br, or o-carboranyl) and a mixed thiophene-benzene-fused derivative, only the 9-o-carboranyl-substituted 9-borafluorene yielded the complete set of chalcogen-containing heteroarenes, including the first 1,2-selenaborinine derivative. To evaluate the aromaticity of this heterocyclic analogue of phenanthrene, nucleus-independent chemical shift (NICS) values were computed and compared to those of its lighter group 16 congeners.
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Affiliation(s)
- Tobias Bischof
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Nele Wieprecht
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Sonja Fuchs
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Lukas Endres
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Maximilian Michel
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Cornelius Mihm
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Maik Finze
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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11
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Al-Yassiri MAH, Puchta R. Predicting a New Δ-Proton Sponge-Base of 4,12-Dihydrogen-4,8,12-triazatriangulene through Proton Affinity, Aromatic Stabilization Energy, and Aromatic Magnetism. Chemphyschem 2023; 24:e202200688. [PMID: 37366055 DOI: 10.1002/cphc.202200688] [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: 09/13/2022] [Revised: 04/12/2023] [Indexed: 06/28/2023]
Abstract
Herein, we report designing a new Δ (delta-shaped) proton sponge base of 4,12-dihydrogen-4,8,12-triazatriangulene (compound 1) and calculating its proton affinity (PA), aromatic stabilization, natural bond orbital (NBO), electron density ρ(r), Laplacian of electron density ∇2 ρ(r), (2D-3D) multidimensional off-nucleus magnetic shielding (σzz (r) and σiso (r)), and scanning nucleus-independent chemical shift (NICSzz and NICS). Density functional theory (DFT) at B3LYP/6-311+G(d,p), ωB97XD/6-311+G(d,p), and PW91/def2TZVP were used to compute the magnetic shielding variables. In addition, relevant bases like pyridine, quinoline, and acridine were also studied and compared. The protonation of compound 1 yields a highly symmetric carbocation of three Hückel benzenic rings. Comparing our findings of the studied molecules showed that compound 1 precedes others in PA, aromatic isomerization stabilization energy, and basicity. Therefore, the basicity may be enhanced when a conjugate acid gains higher aromatic features than its unprotonated base. Both multidimensional σzz (r) and σiso (r) off-nucleus magnetic shieldings outperformed electron-based techniques and can visually monitor changes in aromaticity that occur by protonation. The B3LYP/6-311+G(d,p), ωB97XD/6-311+G(d,p), and PW91/def2TZVP levels showed no significant differences in detailing isochemical shielding surfaces.
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Affiliation(s)
- Muntadar A H Al-Yassiri
- Department of Chemistry - College of Science, University of Baghdad, Al-Jadirya, Baghdad, Iraq
| | - Ralph Puchta
- Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen - Nuremberg, Egerlandstr. 1, 91058, Erlangen, Germany
- Computer Chemistry Center, Department of Chemistry and Pharmacy, University of Erlangen - Nuremberg, Nägelsbachstr. 25, 91052, Erlangen, Germany
- Central Institute for Scientific Computing (ZISC), University of Erlangen - Nuremberg, Martensstr. 5a, 91058, Erlangen, Germany
- Fakultät Angewandte Mathematik, Physik und Allgemeinwissenschaften, Technische Hochschule Nürnberg Georg Simon Ohm, Keßlerplatz 12, 90489, Nürnberg, Germany
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12
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Báez-Grez R, Inostroza D, Vásquez-Espinal A, Islas R, Pino-Rios R. Exploration of the potential energy surface in mixed Zintl clusters applying an automatic Johnson polyhedra generator: the case of arachno E 6M 24- (E = Si, Ge, Sn; M = Sb, Bi). RSC Adv 2023; 13:24499-24504. [PMID: 37588980 PMCID: PMC10426391 DOI: 10.1039/d3ra04308h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/08/2023] [Indexed: 08/18/2023] Open
Abstract
A new algorithm called Automatic Johnson Cluster Generator (AJCG) is presented, which, as its name indicates, allows the definition of the desired Johnson polyhedron to subsequently carry out all the possible permutations between the atoms that form this polyhedron. This new algorithm allows the exhaustive study of the structures' potential energy surface (PES). In addition, the AJCG algorithm is helpful for the study of three-dimensional compounds such as boranes or Zintl clusters and their structural derivatives with two or more different atoms. The automatic filling of vertices is particularly useful in mixed compounds because of the possibility of taking into account all possible configurations in the structure. As a test system, we investigated the arachno-type E6M24- (E = Si, Ge, Sn; M = Sb, Bi) structure which has eight vertices and complies with Wade-Mingos rules. Initially, we defined a bipyramidal structure (10 vertices), and filled the vertices with the atoms in all possible configurations. Since the selected system has eight atoms, the two remaining vertices were filled with pseudo atoms to complete the structure. After re-optimizing the initial population generated with AJCG, a large number of isomers with energy below 10 kcal mol-1 are identified. These results show that the most stable isomers possess homonuclear M-M bonds, except Sn6Bi24-. Although the overall putative minima differ at the PBE0-D3 and DLPNO-CCSD(T) levels, they are always competitive minima. In addition to using high-precision methodologies to correctly study relative energies, applying solvent effects in highly charged systems becomes mandatory. The aromatic character of these studied systems was demonstrated qualitatively with two- and three-dimensional mapping and quantitatively by calculating the value of the z-component of the induced magnetic field at the cage center, including scalar and spin-orbit correction for relativistic effects. The compounds studied have a high degree of aromaticity, which allows us to establish that despite structural modifications (i.e., from closo to arachno), the aromaticity is preserved.
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Affiliation(s)
- Rodrigo Báez-Grez
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello República 275 Santiago Chile 8370146
| | - Diego Inostroza
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello República 275 Santiago Chile 8370146
- Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas, Universidad Andres Bello República 275 Santiago Chile
| | - Alejandro Vásquez-Espinal
- Química y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat Casilla 121 Iquique Chile 1100000
| | - Rafael Islas
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello República 275 Santiago Chile 8370146
- Centro de Química Teórica & Computacional (CQT&C), Facultad de Ciencias Exactas, Universidad Andres Bello República 275 Santiago Chile 8370146
| | - Ricardo Pino-Rios
- Química y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat Casilla 121 Iquique Chile 1100000
- Instituto de Estudios de la Salud, Universidad Arturo Prat Casilla 121 Iquique Chile 1100000
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13
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Al-Yassiri MAH. Tubular Magnetic Shielding Scan (TMSS): A New Technique for Molecular Space Exploration. (i) The Case of Aromaticity of Benzene and [ n]Paracyclophanes. J Phys Chem A 2023; 127:6614-6627. [PMID: 37501257 DOI: 10.1021/acs.jpca.3c03041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Both traditional and novel techniques were employed in this work for magnetic shielding evaluation to shed new light on the magnetic and aromaticity properties of benzene and 12 [n]paracyclophanes with n = 3-14. Density functional theory (DFT) with the B3LYP functional and all-electron Jorge-ATZP and x2c-TZVPPall-s basis sets was utilized for geometry optimization and magnetic shielding calculations, respectively. Additionally, the 6-311+G(d,p) basis set was incorporated for the purpose of comparing the magnetic shielding results. In addition to traditional evaluations such as NICS/NICSzz-Scan, and 2D-3D σiso(r)/σzz(r) maps, two new techniques were implemented: bendable grids (BGs) and cylindrical grids (CGs) of ghost atoms (Bqs). BGs allow for the recording of magnetic shielding from the bent ring levels of [n]pCPs, while CGs provide tubular magnetic shielding scan (TMSS) maps detailing the magnetic shielding from a cylindrical region above and below the ring frame. Our findings suggest that smaller [n]pCPs with n < 6 exhibit deviations in the magnetic shielding above and below the ring, indicating a broken electron delocalization under the ring. In contrast, larger [n]pCPs tend to behave similarly to benzene in terms of magnetic shielding. Moreover, we found that shorter polymethylene chains of [n]pCPs exhibit significantly higher magnetic shielding interactions with the ring. Both of the above techniques offer new and promising tools for characterizing nonplanar aromatic compounds, thereby contributing to a deeper understanding of their magnetic and electronic properties.
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Affiliation(s)
- Muntadar A H Al-Yassiri
- Department of Chemistry, College of Science, University of Baghdad, Al-Jadirya, Baghdad 10071, Iraq
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14
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Casademont-Reig I, Woller T, García V, Contreras-García J, Tiznado W, Torrent-Sucarrat M, Matito E, Alonso M. Quest for the Most Aromatic Pathway in Charged Expanded Porphyrins. Chemistry 2023; 29:e202202264. [PMID: 36194440 PMCID: PMC10099525 DOI: 10.1002/chem.202202264] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Indexed: 11/05/2022]
Abstract
Despite the central role of aromaticity in the chemistry of expanded porphyrins, the evaluation of aromaticity remains difficult for these extended macrocycles. The presence of multiple conjugation pathways and different planar and nonplanar π-conjugation topologies makes the quantification of global and local aromaticity even more challenging. In neutral expanded porphyrins, the predominance of the aromatic conjugation pathway passing through the imine-type nitrogens and circumventing the amino NH groups is established. However, for charged macrocycles, the question about the main conjugation circuit remains open. Accordingly, different conjugation pathways in a set of neutral, anionic, and cationic expanded porphyrins were investigated by means of several aromaticity indices rooted in the structural, magnetic, and electronic criteria. Overall, our results reveal the predominance of the conjugation pathway that passes through all nitrogen atoms to describe the aromaticity of deprotonated expanded porphyrins, while the outer pathway through the perimeter carbon atoms becomes the most aromatic in protonated macrocycles. In nonplanar and charged macrocycles, a discrepancy between electronic and magnetic descriptors is observed. Nevertheless, our work demonstrates AVmin remains the best tool to determine the main conjugation pathway of expanded porphyrins.
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Affiliation(s)
- Irene Casademont-Reig
- Department of General Chemistry (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium
| | - Tatiana Woller
- Department of General Chemistry (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium.,Laboratoire de Chimie Théorique (LCT), Sorbonne Université, place Jussieu 4, 75052, Paris, France
| | - Victor García
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 498, Santiago, Chile.,Departamento Académico de Fisicoquímica, Facultad de Química e Ingeniería Química, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Julia Contreras-García
- Laboratoire de Chimie Théorique (LCT), Sorbonne Université, place Jussieu 4, 75052, Paris, France
| | - William Tiznado
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 498, Santiago, Chile
| | - Miquel Torrent-Sucarrat
- Donostia International Physics Center (DIPC), 20018, Donostia, Euskadi, Spain.,Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Euskadi, Spain.,Department of Organic Chemistry I, Universidad del País Vasco/Euskal Herriko Unibertsitatea, UPV/EHU), 20018 Donostia, Euskadi, Spain
| | - Eduard Matito
- Donostia International Physics Center (DIPC), 20018, Donostia, Euskadi, Spain.,Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Euskadi, Spain
| | - Mercedes Alonso
- Department of General Chemistry (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium
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15
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Báez-Grez R, Yáñez O, Pino-Rios R. Electronic Transmutation Concept: Is the Inverse Process Possible? An Evaluation of Main Group Compounds. ACS OMEGA 2023; 8:2880-2886. [PMID: 36713707 PMCID: PMC9878657 DOI: 10.1021/acsomega.2c03865] [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: 06/21/2022] [Accepted: 12/07/2022] [Indexed: 06/18/2023]
Abstract
The electronic transmutation (ET) concept states that when an element with atomic number Z gains an electron, it transmutes into a Z + 1 element, leading to species that possess similar chemical bonding patterns and geometric structures regarding the original (Z + 1) element. In this work, the opposite concept, that is, the inverse ET, is assessed. For this purpose, several main group compounds have been analyzed in terms of the adaptive natural density partitioning. The obtained results suggest that when an atom Z loses an electron, it transmutes into a Z - 1 atom, acquiring its geometrical structure and bonding pattern.
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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 8320000, Chile
| | - Osvaldo Yáñez
- Facultad
de Ingeniería y Negocios, Universidad
de las Américas, Santiago 7500000, Chile
| | - Ricardo Pino-Rios
- Química
y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat. Casilla 121, Iquique 1100000, Chile
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16
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Theoretical Investigation of Geometries and Bonding of Indium Hydrides in the In 2H x and In 3H y (x = 0-4,6; y = 0-5) Series. Molecules 2022; 28:molecules28010183. [PMID: 36615377 PMCID: PMC9822201 DOI: 10.3390/molecules28010183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Boron hydrides have been an object of intensive theoretical and experimental investigation for many decades due to their unusual and somewhat unique bonding patterns. Despite boron being a neighboring element to carbon, boron hydrides almost always form non-classical structures with multi-center bonds. However, we expect indium to form its interesting molecules with non-classical patterns, though such molecules still need to be extensively studied theoretically. In this work, we investigated indium hydrides of In2Hx (x = 0-4,6) and In3Hy (y = 0-5) series via DFT and ab initio quantum chemistry methods, performing a global minimum search, chemical bonding analysis, and studies of their thermodynamical stability. We found that the bonding pattern of indium hydrides differs from the classical structures composed of 1c-2e lone pairs and 2c-2e bonds and the bonding pattern of earlier investigated boron hydrides of the BnHn+2 series. The studied stoichiometries are characterized by multi-center bonds, aromaticity, and the tendency for indium to preserve the 1c-2e lone pair.
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17
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Liu N, Li Q, Scheiner S, Xie X. Resonance-assisted intramolecular triel bonds. Phys Chem Chem Phys 2022; 24:15015-15024. [PMID: 35695162 DOI: 10.1039/d2cp01244h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The possibility that the intramolecular Tr⋯S triel bond is strengthened by resonance is examined by quantum chemical calculations within the planar five-membered ring of TrH2-CRCR-CRS (Tr = Al, Ga, In; R = NO2, CH3). This internal bond is found to be rather short (2.4-2.7 Å) with a large bond energy between 12 and 21 kcal mol-1. The pattern of bond length alternation and atomic charges within the ring is consistent with resonance involving the conjugated double bonds. This resonance enhances the triel bond strength by some 25%. The electron-withdrawing NO2 group weakens the bond, but it is strengthened by the electron-donating CH3 substituent. NICS analysis suggests the presence of a certain degree of aromaticity within the ring.
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Affiliation(s)
- Na Liu
- The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, P. R. China.
| | - Qingzhong Li
- The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, P. R. China.
| | - Steve Scheiner
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA.
| | - Xiaoying Xie
- The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, P. R. China.
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18
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Abstract
Aromaticity, a very important term in organic chemistry, has never been defined unambiguously. Various ways to describe it come from different phenomena that have been experimentally observed. The most important examples related to some theoretical concepts are presented here.
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19
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Jivani AJ, Kapadiya KM, Khunt RC. Miscellaneous Passerini Reaction for α-Acyloxy Carboxamide: Synthesis
and Process Optimization Study. LETT ORG CHEM 2022. [DOI: 10.2174/1570178618666210125161922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
:
An accelerating effect of “Phase Transfer Catalyst” as additive was exposed for the Passerini three-component
reactions and the influence on the reaction rate was studied concerning direct involvement of reactant molecules. The most
flexible reaction for the rapid formation of diverse “α-acyloxycarboxamides” using passerini reaction involved multicomponent reactions using miscellaneous 2-(prop-2-ynyloxy)benzaldehyde with various aromatic acid and slightly non-polar
fragment i.e. 2-isocyano-2,3,3-trimethylbutane and the representative molecule was characterized with resepct to DEPT135 NMR technique.
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Affiliation(s)
- Amita J. Jivani
- Department of Chemistry, Chemistry Research Laboratory, Saurashtra University, Rajkot-360 005, Gujarat-India
| | - Khushal M. Kapadiya
- Bio-Research and Characterization Centre, School of Science, Department of Chemistry, RK University, Rajkot-360
020, Gujarat-India
| | - Ranjan C. Khunt
- Department of Chemistry, Chemistry Research Laboratory, Saurashtra University, Rajkot-360 005, Gujarat-India
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20
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Báez-Grez R, Pino-Rios R. The hidden aromaticity in borazine. RSC Adv 2022; 12:7906-7910. [PMID: 35424723 PMCID: PMC8982269 DOI: 10.1039/d1ra06457f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/25/2022] [Indexed: 02/05/2023] Open
Abstract
The aromaticity of borazine (B3N3H6), also known as the inorganic benzene, is a controversial issue since this compound has several characteristics that could qualify it as an aromatic compound. However, recent studies using magnetic criteria indicate that this compound should be considered as a non-aromatic system. This assignment is mainly due to diatropic currents in the nitrogen atoms without observation of ring currents. The present work shows by means of the magnetic criteria that borazine has a ring current hidden by the local contributions of degenerate orbitals π1 and π2. Additionally, the study of borazine's first triplet state antiaromaticity using the magnetic and energetic criteria by means of isomerization stabilization energies (ISEs) together with Baird's and Hückel's rules suggests that borazine is best described as an (weakly) aromatic system.
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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 498 Santiago Chile
| | - 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
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21
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Boronski JT, Seed JA, Hunger D, Woodward AW, van Slageren J, Wooles AJ, Natrajan LS, Kaltsoyannis N, Liddle ST. Reply to: [{Th(C 8H 8)Cl 2} 3] 2- is stable but not aromatic. Nature 2022; 603:E21-E22. [PMID: 35322243 DOI: 10.1038/s41586-021-04320-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Josef T Boronski
- Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Manchester, UK
| | - John A Seed
- Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Manchester, UK
| | - David Hunger
- Institute of Physical Chemistry, University of Stuttgart, Stuttgart, Germany
| | - Adam W Woodward
- Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Manchester, UK
| | - Joris van Slageren
- Institute of Physical Chemistry, University of Stuttgart, Stuttgart, Germany
| | - Ashley J Wooles
- Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Manchester, UK
| | - Louise S Natrajan
- Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Manchester, UK
| | - Nikolas Kaltsoyannis
- Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Manchester, UK.
| | - Stephen T Liddle
- Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Manchester, UK.
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22
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Kleinpeter E, Koch A. Cyclazines‐Structure and Aromaticity or Antiaromaticity on the Magnetic Criterion. European J Org Chem 2022. [DOI: 10.1002/ejoc.202101362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Erich Kleinpeter
- Chemisches Institut der Universität Potsdam Karl-Liebknecht-Str. 24–25 14476 Potsdam (Golm) Germany E-mail
| | - Andreas Koch
- Chemisches Institut der Universität Potsdam Karl-Liebknecht-Str. 24–25 14476 Potsdam (Golm) Germany E-mail
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23
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Paenurk E, Gershoni-Poranne R. Simple and efficient visualization of aromaticity: bond currents calculated from NICS values. Phys Chem Chem Phys 2022; 24:8631-8644. [PMID: 35132428 DOI: 10.1039/d1cp05757j] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Aromaticity is a fundamental concept in chemistry, underpinning the properties and reactivity of many organic compounds and materials. The ability to easily and accurately discern aromatic behavior is key to leveraging it as a design element, yet most aromaticity metrics struggle to combine accurate quantitative evaluation, intuitive interpretability, and user-friendliness. We introduce a new method, NICS2BC, which uses simple and inexpensive NICS calculations to generate information-rich and easily-interpreted bond-current graphs. We test the quantitative and qualitative characterizations afforded by NICS2BC for a selection of molecules of varying structural and electronic complexity, to demonstrate its accuracy and ease of analysis. Moreover, we show that NICS2BC successfully identifies ring-current patterns in molecules known to be difficult cases to interpret with NICS and enables deeper understanding of local aromaticity trends, demonstrating that our method adds additional insight.
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Affiliation(s)
- Eno Paenurk
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Renana Gershoni-Poranne
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland.,Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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24
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Bischof T, Guo X, Krummenacher I, Beßler L, Lin Z, Finze M, Braunschweig H. Alkene insertion reactivity of a o-carboranyl-substituted 9-borafluorene. Chem Sci 2022; 13:7492-7497. [PMID: 35872816 PMCID: PMC9244080 DOI: 10.1039/d2sc02750j] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/01/2022] [Indexed: 11/24/2022] Open
Abstract
The synthesis of 9-borafluorene with an electron-withdrawing o-carboranyl substituent and its reactions with a series of alkenes are described. The o-carboranyl substituent is bonded via one of the cluster carbon atoms to the boron atom of the 9-borafluorene moiety. In all cases, the reactions afford partly saturated analogs of borepins (i.e. 6,7-dihydroborepins) by unprecedented alkene insertion into the endocyclic B–C bond of the borole ring. Comparative studies with 9-bromo-9-borafluorene illustrate the superior insertion reactivity of the carboranyl-substituted derivative. A suite of experimental and computational techniques disclose the unique properties of the 9-borafluorene and provide insight into how the 9-carboranyl substituent affects its chemical reactivity. A 9-carboranyl-substituted 9-borafluorene is reported, which is capable of undergoing efficient ring expansion to 6,7-dihydroborepins by a previously unknown alkene insertion.![]()
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Affiliation(s)
- Tobias Bischof
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Xueying Guo
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Lukas Beßler
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Maik Finze
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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25
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Baron T, Zarate X, Hidalgo-Rosa Y, Zambrano-Angulo M, Mall-Haidaraly K, Pino-Rios R, Pellegrin Y, Odobel F, Cárdenas-Jirón G. Zinc phthalocyanine absorbance in the near-infrared with application for transparent and colorless dye-sensitized solar cells. CR CHIM 2021. [DOI: 10.5802/crchim.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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26
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Mauksch M, Tsogoeva SB. Disclosure of Ground-State Zimmerman-Möbius Aromaticity in the Radical Anion of [6]Helicene and Evidence for 4π Periodic Aromatic Ring Currents in a Molecular "Metallic" Möbius Strip. Chemistry 2021; 27:14660-14671. [PMID: 34375466 PMCID: PMC8596793 DOI: 10.1002/chem.202102230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Indexed: 12/19/2022]
Abstract
In 1966, Zimmerman proposed a type of Möbius aromaticity that involves through-space electron delocalization; it has since been widely applied to explain reactivity in pericyclic reactions, but is considered to be limited to transition-state structures. Although the easily accessible hexahelicene radical anion has been known for more than half a century, it was overlooked that it exhibits a ground-state minimum and robust Zimmerman-Möbius aromaticity in its central noose-like opening, becoming, hence, the oldest existing Möbius aromatic system and with smallest Möbius cycle known. Despite its overall aromatic stabilization energy of 13.6 kcal mol-1 (at B3LYP/6-311+G**), the radical also features a strong, globally induced paramagnetic ring current along its outer edge. Exclusive global paramagnetic currents can also be found in other fully delocalized radical anions of 4N+2 π-electron aromatic polycyclic benzenoid hydrocarbons (PAH), thus questioning the established magnetic criterion of antiaromaticity. As an example of a PAH with nontrivial topology, we studied a novel Möbius[16]cyclacene that has a non-orientable surface manifold and a stable closed-shell singlet ground state at several density functional theory levels. Its metallic monoanion radical (0.0095 eV band gap at HSE06/6-31G* level) is also wave-function stable and displays an unusual 4π-periodic, magnetically induced ring current (reminiscent of the transformation behaviour of spinors under spatial rotation), thus indicating the existence of a new, Hückel-rule-evading type of aromaticity.
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Affiliation(s)
- Michael Mauksch
- Department of Chemistry and Pharmacy, Institute of Theoretical Chemistry, Computer Chemistry Center, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nägelsbachstrasse 25a, 91052, Erlangen, Germany
| | - Svetlana B Tsogoeva
- Department of Chemistry and Pharmacy, Organic Chemistry Chair I and, Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nikolaus-Fiebinger Str. 10, 91058, Erlangen, Germany
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27
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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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28
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Analysis of Local and Global Aromaticity in Si3C5 and Si4C8 Clusters. Aromatic Species Containing Planar Tetracoordinate Carbon. CHEMISTRY 2021. [DOI: 10.3390/chemistry3040080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The minimum energy structures of the Si3C5 and Si4C8 clusters are planar and contain planar tetracoordinate carbons (ptCs). These species have been classified, qualitatively, as global (π) and local (σ) aromatics according to the adaptive natural density partitioning (AdNDP) method, which is an orbital localization method. This work evaluates these species’ aromaticity, focusing on confirming and quantifying their global and local aromatic character. For this purpose, we use an orbital localization method based on the partitioning of the molecular space according to the topology of the electronic localization function (LOC-ELF). In addition, the magnetically induced current density is analyzed. The LOC-ELF-based analysis coincides with the AdNDP study (double aromaticity, global, and local). Moreover, the current density analysis detects global and local ring currents. The strength of the global and local current circuit is significant, involving 4n + 2 π- and σ-electrons, respectively. The latter implicates the Si-ptC-Si fragment, which would be related to the 3c-2e σ-bond detected by the orbital localization methods in this fragment.
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Ganguly G, Pathak S, Paul A. Unraveling the stability of cyclobutadiene complexes using aromaticity markers. Phys Chem Chem Phys 2021; 23:16005-16012. [PMID: 34235525 DOI: 10.1039/d1cp01467f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cyclobutadiene (CBD) is the paradigmatic antiaromatic molecule but is known to form highly stable aromatic complexes, e.g. CBD-Fe(CO)3. This intriguing reversal of aromaticity from antiaromatic to aromatic terrain during the complexation process cannot be appropriately handled with single-reference-based theoretical techniques. We explore this aromaticity reversal, for the first time, by a detailed aromaticity analysis using magnetically induced current densities (MICD) and nucleus independent chemical shifts (NICS) using genuine ab initio multi-reference wavefunction-based theory. We trace the dramatic change of aromaticity for a prototypical cyclobutadiene complex, CBD-CH+ (CH+Fe(CO)3), considering a 3D potential energy surface for two independent parameters, namely the approach of CH+ and the automerization cross-section of cyclobutadiene. The 3D potential energy surfaces indicate the presence of a conical intersection/avoided crossing between the ground and the first excited state. The plot of aromaticity indices and the corresponding numerical values show that the change of aromaticity indices is drastic around the conical intersection/avoided crossing and automerization of cyclobutadiene plays a crucial role in the formation of cyclobutadiene complexes. Computations on analogous CBD-Be and CBD-CO systems (Be/COFe(CO)3) emphasize the generality of the conclusions drawn from the CBD-CH+ system.
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Affiliation(s)
- Gaurab Ganguly
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S C Mullick Road, Kolkata 700032, India.
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30
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Pino-Rios R, Báez-Grez R, Solà M. Acenes and phenacenes in their lowest-lying triplet states. Does kinked remain more stable than straight? Phys Chem Chem Phys 2021; 23:13574-13582. [PMID: 34109330 DOI: 10.1039/d1cp01441b] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The larger stability of phenacenes compared to their acene isomers in their ground states is attributed to the larger aromaticity of the former. To our knowledge the relative stability of acenes and phenacenes in their lowest-lying triplet states (T1) has not been discussed yet. Using unrestricted density functional theory calculations, our results show that for the smallest members of the series, acenes in their T1 states are more stable than the corresponding phenacenes. However, when the number of the rings (n) involved increases, the energy difference is reduced and for n > 12, phenacenes become more stable than acenes in their T1 states. To rationalize this trend, we analyze the aromaticity of acenes and phenacenes using a set of aromaticity descriptors. We find that in the T1 states of both acenes and phenacenes, the outer rings form aromatic Clar π-sextets. In acenes, delocalization of spin density in the central rings leads to the preferred formation of the largest antiaromatic diradical. Resonant structures in the form of antiaromatic diradical Baird π-octadectets and π-tetradectets are the major contributors, while the smaller ones, such as π-doublets and π-sextets, contribute the least. In phenacenes, structures with diradical antiaromatic Baird π-sextets in some of the central rings contribute the most. These results are relevant to understand the (anti)aromaticity of larger polycyclic aromatic hydrocarbons in their triplet states.
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Affiliation(s)
- Ricardo Pino-Rios
- Laboratorio de Química Teórica, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Región Metropolitana, Chile.
| | - Rodrigo Báez-Grez
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, Santiago, Chile
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, 17003 Girona, Catalonia, Spain.
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31
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Pino-Rios R, Montenegro-Pohlhammer N, Cárdenas-Jirón G. Assessment of New Expanded Porpholactones as UV/Vis/NIR Chromophores for Dye-Sensitized Solar Cell Applications. J Phys Chem A 2021; 125:2267-2275. [PMID: 33724841 DOI: 10.1021/acs.jpca.0c11188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Expanded porphyrins arise as an alternative for potential application as chromophores in dye-sensitized solar cells. (DSSCs). The modification of the core of these compounds provides remarkable changes in the photoelectronic behavior. In the present article, the improvement of its properties for a potential application as UV/vis/NIR chromophores in DSSCs has been studied, when an oxazolone moiety has replaced an imine ring in analogy to the porpholactones first synthesized by Crossley et al. ( J. Chem. Soc., Chem. Commun. 1984, 920-922). These expanded porpholactones present a noticeable red shift as well as an increase in the intensity of the Q-bands regarding the parent compounds. The photophysical properties of Sapphyrin have been explored through DFT calculations and vibrationally resolved absorption spectra simulations. Energetic parameters showed favorable electron injection from the chromophore to the TiO2 semiconductor. In addition, aromaticity was analyzed and rationalized using magnetic and delocalization criteria. Results showed qualitatively similar trends between aromaticity descriptors and Q bands giving a great opportunity to the use this property in the rational design of chromophores. Finally, the nonequilibrium Green's function formalism shows the ability of expanded porpholactones in electron transport.
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Affiliation(s)
- Ricardo Pino-Rios
- Laboratorio de Química Teórica, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), 8320000 Santiago, Chile
| | - Nicolás Montenegro-Pohlhammer
- Laboratorio de Química Teórica, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), 8320000 Santiago, Chile.,Departamento de Química Física, Universidad de Sevilla, c/Profesor García González, s/n, 41012 Sevilla, Spain
| | - Gloria Cárdenas-Jirón
- Laboratorio de Química Teórica, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), 8320000 Santiago, Chile
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32
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Paenurk E, Feusi S, Gershoni-Poranne R. Predicting bond-currents in polybenzenoid hydrocarbons with an additivity scheme. J Chem Phys 2021; 154:024110. [DOI: 10.1063/5.0038292] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Eno Paenurk
- Laboratorium für Organische Chemie, ETH Zurich, Switzerland
| | - Stefan Feusi
- Laboratorium für Organische Chemie, ETH Zurich, Switzerland
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33
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Radenković S, Đorđević S. Relating nucleus independent chemical shifts with integrated current density strengths. Phys Chem Chem Phys 2021; 23:11240-11250. [PMID: 33949527 DOI: 10.1039/d1cp00784j] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Indices based on the nucleus independent chemical shift (NICS) are the most frequently used in analysis of magnetic aromaticity. The magnetically induced current density, on the other hand, is a key concept in defining magnetic aromaticity. The integrated current strength (current strength susceptibility) was found to be a very useful tool in aromaticity studies. There is widely accepted notion that the properly chosen NICS-based index can provide information on the current density strength and direction in a molecule of interest. In this work, a detailed numerical testing of the relationship between the integrated bond current strength and the most employed NICS indices was performed for a set of 43 monocyclic aromatic molecules. Based on the statistical data analysis, the relationship between the bond current strength and its π and σ electron components, on one side, and the isotropic NICS (NICSiso and NICSπ,iso) and zz-component of the NICS tensor (NICSzz and NICSπ,zz), on the other side, was examined. It was found that between the NICSπ,zz(1) and π-electron bond current strenghts there is very good linear correlation. Quite surprisingly, it was revealed that the NICSiso(1) and NICSzz(1) are not correlated with the π electron bond current strengths. On the other hand, a reasonably good linear correlation was found between the NICSzz(1) and total bond current strengths.
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Affiliation(s)
- Slavko Radenković
- Faculty of Science, University of Kragujevac, P. O. Box 60, 34000 Kragujevac, Serbia.
| | - Slađana Đorđević
- Faculty of Science, University of Kragujevac, P. O. Box 60, 34000 Kragujevac, Serbia.
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34
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Inostroza D, García V, Yañez O, Torres-Vega JJ, Vásquez-Espinal A, Pino-Rios R, Báez-Grez R, Tiznado W. On the NICS limitations to predict local and global current pathways in polycyclic systems. NEW J CHEM 2021. [DOI: 10.1039/d1nj01510a] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here, we analyze the possibility of predicting local and global current densities in a series of bicyclic hydrocarbons with 4n and 4n + 2 π-electrons from the nucleus-independent chemical shifts (NICS) computations.
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Affiliation(s)
- Diego Inostroza
- Computational and Theoretical Chemistry Group
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
| | - Victor García
- Departamento Académico de Fisicoquímica - Facultad de Química e Ingeniería Química
- Universidad Nacional Mayor de San Marcos
- Lima
- Peru
| | - Osvaldo Yañez
- Center of New Drugs for Hypertension (CENDHY)
- Santiago
- Chile
- Department of Pharmaceutical Science and Technology
- School of Chemical and Pharmaceutical Sciences
| | - Juan J. Torres-Vega
- Centro de Investigaciones Tecnológicas
- Biomédicas y Medioambientales
- Callao
- Peru
| | - Alejandro Vásquez-Espinal
- Computational and Theoretical Chemistry Group
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
| | - Ricardo Pino-Rios
- Laboratorio de Química Teórica
- Facultad de Química y Biología. Universidad de Santiago de Chile (USACH)
- Santiago
- Chile
| | - Rodrigo Báez-Grez
- 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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35
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Pino-Rios R, Solà M. The Relative Stability of Indole Isomers Is a Consequence of the Glidewell-Lloyd Rule. J Phys Chem A 2020; 125:230-234. [DOI: 10.1021/acs.jpca.0c09549] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ricardo Pino-Rios
- Laboratorio de Química teórica, Facultad de Química y Biología. Universidad de Santiago de Chile (USACH), Región Metropolitana, 8320000, Chile
| | - Miquel Solà
- Institute of Computational Chemistry and Catalysis, University of Girona, Girona, Catalonia 17003, Spain
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36
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Ota K, Kinjo R. Aromatic nature of neutral and dianionic 1,4-diaza-2,3,5,6-tetraborinine derivatives. RSC Adv 2020; 11:592-598. [PMID: 35423032 PMCID: PMC8691108 DOI: 10.1039/d0ra09040a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/15/2020] [Indexed: 11/21/2022] Open
Abstract
The aromatically relevant parameters of boron-rich inorganic benzenes-neutral and dianionic 1,4-diaza-2,3,5,6-tetraborinine derivatives (B4N2R6)-have been computationally estimated and evaluated from geometric, electronic, magnetic, and energetic points of view. The majority of the criteria (ASE, NICSzz, ELF, and PDI) indicate that the aromaticity of the neutral B4N2 benzene analogue stabilized by Lewis bases lies in between those of benzene and borazine. On the other hand, the aromaticity of the dianionic B4N2 benzene analogue 4' is controversial. The pronounced aromatic nature of 4' is supported by ELFπ, PDI, and NICSπzz, but ASE, the FiPC-NICS plot, and ACID oppose this. These data confirm that even with the same B4N2-skeletal framework of a 6π-system, the aromatic feature varies depending on the overall charge of the B4N2 systems.
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Affiliation(s)
- Kei Ota
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University 21 Nanyang Link Singapore 637371 Singapore
| | - Rei Kinjo
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University 21 Nanyang Link Singapore 637371 Singapore
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37
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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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38
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Báez-Grez R, Inostroza D, García V, Vásquez-Espinal A, Donald KJ, Tiznado W. Aromatic ouroboroi: heterocycles involving a σ-donor-acceptor bond and 4n + 2 π-electrons. Phys Chem Chem Phys 2020; 22:1826-1832. [PMID: 31829390 DOI: 10.1039/c9cp05071j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The aromaticity and dynamics of a set of recently proposed neutral 5- and 6-membered heterocycles that are closed by dative (donor-acceptor) or multi-center σ bonds, and have resonance forms with a Hückel number of π-electrons, are examined. The donors and acceptors in the rings include N, O, and F, and B, Be, and Mg, respectively. The planar geometry of the rings, coupled with evidence from different measures of aromaticity, namely the NICSzz, and NICSπzz components of the conventional nucleus independent chemical shifts (NICS), and ring current strengths (RCS), indicate non-trivial degrees of aromaticity in certain cases, including the cyclic C3B2OH6 and C3BOH5 isomers, both with three bonds to the O site in the ring. The former is lower in energy by at least 17.6 kcal mol-1 relative to linear alternatives obtained from molecular dynamics simulations in this work. Some of the other systems examined are best described as non-aromatic. Ring opening, closing, and isomerization are observed in molecular dynamics simulations for some of the systems studied. In a few cases, the ring indeed persists.
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Affiliation(s)
- Rodrigo Báez-Grez
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 498, Santiago, Chile.
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39
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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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40
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Orozco-Ic M, Celaya CA, Sundholm D. Calculation of magnetic response properties of tetrazines. RSC Adv 2020; 10:18124-18130. [PMID: 35517234 PMCID: PMC9053762 DOI: 10.1039/d0ra01641a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/01/2020] [Indexed: 12/18/2022] Open
Abstract
Magnetic response properties of 1,2,3,5-tetrazine derivatives including the newly synthesized 4,6-diphenyl-1,2,3,5-tetrazine have been studied computationally at the density functional theory (DFT) level. Calculations of magnetically induced current densities and induced magnetic fields show that the unsubstituted 1,2,3,5-tetrazine is almost as aromatic as benzene. Separating the magnetic shielding functions into molecular orbital components provided additional insights into the magnetic response. The aromatic character estimated from magnetically induced current densities and induced magnetic fields shows that NICSπzz(0) values and ring-current strengths yield about the same degree of aromaticity, whereas NICSzz(0) and NICSzz(1) values are contaminated by σ electron contributions. The studied 1,2,3,5-tetrazine derivatives are less aromatic than the unsubstituted one. Calculations of magnetic response properties of 4,6-diphenyl-1,2,3,5-tetrazine showed that it is the least aromatic among the studied molecules according to the ring-current criterion, while 4,6-[1,2,3,5]-ditetrazinyl-1,2,3,5-tetrazine is as aromatic as 4,6-dimethyl-1,2,3,5-tetrazine and slightly less aromatic than the unsubstituted 1,2,3,5-tetrazine. Magnetic response properties of 1,2,3,5-tetrazine derivatives including the newly synthesized 4,6-diphenyl-1,2,3,5-tetrazine have been studied computationally at the density functional theory level.![]()
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Affiliation(s)
- Mesías Orozco-Ic
- Department of Chemistry
- University of Helsinki
- FIN-00014 Helsinki
- Finland
| | - Christian A. Celaya
- Department of Chemistry
- University of Helsinki
- FIN-00014 Helsinki
- Finland
- Departamento de Materiales de Baja Dimensionalidad
| | - Dage Sundholm
- Department of Chemistry
- University of Helsinki
- FIN-00014 Helsinki
- Finland
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41
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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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42
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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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43
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Martins FA, Pires FC, da Cunha EFF, Freitas MP. Does induced current density explain the C-H and C-F Perlin effects? Phys Chem Chem Phys 2019; 21:18622-18628. [PMID: 31414084 DOI: 10.1039/c9cp02558h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Spin-spin coupling constant (SSCC) data may be useful in providing information on the stereochemistry and intramolecular interactions in molecules. One-bond C-H and C-F SSCCs (1JCH and 1JCF) are amongst the most important NMR parameters used to study the structure of alicyclic six-membered rings, because the Perlin effect, defined as 1JCHeq > 1JCHax, and the fluorine Perlin-like effect, defined as |1JCFeq| > |1JCFax|, are in wide currency to probe the conformations of these compounds. The origin of these effects has been usually attributed either to dipolar interactions or hyperconjugation, while the induced current density (ICD) has been recently correlated to the magnetic shielding tensors in some six-membered ring compounds, and then used to explain the Perlin effect. Accordingly, this work reports an analysis of the ICD as a descriptor of 1JCH and 1JCF in a series of six-membered rings to find out the role of the ICD in the conventional and fluorine Perlin effect. The atoms in molecules (AIM) magnetic responses obtained from density functional theory (DFT) calculations for the studied compounds did not show any relationship of the first-order electronic current density (ΔJ(1)) with the calculated Δ1JCHax-eq and Δ1JCFax-eq values. Consequently, the title effects cannot be precisely explained by ICD. Nevertheless, an interesting relationship between ΔJ(1) and Δdelocalization involving σCH* orbitals is observed.
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Affiliation(s)
- Francisco A Martins
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, MG, Brazil.
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44
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Cherni E, Champagne B, Ayadi S, Liégeois V. Magnetically-induced current density investigation in carbohelicenes and azahelicenes. Phys Chem Chem Phys 2019; 21:14678-14691. [PMID: 31215922 DOI: 10.1039/c9cp02071c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A computational study of the magnetically-induced current (MIC) density has been carried out for a variety of ortho fused polycyclic aromatic molecules at the density functional theory level with the gauge including magnetically induced current (GIMIC) method. With this method, the aromatic character of each ring in a homologous series of carbohelicenes with an increasing number of fused benzene rings is assessed and compared with other aromaticity criteria such as the Nucleus Independent Chemical Shift [NICS(0), NICSzz(0)] and Bond Length Alternation (BLA) parameters. All criteria indicate that the two outer rings are the most aromatic ones [i.e. higher induced current, more negative NICS(0) and NICSzz(0) values, and smaller BLA values]. For the large helicenes (n > 10), the current drops along the following four rings and then rises again. Additionally, we have proven that this behavior is not due to a difference of the local magnetic field coming from a difference of orientation of the ring with respect to the external magnetic field (oriented along the helical axis). Upon fusing additional benzene rings to form hexa-peri-hexabenzo[7]helicene, some rings (B, D, and F) are a lot less aromatic (even non-aromatic) than the others. The NICS(0) and NICSzz(0) values exaggerate this behavior because they are all positive values, which is a signature of antiaromaticity. Then, when substituting one, three, or four benzene rings with pyrrole ones to form mono-aza-[7]-helicene, tri-aza-[7]-helicene, and tetra-aza-[7]-helicene, remarkable changes in the electronic structures of the helicenes are observed. Indeed, the induced currents are always smaller in the pyrrole rings than in the benzene ones. This has been further investigated using the streamline and the color map representations, which indicate that the diatropic current density passing through the plane cutting the C-N bonds in the pyrrole rings is stronger but is more localized than the current density passing through the plane cutting the C-C bonds in the benzene rings. This gives a positive but smaller total induced current for the pyrrole rings than for the benzene ones. For these systems, the NICS(0) and even more the NICSzz(0) values are not fully reliable to probe the local aromaticity, contrary to the induced current. Indeed, the NICSzz(0) values for the tri-aza-[7]-helicene molecule range from -14.23 to 1.14 ppm, which cannot lead to the same conclusion as the induced current values (10.03 to 12.87 nA T-1).
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Affiliation(s)
- Emna Cherni
- Chemistry Department, Faculty of Sciences of Tunis, University of Tunis El Manar, B.P 248 El Manar II, 2092 Tunis, Tunisia and Laboratory of Materials Molecules and Applications, Preparatory Institute for Scientific and Technical Studies, Carthage University, B.P:51, La Marsa, 2075 Tunis, Tunisia and Laboratory of Theoretical Chemistry, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium.
| | - Benoît Champagne
- Laboratory of Theoretical Chemistry, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium.
| | - Sameh Ayadi
- Laboratory of Materials Molecules and Applications, Preparatory Institute for Scientific and Technical Studies, Carthage University, B.P:51, La Marsa, 2075 Tunis, Tunisia
| | - Vincent Liégeois
- Laboratory of Theoretical Chemistry, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium.
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Federmann P, Wagner HK, Antoni PW, Mörsdorf JM, Pérez Lustres JL, Wadepohl H, Motzkus M, Ballmann J. P-Protected Diphosphadibenzo[a,e]pentalenes and Their Mono- and Dicationic P-Bridged Ladder Stilbenes. Org Lett 2019; 21:2033-2038. [DOI: 10.1021/acs.orglett.9b00161] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Patrick Federmann
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, D-69120 Heidelberg, Germany
| | - Hannah K. Wagner
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, D-69120 Heidelberg, Germany
| | - Patrick W. Antoni
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, D-69120 Heidelberg, Germany
| | - Jean-Marc Mörsdorf
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
| | - José Luis Pérez Lustres
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, D-69120 Heidelberg, Germany
| | - Marcus Motzkus
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
| | - Joachim Ballmann
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, D-69120 Heidelberg, Germany
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46
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Decomposition Mechanism of 5,5′-Bis(tetrazole)-1,1′-diolate(TKX-50) Anion Initiated by Intramolecular Oxygen Transfer. Chem Res Chin Univ 2019. [DOI: 10.1007/s40242-019-8332-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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47
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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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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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49
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Ahmed F, Ghosh SR, Halder S, Guin S, Alam SM, Ray PP, Jana AD, Mir MH. Metal–ligand ring aromaticity in a 2D coordination polymer used as a photosensitive electronic device. NEW J CHEM 2019. [DOI: 10.1039/c8nj05526b] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
14-Membered metal–ligand ring present in a photosensitive 2D coordination polymer, [Zn2(fum)2(4-phpy)4(H2O)2] (H2fum = fumaric acid and 4-phpy = 4-phenyl pyridine) shows aromatic character as evident by the nucleus-independent chemical shifts (NICS) calculation.
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Affiliation(s)
- Faruk Ahmed
- Department of Chemistry, Aliah University
- Kolkata 700 156
- India
| | - Sourav Ranjan Ghosh
- Department of Physics, Behala College
- Kolkata
- India
- Department of Physics, Heritage Institute of Technology
- Kolkata 700 107
| | - Soumi Halder
- Department of Physics, Jadavpur University
- Kolkata 700 032
- India
| | - Surajit Guin
- Department of Physics, Behala College
- Kolkata
- India
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50
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Charistos ND, Muñoz-Castro A, Sigalas MP. The pseudo-π model of the induced magnetic field: fast and accurate visualization of shielding and deshielding cones in planar conjugated hydrocarbons and spherical fullerenes. Phys Chem Chem Phys 2019; 21:6150-6159. [DOI: 10.1039/c9cp00836e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogen skeletal models accurately reproduce the π-induced magnetic field of planar PAHs and spherical fullerenes.
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Affiliation(s)
- Nickolas D. Charistos
- Laboratory of Quantum and Computational Chemistry
- Department of Chemistry
- Aristotle University of Thessaloniki
- Thessaloniki
- Greece
| | - Alvaro Muñoz-Castro
- Laboratorio de Química Inorgánica y Materiales Moleculares
- Facultad de Ingeniería
- Universidad Autonoma de Chile
- Santiago
- Chile
| | - Michael P. Sigalas
- Laboratory of Quantum and Computational Chemistry
- Department of Chemistry
- Aristotle University of Thessaloniki
- Thessaloniki
- Greece
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