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Coburger P, Zuber D, Schweinzer C, Scharnhölz M. Phosphonium-substituted Diphosphaindenylide (PPI): Exploration of Biradical Character and Ligand Properties. Chemistry 2024; 30:e202302970. [PMID: 38032060 DOI: 10.1002/chem.202302970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 12/01/2023]
Abstract
Starting from C6 H4 (PCl2 )2 and the TMS-substituted ylide (TMS)2 C=PR3 (TMS=trimethylsilyl, R=p-tolyl), the phosphonium-substituted diphosphaindenylide PPI was prepared in two steps. CASSCF calculations as well as the reactivity toward diphenyl acetylene suggest a notable biradical character in PPI. Reaction with [Cr(CO)3 (MeCN)3 ] affords the complex [Cr(CO)3 (η5 -PPI)] (5). This complex was employed to explore the ligand properties of PPI, which demonstrates considerable potential through the combination of strong metal-ligand interactions and the possibility of a pronounced indenyl effect.
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Affiliation(s)
- Peter Coburger
- Department of Inorganic Chemistry, TU München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - David Zuber
- Department of Inorganic Chemistry, TU München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Clara Schweinzer
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093, Zürich, Switzerland
| | - Moritz Scharnhölz
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093, Zürich, Switzerland
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2
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Abstract
Heteroatom-centered diradical(oid)s have been in the focus of molecular main group chemistry for nearly 30 years. During this time, the diradical concept has evolved and the focus has shifted to the rational design of diradical(oid)s for specific applications. This review article begins with some important theoretical considerations of the diradical and tetraradical concept. Based on these theoretical considerations, the design of diradical(oid)s in terms of ligand choice, steric, symmetry, electronic situation, element choice, and reactivity is highlighted with examples. In particular, heteroatom-centered diradical reactions are discussed and compared with closed-shell reactions such as pericyclic additions. The comparison between closed-shell reactivity, which proceeds in a concerted manner, and open-shell reactivity, which proceeds in a stepwise fashion, along with considerations of diradical(oid) design, provides a rational understanding of this interesting and unusual class of compounds. The application of diradical(oid)s, for example in small molecule activation or as molecular switches, is also highlighted. The final part of this review begins with application-related details of the spectroscopy of diradical(oid)s, followed by an update of the heteroatom-centered diradical(oid)s and tetraradical(oid)s published in the last 10 years since 2013.
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Affiliation(s)
- Alexander Hinz
- Institut für Anorganische Chemie (AOC), Karlsruher Institut für Technologie (KIT), Engesserstrasse 15, 76131 Karlsruhe, Germany
| | - Jonas Bresien
- Institut für Chemie, Universität Rostock, Albert-Einstein-Strasse 3a, 18059 Rostock, Germany
| | - Frank Breher
- Institut für Anorganische Chemie (AOC), Karlsruher Institut für Technologie (KIT), Engesserstrasse 15, 76131 Karlsruhe, Germany
| | - Axel Schulz
- Institut für Chemie, Universität Rostock, Albert-Einstein-Strasse 3a, 18059 Rostock, Germany
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3
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Zhu B, Song Y, Zhu J, Rauhut G, Jiang J, Zeng X. FP(μ-N) 2 S: A Sulfur-Pnictogen Four-Membered Ring with 6π Electrons. Chemistry 2023; 29:e202300251. [PMID: 37261435 DOI: 10.1002/chem.202300251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/28/2023] [Accepted: 06/01/2023] [Indexed: 06/02/2023]
Abstract
The new 6π-electron four-membered ring compound 3-fluoro-1λ2 ,2,4,3λ3 -thiadiazaphosphetidine, FP(μ-N)2 S, has been generated in the gas phase through high-vacuum flash pyrolysis (HVFP) of thiophosphoryl diazide, FP(S)(N3 )2 , at 1000 K. Subsequent isolation of FP(μ-N)2 S in cryogenic matrices (Ar, Ne, and N2 ) allows its characterization with matrix-isolation IR and UV-vis spectroscopy by combination with 15 N-isotope labeling and computations at the CCSD(T)-F12a/VTZ-F12 level of theory. Upon visible-light irradiation at 550 nm, this cyclic compound undergoes ring-opening to the thiazyl isomer FPNSN, followed by dissociation to FP and SN2 under subsequent UV-irradiation at 365 nm. In sharp contrast to the square planar structure for the isolobal four-membered ring S2 N2 , a puckered structure with significant biradical character has been found for FP(μ-N)2 S.
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Affiliation(s)
- Bifeng Zhu
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, China
| | - Yanlin Song
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Guntram Rauhut
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart, 70569, Germany
| | - Junjie Jiang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, China
| | - Xiaoqing Zeng
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, China
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4
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Steffenfauseweh H, Rottschäfer D, Vishnevskiy YV, Neumann B, Stammler HG, Szczepanik DW, Ghadwal RS. Isolation of an Annulated 1,4-Distibabenzene Diradicaloid. Angew Chem Int Ed Engl 2023; 62:e202216003. [PMID: 36598396 DOI: 10.1002/anie.202216003] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/23/2022] [Accepted: 01/04/2023] [Indexed: 01/05/2023]
Abstract
The first 1,4-distibabenzene-1,4-diide compound [(ADC)Sb]2 (5) based on an anionic dicarbene (ADC) (ADC=PhC{N(Dipp)C}2 , Dipp=2,6-iPr2 C6 H3 ) is reported as a bordeaux-red solid. Compound 5, featuring a central six-membered C4 Sb2 ring with formally SbI atoms may be regarded as a base-stabilized cyclic bis-stibinidene in which each of the Sb atoms bears two lone-pairs of electrons. 5 undergoes 2 e-oxidation with Ph3 C[B(C6 F5 )4 ] to afford [(ADC)Sb]2 [B(C6 F5 )4 ]2 (6) as a brick-red solid. Each of the Sb atoms of 6 has an unpaired electron and a lone-pair. The broken-symmetry open-shell singlet diradical solution for (6)2+ is calculated to be 2.13 kcal mol-1 more stable than the closed-shell singlet. The diradical character of (6)2+ according to SS-CASSCF (state-specific complete active space self-consistent field) and UHF (unrestricted Hartree-Fock) methods amounts to 36 % and 39 %, respectively. Treatments of 6 with (PhE)2 yield [(ADC)Sb(EPh)]2 [B(C6 F5 )4 ]2 (7-E) (E=S or Se). Reaction of 5 with (cod)Mo(CO)4 affords [(ADC)Sb]2 Mo(CO)4 (8).
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Affiliation(s)
- Henric Steffenfauseweh
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Dennis Rottschäfer
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany.,Current address: Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Str. 4, Marburg, Germany
| | - Yury V Vishnevskiy
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Beate Neumann
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Hans-Georg Stammler
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Dariusz W Szczepanik
- Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Rajendra S Ghadwal
- Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, 33615, Bielefeld, Germany
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5
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Steffenfauseweh H, Vishnevskiy YV, Neumann B, Stammler H, Andrada DM, Ghadwal RS. Isolation of an Arsenic Diradicaloid with a Cyclic C 2 As 2 -Core. Angew Chem Int Ed Engl 2022; 61:e202207415. [PMID: 35652361 PMCID: PMC9545666 DOI: 10.1002/anie.202207415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Indexed: 01/08/2023]
Abstract
Herein, we report on the synthesis, characterization, and reactivity studies of the first cyclic C2 As2 -diradicaloid {(IPr)CAs}2 (6) (IPr = C{N(Dipp)CH}2 ; Dipp = 2,6-iPr2 C6 H3 ). Treatment of (IPr)CH2 (1) with AsCl3 affords the Lewis adduct {(IPr)CH2 }AsCl3 (2). Compound 2 undergoes stepwise dehydrochlorination to yield {(IPr)CH}AsCl2 (3) and {(IPr)CAsCl}2 (5 a) or [{(IPr)CAs}2 Cl]OTf (5 b). Reduction of 5 a (or 5 b) with magnesium turnings gives 6 as a red crystalline solid in 90% yield. Compound 6 featuring a planar C2 As2 ring is diamagnetic and exhibits well resolved NMR signals. DFT calculations reveal a singlet ground state for 6 with a small singlet-triplet energy gap of 8.7 kcal mol-1 . The diradical character of 6 amounts to 20% (CASSCF, complete active space self consistent field) and 28% (DFT). Treatments of 6 with (PhSe)2 and Fe2 (CO)9 give rise to {(IPr)CAs(SePh)}2 (7) and {(IPr)CAs}2 Fe(CO)4 (8), respectively.
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Affiliation(s)
- Henric Steffenfauseweh
- Molecular Inorganic Chemistry and CatalysisInorganic and Structural ChemistryCenter for Molecular MaterialsFaculty of ChemistryUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
| | - Yury V. Vishnevskiy
- Molecular Inorganic Chemistry and CatalysisInorganic and Structural ChemistryCenter for Molecular MaterialsFaculty of ChemistryUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
| | - Beate Neumann
- Molecular Inorganic Chemistry and CatalysisInorganic and Structural ChemistryCenter for Molecular MaterialsFaculty of ChemistryUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
| | - Hans‐Georg Stammler
- Molecular Inorganic Chemistry and CatalysisInorganic and Structural ChemistryCenter for Molecular MaterialsFaculty of ChemistryUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
| | - Diego M. Andrada
- Faculty of Natural Sciences and TechnologyDepartment of ChemistrySaarland UniversityCampus C4.166123SaarbrückenGermany
| | - Rajendra S. Ghadwal
- Molecular Inorganic Chemistry and CatalysisInorganic and Structural ChemistryCenter for Molecular MaterialsFaculty of ChemistryUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
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6
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Steffenfauseweh H, Vishnevskiy YV, Neumann B, Stammler HG, Andrada DM, Ghadwal R. Isolation of an Arsenic Diradicaloid with a Cyclic C2As2‐Core. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | | | - Beate Neumann
- Bielefeld University: Universitat Bielefeld Chemistry GERMANY
| | | | - Diego M. Andrada
- Saarland University: Universitat des Saarlandes Chemistry GERMANY
| | - Rajendra Ghadwal
- Universitat Bielefeld Institut für Anorganische Chemie Universitätstrasse 25 33615 Bielefeld GERMANY
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7
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Thomas A, Ji C, Siddlingeshwar B, Manohar PU, Ying F, Wu W. Revealing the biradicaloid nature inherited in the derivatives of thieno[3,4- c][1,2,5]thiadiazole: a computational study. Phys Chem Chem Phys 2021; 23:1050-1061. [PMID: 33346279 DOI: 10.1039/d0cp05106c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Computational studies were performed on non-classical thieno[3,4-c][1,2,5] thiadiazole and its pi donor derivatives (TT dyes) so as to delineate the factors responsible for their near-infrared (NIR) absorption. For all dyes except the unsubstituted bare dye, adiabatic singlet-triplet energy gaps (estimated through the ΔSCF procedure using the B3LYP and M062X DFT methods and SFTDDFT with the 5050 functional) were less than 1eV. Percentage calculations of the biradicaloid character suggested a moderate biradicaloid nature in all derivatives. There was a resemblance between the frontier molecular orbital (MO) picture of the TT bicyclic ring and the degenerate non-bonding molecular orbitals of Trimethyleneethane (TME, a known biradical). Inter-fragment charge transfer analysis revealed not only a considerable donation of charge to the central ring (Acceptor, TT part) but also substantial charge redistribution within the ring itself. From these results, it was inferred that NIR absorption, in these dyes, was due to: (1) a reduced HOMO-LUMO gap (HLG) as a TME biradical substructure forms its chromophoric part; and (2) charge transfer from the donor substituents. The non-bonding nature of the S atom, in the bare dye, with its neighbouring N/C atom (of the highest occupied π-MOs), led to an examination of its electronic structure using the ab initio valence bond method. The relatively large weight and energetic stability of the biradicaloid VB structures compared to those of the ylidic structures clearly disclosed the importance of biradicaloid structures in the overall resonance of the bare dye. Their utility as singlet fission materials was screened using singlet and triplet energy-based molecular structure activity criteria. The results were encouraging, demanding experiments to reaffirm the materials' usefulness.
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Affiliation(s)
- Anup Thomas
- Center for Computational Research in Clean Energy Technologies, Sree Chitra Thirunal College of Engineering, Pappanamcode, Trivandrum 695018, India
| | - Chenru Ji
- Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, The State Key Laboratory of Physical Chemistry of Solid Surfaces, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
| | - B Siddlingeshwar
- Department of Physics, M. S. Ramaiah Institute of Technology, Bengaluru 560054, India.
| | - Prashant Uday Manohar
- Department of Chemistry, Birla Institute of Technology and Science, Pilani 333031, Rajasthan, India
| | - Fuming Ying
- Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, The State Key Laboratory of Physical Chemistry of Solid Surfaces, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
| | - Wei Wu
- Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, The State Key Laboratory of Physical Chemistry of Solid Surfaces, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
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8
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Coburger P, Wolf R, Grützmacher H. Isomerism and Biradical Character of Tetrapnictide Dianions: A Computational Study. Eur J Inorg Chem 2020; 2020:3580-3586. [PMID: 33132751 PMCID: PMC7590082 DOI: 10.1002/ejic.202000422] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Indexed: 11/17/2022]
Abstract
We present a computational study on tetrapnictide dianions Pn42– (Pn = P, As, Sb, Bi), using density functional theory (DFT), coupled‐cluster [DLPNO‐CCSD(T)] and complete active space self‐consistent field (CASSCF) methods. Environmental effects such as solvation and coordination of counterions are included. The calculations reveal that out of three isomers (square‐planar, butterfly and capped‐triangle), the square planar isomers are generally the most stable. The counterion (Li+ and Mg2+) used in the calculations have a substantial effect on the relative stabilities. The square planar isomers show considerable biradical character. Calculated reactions toward alkenes indicate that this unusual electronic structure has significant implications on the reactivity of the Pn42– dianions.
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Affiliation(s)
- Peter Coburger
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany.,Laboratory of Inorganic Chemistry ETH Zurich 8093 Zürich Switzerland
| | - Robert Wolf
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
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9
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Chivers T, Laitinen RS. Neutral binary chalcogen-nitrogen and ternary S,N,P molecules: new structures, bonding insights and potential applications. Dalton Trans 2020; 49:6532-6547. [PMID: 32342078 DOI: 10.1039/d0dt00807a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Early theoretical and experimental investigations of inorganic sulfur-nitrogen compounds were dominated by (a) assessments of the purported aromatic character of cyclic, binary S,N molecules and ions, (b) the unpredictable reactions of the fascinating cage compound S4N4, and (c) the unique structure and properties of the conducting polymer (SN)x. In the last few years, in addition to unexpected developments in the chemistry of well-known sulfur nitrides, the emphasis of these studies has changed to include nitrogen-rich species formed under high pressures, as well as the selenium analogues of well-known S,N compounds. Novel applications have been established or predicted for many binary S/Se,N molecules, including their use for fingerprint detection, in optoelectronic devices, as high energy-density compounds or as hydrogen-storage materials. The purpose of this perspective is to evaluate critically these new aspects of the chemistry of neutral, binary chalcogen-nitrogen molecules and to suggest experimental approaches to the synthesis of target compounds. Recently identified ternary S,N,P compounds will also be considered in light of their isoelectronic relationship with binary S,N cations.
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Affiliation(s)
- Tristram Chivers
- Department of Chemistry, University of Calgary, AB, CanadaT2N 1N4.
| | - Risto S Laitinen
- Laboratory of Inorganic Chemistry, Environmental and Chemical Engineering, University of Oulu, P. O. Box 3000, 90014, Finland.
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10
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Stuyver T, Chen B, Zeng T, Geerlings P, De Proft F, Hoffmann R. Do Diradicals Behave Like Radicals? Chem Rev 2019; 119:11291-11351. [DOI: 10.1021/acs.chemrev.9b00260] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Thijs Stuyver
- Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Bo Chen
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca New York 14853, United States
| | - Tao Zeng
- Department of Chemistry, York University, Toronto, Ontario M3J1P3, Canada
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S5B6, Canada
| | - Paul Geerlings
- Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Frank De Proft
- Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Roald Hoffmann
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca New York 14853, United States
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11
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Stuyver T, Danovich D, Shaik S. Captodative Substitution Enhances the Diradical Character of Compounds, Reduces Aromaticity, and Controls Single-Molecule Conductivity Patterns: A Valence Bond Study. J Phys Chem A 2019; 123:7133-7141. [PMID: 31318209 DOI: 10.1021/acs.jpca.9b06096] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The present contribution uses a valence bond (VB) perspective to consider the captodative substitution strategy, a method to enhance the diradical character of (potentially aromatic) compounds. We confirm the qualitative reasoning that has generally been used to rationalize the diradical-character-enhancing effect of captodative substitution: this type of substitution scheme disproportionally stabilizes specific Dewar/diradical(oid) VB structures, thus increasing their weight in the full ground-state wave function. Furthermore, we assess the effect of captodative substitution on the aromaticity of the considered compound. We observe a clear trade-off between diradical character and aromaticity for our model systems: as one of these properties increases, the other decreases. This finding is especially significant within the field of single-molecule electronics because it enables unification of the previously observed inverse proportionality between the aromaticity of a compound and the magnitude of conductance through that molecule, with the observed proportionality between diradical character and the magnitude of conductance associated with a compound. To some extent, both properties, i.e., aromaticity and diradical character, appear to be the flip-sides of the same coin.
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Affiliation(s)
- Thijs Stuyver
- Department of Organic Chemistry and the Lise Meitner-Minerva Centre for Computational Quantum Chemistry , The Hebrew University , Jerusalem 91904 , Israel.,Algemene Chemie , Vrije Universiteit Brussel , Pleinlaan 2 , 1050 Brussels , Belgium
| | - David Danovich
- Department of Organic Chemistry and the Lise Meitner-Minerva Centre for Computational Quantum Chemistry , The Hebrew University , Jerusalem 91904 , Israel
| | - Sason Shaik
- Department of Organic Chemistry and the Lise Meitner-Minerva Centre for Computational Quantum Chemistry , The Hebrew University , Jerusalem 91904 , Israel
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12
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Karadakov PB, Al-Yassiri MAH, Cooper DL. Magnetic Shielding, Aromaticity, Antiaromaticity and Bonding in the Low-Lying Electronic States of S 2 N 2. Chemistry 2018; 24:16791-16803. [PMID: 30270473 DOI: 10.1002/chem.201804292] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 09/27/2018] [Indexed: 11/08/2022]
Abstract
Aromaticity, antiaromaticity and chemical bonding in the ground (S0 ), first singlet excited (S1 ) and lowest triplet (T1 ) electronic states of disulfur dinitride, S2 N2 , were investigated by analysing the isotropic magnetic shielding, σiso (r), in the space surrounding the molecule for each electronic state. The σiso (r) values were calculated by state-optimized CASSCF/cc-pVTZ wave functions with 22 electrons in 16 orbitals constructed from gauge-including atomic orbitals (GIAOs). The S1 and T1 electronic states were confirmed as 11 Au and 13 B3u , respectively, through linear response CC3/aug-cc-pVTZ calculations of the vertical excitation energies for eight singlet (S1 -S8 ) and eight triplet (T1 -T8 ) electronic states. The aromaticities of S0 , S1 and T1 were also assessed using additional magnetic criteria including nucleus-independent chemical shifts (NICS) and magnetic susceptibilities calculated at several levels of theory, the highest of which were CCSDT-GIAO/cc-pVTZ for S0 and CASSCF(22,16)-GIAO/aug-cc-pVQZ for S1 and T1 . The results strongly suggest that: 1) the S0 electronic ground state of S2 N2 is aromatic but less so than the electronic ground state of benzene; 2) S1 is profoundly antiaromatic, to an extent that removes any bonding interactions that would keep the atoms together; and 3) T1 is also antiaromatic, but its antiaromaticity is more moderate and similar to that observed in the electronic ground state of square cyclobutadiene. S2 N2 is the first example of an inorganic ring for which theory predicts substantial changes in aromaticity upon vertical transition from the ground state to the first singlet excited or lowest triplet electronic states.
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Affiliation(s)
- Peter B Karadakov
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | | | - David L Cooper
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
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13
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Karach I, Botvinik A, Truhlar DG, Wu W, Shurki A. Assessing the performance of ab initio classical valence bond methods for hydrogen transfer reactions. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.05.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Braïda B, Galembeck SE, Hiberty PC. Ozone and Other 1,3-Dipoles: Toward a Quantitative Measure of Diradical Character. J Chem Theory Comput 2017; 13:3228-3235. [DOI: 10.1021/acs.jctc.7b00399] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Benoît Braïda
- UPMC Université Paris 06, CNRS UMR 7616, Laboratoire de Chimie Théorique, Case Courrier 137, 4 Place Jussieu, 75252 Paris, France
| | - Sérgio E. Galembeck
- Departamento
de Química, Faculdade de Filosofia, Ciências e Letras
de Ribeirão Preto, Universidade de São Paulo, 14040-901, Ribeirão Preto − SP Brazil
| | - Philippe C. Hiberty
- Laboratoire
de Chimie Physique, Groupe de Chimie Théorique, CNRS UMR 8000, Université de Paris-Sud, 91405 Orsay Cédex, France
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15
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Density functional and ab initio investigation of S2N2 and (SN)2. Chem Phys 2017. [DOI: 10.1016/j.chemphys.2017.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Perrin A, Flores Antognini A, Zeng X, Beckers H, Willner H, Rauhut G. Vibrational Spectrum and Gas-Phase Structure of Disulfur Dinitride (S2N2). Chemistry 2014; 20:10323-31. [DOI: 10.1002/chem.201402404] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Indexed: 11/08/2022]
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He G, Shynkaruk O, Lui MW, Rivard E. Small Inorganic Rings in the 21st Century: From Fleeting Intermediates to Novel Isolable Entities. Chem Rev 2014; 114:7815-80. [DOI: 10.1021/cr400547x] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Gang He
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Olena Shynkaruk
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Melanie W. Lui
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
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Harcourt RD. Notes on Valence Bond Structures for S2N2and Related Systems. Chemphyschem 2013; 14:2859-64. [DOI: 10.1002/cphc.201300360] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Indexed: 11/07/2022]
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Braida B, Hendrickx K, Domin D, Dinnocenzo JP, Hiberty PC. Multicenter Bonding in Ditetracyanoethylene Dianion: A Simple Aromatic Picture in Terms of Three-Electron Bonds. J Chem Theory Comput 2013; 9:2276-85. [PMID: 26583721 DOI: 10.1021/ct400290n] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nature of the multicenter, long bond in ditetracyanoethylene dianion complex [TCNE]2(2-) is elucidated using high level ab initio Valence Bond (VB) theory coupled with Quantum Monte Carlo (QMC) methods. This dimer is the prototype of the general family of pancake-bonded dimers with large interplanar separations. Quantitative results obtained with a compact wave function in terms of only six VB structures match the reference CCSD(T) bonding energies. Analysis of the VB wave function shows that the weights of the VB structures are not compatible with a covalent bond between the π* orbitals of the fragments. On the other hand, these weights are consistent with a simple picture in terms of two resonating bonding schemes, one displaying a pair of interfragment three-electron σ bonds and the other displaying intrafragment three-electron π bonds. This simple picture explains at once (1) the long interfragment bond length, which is independent of the countercations but typical of three-electron (3-e) CC σ bonds, (2) the interfragment orbital overlaps which are very close to the theoretical optimal overlap of 1/6 for a 3-e σ bond, and (3) the unusual importance of dynamic correlation, which is precisely the main bonding component of 3-e bonds. Moreover, it is shown that the [TCNE]2(2-) system is topologically equivalent to the square C4H4(2-) dianion, a well-established aromatic system. To better understand the role of the cyano substituents, the unsubstituted diethylenic Na(+)2[C2H4]2(2-) complex is studied and shown to be only metastable and topologically equivalent to a rectangular C4H4(2-) dianion, devoid of aromaticity.
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Affiliation(s)
- Benoit Braida
- UPMC Université Paris 06, CNRS UMR 7616, Laboratoire de Chimie Théorique, C. 137, 4 Place Jussieu, 75252 Paris Cedex 05, France
| | - Kevin Hendrickx
- UPMC Université Paris 06, CNRS UMR 7616, Laboratoire de Chimie Théorique, C. 137, 4 Place Jussieu, 75252 Paris Cedex 05, France
| | - Dominik Domin
- UPMC Université Paris 06, CNRS UMR 7616, Laboratoire de Chimie Théorique, C. 137, 4 Place Jussieu, 75252 Paris Cedex 05, France
| | - Joseph P Dinnocenzo
- University of Rochester, Department of Chemistry, Rochester, New York 14627, United States
| | - Philippe C Hiberty
- Laboratoire de Chimie Physique, UMR CNRS 8000, Groupe de Chimie Théorique, Université de Paris-Sud, 91405 Orsay Cédex, France
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Islas R, Poater J, Matito E, Solà M. Molecular structures of M2N22− (M and N = B, Al, and Ga) clusters using the gradient embedded genetic algorithm. Phys Chem Chem Phys 2012; 14:14850-9. [DOI: 10.1039/c2cp42210g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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