1
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Riffle JR, Hemingway TM, Smith MD, Peryshkov DV. Synthesis and cluster structure distortions of biscarborane dithiol, thioether, and disulfide. Dalton Trans 2024; 53:4444-4450. [PMID: 38353929 DOI: 10.1039/d3dt04289h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
The synthesis and structural characterization of the first sulfur-containing derivatives of the C,C-biscarborane {ortho-C2B10}2 cluster - thiol, thioether, and disulfide - are reported. The biscarboranyl dithiol (1-HS-C2B10H10)2 exhibits an exceedingly long intracluster carbon-carbon bond length of 1.858(3) Å, which is attributed to the extensive interaction between the lone pairs of the thiol groups and the unoccupied molecular orbital of the carborane cluster. The structures of the doubly deprotonated biscarboranyl dithiolate anion (1-S-C2B10H10)22- with various counter cations feature an even longer carbon-carbon bond length of 2.062(10) Å within the cluster along with a short carbon-sulfur bond of 1.660(7) Å, both indicative of significant delocalization of electron density from the sulfur atoms into the cluster.
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Affiliation(s)
- Jared R Riffle
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, South Carolina 29208, USA.
| | - Tyler M Hemingway
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, South Carolina 29208, USA.
| | - Mark D Smith
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, South Carolina 29208, USA.
| | - Dmitry V Peryshkov
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, South Carolina 29208, USA.
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2
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Korpela EJ, Carvalho JR, Lischka H, Kertesz M. Extremely Long C-C Bonds Predicted beyond 2.0 Å. J Phys Chem A 2023; 127:4440-4454. [PMID: 37166124 PMCID: PMC10950299 DOI: 10.1021/acs.jpca.3c01209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/25/2023] [Indexed: 05/12/2023]
Abstract
A number of conjugated molecules are designed with extremely long single C-C bonds beyond 2.0 Å. Some of the investigated molecules are based on analogues to the recently discovered molecule by Kubo et al. These bonds are analyzed by a variety of indices in addition to their equilibrium bond length including the Wiberg bond index, bond dissociation energy (BDE), and measures of diradicaloid character. All unrestricted DFT calculations indicate no diradical character supported by high-level multireference calculations. Finally, NFOD was computed through fractional orbital density (FOD) calculations and used to compare relative differences of diradicaloid character across twisted molecules without central C-C bonding and those with extremely elongated C-C bonds using a comparison with the C-C bond breaking in ethane. No example of direct C-C bonds beyond 2.4 Å are seen in the computational modeling; however, extremely stretched C-C bonds in the vicinity of 2.2 Å are predicted to be achievable with a BDE of 15-25 kcal mol-1.
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Affiliation(s)
- Eero J.
J. Korpela
- Chemistry
Department and Institute of Soft Matter, Georgetown University, 37th and O Streets, NW, Washington, District of Columbia 20057-1227, United States
| | - Jhonatas R. Carvalho
- Department
of Chemistry and Biochemistry, Texas Tech
University, Lubbock, Texas 79409, United States
| | - Hans Lischka
- Department
of Chemistry and Biochemistry, Texas Tech
University, Lubbock, Texas 79409, United States
| | - Miklos Kertesz
- Chemistry
Department and Institute of Soft Matter, Georgetown University, 37th and O Streets, NW, Washington, District of Columbia 20057-1227, United States
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3
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Sha Y, Zhou Z, Zhu M, Luo Z, Xu E, Li X, Yan H. The Mechanochemistry of Carboranes. Angew Chem Int Ed Engl 2022; 61:e202203169. [DOI: 10.1002/anie.202203169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Ye Sha
- Department of Chemistry and Material Science College of Science Nanjing Forestry University Nanjing 210037 China
| | - Zhou Zhou
- Department of Chemistry and Material Science College of Science Nanjing Forestry University Nanjing 210037 China
| | - Miao Zhu
- Jiangsu Key Laboratory of Pesticide Science and Department of Chemistry College of Science Nanjing Agricultural University Nanjing 210095 China
| | - Zhenyang Luo
- Department of Chemistry and Material Science College of Science Nanjing Forestry University Nanjing 210037 China
| | - Enhua Xu
- Graduate School of System Informatics Kobe University Kobe 657-8501 Japan
| | - Xiang Li
- Jiangsu Key Laboratory of Pesticide Science and Department of Chemistry College of Science Nanjing Agricultural University Nanjing 210095 China
| | - Hong Yan
- State Key Laboratory of Coordination Chemistry Nanjing University Nanjing 210023 China
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4
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Sha Y, Zhou Z, Zhu M, Luo Z, Xu E, Li X, Yan H. The Mechanochemistry of Carboranes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202203169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ye Sha
- Nanjing Forestry University Chemistry and Biochemistry 159 Longpan StNanjing Forestry University 210037 Nanjing CHINA
| | - Zhou Zhou
- Nanjing Forestry University Chemistry CHINA
| | - Miao Zhu
- Nanjing Agricultural University Chemistry CHINA
| | | | - Enhua Xu
- Kobe University Graduate School of System Informatics: Kobe Daigaku Daigakuin System Johogaku Kenkyuka Chemistry JAPAN
| | - Xiang Li
- Nanjing Agricultural University Chemistry CHINA
| | - Hong Yan
- Nanjing University Chemistry CHINA
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5
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Li H, He Y, Liu C, Tan G. A bis(imino)carbazolate pincer ligand stabilized mononuclear gallium(I) compound: synthesis, characterization, and reactivity. Dalton Trans 2021; 50:12674-12680. [PMID: 34545878 DOI: 10.1039/d1dt02209a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The first bis(imino)carbazolate pincer ligand supported mononuclear Ga(I) compound LGa: (3) was synthesized and fully characterized. Oxidation of 3 with elemental selenium afforded the dinuclear Ga(III) compound [LGa(μ-Se)]2 (4) bearing two bridging Se atoms. Ligand substitution of Cr(CO)6 with 3 under UV light irradiation afforded the gallylene-chromium complex LGa: → Cr(CO)5 (5). In addition, the attempted synthesis of the aluminium analogue LAl: through reduction of LAlI2 (7) only led to isolation of the dinuclear Al(III) compound (LAlI)2 (8), most probably formed through the C-C coupling of two imino radicals.
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Affiliation(s)
- Hao Li
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Yuhao He
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Chunmeng Liu
- Center for Molecular Imaging and Nuclear Medicine, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, China
| | - Gengwen Tan
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
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6
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Schwamm RJ, Randow CA, Mouchfiq A, Evans MJ, Coles MP, Robin Fulton J. Synthesis of Heavy
N‐
Heterocyclic Tetrylenes: Influence of Ligand Sterics on Structure. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ryan J. Schwamm
- School of Chemical and Physical Sciences Victoria University of Wellington PO Box 600 Wellington 6012 New Zealand
| | - Clara A. Randow
- School of Chemical and Physical Sciences Victoria University of Wellington PO Box 600 Wellington 6012 New Zealand
| | - Ahmed Mouchfiq
- School of Chemical and Physical Sciences Victoria University of Wellington PO Box 600 Wellington 6012 New Zealand
| | - Matthew J. Evans
- School of Chemical and Physical Sciences Victoria University of Wellington PO Box 600 Wellington 6012 New Zealand
| | - Martyn P. Coles
- School of Chemical and Physical Sciences Victoria University of Wellington PO Box 600 Wellington 6012 New Zealand
| | - J. Robin Fulton
- School of Chemical and Physical Sciences Victoria University of Wellington PO Box 600 Wellington 6012 New Zealand
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Krebs J, Haehnel M, Krummenacher I, Friedrich A, Braunschweig H, Finze M, Ji L, Marder TB. Synthesis and Structure of an o-Carboranyl-Substituted Three-Coordinate Borane Radical Anion. Chemistry 2021; 27:8159-8167. [PMID: 33769625 PMCID: PMC8252506 DOI: 10.1002/chem.202100938] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Indexed: 12/14/2022]
Abstract
Bis(1-(4-tolyl)-carboran-2-yl)-(4-tolyl)-borane [(1-(4-MeC6 H4 )-closo-1,2-C2 B10 H10 -2-)2 (4-MeC6 H4 )B] (1), a new bis(o-carboranyl)-(R)-borane was synthesised by lithiation of the o-carboranyl precursor and subsequent salt metathesis reaction with (4-tolyl)BBr2 . Cyclic voltammetry experiments on 1 show multiple distinct reduction events with a one-electron first reduction. In a selective reduction experiment the corresponding paramagnetic radical anion 1.- was isolated and characterized. Single-crystal structure analyses allow an in-depth comparison of 1, 1.- , their calculated geometries, and the S1 excited state of 1. Photophysical studies of 1 show a charge transfer (CT) emission with low quantum yield in solution but a strong increase in the solid state. TD-DFT calculations were used to identify transition-relevant orbitals.
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Affiliation(s)
- Johannes Krebs
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Martin Haehnel
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Ivo Krummenacher
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Alexandra Friedrich
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Holger Braunschweig
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Maik Finze
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Lei Ji
- Frontiers Science Center for Flexible Electronics (FSCFE)Shaanxi Institute of Flexible Electronics (SIFE)Northwestern Polytechnical University127 West Youyi Road710072Xi'anP. R. China
| | - Todd B. Marder
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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8
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Li J, Goffitzer DJ, Xiang M, Chen Y, Jiang W, Diefenbach M, Zhu H, Holthausen MC, Roesky HW. 1-Aza-2,4-disilabicyclo[1.1.0]butanes with Superelongated C-N σ-Bonds. J Am Chem Soc 2021; 143:8244-8248. [PMID: 34037391 DOI: 10.1021/jacs.1c03149] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two silylene molecules oxidatively react under formal [1 + 2 + 1]-cycloaddition to the C≡N bond of nitriles to yield 1-aza-2,4-disilabicyclo[1.1.0]butanes (L)(Cl)Si[μ-η1,2-NC(p-RC6H4)]Si(Cl)(L) (L = PhC(NtBu)2, R = CF3 (2), F (3), Cl (4), Br (5)). The strongly folded bicyclic SiCNSi cores in 2-5 feature inverted bridgehead carbon atoms and superelongated C-N bonds [1.745(12) to 1.801(2) Å], exceeding the lengths of C-N single bonds in known silaaziridines by up to 23%. Detailed bonding analysis discloses C-N bonding interactions, sharing far-reaching similarities with the central C-C bond in [1.1.1]propellane.
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Affiliation(s)
- Jiancheng Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Daniel J Goffitzer
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Meiyu Xiang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Yilin Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Wenjun Jiang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Martin Diefenbach
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Hongping Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Max C Holthausen
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Herbert W Roesky
- Institut für Anorganische Chemie, Georg-August-Universität, 37077 Göttingen, Germany
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9
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Delgado AAA, Humason A, Kalescky R, Freindorf M, Kraka E. Exceptionally Long Covalent CC Bonds-A Local Vibrational Mode Study. Molecules 2021; 26:molecules26040950. [PMID: 33670107 PMCID: PMC7916873 DOI: 10.3390/molecules26040950] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/04/2021] [Accepted: 02/07/2021] [Indexed: 01/29/2023] Open
Abstract
For decades one has strived to synthesize a compound with the longest covalent C−C bond applying predominantly steric hindrance and/or strain to achieve this goal. On the other hand electronic effects have been added to the repertoire, such as realized in the electron deficient ethane radical cation in its D3d form. Recently, negative hyperconjugation effects occurring in diamino-o-carborane analogs such as di-N,N-dimethylamino-o-carborane have been held responsible for their long C−C bonds. In this work we systematically analyzed CC bonding in a diverse set of 53 molecules including clamped bonds, highly sterically strained complexes such as diamondoid dimers, electron deficient species, and di-N,N-dimethylamino-o-carborane to cover the whole spectrum of possibilities for elongating a covalent C−C bond to the limit. As a quantitative intrinsic bond strength measure, we utilized local vibrational CC stretching force constants ka(CC) and related bond strength orders BSO n(CC), computed at the ωB97X-D/aug-cc-pVTZ level of theory. Our systematic study quantifies for the first time that whereas steric hindrance and/or strain definitely elongate a C−C bond, electronic effects can lead to even longer and weaker C−C bonds. Within our set of molecules the electron deficient ethane radical cation, in D3d symmetry, acquires the longest C−C bond with a length of 1.935 Å followed by di-N,N-dimethylamino-o-carborane with a bond length of 1.930 Å. However, the C−C bond in di-N,N-dimethylamino-o-carborane is the weakest with a BSO n value of 0.209 compared to 0.286 for the ethane radical cation; another example that the longer bond is not always the weaker bond. Based on our findings we provide new guidelines for the general characterization of CC bonds based on local vibrational CC stretching force constants and for future design of compounds with long C−C bonds.
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10
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Beau M, Lee S, Kim S, Han WS, Jeannin O, Fourmigué M, Aubert E, Espinosa E, Jeon IR. Strong σ-Hole Activation on Icosahedral Carborane Derivatives for a Directional Halide Recognition. Angew Chem Int Ed Engl 2021; 60:366-370. [PMID: 32926491 DOI: 10.1002/anie.202010462] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Indexed: 12/14/2022]
Abstract
Crystal engineering based on σ-hole interactions is an emerging approach for realization of new materials with higher complexity. Neutral inorganic clusters derived from 1,2-dicarba-closo-dodecaborane, substituted with -SeMe, -TeMe, and -I moieties on both skeletal carbon vertices are experimentally demonstrated herein as outstanding chalcogen- and halogen-bond donors. In particular, these new molecules strongly interact with halide anions in the solid-state. The halide ions are coordinated by one or two donor groups (μ1 - and μ2 -coordinations), to stabilize a discrete monomer or dimer motifs to 1D supramolecular zig-zag chains. Crucially, the observed chalcogen bond and halogen bond interactions feature remarkably short distances and high directionality. Electrostatic potential calculations further demonstrate the efficiency of the carborane derivatives, with Vs,max being similar or even superior to that of reference organic halogen-bond donors, such as iodopentafluorobenzene.
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Affiliation(s)
- Maxime Beau
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Campus de Beaulieu, 35000, Rennes, France
| | - Sunhee Lee
- Department of Chemistry, Seoul Women's University, Seoul, 01797, Republic of Korea
| | - Sooyeon Kim
- Department of Chemistry, Seoul Women's University, Seoul, 01797, Republic of Korea
| | - Won-Sik Han
- Department of Chemistry, Seoul Women's University, Seoul, 01797, Republic of Korea
| | - Olivier Jeannin
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Campus de Beaulieu, 35000, Rennes, France
| | - Marc Fourmigué
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Campus de Beaulieu, 35000, Rennes, France
| | - Emmanuel Aubert
- Laboratoire CRM2, UMR CNRS 7036, Institut Jean Barriol, Université de Lorraine, BP 70239, 54506, Vandoeuvre-lès-Nancy, France
| | - Enrique Espinosa
- Laboratoire CRM2, UMR CNRS 7036, Institut Jean Barriol, Université de Lorraine, BP 70239, 54506, Vandoeuvre-lès-Nancy, France
| | - Ie-Rang Jeon
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Campus de Beaulieu, 35000, Rennes, France
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11
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Beau M, Lee S, Kim S, Han W, Jeannin O, Fourmigué M, Aubert E, Espinosa E, Jeon I. Strong
σ
‐Hole Activation on Icosahedral Carborane Derivatives for a Directional Halide Recognition. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202010462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Maxime Beau
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) Campus de Beaulieu 35000 Rennes France
| | - Sunhee Lee
- Department of Chemistry Seoul Women's University Seoul 01797 Republic of Korea
| | - Sooyeon Kim
- Department of Chemistry Seoul Women's University Seoul 01797 Republic of Korea
| | - Won‐Sik Han
- Department of Chemistry Seoul Women's University Seoul 01797 Republic of Korea
| | - Olivier Jeannin
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) Campus de Beaulieu 35000 Rennes France
| | - Marc Fourmigué
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) Campus de Beaulieu 35000 Rennes France
| | - Emmanuel Aubert
- Laboratoire CRM2 UMR CNRS 7036 Institut Jean Barriol Université de Lorraine BP 70239, 54506 Vandoeuvre-lès-Nancy France
| | - Enrique Espinosa
- Laboratoire CRM2 UMR CNRS 7036 Institut Jean Barriol Université de Lorraine BP 70239, 54506 Vandoeuvre-lès-Nancy France
| | - Ie‐Rang Jeon
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) Campus de Beaulieu 35000 Rennes France
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12
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Mandal N, Datta A. Molecular designs for expanding the limits of ultralong C-C bonds and ultrashort HH non-bonded contacts. Chem Commun (Camb) 2020; 56:15377-15386. [PMID: 33210669 DOI: 10.1039/d0cc06690g] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent experiments have reported the formation of very long C-C bonds (dC-C > 1.80 Å) and very short HH non-bonded contacts (dHH < 1.5 Å) in several sets of molecules. Both these rare phenomena arise due to specific donor-acceptor interactions and London dispersion interactions respectively. Favorable negative hyperconjugation, namely H2N(lone-pair) →σ*(C-C), creates an ultralong C-C bond in diamino-o-carborane with dC-C > 1.829 Å and a planar amine reminiscent of a transition-state like structure for ammonia inversion. The small and narrow barrier favours rapid inversion through quantum mechanical tunnelling (QMT) and produces a translationally averaged planar amine as observed in the experiments. On the other hand, designing specific confined molecular cavities or chambers like in,in-bis(hydrosilane) or its germanane analogs furnishes an ultrashort HH distance = 1.47 Å and 1.38 Å respectively. The predisposition of such closely placed HH contacts arises from the rather effective attractive dispersion interactions between them. Controlling the strength of the dispersion interactions provides a rich landscape for realizing such close HH distances. Molecular design ably assisted by computational modeling to further tune these interactions provides new avenues to break the glass-ceilings of ultralong C-C bonds or ultrashort HH contacts. Dispersion-corrected DFT calculations and ab initio molecular dynamics simulations generate a large library of such unique features in a diverse class of molecules. This feature article highlights the design principles to realize hitherto longest C-C bonds/shortest HH contacts.
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Affiliation(s)
- Nilangshu Mandal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur - 700032, Kolkata, West Bengal, India.
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13
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Mandal N, Pal AK, Gain P, Zohaib A, Datta A. Transition-State-like Planar Structures for Amine Inversion with Ultralong C-C Bonds in Diamino- o-carborane and Diamino- o-dodecahedron. J Am Chem Soc 2020; 142:5331-5337. [PMID: 32090580 DOI: 10.1021/jacs.0c00181] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Umbrella-like inversion of pyramidalized amines proceed through a planar transition state (TS). Stabilization of the TS through N(lone-pair) → σ*(C-C) "negative hyperconjugation" in diamino-o-carborane (1) causes rapid inversion in the amine, which results in the observation of a planarized -NH2 from the X-ray crystal structure. This proceeds through quantum mechanical tunneling across the small and narrow barrier (low pyramidalization). Tuning this secondary orbital (donor-acceptor) interaction for various derivatives of 1 and diamino-o-dodecahedron (2) provides a rational approach toward increasing dC-C to as large as 2.001, 2.011, and 1.807 Å for 1b (amino oxide-o-carborane), 1i (di-N,N-dimethylamino-o-carborane), and 2g (di-N,N-diisopropylamino-o-dodecahedron), respectively.
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Affiliation(s)
- Nilangshu Mandal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032 Kolkata, West Bengal, India
| | - Arun K Pal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032 Kolkata, West Bengal, India
| | - Pranab Gain
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032 Kolkata, West Bengal, India
| | - Ahsan Zohaib
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032 Kolkata, West Bengal, India
| | - Ayan Datta
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032 Kolkata, West Bengal, India
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