1
|
Fokin AA. Long but Strong C-C Single Bonds: Challenges for Theory. CHEM REC 2024; 24:e202300170. [PMID: 37358335 DOI: 10.1002/tcr.202300170] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/02/2023] [Indexed: 06/27/2023]
Abstract
Theoretical challenges in describing molecules with anomalously long single C-C bonds are analyzed in terms of the relative contributions of stabilizing and destabilizing intramolecular interactions. Diamondoid dimers that are stable despite the presence of C-C bonds up to 1.7 Å long, as well as other bulky molecules stabilized due to intramolecular noncovalent interactions (London dispersions) are discussed. The unexpected stability of highly crowded molecules, such as diamondoid dimers and tert-butyl-substituted hexaphenylethanes, calls for reconsideration of the "steric effect" traditionally thought to destabilize the molecule. Alternatively, "steric attraction" helps to understand bonding in sterically overloaded molecules, whose structural and energetic analysis requires a proper theoretical description of noncovalent interactions.
Collapse
Affiliation(s)
- Andrey A Fokin
- Department of Organic Chemistry, Igor Sikorsky Kyiv Polytechnic Institute, Beresteiskyi Ave 37, Kyiv, Ukraine
| |
Collapse
|
2
|
Davidson JJ, Gunther SO, Leong DW, Ozerov OV. Synthesis of fluorinated aminium cations coupled with carborane anions for use as strong one-electron oxidants. Dalton Trans 2023; 52:16027-16031. [PMID: 37850380 DOI: 10.1039/d3dt02127k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2023]
Abstract
Synthesis of a series of hydrocarbon-soluble triarylamines bearing F, CF3, and Br substituents showing quasi-reversible redox events in the 0.59-1.32 V range is reported. Chemical oxidation of the amines was carried out with 0.5PhI(OAc)2/Me3SiX/Na[RCB11Cl11] (X = Cl or OTf, R = H or Me), and a few aminium salts were isolated as pure solids.
Collapse
Affiliation(s)
- Jillian J Davidson
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
| | - S Olivia Gunther
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
| | - Derek W Leong
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
| | - Oleg V Ozerov
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
| |
Collapse
|
3
|
Nishimura Y, Harimoto T, Suzuki T, Ishigaki Y. One-Pot Synthesis of Helical Azaheptalene and Chiroptical Switching of an Isolable Radical Cation. Chemistry 2023; 29:e202301759. [PMID: 37280181 DOI: 10.1002/chem.202301759] [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: 06/02/2023] [Revised: 06/06/2023] [Accepted: 06/06/2023] [Indexed: 06/08/2023]
Abstract
A nitrogen-centered heptalene, azaheptalene, was designed as a representative of a new class of redox-responsive molecules with a large steric strain that originates from the adjacent seven-membered rings. The pentabenzo derivative of azaheptalene was efficiently synthesized by a palladium-catalyzed one-pot reaction of commercially available reagents. Bromination led to mono- and dibrominated derivatives, the latter of which is interconvertible with isolable radical cation species exhibiting near-infrared absorption. Since the azaheptalene skeleton shows configurationally stable helicity with a large torsion angle, enantiomers could be successfully separated. Thus, optically pure azaheptalenes with P- or M-helicity showed strong chiroptical properties (|gabs |≥0.01), which could be changed by an electric potential.
Collapse
Affiliation(s)
- Yuta Nishimura
- Department of Chemistry, Faculty of Science, Hokkaido University, N10 W8, North-ward, 060-0810, Sapporo, Japan
| | - Takashi Harimoto
- Department of Chemistry, Faculty of Science, Hokkaido University, N10 W8, North-ward, 060-0810, Sapporo, Japan
| | - Takanori Suzuki
- Department of Chemistry, Faculty of Science, Hokkaido University, N10 W8, North-ward, 060-0810, Sapporo, Japan
| | - Yusuke Ishigaki
- Department of Chemistry, Faculty of Science, Hokkaido University, N10 W8, North-ward, 060-0810, Sapporo, Japan
| |
Collapse
|
4
|
Nayak MK, Elvers BJ, Mandal D, Das A, Ramakrishnan R, Mote KR, Schulzke C, Yildiz CB, Jana A. Reduction of 2- H-substituted pyrrolinium cations: the carbon-carbon single bond in air stable 2,2'-bipyrrolidines as a two-electron-source. Chem Commun (Camb) 2023; 59:6698-6701. [PMID: 37183853 DOI: 10.1039/d3cc00891f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Reduction of 2-H-substituted pyrrolinium cations via initially formed secondary radicals results in either dimerisation or H-abstracted products, while the outcome depends on the N-substituents. The resultant central carbon-carbon single bond in the dimerised 2,2'-bipyrrolidine derivatives can be oxidised chemically and electrochemically. The notably air and moisture-stable dimers were subsequently utilised as a source of two electrons in various chemical transformations.
Collapse
Affiliation(s)
- Mithilesh Kumar Nayak
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, Greifswald D-17489, Germany.
| | - Debdeep Mandal
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
| | - Ayan Das
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
| | - Raghunathan Ramakrishnan
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
| | - Kaustubh R Mote
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, Greifswald D-17489, Germany.
| | - Cem Burak Yildiz
- Department of Aromatic and Medicinal Plants, Aksaray University, Aksaray-68100, Türkiye.
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
| |
Collapse
|
5
|
Dolai R, Kumar R, Elvers BJ, Pal PK, Joseph B, Sikari R, Nayak MK, Maiti A, Singh T, Chrysochos N, Jayaraman A, Krummenacher I, Mondal J, Priyakumar UD, Braunschweig H, Yildiz CB, Schulzke C, Jana A. Carbodicarbenes and Striking Redox Transitions of their Conjugate Acids: Influence of NHC versus CAAC as Donor Substituents. Chemistry 2023; 29:e202202888. [PMID: 36129127 PMCID: PMC10100033 DOI: 10.1002/chem.202202888] [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: 09/15/2022] [Indexed: 01/11/2023]
Abstract
Herein, a new type of carbodicarbene (CDC) comprising two different classes of carbenes is reported; NHC and CAAC as donor substituents and compare the molecular structure and coordination to Au(I)Cl to those of NHC-only and CAAC-only analogues. The conjugate acids of these three CDCs exhibit notable redox properties. Their reactions with [NO][SbF6 ] were investigated. The reduction of the conjugate acid of CAAC-only based CDC with KC8 results in the formation of hydrogen abstracted/eliminated products, which proceed through a neutral radical intermediate, detected by EPR spectroscopy. In contrast, the reduction of conjugate acids of NHC-only and NHC/CAAC based CDCs led to intermolecular reductive (reversible) carbon-carbon sigma bond formation. The resulting relatively elongated carbon-carbon sigma bonds were found to be readily oxidized. They were, thus, demonstrated to be potent reducing agents, underlining their potential utility as organic electron donors and n-dopants in organic semiconductor molecules.
Collapse
Affiliation(s)
- Ramapada Dolai
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - Rahul Kumar
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Strasse 4, 17489, Greifswald, Germany
| | - Pradeep Kumar Pal
- International Institute of Information Technology Gachibowli, Hyderabad, 500032, India
| | - Benson Joseph
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - Rina Sikari
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - Mithilesh Kumar Nayak
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - Avijit Maiti
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - Tejender Singh
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - Arumugam Jayaraman
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Jagannath Mondal
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| | - U Deva Priyakumar
- International Institute of Information Technology Gachibowli, Hyderabad, 500032, India
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Cem B Yildiz
- Department of Aromatic and Medicinal Plants, Aksaray University, Aksaray, 68100, Turkey
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Strasse 4, 17489, Greifswald, Germany
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad Gopanpally, Hyderabad, 500046, Telangana, India
| |
Collapse
|
6
|
Hayashi Y, Suzuki S, Suzuki T, Ishigaki Y. Dibenzotropylium-Capped Orthogonal Geometry Enabling Isolation and Examination of a Series of Hydrocarbons with Multiple 14π-Aromatic Units. J Am Chem Soc 2023; 145:2596-2608. [PMID: 36606368 PMCID: PMC9896550 DOI: 10.1021/jacs.2c12574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A series of six dications composed of pure hydrocarbons with one to six non-substituted 9,10-anthrylene units end-capped with two dibenzotropyliums were designed and synthesized to elucidate the electronic properties of huge oligo(9,10-anthrylene) backbones. Their structures were successfully determined by X-ray analyses even in the case of eight planar 14π-electron units, revealing that all dications adopt almost orthogonally twisted structures between neighboring units. Spectroscopic and voltammetric analyses show that neither the significant overlap of orbitals nor the delocalization of electrons between 14π-electron units occurs due to the orthogonally twisted geometry even in solution. As a result, sequential oxidation processes were observed with the reversible formation of multivalent cations with the release of the same number of electrons as the number of anthrylene units. Upon two-electron reduction, a closed-shell butterfly-shaped form was obtained from the dication containing one anthrylene unit, whereas open-shell twisted biradicals were isolated as stable entities in the cases of derivatives containing three to six anthrylene units. Notably, from the derivative with two anthrylene units, a metastable open-shell isomer was obtained quantitatively and underwent slow thermal conversion to the most stable closed-shell isomer (Ea = 23.1 kcal mol-1). There is a drastic change in oxidation potentials between two neutral species (ΔE = 1.32 V in CH2Cl2). Since the present dications were regenerated upon oxidation of the isolated reduction products, these systems may contribute to the development of advanced response systems capable of switching color, magnetic properties, and oxidative properties by using a "cation-capped orthogonal geometry".
Collapse
Affiliation(s)
- Yuki Hayashi
- Department
of Chemistry, Faculty of Science, Hokkaido
University, Sapporo 060-0810, Japan
| | - Shuichi Suzuki
- Graduate
School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Takanori Suzuki
- Department
of Chemistry, Faculty of Science, Hokkaido
University, Sapporo 060-0810, Japan
| | - Yusuke Ishigaki
- Department
of Chemistry, Faculty of Science, Hokkaido
University, Sapporo 060-0810, Japan,
| |
Collapse
|
7
|
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
| |
Collapse
|
8
|
Naskar S, Moi R, Das I, Biradha K. Halogen⋅⋅⋅Halogen and Halogen⋅⋅⋅π Interactions Enabled Reversible Photo-oligomerization of Conjugated Dienones: Visible Light Triggered Single-Crystal-to-Single-Crystal Transformation. Angew Chem Int Ed Engl 2022; 61:e202204141. [PMID: 35334146 DOI: 10.1002/anie.202204141] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Indexed: 11/08/2022]
Abstract
The synthesis of reversible oligomer/polymers is fascinating both from the perspective of the fundamental understanding as well as their applications, ranging from biomedical to self-healing smart materials. On the other hand, the reactions that occur in single-crystal-to-single-crystal (SCSC) fashion offer great details of the structure, geometry and stereochemistry of the product. However, SCSC [2+2] oligomerization is rather difficult and rare. Further, till date there are no reports for a reversible [2+2] oligomerization in SCSC fashion. In this work, four halogen-substituted acrylic dienone molecules were deliberately designed and their ability to participate in [2+2] cycloaddition reaction in solid state was studied under visible light. Despite of having the required alignment of double bonds of dienes in all four crystal structures, they were found to exhibit variable reactivities given the differences in their weak intermolecular interactions such as halogen⋅⋅⋅halogen, halogen⋅⋅⋅π and C-H⋅⋅⋅O interactions. Notably, one of these materials exhibits reversible oligomerization in a SCSC manner.
Collapse
Affiliation(s)
- Sandip Naskar
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India
| | - Rajib Moi
- Department of Chemistry, Indian Institute of Technology (IIT) Kharagpur, Kharagpur, West Bengal 721302, India
| | - Indrajit Das
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India
| | - Kumar Biradha
- Department of Chemistry, Indian Institute of Technology (IIT) Kharagpur, Kharagpur, West Bengal 721302, India
| |
Collapse
|
9
|
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
| |
Collapse
|
10
|
The Synergetic and Multifaceted Nature of Carbon‐Carbon Rotation Reveals the Origin of Conformational Barrier Heights with Bulky Alkane Groups. J PHYS ORG CHEM 2022. [DOI: 10.1002/poc.4352] [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]
|
11
|
Naskar S, Moi R, Das I, Biradha K. Halogen‐Halogen and Halogen‐π Interactions Enabled Reversible Photo‐oligomerization of Conjugated Dienones: Visible Light Triggered Single‐Crystal‐to‐Single‐Crystal Transformation. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204141] [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)
- Sandip Naskar
- IICB: Indian Institute of Chemical Biology CSIR Organic and Medicinal Chemistry Division INDIA
| | - Rajib Moi
- Indian Institute of Technology Kharagpur Chemistry INDIA
| | - Indrajit Das
- IICB: Indian Institute of Chemical Biology CSIR Organic and Medicinal Chemistry Division INDIA
| | - Kumar Biradha
- Indian Institute of Technology Chemistry Department of Chemistry 721320 Kharagpur INDIA
| |
Collapse
|
12
|
Harimoto T, Ishigaki Y. Redox‐Active Hydrocarbons: Isolation and Structural Determination of Cationic States toward Advanced Response Systems. Chempluschem 2022; 87:e202200013. [DOI: 10.1002/cplu.202200013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/17/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Takashi Harimoto
- Hokkaido University: Hokkaido Daigaku Department of Chemistry, Faculty of Science JAPAN
| | - Yusuke Ishigaki
- Hokkaido University: Hokkaido Daigaku Department of Chemistry, Faculty of Science North 10, West 8, North-ward 060-0810 Sapporo JAPAN
| |
Collapse
|
13
|
Ishigaki Y, Sugawara K, Tadokoro T, Hayashi Y, Harimoto T, Suzuki T. Redox-active tetraaryldibenzoquinodimethanes. Chem Commun (Camb) 2021; 57:7201-7214. [PMID: 34169942 DOI: 10.1039/d1cc02260a] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Quinodimethanes (QDs) are a class of non-aromatic π-conjugated compounds that are well-known to be interconvertible scaffolds in many response systems. While parent ortho- and para-QDs (o-QD and p-QD) can be easily converted to benzocyclobutenes or oligomers/polymers by the formation of C-C bonds at α-positions, the attachment of four phenyl groups to these reactive sites makes o-Ph4QD and p-Ph4QD long-lived. We have demonstrated that further dibenzo-annulation of such tetraaryl QD units also drastically increases their stability, and many tetraarylated dibenzoquinodimethane derivatives have been developed. This Feature Article shows our milestones in creating functional redox systems, where drastic changes in structure occur upon electron transfer (dynamic redox "dyrex" behaviour).
Collapse
Affiliation(s)
- Yusuke Ishigaki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.
| | | | | | | | | | | |
Collapse
|
14
|
Abstract
![]()
A macrocyclic motif
composed of carbazole and pyridine subunits
linked by a carbonyl bridge (C=O) forms a skeleton with a peripheral
reactivity that leads to a pinacol-like coupling activated by BBr3, eventually entrapping a substantially elongated C–C
bond. Slightly modified conditions lead to the efficient transformation
of the C=O unit to a CH2 linker that, after exposure
to air, gives a dimeric molecule with multiple bonds between two macrocyclic
units, as documented in spectroscopy and X-ray analysis.
Collapse
Affiliation(s)
- Monika Kijewska
- Department of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50383 Wrocław, Poland
| | - Miłosz Siczek
- Department of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50383 Wrocław, Poland
| | - Miłosz Pawlicki
- Department of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50383 Wrocław, Poland.,Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30387 Kraków, Poland
| |
Collapse
|
15
|
Ishigaki Y, Uchimura Y, Shimajiri T, Suzuki T. Expandability of the Covalent Bond: A New Facet Discovered in Extremely Long Csp3-Csp3 Single Bonds. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20200374] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Yusuke Ishigaki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Yasuto Uchimura
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Takuya Shimajiri
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Takanori Suzuki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| |
Collapse
|
16
|
Ishigaki Y. Redox-active and Highly Strained Hydrocarbons: Control of HOMO Levels Based on Flexibility of Covalent Bonds. J SYN ORG CHEM JPN 2021. [DOI: 10.5059/yukigoseikyokaishi.79.290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yusuke Ishigaki
- Department of Chemistry, Faculty of Science, Hokkaido University
| |
Collapse
|
17
|
Nishiuchi T, Kisaka K, Kubo T. Synthesis of Anthracene‐Based Cyclic π‐Clusters and Elucidation of their Properties Originating from Congested Aromatic Planes. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202013349] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Tomohiko Nishiuchi
- Department of Chemistry Graduate School of Science Osaka University 1-1 Machikaneyama, Toyonaka Osaka 560-0043 Japan
| | - Kazuki Kisaka
- Department of Chemistry Graduate School of Science Osaka University 1-1 Machikaneyama, Toyonaka Osaka 560-0043 Japan
| | - Takashi Kubo
- Department of Chemistry Graduate School of Science Osaka University 1-1 Machikaneyama, Toyonaka Osaka 560-0043 Japan
| |
Collapse
|
18
|
Nishiuchi T, Kisaka K, Kubo T. Synthesis of Anthracene-Based Cyclic π-Clusters and Elucidation of their Properties Originating from Congested Aromatic Planes. Angew Chem Int Ed Engl 2021; 60:5400-5406. [PMID: 33219584 DOI: 10.1002/anie.202013349] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Indexed: 11/07/2022]
Abstract
Synthesis and properties of anthracene-based cyclic π-clusters which possess two and four anthracene units are discussed. The optimal cyclization conditions were determined based on a nickel(0)-mediated reaction that afforded a cyclic anthracene dimer as the major product. Bringing two anthracene planes in close proximity in a face-to-face manner resulted in red-shifted absorption owing to the narrowing of the HOMO-LUMO gap. The cyclic anthracene dimer exhibits multi-stimuli responsiveness due to high π-congestion. For example, photoirradiation on the anthracene dimer affords its photoisomer having C-C bonds that are longer than 1.65 Å, which can undergo thermal reversion under gentle heating. This enabled mechanochromism of the photoisomer (colorless) to the original anthracene dimer (red). Photoisomerization was also observed in the crystalline state, accompanied by crystal jumping or collapsing, that is, the photosalient effect.
Collapse
Affiliation(s)
- Tomohiko Nishiuchi
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Kazuki Kisaka
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Takashi Kubo
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| |
Collapse
|
19
|
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.
Collapse
|
20
|
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.
Collapse
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.
| | | |
Collapse
|