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Planarization of negatively curved [7] circulene on a graphene monolayer. Chem Phys 2023. [DOI: 10.1016/j.chemphys.2023.111853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Marforio TD, Tomasini M, Bottoni A, Zerbetto F, Mattioli EJ, Calvaresi M. Deciphering the Reactive Pathways of Competitive Reactions inside Carbon Nanotubes. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 13:8. [PMID: 36615918 PMCID: PMC9823513 DOI: 10.3390/nano13010008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/16/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
Nanoscale control of chemical reactivity, manipulation of reaction pathways, and ultimately driving the outcome of chemical reactions are quickly becoming reality. A variety of tools are concurring to establish such capability. The confinement of guest molecules inside nanoreactors, such as the hollow nanostructures of carbon nanotubes (CNTs), is a straightforward and highly fascinating approach. It mechanically hinders some molecular movements but also decreases the free energy of translation of the system with respect to that of a macroscopic solution. Here, we examined, at the quantum mechanics/molecular mechanics (QM/MM) level, the effect of confinement inside CNTs on nucleophilic substitution (SN2) and elimination (syn-E2 and anti-E2) using as a model system the reaction between ethyl chloride and chloride. Our results show that the three reaction mechanisms are kinetically and thermodynamically affected by the CNT host. The size of the nanoreactor, i.e., the CNT diameter, represents the key factor to control the energy profiles of the reactions. A careful analysis of the interactions between the CNTs and the reactive system allowed us to identify the driving force of the catalytic process. The electrostatic term controls the reaction kinetics in the SN2 and syn/anti-E2 reactions. The van der Waals interactions play an important role in the stabilization of the product of the elimination process.
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Affiliation(s)
- Tainah Dorina Marforio
- Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum-Università di Bologna, Via Francesco Selmi 2, 40126 Bologna, Italy
- Center for Chemical Catalysis—C3, Alma Mater Studiorum—Università di Bologna, Via Selmi 2, 40126 Bologna, Italy
| | - Michele Tomasini
- Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum-Università di Bologna, Via Francesco Selmi 2, 40126 Bologna, Italy
| | - Andrea Bottoni
- Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum-Università di Bologna, Via Francesco Selmi 2, 40126 Bologna, Italy
| | - Francesco Zerbetto
- Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum-Università di Bologna, Via Francesco Selmi 2, 40126 Bologna, Italy
| | - Edoardo Jun Mattioli
- Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum-Università di Bologna, Via Francesco Selmi 2, 40126 Bologna, Italy
- Center for Chemical Catalysis—C3, Alma Mater Studiorum—Università di Bologna, Via Selmi 2, 40126 Bologna, Italy
| | - Matteo Calvaresi
- Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum-Università di Bologna, Via Francesco Selmi 2, 40126 Bologna, Italy
- Center for Chemical Catalysis—C3, Alma Mater Studiorum—Università di Bologna, Via Selmi 2, 40126 Bologna, Italy
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Kroeger AA, Karton A. Graphene-induced planarization of cyclooctatetraene derivatives. J Comput Chem 2022; 43:96-105. [PMID: 34677827 DOI: 10.1002/jcc.26774] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 09/10/2021] [Accepted: 10/08/2021] [Indexed: 11/09/2022]
Abstract
Stable equilibrium compounds containing a planar antiaromatic cyclooctatetraene (COT) ring are promising candidates for organic electronic devices such as organic semiconductor transistors. The planarization of COT by incorporation into rigid planar π-systems, as well as by oxidation or reduction has attracted considerable attention in recent years. Using dispersion-corrected density functional theory calculations, we explore an alternative approach of planarizing COT derivatives by adsorption onto graphene. We show that strong π-π stacking interactions between graphene and COT derivatives induce a planar structure with an antiaromatic central COT ring. In addition to being reversible, this strategy provides a novel approach for planarizing COT without the need for incorporation into a rigid structure, atomic substitution, oxidation, or reduction.
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Affiliation(s)
- Asja A Kroeger
- School of Molecular Sciences, The University of Western Australia, Perth, Australia
| | - Amir Karton
- School of Molecular Sciences, The University of Western Australia, Perth, Australia
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Mukhtar A, Sarfaraz S, Ayub K. Organic transformations in the confined space of porous organic cage CC2; catalysis or inhibition. RSC Adv 2022; 12:24397-24411. [PMID: 36128520 PMCID: PMC9415023 DOI: 10.1039/d2ra03399b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/11/2022] [Indexed: 12/04/2022] Open
Abstract
Porous organic cages have shape persistent cavities which provide a suitable platform for encapsulation of guest molecules with size suitably fitting to the cavity. The interactions of the guest molecule with the porous organic cage significantly alter the properties of the guest molecule. Herein, we report the effect of encapsulation on the kinetics of various organic transformations including 2 + 4 cycloaddition, 1,5-sigmatropic, 6π-electrocyclization, ring expansion, cheletropic, dyotropic, trimerization and tautomerization reactions. Non-bonding interactions are generated between the CC2 cage and encapsulated species. However, the number and nature/strength of interactions are different for reactant and TS with the CC2 cage and this difference detects the reaction to be accelerated or slowed down. A significant drop in the barrier of reactions is observed for reactions involving strong interactions of the transition state within the cage. However, for some reactions such as the Claisen rearrangement, reactants are stabilized more than the transition state and therefore an increase in activation barrier is observed. Furthermore, non-covalent analyses of all transition states (inside the cage) confirm the interaction between the CC2 cage and substrate. The current study will promote further exploration of the potential of other porous structures for similar applications. Porous organic cages have shape persistent cavities which provide a suitable platform for encapsulation of guest molecules with size suitably fitting to the cavity.![]()
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Affiliation(s)
- Ayesha Mukhtar
- Department of Chemistry, COMSATS University, Abbottabad Campus, KPK, Pakistan, 22060
| | - Sehrish Sarfaraz
- Department of Chemistry, COMSATS University, Abbottabad Campus, KPK, Pakistan, 22060
| | - Khurshid Ayub
- Department of Chemistry, COMSATS University, Abbottabad Campus, KPK, Pakistan, 22060
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Pinto AV, Magalhães AL. Intramolecular Hydrogen Bonds in Tip-Functionalized Single-Walled Carbon Nanotubes as pH-Sensitive Gates. J Phys Chem A 2020; 124:9542-9551. [PMID: 33169998 DOI: 10.1021/acs.jpca.0c03710] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Since their discovery, carbon nanotubes and other related nanomaterials are in the spotlight due to their unique molecular structures and properties, having a wide range of applications. The cage-like structure of carbon nanotubes is especially appealing as a route to confine molecules, isolating them from the solvent medium. This study aims to explore and characterize, through density functional theory (DFT) calculations, covalent tip-functionalization of single-walled carbon nanotubes (SWCNTS) with carboxymethyl moieties that establish pH sensitive molecular gates. The response of the molecular gate to pH fluctuations arises from variations in the noncovalent interactions between functionalized groups, which depend on the extent of protonation, leading to conformational changes. Overall, the hydrogen bonds present in the molecular models under study, as evaluated through topological analysis and pKa calculations, suggest that functionalized SWCNTs may be suitable for the design of drug delivery systems to enhance the efficiency of some pharmacological treatments, or even in the area of catalysis and separation processes, through their incorporation in nanocomposites.
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Affiliation(s)
- A V Pinto
- LAQV/Requimte, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - A L Magalhães
- LAQV/Requimte, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
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Shao C, Rui C, Liu J, Chen A, Zhu K, Shao Q. First-Principles Study on the Electronic Transport Properties of B/P, B/As, and B/Sb Co-doped Single-Walled Carbon Nanotubes. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c03804] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Cheng Shao
- Guangdong Provincial Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Nuclear Science, Institute of Quantum Matter, South China Normal University, Guangzhou 510006, China
| | - Chenkang Rui
- Guangdong Provincial Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Jiaxu Liu
- Guangdong Provincial Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Aqing Chen
- College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Kaigui Zhu
- Department of Physics, Beihang University, Beijing 100191, China
| | - Qingyi Shao
- Guangdong Provincial Engineering Technology Research Center of Efficient Green Energy and Environmental Protection Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Nuclear Science, Institute of Quantum Matter, South China Normal University, Guangzhou 510006, China
- School of Science, Jiangnan University, Wuxi, Jiangsu 214122, China
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