1
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Barluzzi L, Ogilvie SP, Dalton AB, Kaden P, Gericke R, Mansikkamäki A, Giblin SR, Layfield RA. Triply Bonded Pancake π-Dimers Stabilized by Tetravalent Actinides. J Am Chem Soc 2024; 146:4234-4241. [PMID: 38317384 PMCID: PMC10870716 DOI: 10.1021/jacs.3c13914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/07/2024]
Abstract
Aromatic π-stacking is a weakly attractive, noncovalent interaction often found in biological macromolecules and synthetic supramolecular chemistry. The weak nondirectional nature of π-stacking can present challenges in the design of materials owing to their weak, nondirectional nature. However, when aromatic π-systems contain an unpaired electron, stronger attraction involving face-to-face π-orbital overlap is possible, resulting in covalent so-called "pancake" bonds. Two-electron, multicenter single pancake bonds are well known, whereas four-electron double pancake bonds are rare. Higher-order pancake bonds have been predicted, but experimental systems are unknown. Here, we show that six-electron triple pancake bonds can be synthesized by a 3-fold reduction of hexaazatrinaphthylene (HAN) and subsequent stacking of the [HAN]3- triradicals. Our analysis reveals a multicenter covalent triple pancake bond consisting of a σ-orbital and two equivalent π-orbitals. An electrostatic stabilizing role is established for the tetravalent thorium and uranium ions in these systems. We also show that the electronic absorption spectrum of the triple pancake bonds closely matches computational predictions, providing experimental verification of these unique interactions. The discovery of conductivity in thin films of triply bonded π-dimers presents new opportunities for the discovery of single-component molecular conductors and other spin-based molecular materials.
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Affiliation(s)
- Luciano Barluzzi
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QR, U.K.
| | - Sean P. Ogilvie
- Department
of Physics and Astronomy, School of Mathematical and Physical Sciences, University of Sussex, Brighton BN1 9QR, U.K.
| | - Alan B. Dalton
- Department
of Physics and Astronomy, School of Mathematical and Physical Sciences, University of Sussex, Brighton BN1 9QR, U.K.
| | - Peter Kaden
- Institute
of Resource Ecology, Helmoltz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, Dresden 01328, Germany
| | - Robert Gericke
- Institute
of Resource Ecology, Helmoltz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, Dresden 01328, Germany
| | - Akseli Mansikkamäki
- NMR
Research Unit, University of Oulu, P.O. Box 8000, Oulu FI-90014, Finland
| | - Sean R. Giblin
- School
of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, U.K.
| | - Richard A. Layfield
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QR, U.K.
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2
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Rizo L, Janesko BG. Reimagining the Wave Function in Density Functional Theory: Exploring Strongly Correlated States in Pancake-Bonded Radical Dimers. J Phys Chem A 2023; 127:3684-3691. [PMID: 37053451 DOI: 10.1021/acs.jpca.2c08616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Pancake bonding between π-conjugated radicals challenges conventional electronic structure approximations, due to the presence of both dispersion (van der Waals) interactions and "strong" electron correlation. Here we use a reimagined wave function-in-density functional theory (DFT) approach to model pancake bonds. Our generalized self-interaction correction extends DFT's reference system of noninteracting electrons, by introducing electron-electron interactions within an active space. We show that a small variation on our previous derivation recovers a DFT-corrected complete active space method proposed by Pijeau and Hohenstein. Comparison of the two approaches shows that the latter provides reasonable dissociation curves for single bonds and pancake bonds, including excited states inaccessible to conventional linear response time-dependent DFT. The results motivate broader adoption of wavefunction-in-DFT approaches for modeling pancake bonds.
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Affiliation(s)
- Luis Rizo
- Intense Laser Physics Theory Unit, Illinois State University, Normal, Illinois 61790, United States
| | - Benjamin G Janesko
- Department of Chemistry & Biochemistry, Texas Christian University, 2800 S. University Drive, Fort Worth, Texas 75039, United States
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3
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Xiang Q, Sun Z. Doublet Open-Shell Graphene Fragments. Chem Asian J 2022; 17:e202200251. [PMID: 35438845 DOI: 10.1002/asia.202200251] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/13/2022] [Indexed: 11/11/2022]
Abstract
The recent advances on neutral delocalized radical species based on polycyclic aromatic hydrocarbons with fused hexagonal rings, herein defined as doublet open-shell graphene fragments, are summarized in this review. A few simple yet useful theoretical approaches for structural analysis and molecular design were introduced at first. Then, based on the number of fused hexagonal rings, molecular systems with different size, symmetry and edge structure were discussed with emphasis on those isolated in the crystalline form. Their unique self-association behavior, chemical reactivity and physical properties were summarized and discussed, and insights on their functions and potential applications were provided.
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Affiliation(s)
- Qin Xiang
- Tianjin University, Institute of Molecular Plus, CHINA
| | - Zhe Sun
- Tianjin University, Institute of molecular plus, No. 92 Weijin Road, Nankai District, 300072, Tianjin, CHINA
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4
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Flynn C, Zhou Z, McCormack ME, Wei Z, Petrukhina MA, Kertesz M. Bonding and uneven charge distribution in infinite pyrene π-stacks. CrystEngComm 2022. [DOI: 10.1039/d2ce00933a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unusual intermolecular π-stacking in a new charge transfer salt of pyrene (Py), (Py)2+(Ga2Cl7)−, has been observed.
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Affiliation(s)
- Chase Flynn
- Chemistry Department and Institute of Soft Matter, Georgetown University, 37th and O Streets, NW, Washington DC 20057-1227, USA
| | - Zheng Zhou
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA
- School of Materials Science and Engineering, Tongji University, 4800 Cao'an Road, Shanghai 201804, China
| | - Megan E. McCormack
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA
| | - Zheng Wei
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA
| | - Marina A. Petrukhina
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA
| | - Miklos Kertesz
- Chemistry Department and Institute of Soft Matter, Georgetown University, 37th and O Streets, NW, Washington DC 20057-1227, USA
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5
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Chen WC, Chang YC. Rational design of organic semiconductors with low internal reorganization energies for hole and electron transport: position effect of aza-substitution in phenalenyl derivatives. Phys Chem Chem Phys 2021; 23:18163-18172. [PMID: 34612279 DOI: 10.1039/d1cp02902a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Amphoteric-redox phenalenyl radical (PLY) is a suitable candidate used to design ambipolar organic materials. Because the singly occupied nonbonding molecular orbital (NBMO) of PLY has a perfect local nonbonding character, its internal reorganization energy (λ) for transporting holes (λ+) or electrons (λ-) is known to be small. Herein, PLY is employed to study the position effect of the aza group on the λ. By adding or extracting an electron from the NBMO, the bond length alterations can be minute. Therefore, the PLY derivatives are also an excellent candidate to study the contributions from the bond angle alterations to the λ. Substituting the aza groups at the β- or α-positions of PLY shows two different trends. When consecutively substituting the aza group at the three β-positions of PLY, the λs are consistently decreased. Contrarily, a series of double functionalization of aza groups at the four α-positions of PLY, the λs are increased. It is because the local bonding or antibonding character in frontier orbitals (FMO) is observed in α2N-PLY and α4N-PLY. As the FMOs of the three β-substituted PLYs and α6N-PLY have perfect local nonbonding character, we found the bond angle alterations are the main contributors of λ. The λs for most aza-PLYs were smaller than 100 meV. Thus, we propose a design rule for substituting aza groups on the parent molecules with strong local nonbonding character in their FMOs. Based on the adiabatic ionization potential and electron affinity, two π-extended PLY derivatives with small λ were recommended for fabricating air-stable ambipolar OFET.
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Affiliation(s)
- Wei-Chih Chen
- Department of Chemistry, National Taiwan University, Taipei City 10617, Taiwan
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6
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Minkin VI, Starikov AG, Starikova AA. Acene-Linked Zethrenes and Bisphenalenyls: A DFT Search for Organic Tetraradicals. J Phys Chem A 2021; 125:6562-6570. [PMID: 34310142 DOI: 10.1021/acs.jpca.1c02794] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Polycyclic aromatic hydrocarbons are of special interest due to their promising nonlinear optical and magnetic properties. A series of acene-linked zethrenes and bisphenalenyls comprising from five to nine benzene rings in the linker group have been computationally studied by the DFT UB3LYP/6-311++G(d,p) quantum-chemical modeling of their electronic structure, possible spin states, and exchange interactions. The zethrenes with octacene and nonacene linkers as well as bisphenalenyls comprising heptacene, octacene, and nonacene linker groups have been revealed to possess tetraradicaloid nature, which makes them promising building blocks for organic optoelectronic and spintronic devices. The results obtained open a way of constructing tetraradicaloid organic molecules characterized by the presence of two types of paramagnetic centers.
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Affiliation(s)
- Vladimir I Minkin
- Institute of Physical and Organic Chemistry, Southern Federal University, 344090 Rostov-on-Don, Russian Federation
| | - Andrey G Starikov
- Institute of Physical and Organic Chemistry, Southern Federal University, 344090 Rostov-on-Don, Russian Federation
| | - Alyona A Starikova
- Institute of Physical and Organic Chemistry, Southern Federal University, 344090 Rostov-on-Don, Russian Federation
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7
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Chen WC, Chao I. Charge transport properties of open-shell graphene fragments: a computational study of the phenalenyl tilings. Phys Chem Chem Phys 2021; 23:3256-3266. [PMID: 33319889 DOI: 10.1039/d0cp03140b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Thinking outside the box of the phenalenyl radical: a systematic structure design strategy, phenalenyl tiling, is found to benefit the electron transport properties of open-shell graphene fragments with one free radical. Compared with the closed-shell species, phenalenyl-based π-radicals exhibit smaller intramolecular reorganization energies and larger intermolecular electronic couplings. However, the on-site Coulomb repulsion can be too strong and impedes the charge transport efficiency of such materials. The repulsion can be weakened in radical species by spin delocalization. In this paper, the extended π-radicals we studied are categorized into three types of open-shell structures: the zigzag, the armchair and the discotic odd alternant hydrocarbons. The latter two belong to phenalenyl tilings. We found that the phenalenyl tilings fully inherit the desirable features of the singly occupied molecular orbital of the phenalenyl radical in a predictable and delocalized fashion, and their on-site Coulomb repulsion is effectively reduced. The zigzag π-radicals are less satisfactory. Therefore, the phenalenyl tilings are favorable candidates for charge transporting materials.
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Affiliation(s)
- Wei-Chih Chen
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan.
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8
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Tada K, Kawakami T, Tanaka S, Okumura M, Yamaguchi K. Clarification of the Relationship between the Magnetic and Conductive Properties of Infinite Chains in Trioxotriangulene Radical Crystals by Spin‐Projected DFT/Plane‐Wave Calculations. ADVANCED THEORY AND SIMULATIONS 2020. [DOI: 10.1002/adts.202000050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kohei Tada
- Research Institute of Electrochemical EnergyDepartment of Energy and Environment (RIECEN)National Institute of Advanced Industrial Science and Technology (AIST) Ikeda Osaka 563‐8577 Japan
| | - Takashi Kawakami
- Department of ChemistryGraduate School of ScienceOsaka University Toyonaka Osaka 560‐0043 Japan
- Riken Center for Computational Science Kobe Hyogo 650‐0047 Japan
| | - Shingo Tanaka
- Research Institute of Electrochemical EnergyDepartment of Energy and Environment (RIECEN)National Institute of Advanced Industrial Science and Technology (AIST) Ikeda Osaka 563‐8577 Japan
| | - Mitsutaka Okumura
- Department of ChemistryGraduate School of ScienceOsaka University Toyonaka Osaka 560‐0043 Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB)Kyoto University Kyoto 615‐8245 Japan
| | - Kizashi Yamaguchi
- Riken Center for Computational Science Kobe Hyogo 650‐0047 Japan
- The Institute of Scientific and Industrial ResearchOsaka University Ibaraki Osaka 567‐0047 Japan
- NanoScience Design CenterOsaka University Toyonaka Osaka 560‐8531 Japan
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9
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Kher-Elden MA, Piquero-Zulaica I, Abd El-Aziz KM, Ortega JE, Abd El-Fattah ZM. Metallic bands in chevron-type polyacenes. RSC Adv 2020; 10:33844-33850. [PMID: 36303597 PMCID: PMC9528856 DOI: 10.1039/d0ra06007k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/04/2020] [Indexed: 11/21/2022] Open
Abstract
We present electronic structure calculations based on a single-parameter plane wave expansion method for basic graphene building blocks, namely n-oligophenylenes and n-oligoacenes, revealing excellent agreement with density-functional theory. When oligophenylene molecules are joined through meta (zigzag) or ortho (chevron) junctions, the resulting molecular dimers and polymers exhibit a semiconducting character. While zigzag dimers of oligoacenes also exhibit gapped electronic structures, their chevron-phase features a sharp metallic band at the Fermi energy. This zero-point-energy state, which transforms into Dirac-like band in chevron polymers, survives at the outer elbows of the dimer irrespective of the molecular length, and has the same origin as reported for the polyacetylene and topologically induced edge states at edge-decorated graphene nanoribbons. These findings assist the engineering of topological electronic states at the molecular level and complement the toolbox of quantum phases in carbon-based nanostructures. We present electronic structure calculations based on a single-parameter plane wave expansion method for molecular nanostructures revealing excellent agreement with density functional theory and predicting metallic bands for chevron molecular dimers.![]()
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Affiliation(s)
- Mohammed A. Kher-Elden
- Physics Department, Faculty of Science, Al-Azhar University, Nasr City, 11884 Cairo, Egypt
| | | | - Kamel M. Abd El-Aziz
- Physics Department, Faculty of Science, Al-Azhar University, Nasr City, 11884 Cairo, Egypt
| | - J. Enrique Ortega
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain
- Departamento de Física Aplicada I, Universidad del País Vasco, San Sebastián, Spain
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10
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Mailman A, Robertson CM, Winter SM, Dube PA, Oakley RT. The Importance of Electronic Dimensionality in Multiorbital Radical Conductors. Inorg Chem 2019; 58:6495-6506. [PMID: 31021620 DOI: 10.1021/acs.inorgchem.9b00691] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The exceptional performance of oxobenzene-bridged bis-1,2,3-dithiazolyls 6 as single-component neutral radical conductors arises from the presence of a low-lying π-lowest unoccupied molecular orbital, which reduces the potential barrier to charge transport and increases the kinetic stabilization energy of the metallic state. As part of ongoing efforts to modify the solid-state structures and transport properties of these so-called multiorbital materials, we report the preparation and characterization of the acetoxy, methoxy, and thiomethyl derivatives 6 (R = OAc, OMe, SMe). The crystal structures are based on ribbonlike arrays of radicals laced together by S···N' and S···O' secondary bonding interactions. The steric and electronic effects of the exocyclic ligands varies, affording one-dimensional (1D) π-stacked radicals for R = OAc, 1D cofacial dimer π-stacks for R = SMe, and a pseudo two-dimensional (2D) brick-wall arrangement for R = OMe. Variable-temperature magnetic and conductivity measurements reveal strong antiferromagnetic interactions and Mott insulating behavior for the two radical-based structures (R = OAc, OMe), with lower room-temperature conductivities (σRT ≈ 1 × 10-4 and ∼1 × 10-3 S cm-1, respectively) and higher thermal activation energies ( Eact = 0.24 and 0.21 eV, respectively) than found for the ideal 2D brick-wall structure of 6 (R = F), where σRT ≈ 1 × 10-2 S cm-1 and Eact = 0.10 eV. The performance of R = OMe, OAc relative to that of R = F, is consistent with the results of density functional theory band electronic structure calculations, which indicate a lower kinetic stabilization energy of the putative metallic state arising from their reduced electronic dimensionality.
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Affiliation(s)
- Aaron Mailman
- Department of Chemistry , University of Jyväskylä , P.O. Box 35, Jyväskylä , Finland.,Department of Chemistry , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - Craig M Robertson
- Department of Chemistry , University of Liverpool , Liverpool L69 7ZD , United Kingdom
| | - Stephen M Winter
- Institut für Theoretische Physik , Goethe-Universität , Frankfurt am Main 60438 , Germany
| | - Paul A Dube
- Brockhouse Institute for Materials Research , McMaster University , Hamilton , Ontario L8S 4M1 , Canada
| | - Richard T Oakley
- Department of Chemistry , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
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11
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Sandoval-Salinas ME, Carreras A, Casanova D. Triangular graphene nanofragments: open-shell character and doping. Phys Chem Chem Phys 2019; 21:9069-9076. [DOI: 10.1039/c9cp00641a] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In this work we study the intricacies of the electronic structure properties of triangular graphene nanofragments (TGNFs) in their ground and low-lying excited states by means ofab initioquantum chemistry calculations.
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Affiliation(s)
- María E. Sandoval-Salinas
- Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona
- Barcelona
- Spain
- Donostia International Physics Center (DIPC)
- Paseo Manuel de Lardizabal 4
| | - Abel Carreras
- Donostia International Physics Center (DIPC)
- Paseo Manuel de Lardizabal 4
- 20018 Donostia
- Spain
| | - David Casanova
- Donostia International Physics Center (DIPC)
- Paseo Manuel de Lardizabal 4
- 20018 Donostia
- Spain
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12
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Molčanov K, Milašinović V, Ivić N, Stilinović V, Kolarić D, Kojić-Prodić B. Influence of organic cations on the stacking of semiquinone radical anions. CrystEngComm 2019. [DOI: 10.1039/c9ce00919a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of salts of tetrachloro- and tetrabromosemiquinone radical anions reveal four types of stacks: 1) pancake bonded dimers, 2) pancake-bonded trimers, 3) equidistant radicals and 4) a novel type of equidistant stacks of partially charged radicals.
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Affiliation(s)
| | | | - Nives Ivić
- Ruđer Bošković Institute
- Zagreb HR-10000
- Croatia
| | - Vladimir Stilinović
- Department of Chemistry
- Faculty of Science
- University of Zagreb
- Zagreb HR-10000
- Croatia
| | - Dinko Kolarić
- Special Hospital for Medical Rehabilitation
- Daruvarske Toplice
- Daruvar HR-43500
- Croatia
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13
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Boeré RT. Experimental and Computational Evidence for "Double Pancake Bonds": The Role of Dispersion-Corrected DFT Methods in Strongly Dimerized 5-Aryl-1λ 2,3λ 2-dithia-2,4,6-triazines. ACS OMEGA 2018; 3:18170-18180. [PMID: 31458400 PMCID: PMC6644306 DOI: 10.1021/acsomega.8b03211] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 12/11/2018] [Indexed: 06/10/2023]
Abstract
Crystal structures are reported for bicyclic 3-CF3C6H4CN5S3 and monocyclic 3-CF3C6H4CN3S2, the latter of which is strongly dimerized in a cis-cofacial geometry [3-CF3C6H4CN3S2]2. The title compounds have previously been characterized in solution by NMR, displaying spectra that are consistent with the structure of [3-CF3C6H4CN3S2]2 in the crystal with anti-oriented CF3 substituents. The interannular binding was investigated using density functional theory (DFT) methods. However, the DFT-optimized geometry spreads the aryl rings too far apart (centroid-centroid distances of ≥4.353 Å versus experimental distance of 3.850 Å). Significant improvements are obtained with dispersion-corrected DFT functionals B3LYP-D3, B3LYP-D3BJ, M062X, and APFD using the 6-311+G(2d,p) basis set. However, all of these overbind the aryl rings with centroid-centroid distances of 3.612, 3.570, 3.526, and 3.511 Å, respectively. After selecting B3LYP-D3BJ/6-311+G(2d,p) as the best method, five alternative dimer geometries were tested, and all were found to be binding; however, anti cofacial-4 (matching the structure in the solid state) is the most stable. Computed energies of the remainder are as follows: +7.0 kJ mol-1 (syn-cofacial-5), +26.7 kJ mol-1 (anti-cofacial-64), +27.0 kJ mol-1 (syn-cofacial-150), +102.0 kJ mol-1 (S,S-antarafacial), and +103.7 kJ mol-1 (S,N-antarafacial), where the suffixes are torsional angles around the CN3S2 thiazyl ring centroids. The binding in the four most stable cofacial dimers may be described by "double pancake bonding".
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14
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Maruyama M, Okada S. Energetics and Electronic Structure of Triangular Hexagonal Boron Nitride Nanoflakes. Sci Rep 2018; 8:16657. [PMID: 30413786 PMCID: PMC6226470 DOI: 10.1038/s41598-018-34874-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/26/2018] [Indexed: 12/03/2022] Open
Abstract
We studied the energetics and electronic structures of hexagonal boron nitrogen (h-BN) nanoflakes with hydrogenated edges and triangular shapes with respect to the edge atom species. Our calculations clarified that the hydrogenated h-BN nanoflakes with a triangular shape prefer the N edges rather than B edges irrespective of the flake size. The electronic structure of hydrogenated h-BN nanoflakes depends on the edge atom species and their flake size. The energy gap between the lowest unoccupied (LU) and the highest occupied (HO) states of the nanoflakes with N edges is narrower than that of the nanoflakes with B edges and the band gap of h-BN. The nanoflakes possess peculiar non-bonding states around their HO and LU states for the N and B edges, respectively, which cause spin polarization under hole or electron doping, depending on the edge atom species.
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Affiliation(s)
- Mina Maruyama
- University of Tsukuba, Graduate School of Pure and Applied Sciences, Tsukuba, 305-8571, Japan.
| | - Susumu Okada
- University of Tsukuba, Graduate School of Pure and Applied Sciences, Tsukuba, 305-8571, Japan
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15
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Kertesz M. Pancake Bonding: An Unusual Pi‐Stacking Interaction. Chemistry 2018; 25:400-416. [DOI: 10.1002/chem.201802385] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 06/14/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Miklos Kertesz
- Chemistry Department and Institute of Soft Matter Georgetown University 37th and O Streets NW Washington, DC 20057-1227 USA
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16
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Gao F, Zhong R, Xu H, Su Z. Constructing Stable π‐Dimers: Two Parallel Pancake π–π Bonds. Chemistry 2018; 24:16919-16924. [DOI: 10.1002/chem.201804598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Feng‐Wei Gao
- Institute of Functional Material Chemistry, National & Local United Engineering Laboratory for Power Batteries Department of Chemistry Northeast Normal University Changchun 130024 P. R. China
| | - Rong‐Lin Zhong
- Institute of Theoretical Chemistry Jilin University Changchun 130023 P. R. China
| | - Hong‐Liang Xu
- Institute of Functional Material Chemistry, National & Local United Engineering Laboratory for Power Batteries Department of Chemistry Northeast Normal University Changchun 130024 P. R. China
| | - Zhong‐Min Su
- Institute of Functional Material Chemistry, National & Local United Engineering Laboratory for Power Batteries Department of Chemistry Northeast Normal University Changchun 130024 P. R. China
- School of Chemistry & Environmental Engineering Changchun University of Science and Technology Changchun 130012 P. R. China
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17
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Mou Z, Kertesz M. Pancake Bond Orders of a Series of π‐Stacked Triangulene Radicals. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201704941] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Zhongyu Mou
- Chemistry Department Georgetown University 37th and O Streets, NW Washington DC 20057-1227 USA
| | - Miklos Kertesz
- Chemistry Department Georgetown University 37th and O Streets, NW Washington DC 20057-1227 USA
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18
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Mou Z, Kertesz M. Pancake Bond Orders of a Series of π‐Stacked Triangulene Radicals. Angew Chem Int Ed Engl 2017; 56:10188-10191. [DOI: 10.1002/anie.201704941] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Zhongyu Mou
- Chemistry Department Georgetown University 37th and O Streets, NW Washington DC 20057-1227 USA
| | - Miklos Kertesz
- Chemistry Department Georgetown University 37th and O Streets, NW Washington DC 20057-1227 USA
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19
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Gautam R, Astashkin AV, Chang TM, Shearer J, Tomat E. Interactions of Metal-Based and Ligand-Based Electronic Spins in Neutral Tripyrrindione π Dimers. Inorg Chem 2017; 56:6755-6762. [PMID: 28497967 DOI: 10.1021/acs.inorgchem.7b01030] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ability of tetrapyrrolic macrocycles to stabilize unpaired electrons and engage in π-π interactions is essential for many electron-transfer processes in biology and materials engineering. Herein, we demonstrate that the formation of π dimers is recapitulated in complexes of a linear tripyrrolic analogue of naturally occurring pigments derived from heme decomposition. Hexaethyltripyrrindione (H3TD1) coordinates divalent transition metals (i.e., Pd, Cu, Ni) as a stable dianionic radical and was recently described as a robust redox-active ligand. The resulting planar complexes, which feature a delocalized ligand-based electronic spin, are stable at room temperature in air and support ligand-based one-electron processes. We detail the dimerization of neutral tripyrrindione complexes in solution through electron paramagnetic resonance (EPR) and visible absorption spectroscopic methods. Variable-temperature measurements using both EPR and absorption techniques allowed determination of the thermodynamic parameters of π dimerization, which resemble those previously reported for porphyrin radical cations. The inferred electronic structure, featuring coupling of ligand-based electronic spins in the π dimers, is supported by density functional theory (DFT) calculations.
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Affiliation(s)
- Ritika Gautam
- Department of Chemistry and Biochemistry, The University of Arizona , Tucson, Arizona 85721, United States
| | - Andrei V Astashkin
- Department of Chemistry and Biochemistry, The University of Arizona , Tucson, Arizona 85721, United States
| | - Tsuhen M Chang
- Department of Chemistry and Biochemistry, The University of Arizona , Tucson, Arizona 85721, United States
| | - Jason Shearer
- Department of Chemistry, University of Nevada , Reno, Nevada 89577, United States
| | - Elisa Tomat
- Department of Chemistry and Biochemistry, The University of Arizona , Tucson, Arizona 85721, United States
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20
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Mailman A, Wong JWL, Winter SM, Claridge RCM, Robertson CM, Assoud A, Yong W, Steven E, Dube PA, Tse JS, Desgreniers S, Secco RA, Oakley RT. Fine Tuning the Performance of Multiorbital Radical Conductors by Substituent Effects. J Am Chem Soc 2017; 139:1625-1635. [DOI: 10.1021/jacs.6b11779] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Aaron Mailman
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Joanne W. L. Wong
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Stephen M. Winter
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | | | - Craig M. Robertson
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Abdeljalil Assoud
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Wenjun Yong
- Department
of Earth Sciences, University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Eden Steven
- Department
of Physics, Florida State University, Tallahassee, Florida 32310, United States
| | - Paul A. Dube
- Brockhouse
Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - John S. Tse
- Department
of Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Serge Desgreniers
- Department
of Physics, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Richard A. Secco
- Department
of Earth Sciences, University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Richard T. Oakley
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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21
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Guan Y, Jones ML, Miller AE, Wheeler SE. Conformational behavior and stacking interactions of contorted polycyclic aromatics. Phys Chem Chem Phys 2017; 19:18186-18193. [PMID: 28513691 DOI: 10.1039/c7cp02637d] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Computational studies of non-covalent dimers of saddle-shaped molecules unveil widely varying conformations and stacking configurations.
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Affiliation(s)
- Yanfei Guan
- Department of Chemistry
- Texas A&M University
- College Station
- USA
| | | | | | - Steven E. Wheeler
- Department of Chemistry
- Texas A&M University
- College Station
- USA
- Center for Computational Quantum Chemistry
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22
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Mou Z, Tian YH, Kertesz M. Validation of density functionals for pancake-bonded π-dimers; dispersion is not enough. Phys Chem Chem Phys 2017; 19:24761-24768. [DOI: 10.1039/c7cp04637e] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
π-Stacking pancake bonding between radicals poses special challenges to density functional theories (DFTs) due to their shorter than van der Waals contact distances, their multireference singlet ground states and the concurrently important dispersion interactions.
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Affiliation(s)
- Zhongyu Mou
- Department of Chemistry and the Institute of Soft Matter Synthesis and Metrology
- Georgetown University
- Washington
- USA
| | - Yong-Hui Tian
- College of Life Sciences
- Research Center of Analytical Instrumentation
- Sichuan University
- Chengdu
- P. R. China
| | - Miklos Kertesz
- Department of Chemistry and the Institute of Soft Matter Synthesis and Metrology
- Georgetown University
- Washington
- USA
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23
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Cui Y, Cheng L. The nature of the multicenter bonding in π-[TCNE] 22− dimer: 4c/2e, 12c/2e, or 20c/2e? RSC Adv 2017. [DOI: 10.1039/c7ra09023d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Composition of the 20c–2e bonding orbital in the π-[TCNE]22− dimer, and the partial occupancy numbers C1, C2 and N in the 20c–2e bond.
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Affiliation(s)
- Yujie Cui
- Department of Chemistry
- Anhui University
- Hefei
- P. R. China
| | - Longjiu Cheng
- Department of Chemistry
- Anhui University
- Hefei
- P. R. China
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials
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24
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Sepúlveda D, Guan Y, Rangel U, Wheeler SE. Stacked homodimers of substituted contorted hexabenzocoronenes and their complexes with C60 fullerene. Org Biomol Chem 2017; 15:6042-6049. [DOI: 10.1039/c7ob01333g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Computations show that the tendency of contorted hexabenzocoronene (c-HBC) to form either homodimers or complexes with C60 can be tuned by changing the curvature of the c-HBC via the addition of substituents.
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Affiliation(s)
- Diana Sepúlveda
- Department of Chemistry
- Texas A&M University
- College Station
- USA
| | - Yanfei Guan
- Department of Chemistry
- Texas A&M University
- College Station
- USA
| | - Ulises Rangel
- Department of Chemistry
- Texas A&M University
- College Station
- USA
| | - Steven E. Wheeler
- Department of Chemistry
- Texas A&M University
- College Station
- USA
- Center for Computational Quantum Chemistry
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25
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Allão Cassaro RA, Friedman JR, Lahti PM. Copper(II) coordination compounds with sterically constraining pyrenyl nitronyl nitroxide and imino nitroxide. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.05.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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Uchida K, Mou Z, Kertesz M, Kubo T. Fluxional σ-Bonds of the 2,5,8-Trimethylphenalenyl Dimer: Direct Observation of the Sixfold σ-Bond Shift via a π-Dimer. J Am Chem Soc 2016; 138:4665-72. [DOI: 10.1021/jacs.6b01791] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Kazuyuki Uchida
- Department
of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Zhongyu Mou
- Department
of Chemistry, Georgetown University, Washington, D.C. 20057, United States
| | - Miklos Kertesz
- Department
of Chemistry, Georgetown University, Washington, D.C. 20057, United States
| | - Takashi Kubo
- Department
of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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27
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Das A, Müller T, Plasser F, Lischka H. Polyradical Character of Triangular Non-Kekulé Structures, Zethrenes, p-Quinodimethane-Linked Bisphenalenyl, and the Clar Goblet in Comparison: An Extended Multireference Study. J Phys Chem A 2016; 120:1625-36. [PMID: 26859789 PMCID: PMC4789636 DOI: 10.1021/acs.jpca.5b12393] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
In
this work, two different classes of polyaromatic hydrocarbon
(PAH) systems have been investigated in order to characterize the
amount of polyradical character and to localize the specific regions
of chemical reactivity: (a) the non-Kekulé triangular structures
phenalenyl, triangulene and a π-extended triangulene system
with high-spin ground state and (b) PAHs based on zethrenes, p-quinodimethane-linked bisphenalenyl, and the Clar goblet
containing varying polyradical character in their singlet ground state.
The first class of structures already have open-shell character because
of their high-spin ground state, which follows from the bonding pattern,
whereas for the second class the open-shell character is generated
either because of the competition between the closed-shell quinoid
Kekulé and the open-shell singlet biradical resonance structures
or the topology of the π-electron arrangement of the non-Kekulé
form. High-level ab initio calculations based on multireference theory
have been carried out to compute singlet–triplet splitting
for the above-listed compounds and to provide insight into their chemical
reactivity based on the polyradical character by means of unpaired
densities. Unrestricted density functional theory and Hartree–Fock
calculations have been performed for comparison also in order to obtain
better insight into their applicability to these types of complicated
radical systems.
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Affiliation(s)
- Anita Das
- Department of Chemistry and Biochemistry, Texas Tech University , Lubbock 79409, Texas United States
| | - Thomas Müller
- Institute for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich , 52425 Jülich, Germany
| | - Felix Plasser
- Institute for Theoretical Chemistry, University of Vienna , A-1090 Vienna, Austria
| | - Hans Lischka
- Department of Chemistry and Biochemistry, Texas Tech University , Lubbock 79409, Texas United States.,Institute for Theoretical Chemistry, University of Vienna , A-1090 Vienna, Austria.,School of Pharmaceutical Sciences and Technology, Tianjin University , Tianjin, 300072 P.R. China
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28
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Silva NJ, Machado FBC, Lischka H, Aquino AJA. π–π stacking between polyaromatic hydrocarbon sheets beyond dispersion interactions. Phys Chem Chem Phys 2016; 18:22300-10. [DOI: 10.1039/c6cp03749f] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A slipped parallel structure of a stacked graphene flake showing a biconcave curvature.
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Affiliation(s)
- Nadeesha J. Silva
- Department of Chemistry and Biochemistry
- Texas Tech University
- Lubbock Texas 79409
- USA
| | | | - Hans Lischka
- Department of Chemistry and Biochemistry
- Texas Tech University
- Lubbock Texas 79409
- USA
- Institute for Theoretical Chemistry
| | - Adelia J. A. Aquino
- Department of Chemistry and Biochemistry
- Texas Tech University
- Lubbock Texas 79409
- USA
- School of Pharmaceutical Sciences and Technology
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