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Noriega L, Díaz A, Limón D, Castro ME, Caballero NA, Ramírez RE, Perez-Aguilar JM, Melendez FJ. Inhibitory mechanism of 17β-aminoestrogens in the formation of Aβ aggregates. J Mol Model 2019; 25:229. [PMID: 31321557 DOI: 10.1007/s00894-019-4128-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/07/2019] [Indexed: 12/01/2022]
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disorder associated with the aggregation of the amyloid-beta peptide (Aβ) into large oligomers and fibrils that damage healthy brain cells. The predominant peptide fragments in the plaques are mainly formed by the Aβ1-40 and Aβ1-42 peptides, albeit the eleven-residue Aβ25-35 segment is largely used in biological studies because it retains the neurotoxic properties of the longer Aβ peptides. Recent studies indicate that treatment with therapeutic steroid hormones reduces the progress of the disease in AD models. Particularly, treatment with 17β-aminoestrogens (AEs) has shown a significant alleviation of the AD development by inhibiting oxidative stress and neuronal death. Yet, the mechanism by which the AE molecules exhibit their beneficial effects remains speculative. To shed light into the molecular mechanism of inhibition of the AD development by AEs, we investigated the possibility of direct interaction with the Aβ25-35 peptide. First, we calculate various interacting electronic properties of three AE derivatives as follows: prolame, butolame, and pentolame by performing DFT calculations. To account for the polymorphic nature of the Aβ aggregates, we considered four different Aβ25-35 systems extracted from AD relevant fibril structures. From the calculation of different electron density properties, specific interacting loci were identified that guided the construction and optimization of various complexes. Interestingly, the results suggest a similar inhibitory mechanism based on the direct interaction between the AEs and the M35 residue that seems to be general and independent of the polymorphic properties of the Aβ aggregates. Our analysis of the complex formation provides a structural framework for understanding the AE therapeutic properties in the molecular inhibitory mechanism of Aβ aggregation.
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Affiliation(s)
- Lisset Noriega
- Laboratorio de Química Teórica, Centro de Investigación. Depto. de Fisicoquímica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Edif 105-I, San Claudio y 22 Sur, Ciudad Universitaria, Col. San Manuel, 72570, Puebla, Mexico
| | - Alfonso Díaz
- Departamento de Farmacia, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y 14 Sur, Col. San Manuel, 72570, Puebla, Mexico
| | - Daniel Limón
- Laboratorio de Neurofarmacología, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y 14 Sur, Col. San Manuel, 72570, Puebla, Mexico
| | - María Eugenia Castro
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Complejo de Ciencias, ICUAP, Edif. IC8, 22 Sur y San Claudio, Ciudad Universitaria, 72570, Puebla, Mexico
| | - Norma A Caballero
- Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, San Claudio y 14 Sur, Ciudad Universitaria, Col. San Manuel, 72570, Puebla, Mexico
| | - Ramsés E Ramírez
- Departamento de Fisicomatemáticas, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Edif 105-I, San Claudio y 22 Sur, Ciudad Universitaria, Col. San Manuel, 72570, Puebla, Mexico
| | - Jose Manuel Perez-Aguilar
- Laboratorio de Química Teórica, Centro de Investigación. Depto. de Fisicoquímica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Edif 105-I, San Claudio y 22 Sur, Ciudad Universitaria, Col. San Manuel, 72570, Puebla, Mexico.
| | - Francisco J Melendez
- Laboratorio de Química Teórica, Centro de Investigación. Depto. de Fisicoquímica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Edif 105-I, San Claudio y 22 Sur, Ciudad Universitaria, Col. San Manuel, 72570, Puebla, Mexico.
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2
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Farajpour E, Sohrabi B, Beheshtian J. Selective separation behavior of graphene flakes in interaction with halide anions in the presence of an external electric field. Phys Chem Chem Phys 2016; 18:7293-9. [DOI: 10.1039/c5cp07710a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The adsorption of halide anions in the absence, and presence, of a perpendicularly external electric field on the C54H18 graphene surface has been investigated using M06-2X/6-31G(d,p) density functional theory (DFT).
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Affiliation(s)
- E. Farajpour
- Department of Chemistry
- Surface Chemistry Research Laboratory
- Iran University of Science and Technology
- Tehran
- Iran
| | - B. Sohrabi
- Department of Chemistry
- Surface Chemistry Research Laboratory
- Iran University of Science and Technology
- Tehran
- Iran
| | - J. Beheshtian
- Chemistry Department
- Faculty of Sciences
- Shahid Rajaee Teacher Training University
- Tehran
- Iran
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3
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Atta NF, Amin KM, Abd El-Rehim HA, Galal A. Graphene prepared by gamma irradiation for corrosion protection of stainless steel 316 in chloride containing electrolytes. RSC Adv 2015; 5:71627-71636. [DOI: 10.1039/c5ra11287g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
Abstract
Graphene prepared by gamma irradiation of GO and used as a coating against pitting corrosion of AISI 316 in NaCl.
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Affiliation(s)
- Nada F. Atta
- Department of Chemistry
- Faculty of Science
- Cairo University
- 12613 Giza
- Egypt
| | - Khaled M. Amin
- National Center for Radiation Research and Technology
- Atomic Energy Authority
- Nasr City
- Egypt
| | - Hassan A. Abd El-Rehim
- National Center for Radiation Research and Technology
- Atomic Energy Authority
- Nasr City
- Egypt
| | - Ahmed Galal
- Department of Chemistry
- Faculty of Science
- Cairo University
- 12613 Giza
- Egypt
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4
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Atta NF, Hassan HK, Galal A. Rapid and simple electrochemical detection of morphine on graphene–palladium-hybrid-modified glassy carbon electrode. Anal Bioanal Chem 2014; 406:6933-42. [DOI: 10.1007/s00216-014-7999-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 06/02/2014] [Accepted: 06/25/2014] [Indexed: 10/25/2022]
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5
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Yadav A, Mishra P. Lowest Π–Π* electronic transitions in linear and two-dimensional polycyclic aromatic hydrocarbons: enhanced electron density edge effect. Mol Phys 2013. [DOI: 10.1080/00268976.2013.830786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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6
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Yadav A, Mishra PC. Polyradicals of polycyclic aromatic hydrocarbons as finite size models of graphene: highly open-shell nature, symmetry breaking, and enhanced-edge electron density. J Phys Chem A 2013; 117:8958-68. [PMID: 23941534 DOI: 10.1021/jp4058719] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Properties of polyradicals (all CH bonds dissociated) of benzene and certain polycyclic aromatic hydrocarbons (PAHs) were studied. The occurrence of symmetry breaking is revealed in going from benzene and the PAHs to their polyradicals. Polyradicals would serve as finite size models of graphene with unpassivated edges in a more realistic way than the PAHs. Monoradicals (one CH bond dissociated) of benzene and all of the PAHs and higher radicals of benzene and one PAH (two to all CH bonds successively dissociated) were also investigated. Reliability of the methodology employed was ascertained by a comparison of our calculated single CH bond dissociation energy of benzene with the available previous experimental and theoretical results. Besides ground-state geometries, the aspects studied include single and successive CH bond dissociation energies, and electron density, molecular electrostatic potential (MEP), and spin density distributions. All of the monoradicals studied were found to have doublet spin multiplicity, while polyradicals with 4 to 16 rings and zigzag or mixed-type edges were found to have spin multiplicities varying from triplet to 11et. Bond lengths and bond angles of rings located at the edges are appreciably modified in going from PAHs to polyradicals. Electron density and spin density are found to be enhanced at the edges of monoradicals and polyradicals of PAHs, as found previously for PAHs. However, MEP maps of polyradicals have significantly different features from those of monoradicals and PAHs, which has a significant implication.
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Affiliation(s)
- Amarjeet Yadav
- Department of Physics, Banaras Hindu University , Varanasi - 221 005, Uttar Pradesh, India
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7
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Yadav A, Mishra P. Dimers and trimers of polycyclic aromatic hydrocarbons as models of graphene bilayers and trilayers: enhanced electron density at the edges. Mol Phys 2013. [DOI: 10.1080/00268976.2013.800918] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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8
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Hassan HK, Atta NF, Galal A. Electrodeposited nanostructured Pt–Ru co-catalyst on graphene for the electrocatalytic oxidation of formaldehyde. J Solid State Electrochem 2013. [DOI: 10.1007/s10008-013-2008-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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The average local ionization energy as a tool for identifying reactive sites on defect-containing model graphene systems. J Mol Model 2012. [DOI: 10.1007/s00894-012-1693-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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10
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Global and local reactivity indexes applied to understand the chemistry of graphene oxide and doped graphene. J Mol Model 2012; 19:919-30. [DOI: 10.1007/s00894-012-1642-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 10/07/2012] [Indexed: 10/27/2022]
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Bulat FA, Burgess JS, Matis BR, Baldwin JW, Macaveiu L, Murray JS, Politzer P. Hydrogenation and Fluorination of Graphene Models: Analysis via the Average Local Ionization Energy. J Phys Chem A 2012; 116:8644-52. [DOI: 10.1021/jp3053604] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Felipe A. Bulat
- Fable Theory & Computation LLC, Washington, DC 20009, United States
| | - James S. Burgess
- U.S. Naval Research Laboratory, Washington, DC 20375, United States
| | - Bernard R. Matis
- U.S. Naval Research Laboratory, Washington, DC 20375, United States
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12
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Polycyclic aromatic hydrocarbons as finite size models of graphene and graphene nanoribbons: Enhanced electron density edge effect. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2012.04.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Anota EC, Gutiérrez RER, Morales AE, Cocoletzi GH. Influence of point defects on the electronic properties of boron nitride nanosheets. J Mol Model 2011; 18:2175-84. [PMID: 21947446 DOI: 10.1007/s00894-011-1233-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Accepted: 08/24/2011] [Indexed: 10/17/2022]
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14
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Remarkable diversity of carbon–carbon bonds: structures and properties of fullerenes, carbon nanotubes, and graphene. Struct Chem 2010. [DOI: 10.1007/s11224-010-9670-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Hernández Rosas JJ, Ramírez Gutiérrez RE, Escobedo-Morales A, Chigo Anota E. First principles calculations of the electronic and chemical properties of graphene, graphane, and graphene oxide. J Mol Model 2010; 17:1133-9. [PMID: 20680365 DOI: 10.1007/s00894-010-0818-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 07/20/2010] [Indexed: 10/19/2022]
Abstract
The electrical and chemical properties of graphene (C(24)H(12)), graphane (C(24)H(24)) and graphene oxide (C(54)H(17)+O+(OH)(3)+COOH) were studied through the density functional theory (DFT) at level of Local Density Approximation (LDA) using a model C(n)H(m) like. The optimized geometry, energy gap and chemical reactivity for the proposed carbon 2D models are reported. It was found that while the graphene and graphane structures have semiconductor behavior, the graphene oxide behaves as semi-metal. However, a transition from semi-mental to semiconductor is predicted if the carboxyl group (COOH) is removed from such structure. The chemically active sites are analyzed on the basis of the electrophilic Fukui functions for each structure.
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Affiliation(s)
- J J Hernández Rosas
- Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, CP 72570 Puebla, Pue., Mexico
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16
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Politzer P, Murray JS, Bulat FA. Average local ionization energy: A review. J Mol Model 2010; 16:1731-42. [DOI: 10.1007/s00894-010-0709-5] [Citation(s) in RCA: 228] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 03/18/2010] [Indexed: 10/19/2022]
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17
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Dinadayalane TC, Murray JS, Concha MC, Politzer P, Leszczynski J. Reactivities of Sites on (5,5) Single-Walled Carbon Nanotubes with and without a Stone-Wales Defect. J Chem Theory Comput 2010. [DOI: 10.1021/ct900669t] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- T. C. Dinadayalane
- Interdisciplinary Center for Nanotoxicity (ICN), Department of Chemistry and Biochemistry, Jackson State University, 1400 JR Lynch Street, Jackson, Mississippi 39217, and Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
| | - Jane S. Murray
- Interdisciplinary Center for Nanotoxicity (ICN), Department of Chemistry and Biochemistry, Jackson State University, 1400 JR Lynch Street, Jackson, Mississippi 39217, and Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
| | - Monica C. Concha
- Interdisciplinary Center for Nanotoxicity (ICN), Department of Chemistry and Biochemistry, Jackson State University, 1400 JR Lynch Street, Jackson, Mississippi 39217, and Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
| | - Peter Politzer
- Interdisciplinary Center for Nanotoxicity (ICN), Department of Chemistry and Biochemistry, Jackson State University, 1400 JR Lynch Street, Jackson, Mississippi 39217, and Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
| | - Jerzy Leszczynski
- Interdisciplinary Center for Nanotoxicity (ICN), Department of Chemistry and Biochemistry, Jackson State University, 1400 JR Lynch Street, Jackson, Mississippi 39217, and Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
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Abstract
We investigate, using benzenoid graph theory and first-principles calculations, the magnetic properties of arbitrarily shaped finite graphene fragments to which we refer as graphene nanoflakes (GNFs). We demonstrate that the spin of a GNF depends on its shape due to topological frustration of the pi-bonds. For example, a zigzag-edged triangular GNF has a nonzero net spin, resembling an artificial ferrimagnetic atom, with the spin value scaling with its linear size. In general, the principle of topological frustration can be used to introduce large net spin and interesting spin distributions in graphene. These results suggest an avenue to nanoscale spintronics through the sculpting of graphene fragments.
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Affiliation(s)
- Wei L Wang
- Department of Physics and School of Engineering & Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
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The Remarkable Capacities of (6,0) Carbon and Carbon/Boron/Nitrogen Model Nanotubes for Transmission of Electronic Effects. ACTA ACUST UNITED AC 2007. [DOI: 10.1007/1-4020-5372-x_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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20
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Merino G, Vela A, Heine T. Description of Electron Delocalization via the Analysis of Molecular Fields. Chem Rev 2005; 105:3812-41. [PMID: 16218568 DOI: 10.1021/cr030086p] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriel Merino
- Institut für Physikalische Chemie und Elektrochemie, TU Dresden, D-01062 Dresden, Germany.
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Politzer P, Murray JS, Lane P, Concha MC, Jin P, Peralta-Inga Z. An unusual feature of end-substituted model carbon (6,0) nanotubes. J Mol Model 2005; 11:258-64. [PMID: 15889290 DOI: 10.1007/s00894-005-0265-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Accepted: 03/04/2005] [Indexed: 10/25/2022]
Abstract
We have examined the effects of substituents on the computed electrostatic potentials V(S)(r) and average local ionization energies I(S)(r) on the surfaces of model carbon nanotubes of the types (5,5), (6,1) and (6,0). For the (5,5) and the (6,1), the effects upon both V(S)(r) and I(S)(r) of substituting a hydroxyl group at one end are primarily localized to that part of the system. For the (6,0) tube, however, a remarkable change is observed over its entire length, with V(S)(r) showing a marked gradation from strongly positive at the substituted end to strongly negative at the other; I(S)(r) correspondingly goes from higher to lower values. Replacing OH by another resonance- donor, NH2, produces similar results in the (6,0) system, while the resonance withdrawing NO2 does the opposite, but in equally striking fashion. We explain these observations by noting that the arrangement of the C-C bonds in the (6,0) tube facilitates charge delocalization over the full length and entire surface of the tube. Substituting NH2 and NO2 at opposite ends of the (6,0) tube greatly strengthens the gradations in both V(S)(r) and I(S)(r). The first hyperpolarizability of this system was found to be nine times that of para-nitroaniline, suggesting possible nonlinear optical applications. [figure: see text]. HF/STO-5G electrostatic potential on outer surface of open (6,0) C72H10NH2NO2. The nitro group is at the right end of the tube, the amino group at the left. In eV: purple is less than 14, blue is between 14 and 15, green is between 15 and 16.5, yellow is between 16.5 and 17.5, and red is more than 17.5.
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Affiliation(s)
- Peter Politzer
- Department of Chemistry, University of New Orleans, New Orleans, LA, 70148, USA.
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Radovic LR, Bockrath B. On the Chemical Nature of Graphene Edges: Origin of Stability and Potential for Magnetism in Carbon Materials. J Am Chem Soc 2005; 127:5917-27. [PMID: 15839691 DOI: 10.1021/ja050124h] [Citation(s) in RCA: 439] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Heretofore disconnected experimental observations are combined with a theoretical study to develop a model of the chemical composition of the edges of graphene sheets in both flat and curved sp(2)-hybridized carbon materials. It is proposed that under ambient conditions a significant fraction of the oxygen-free edge sites are neither H-terminated nor unadulterated sigma free radicals, as universally assumed. The zigzag sites are carbene-like, with the triplet ground state being most common. The armchair sites are carbyne-like, with the singlet ground state being most common. This proposal is not only consistent with the key electronic properties and surface (re)activity behavior of carbons, but it can also explain the recently documented and heretofore puzzling ferromagnetic properties of some impurity-free carbon materials.
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Affiliation(s)
- Ljubisa R Radovic
- The Pennsylvania State University, 205 Hosler Building, University Park, Pennsylvania 16802, USA.
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Politzer P, Lane P, Murray JS, Concha MC. Comparative analysis of surface electrostatic potentials of carbon, boron/nitrogen and carbon/boron/nitrogen model nanotubes. J Mol Model 2004; 11:1-7. [PMID: 15490284 DOI: 10.1007/s00894-004-0202-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2004] [Accepted: 08/18/2004] [Indexed: 11/29/2022]
Abstract
We have extended an earlier study, in which we characterized in detail the electrostatic potentials on the inner and outer surfaces of a group of carbon and B(x)N(x) model nanotubes, to include several additional ones with smaller diameters plus a new category, C(2x)B(x)N(x). The statistical features of the surface potentials are presented and analyzed for a total of 19 tubes as well as fullerene and a small model graphene. The potentials on the surfaces of the carbon systems are relatively weak and rather bland; they are much stronger and more variable for the B(x)N(x) and C(2x)B(x)N(x). A qualitative correlation with free energies of solvation indicates that the latter two categories should have considerably greater water solubilities. The inner surfaces are generally more positive than the corresponding outer ones, while both positive and negative potentials are strengthened by increasing curvature. The outsides of B(x)N(x) tubes have characteristic patterns of alternating positive and negative regions, while the insides are strongly positive. In the closed C(2x)B(x)N(x) systems, half of the C-C bonds are double-bond-like and have negative potentials above them; the adjacent rows of boron and nitrogens show the usual B(x)N(x) pattern. When the C(2x)B(x)N(x) tubes are open, with hydrogens at the ends, the surface potentials are dominated by the B+-H- and N(-)-H+ linkages.
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Affiliation(s)
- Peter Politzer
- Department of Chemistry, University of New Orleans, New Orleans, LA 70148, USA.
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