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Fullerenes as polyradicals

Elena F. Sheka
2004 Future generations computer systems  
A polyradical character of the species, weak for C 60 and strong for Si 60; is established.  ...  Therefore, silicon fullerene is, on average, made of ¹ 100% polyradical while its carbon counterpart is only of ¹ 20% polyradical.  ...  Thus the disclosed polyradical character of the basic fullerene molecule C 60 is indeed consistent with extreme diversity of its properties which sometimes seem to be somewhat contradictory.  ... 
doi:10.1016/j.future.2003.11.025 fatcat:oyhnnmlvt5dmdak23wkv4axyae

Fullerenes as polyradicals

Elena Sheka
2004 Open Physics  
A polyradical character of the species, weak for C60 and strong for Si60, is established.  ...  Therefore, silicon fullerene is, on average, made of ¹ 100% polyradical while its carbon counterpart is only of ¹ 20% polyradical.  ...  Thus the disclosed polyradical character of the basic fullerene molecule C 60 is indeed consistent with extreme diversity of its properties which sometimes seem to be somewhat contradictory.  ... 
doi:10.2478/bf02476279 fatcat:ua2xpahlpjfgnkbu5c5ihyq3a4

Resonance Topology and Related Aspects of Fluoranthenoid / Fluorenoid and Indacenoid Hydrocarbon Radicals

Gordon G. Cash, Jerry Ray Dias
2002 Zeitschrift fur Naturforschung A-A Journal of Physical Sciences  
The first examples of fluoranthenoid / fluorenoid and indacenoid polyradical systems are presented.  ...  Some comparative generalizations between benzenoid free radicals and fluoranthenoid / fluorenoid and indacenoid polyradical systems are formulated.  ...  There are 1812 fullerene isomers of C 60 , and the leapfrog of the dodecahedron fullerene (C 20 ) identifies the icosahedral buckminsterfullerene as the most stable isomer [13] .  ... 
doi:10.1515/zna-2002-0803 fatcat:6ans4rduundczbfxe2pw2yx6se

Page 4839 of Mathematical Reviews Vol. , Issue 2003f [page]

2003 Mathematical Reviews  
For the general case, the enumeration of LM-conjugated circuits may be tedious, as it re- quires constructon of all Kekulé structures.  ...  .; Dias, Jerry Ray (1-MOKC-K; Kansas City, MO) Computation, properties and resonance topology of benzenoid monoradicals and polyradicals and the eigenvectors belonging to their zero eigenvalues.  ... 

Spin-orbit concept of open-shell systems [article]

Elena F. Sheka
2015 arXiv   pre-print
Polyradicalism of fullerenes has not been so far of a long history and have been still considered by the majority of computationists as nothing to have in common with closed-shell fullerene molecules.  ...  View on CNTs as polyradicals is not popular among the large scientific community as well, which prefers to attribute them to closed-shell systems.  ... 
arXiv:1511.05480v1 fatcat:xole3xlszjdzlfk25zf6npe2fy

Further Developments in Determining the Number of Resonance Structures in Benzenoid Free Radicals: Analytical Expressions and Elementary Substructures

Jerry Ray Dias
2001 Journal of chemical information and computer sciences  
The ultimate excised internal structures in Figure 2 are the smallest possible polyradicals and, as it will be shown, are elementary substructures having importance in determining the coefficients to  ...  and the latter as inner catacondensed.  ... 
doi:10.1021/ci000141k pmid:11410047 fatcat:qvccjqaifnhgreohyrhozcmaga

Electronic properties of the coronene series from thermally-assisted-occupation density functional theory

Chia-Nan Yeh, Can Wu, Haibin Su, Jeng-Da Chai
2018 RSC Advances  
For brevity, HOMO is denoted as H, LUMO is denoted as L, and so on.  ...  As shown in Fig. 5 , the number of fractionally occupied orbitals increases with increasing n, clearly demonstrating that the polyradical character of n-coronene indeed increases with the side length.  ... 
doi:10.1039/c8ra01336e pmid:35548596 pmcid:PMC9087050 fatcat:e3553jxgvfbexmv3mxt3ruqv44

Indices of the fullerenes reactivity

2011 ARKIVOC  
(curvature and polarizability indices).The prognostic potential of the mentioned approaches as well the trends of their application and further development are considered.  ...  Dzhemilev on the occasion of his 65 th birthday Abstract The review summarizes articles devoted to studies of fullerenes reactivity by quantum-chemical methods using of diverse reactivity indices, e.g.  ...  All of the odd electrons in Si 60 have been found to be unpaired that explains the polyradical nature of Si 60 and, as consequence, its instability.  ... 
doi:10.3998/ark.5550190.0012.816 fatcat:mqs656fg4jcbzan6sxj7otw7k4

Design of carborane molecular architectures with electronic structure computations: From endohedral and polyradical systems to multidimensional networks

Josep M. Oliva, Douglas J. Klein, Paul von Ragué Schleyer, Luis Serrano-Andrés
2009 Pure and Applied Chemistry  
We consider ejection mechanisms for the inner atom/ion in endohedral carborane complexes, singlet-triplet energy gaps in carborane biradicals, as well as geometry reorganization in carborane neutral and  ...  While the chemistry of endohedral fullerene has been developed extensively, this is not the case with endohedral boranes and carboranes.  ...  Thus, we computed structures, relative stabilities, singlet-triplet gaps, and the ground-state character of mono- and biradicals derived from the three icosahedral carborane cage isomers, as well as BDEs  ... 
doi:10.1351/pac-con-08-09-18 fatcat:wv6sky23tzfttc6e7otj7w62ae

The role of topology in organic molecules: origin and comparison of the radical character in linear and cyclic oligoacenes and related oligomers

A. Pérez-Guardiola, M. E. Sandoval-Salinas, D. Casanova, E. San-Fabián, A. J. Pérez-Jiménez, J. C. Sancho-García
2018 Physical Chemistry, Chemical Physics - PCCP  
As a result, cyclo[a]decacene and cyclo[a]undecacene present strong polyradical character with unpaired electrons localized mainly on the up and down (non-bridging) C atoms further from the kink.  ...  , 79 (ii) nanocontainers for encapsulating pristine or fine-tuned fullerenes, 80-82 and (iii) creation of (sub)-nanochannels or tweezers of controlled length and/or chirality 83 after dimerization.  ... 
doi:10.1039/c8cp00135a pmid:29479605 fatcat:ixf7xkcvtjdpvciawl6ef2iopi

Violation of Covalent Bonding in Fullerenes [chapter]

E. F. Sheka
2003 Lecture Notes in Computer Science  
A polyradical character of the species, weak for C 60 and strong for Si 60, is established.  ...  Individual pairs in the fullerenes structure can be formed by a virtual dehydrogenation of the X 60 60 molecules, as shown in Fig.2 .  ...  However, as occurred, the observation is of much bigger importance since it concerns the basic properties of odd electrons behavior in fullerenic structures.  ... 
doi:10.1007/3-540-44862-4_42 fatcat:o5ql2edn45hnpcuawemy7colgy

TAO-DFT investigation of electronic properties of linear and cyclic carbon chains

Sonai Seenithurai, Jeng-Da Chai
2020 Scientific Reports  
As n increases, l-CC[n]/c-CC[n] possess increasing polyradical nature in their ground states, where the active orbitals are delocalized over the entire length of l-CC[n] or the whole circumference of c-CC  ...  Since the S vN value can be regarded as a quantitative measure of the radical nature of a molecule, the larger l-CC[n]/c-CC[n] are expected to exhibit increasing polyradical nature in their ground states  ...  Note that c-CC [n] (where the carbon atoms are also sp-hybridized) are hypothesized to be the building blocks of fullerenes in the initial stages of growth 21 .  ... 
doi:10.1038/s41598-020-70023-z pmid:32753715 fatcat:fn634n6avvb2jctq7aebzvtg3m

Modeling of Nontraditional Structures of Carbon

Eva Scholtzová, Ladislav Turi Nagy, Karol Putyera
2001 Journal of chemical information and computer sciences  
sp n , where n can be a nonintegral but a fractional number. 7 This group contains such interesting carbon structures such as fullerenes, carbon onions, 18, 19 and nanotubes [20] [21] [22] and acetylenic  ...  amorphous carbon, diamond-like carbon, and vitreous carbon as well as various carbon blacks, soot, cokes, etc.  ... 
doi:10.1021/ci0001132 pmid:11277736 fatcat:6t3a3sl4nzhizolwd7owccivre

Progress of organic magnetic materials

Mengmeng Wei, Yingcai Fan, Wei Qin
2019 Science China Physics Mechanics and Astronomy  
possesses various distributions under different conditions as follows. (i) With low O 2 pressure, oxygen interacts with the fullerene, resulting in the spins localized at the reactive O 2− species.  ...  The spin in oxidized C 60 Aside from fullerene oxidation, the hydrogenation of fullerene [80, 81] can also result in a high-spin polarization at ground state with high Curie temperature.  ... 
doi:10.1007/s11433-018-9328-7 fatcat:r6bs6nyzvbgdtanhrarimmfymu

Graph theoretical invariants and elementary subgraphs of polyhex and polypent/polyhex systems of chemical relevance

Jerry Ray Dias
1996 Discrete Applied Mathematics  
These latter formulas are derived in a formal sense from fullerene formulas by addition of H2 and 2Hz in such a way as to disrupt the fullerene cage structure and must contain < 13 pentagonal rings with  ...  N Fullerene edge Fullerenes and leapfrogging The leapfrog rule says that for every isomer of a fullerene with n carbon atoms (C,), there is a corresponding unique closed-shell isomer of the fullerene  ... 
doi:10.1016/0166-218x(95)00012-g fatcat:k7bknejbdjffrcl55vcj3kbv3q
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