Results 1 to 10 of about 14,177,191 (172)

Data on generation of Kekulé structures for graphenes, graphynes, nanotubes and fullerenes and their aza-analogs. [PDF]

Data Brief, 2018
Two new features are added to existing algorithms for kekulization of chemical structures, i.e., handling of triple and cumulene bonds in cycles and use of random atom sorting to remove unmatched atoms.
Trepalin S, Gurke S, Akhukov M, Knizhnik A, Potapkin B.   +4 more
europepmc   +5 more sources

Polyradical Character of Triangular Non-Kekulé Structures, Zethrenes, p-Quinodimethane-Linked Bisphenalenyl, and the Clar Goblet in Comparison: An Extended Multireference Study. [PDF]

J Phys Chem A, 2016
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 ...
Das A, Müller T, Plasser F, Lischka H.
europepmc   +5 more sources

Role of Kekulé and Non-Kekulé Structures in the Radical Character of Alternant Polycyclic Aromatic Hydrocarbons: A TAO-DFT Study. [PDF]

Sci Rep, 2016
We investigate the role of Kekulé and non-Kekulé structures in the radical character of alternant polycyclic aromatic hydrocarbons (PAHs) using thermally-assisted-occupation density functional theory (TAO-DFT), an efficient electronic structure method ...
Yeh CN, Chai JD.
europepmc   +5 more sources

On the number of Kekulé structures of fluoranthene congeners [PDF]

Journal of the Serbian Chemical Society, 2010
The Kekulé structure count K of fluoranthene congeners is studied. It is shown that for such polycyclic conjugated π-electron systems, either K = 0 or K ≥ 3.
Damir Vukičević, Jelena Djurdjevic, İvan Gutman   +2 more
doaj   +4 more sources

Stability order of isomeric benzenoid hydrocarbons and Kekulé structure count [PDF]

Journal of the Serbian Chemical Society, 2009
The commonly accepted opinion that the thermodynamic stability of isomeric benzenoid hydrocarbons (assessed by their total π-electron energy and various resonance energies) increases with increasing number of Kekulé structures is shown to be violated in ...
Slavko Radenković, İvan Gutman
doaj   +5 more sources

Topological Dirac-vortex modes in a three-dimensional photonic topological insulator. [PDF]

Nat Commun
Recently, topological Dirac-vortex modes in Kekulé-distorted photonic lattices have attracted broad interest and exhibited promising applications in robust photonic devices such as topological cavities, lasers, and fibers.
Yan B, Qi Y, Wang Z, Meng Y, Yang L, Zhu ZX, Chen JM, Zhong Y, Cheng MQ, Xi X, Gao Z.   +10 more
europepmc   +2 more sources

Kekulé Counts, Clar Numbers, and ZZ Polynomials for All Isomers of (5,6)-Fullerenes C₅₂-C₇₀. [PDF]

Molecules
We report an extensive tabulation of several important topological invariants for all the isomers of carbon (5,6)-fullerenes Cn with n = 52–70. The topological invariants (including Kekulé count, Clar count, and Clar number) are computed and reported in ...
Witek HA, Podeszwa R.
europepmc   +2 more sources

Backbone Engineering of Carbon-Centered NHC-Derived Diradicals: From Electronic State Tuning to High-Performance Organic Field-Effect Transistors. [PDF]

Adv Mater
The open‐shell nature of diradicals facilitates charge separation, and compounds with moderate diradical character demonstrate remarkable potential in organic field‐effect transistors (OFET) applications due to their low reorganization energies for hole and electron transport.
Liu XX, Li L, Li X, Chen C, Li M, Tian S, Dyson PJ, Han YF.   +7 more
europepmc   +2 more sources

Toward Larger Cyclo-9,10-Anthryleneparaphenylenes. [PDF]

Chemistry
During a macrocyclization with a dihydroanthracene diol as corner unit, larger oligomers than the trimer and tetramer were formed and isolated up to the nonamer. Their three‐dimensional structures were studied by X‐ray diffraction. The most abundant macrocycles were rearomatized to the corresponding CPP derivatives.
Schuldt MP, Rominger F, Elbert SM, Mastalerz M.   +3 more
europepmc   +2 more sources

The Hall rule in fluoranthene-type benzenoid hydrocarbons [PDF]

Journal of the Serbian Chemical Society, 2008
The applicability of the Hall rule (linear relation between the total π-electron energy and the number of Kekulé structures) was investigated in the case of fluoranthene-type benzenoid hydrocarbons. It was found that the originnal Hall rule is not obeyed,
Đurđević Jelena, Radenković Slavko, Gutman Ivan   +2 more
doaj   +3 more sources