Results 21 to 30 of about 1,373 (200)
Aromaticity-Induced Spin State Switching and High-Spin States in Non-Alternant Polyradicals. [PDF]
J Comput ChemThe peculiar topology of some non‐alternant systems allows such a degree of freedom in favored spin‐alignment between unpaired electrons that the polyradical can be in low‐, intermediate‐, and high‐spin ground state. Thus, the modulation of resonance energy upon distortions of pro‐aromatic units via external stimuli may result in switching the lowest ...
Betkhoshvili S +3 more
europepmc +2 more sources
Estrada Index of Benzenoid Hydrocarbons
Zeitschrift Fur Naturforschung - Section A Journal of Physical Sciences, 2007 A structure-descriptor EE, recently proposed by Estrada, is examined. If λ1, λ2, . . . ,λn are the eigenvalues of the molecular graph, then . In the case of benzenoid hydrocarbons with n carbon atoms and m carbon-carbon bonds, EE is found to be accurately ...
Ivan Gutman, Slavko Radenkovic
exaly +2 more sources
Optimization model for predicting quantum theoretic characteristics of hexagonal systems using temperature dependent graph theoretic estimators [PDF]
Scientific ReportsThis study explores how graph-based models can be used to predict key electronic properties of molecular structures, particularly benzenoid hydrocarbons as hexagonal systems. By focusing on temperature-related indices that reflect how atoms are connected
Yunji Huang +5 more
doaj +2 more sources
Resonance in Large Benzenoid Hydrocarbons
Croatica Chemica Acta, 1996 Pi-sextet resonance between Kekulé valence structures of benzenoid hydrocarbons are depicted by benzenoid resonance graphs. We outline the construction of the resonance graphs for families of benzenoid compounds. For the compounds considered the resonance graphs are built from fused ra-dimensional cubes.
Randić, Milan +3 more
openaire +3 more sources
On π-electron conjugation in the five-membered ring of fluoranthene-type benzenoid hydrocarbons [PDF]
Journal of the Serbian Chemical Society, 2009 A fluoranthene-type benzenoid hydrocarbon (FTBH) is a polycyclic conjugated system obtained by joining two ordinary benzenoid hydrocarbons so as to form a five-membered ring.
Gutman Ivan, Đurđević Jelena
doaj +1 more source
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 +2 more
doaj +3 more sources
On the oxidation of dibenzo[fg,ij]pentaphene and dinaphtho[2,1,8,7-defg:2',1',8',7'-ijkl]pentaphene dianions [PDF]
Journal of the Serbian Chemical Society, 1999 The dianion of dibenzo[fg,ij]pentaphene has recently been synthesized and shown to react with oxygen, forming the 15,16-dioxo derivative in nearly quantitative yield. Oxidation of the dianion of dinaphtho[2,1,8,7-defg:2',1',8',7'-ijkl]pentaphene
Gutman Ivan
doaj +3 more sources
On Computation and Analysis of Topological Index-Based Invariants for Complex Coronoid Systems
Complexity, 2021 In chemical graph theory, benzenoid systems are interrogated as they exhibit the chemical compounds known as benzenoid hydrocarbons. Benzenoid schemes are circumscribed as planar connected finite graphs having no cut vertices wherein the entire internal ...
Muhammad Aamer Rashid +3 more
doaj +1 more source
Topological properties of altan-benzenoid hydrocarbons [PDF]
Journal of the Serbian Chemical Society, 2014 The main topological characteristics of altan-benzenoids are established. In particular, it is shown that the perimeter of Kekuléan altan-benzenoids is of size 4k , having a destablizing (antiaromatic) energy effect, similar to (4k)-annulenes.
Gutman Ivan
doaj +1 more source
Wiener Index of Edge Thorny Graphs of Catacondensed Benzenoids
Mathematics, 2020 The Wiener index is a topological index of a molecular graph, defined as the sum of distances between all pairs of its vertices. Benzenoid graphs include molecular graphs of polycyclic aromatic hydrocarbons.
Andrey A. Dobrynin, Ali Iranmanesh
doaj +1 more source