Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.4
2.2
Journals
Symmetry
Special Issues
Symmetry on the Genealogy of Conjugated Acyclic Polyenes ‑ Dedicated...
share announcement

Symmetry on the Genealogy of Conjugated Acyclic Polyenes ‑ Dedicated to the Two Active Mathematical Chemists, Diudea and Aihara

A special issue of Symmetry (ISSN 2073-8994). This special issue belongs to the section "Chemistry: Symmetry/Asymmetry".

Deadline for manuscript submissions: closed (28 February 2021) | Viewed by 7380

Special Issue Editor

Prof. Dr. Haruo Hosoya

E-Mail Website
Guest Editor
Department of Information Sciences, Faculty of Science, Ochanomizu University (Emeritus), Otsuka 2-1-1, Bunkyo-ku, Tokyo 112-8610, Japan
Interests: experimental and theoretical study on the reactive intermediate of organic reactions; molecular orbital calculations on the electronic structure of conjugated organic molecules; application of graph theory to chemistry and physics; chemistry in information sciences; construction of a new field, mathematical chemistry, in chemistry; chemical education
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

It goes without saying that the hydrocarbon family plays a central role among organic compounds, which are roughly divided into four with regard to saturation and cyclization. Among them, the realm of acyclic conjugated polyenes, which are important not only in the biochemical activity of life but also for future molecular electronic devices, has been something similar to a desert in experimental and theoretical organic chemistry. The reason was simply the scarcity of isolation of a variety of the hydrocarbon isomers. However, owing to the rapid development of synthesizing techniques, a number of relatively large conjugated acyclic hydrocarbons, such as dendralenes, radialenes, and other conjugated polyene isomers, were synthesized and/or isolated.

According to a recent study by Hosoya (Bull. Chem. Soc. Jpn., 92 (2019) 205) the genealogy of conjugated polyene isomers can easily be understood using relatively simple indices, such as the Z-index and mean length of conjugation. The success of this early-stages trial is inviting more sophisticated and systematic research. Vital discussions involving symmetry, cross-conjugation, and aromaticity are welcome.

Prof. Dr. Haruo Hosoya
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Symmetry is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Genealogy
  • Conjugated polyene
  • Isomer
  • Stability
  • Topological index
  • Symmetry
  • Cross-conjugation
  • Aromaticity

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (3 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

14 pages, 1056 KiB  
Article
Zhang–Zhang Polynomials of Ribbons
by Bing-Hau He, Chien-Pin Chou, Johanna Langner and Henryk A. Witek
Symmetry 2020, 12(12), 2060; https://doi.org/10.3390/sym12122060 - 11 Dec 2020
Cited by 11 | Viewed by 1722
Abstract
We report a closed-form formula for the Zhang–Zhang polynomial (also known as ZZ polynomial or Clar covering polynomial) of an important class of elementary peri-condensed benzenoids Rbn1,n2,m1,m2, usually referred to [...] Read more.
We report a closed-form formula for the Zhang–Zhang polynomial (also known as ZZ polynomial or Clar covering polynomial) of an important class of elementary peri-condensed benzenoids Rbn1,n2,m1,m2, usually referred to as ribbons. A straightforward derivation is based on the recently developed interface theory of benzenoids [Langner and Witek, MATCH Commun. Math. Comput. Chem.2020, 84, 143–176]. The discovered formula provides compact expressions for various topological invariants of Rbn1,n2,m1,m2: the number of Kekulé structures, the number of Clar covers, its Clar number, and the number of Clar structures. The last two classes of elementary benzenoids, for which closed-form ZZ polynomial formulas remain to be found, are hexagonal flakes Ok,m,n and oblate rectangles Orm,n. Full article
(This article belongs to the Special Issue Symmetry on the Genealogy of Conjugated Acyclic Polyenes ‑ Dedicated to the Two Active Mathematical Chemists, Diudea and Aihara)
►▼ Show Figures

Figure 1

20 pages, 3110 KiB  
Article
Clar Covers of Overlapping Benzenoids: Case of Two Identically-Oriented Parallelograms
by Henryk A. Witek and Johanna Langner
Symmetry 2020, 12(10), 1599; https://doi.org/10.3390/sym12101599 - 25 Sep 2020
Cited by 10 | Viewed by 2076
Abstract
We present a complete set of closed-form formulas for the ZZ polynomials of five classes of composite Kekuléan benzenoids that can be obtained by overlapping two parallelograms: generalized ribbons Rb, parallelograms M, vertically overlapping parallelograms MvM, horizontally [...] Read more.
We present a complete set of closed-form formulas for the ZZ polynomials of five classes of composite Kekuléan benzenoids that can be obtained by overlapping two parallelograms: generalized ribbons Rb, parallelograms M, vertically overlapping parallelograms MvM, horizontally overlapping parallelograms MhM, and intersecting parallelograms MxM. All formulas have the form of multiple sums over binomial coefficients. Three of the formulas are given with a proof based on the interface theory of benzenoids, while the remaining two formulas are presented as conjectures verified via extensive numerical tests. Both of the conjectured formulas have the form of a 2×2 determinant bearing close structural resemblance to analogous formulas for the number of Kekulé structures derived from the John-Sachs theory of Kekulé structures. Full article
(This article belongs to the Special Issue Symmetry on the Genealogy of Conjugated Acyclic Polyenes ‑ Dedicated to the Two Active Mathematical Chemists, Diudea and Aihara)
►▼ Show Figures

Figure 1

18 pages, 2405 KiB  
Article
Combinatorics of Edge Symmetry: Chiral and Achiral Edge Colorings of Icosahedral Giant Fullerenes: C80, C180, and C240
by Krishnan Balasubramanian
Symmetry 2020, 12(8), 1308; https://doi.org/10.3390/sym12081308 - 5 Aug 2020
Cited by 4 | Viewed by 3149
Abstract
We develop the combinatorics of edge symmetry and edge colorings under the action of the edge group for icosahedral giant fullerenes from C80 to C240. We use computational symmetry techniques that employ Sheehan’s modification of Pόlya’s theorem and the Möbius [...] Read more.
We develop the combinatorics of edge symmetry and edge colorings under the action of the edge group for icosahedral giant fullerenes from C80 to C240. We use computational symmetry techniques that employ Sheehan’s modification of Pόlya’s theorem and the Möbius inversion method together with generalized character cycle indices. These techniques are applied to generate edge group symmetry comprised of induced edge permutations and thus colorings of giant fullerenes under the edge symmetry action for all irreducible representations. We primarily consider high-symmetry icosahedral fullerenes such as C80 with a chamfered dodecahedron structure, icosahedral C180, and C240 with a chamfered truncated icosahedron geometry. These symmetry-based combinatorial techniques enumerate both achiral and chiral edge colorings of such giant fullerenes with or without constraints. Our computed results show that there are several equivalence classes of edge colorings for giant fullerenes, most of which are chiral. The techniques can be applied to superaromaticity, sextet polynomials, the rapid computation of conjugated circuits and resonance energies, chirality measures, etc., through the enumeration of equivalence classes of edge colorings. Full article
(This article belongs to the Special Issue Symmetry on the Genealogy of Conjugated Acyclic Polyenes ‑ Dedicated to the Two Active Mathematical Chemists, Diudea and Aihara)
►▼ Show Figures

Graphical abstract

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-3
Back to TopTop