نتایج جستجو برای: catacondensed benzenoid

تعداد نتایج: 488  

2007
Ivan Gutman Peter Paule

We predict the number of hexagonal systems consisting of 24 and 25 hexagons to be H 24 = 122237774262384 and H 25 = 606259305418149, with 6 and 5 signiicant digits, respectively. Further estimates for H n up to n = 31 are also given. Informally speaking, a hexagonal system can be viewed as a connected arrangement of hexagonal cells packed in the same way as the typical honeycomb arrangement in ...

2004
Ivan Gutman Peter Paule

We predict the number of hexagonal systems consisting of and hexagons to be H and H with and signi cant digits respectively Further estimates for Hn up to n are also given Hexagonal Systems Informally speaking a hexagonal system can be viewed as a connected arrangement of hexagonal cells packed in the same way as the typical honeycomb arrangement in a bee hive More formally it is a nite connect...

Journal: :Chemical communications 2004
Chi-Keung Lam Mei-Fun Cheng Chi-Lun Li Jie-Peng Zhang Xiao-Ming Chen Wai-Kee Li Thomas C W Mak

The non-benzenoid aromatic D(5h) and enediolate C(2v) form of C5O5(2-) have been stabilized by hydrogen bonding with urea and 1,3-dimethylurea, respectively, in the host lattices of two novel crystalline inclusion compounds.

Journal: :Angewandte Chemie 2023

Non-alternant non-benzenoid hydrocarbons exhibit very different optical and electronic properties than their well-studied benzenoid analogues. However, preparing such structures with extended conjugation length, remains challenging. Herein, we report the synthesis of azuleno[2,1,8-ija]azulene derivatives using a two-step sequence involving four-fold aldol condensation between aromatic dialdehyd...

Journal: :iranian journal of mathematical chemistry 2012
g. fath-tabar z. gholam-rezaei a. r. ashrafi

the tutte polynomial of a graph g, t(g, x,y) is a polynomial in two variables defined for every undirected graph contains information about how the graph is connected. in this paper a simple formula for computing tutte polynomial of a benzenoid chain is presented.

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1978
H E Auer T N Thompson

Titrations of actinomycin D (AMD) with dG and with dG-dC were monitored by circular dichroism at 380 nm and 470 nm. These wavelengths are sensitive predominantly to nucleotide binding processes at the benzenoid and quinoid portions, respectively, of the phenoxazone ring of the drug chromophore [Auer, H.E., Pawlowski-Konopnicki, B.E., Chiao, Y.C.C. & Krugh, T.R. (1978), Biopolymers, 17, 1891-191...

Journal: :Journal of chemical information and computer sciences 2002
Jan Cz. Dobrowolski

The structure and stability of ca. 100 nonplanar constitutional isomers of the coronene molecule of general formula C(24)H(12) have been estimated by semiempirical and by ab initio calculations. The isomers studied are unbranched cyclic catacondensed structures and fall into two classes, viz., the belt (B) and the Moebius (M) type. The calculations have shown some of the M-isomers to be more st...

Journal: :SIAM J. Discrete Math. 2008
Heping Zhang Peter Che Bor Lam Wai Chee Shiu

Applying the recently obtained distributive lattice structure on the set of 1-factors, we show that the resonance graphs of any benzenoid systems G, as well as of general plane (weakly) elementary bipartite graphs, are median graphs and thus extend greatly Klavžar et al.’s result. The n-dimensional vectors of nonnegative integers as a labelling for the 1-factors of G with n inner faces are desc...

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