Essentially, a 2-tree is a simple connected graph composed by triangles glued along their edges in a tree-like fashion, that is, without cycles (of triangles). The enumeration of 2-trees has been extensively studied in the literature. See, for instance, Harary and Palmer [8] and Fowler et al [6]. Here we consider more general 2-trees, where the triangles are replaced by quadrilaterals, pentagon...

(24) Ritter, G. L.; Isenhour, T. L. Minimal Spanning Tree Clustering of Gas Chromatographic Liquid Phases. Comput. Chem. 1977, 1, 145-153. Everitt, B. Cluster Analysis; Halsted: New York, 1974. Balaban, A. T. Chemical Graphs. XXXIV. Five New Topological Indices for the Branching of Tree-Like Graphs. Theor. Chim. Acra 1979, 53, 355-375. Balaban, A. T.; Motoc, I. Chemical Graphs. XXXVI. Correlati...

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.

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...

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...

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...

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...