Decomposition of the total π-electron energy of polycyclic hydrocarbons into benzene ring increments

Spectral Moments of the Edge Adjacency Matrix in Molecular Graphs. 1. Definition and Applications to the Prediction of Physical Properties of Alkanes

“…23 The analogous concept of spectral moments of vertexadjacency matrix has been discussed by different authors. [24][25][26] Several relations between these moments and the structures of alternant molecules has been reported in chemical literature. 24,25 Some of these relations hold for the spectral moments of edge-adjacency matrix too, especially those obtained for simple cycles for which both matrices (A and E) are the same.…”

“…[24][25][26] Several relations between these moments and the structures of alternant molecules has been reported in chemical literature. 24,25 Some of these relations hold for the spectral moments of edge-adjacency matrix too, especially those obtained for simple cycles for which both matrices (A and E) are the same. A most detailed study of spectral moments of edge matrix for cyclic graphs will appear in a forthcoming paper.…”

Aromaticity of Polycyclic Conjugated Hydrocarbons

“…The Kekulene Problem." 747 Aihara has examined the kekulene problem on the basis of several theoretical approaches, such as the method of additive nodal increments of Cioslowski, 749,750 the method of conjugated circuits, the topological resonance energy, and the circuit resonance energies, and concluded the following: 747 Graph-theoretical analysis have clarified that super-conjugation resulting from the cyclic array of benzene rings does not yield appreciable super-aromatic energetic effects. Decisive evidence for the lack of super-aromaticity in kekulene was given simply by calculating the energy difference between true kekulene and superantiaromatic kekulene.…”

“…In fact this question has been raised by Aihara in an article entitled, “Is Superaromaticity a Fact or an Artifact? The Kekulene Problem.” 747 Aihara has examined the kekulene problem on the basis of several theoretical approaches, such as the method of additive nodal increments of Cioslowski, , the method of conjugated circuits, the topological resonance energy, and the circuit resonance energies, and concluded the following: 747…”

Topology and Stability of Conjugated Hydrocarbons. The Dependence of Total π‐Electron Energy on Molecular Topology

“…Some other approaches to approximate the total p-electron energy of polymers, 57,81 linear polyacenes, 58 benzenoid hydrocarbons, [82][83][84] and phenylenes 60,85,86 deserve to be mentioned.…”