Cyclic conjugation in benzo- and benzocyclobutadieno-annelated terrylenes and higher rylenes

Abstract

The effect of benzo- and benzocyclobutadieno-annelation on cyclic conjugation in terrylene and the higher members of the rylene homologous series is examined. Some peculiar regularities are established, that could not be observed in the case of perylene (the first member of the rylene series)

A test of Clar aromatic sextet theory

“…[1][2][3][4][5][6][7] Cyclic conjugation in benzenoid hydrocarbons was especially much studied, see the papers [8][9][10][11][12][13][14] and the references cited therein. The "aromatic sextet theory" of Erich Clar 1,3 provides the simplest and most direct way by which an insight into the dominant modes of cyclic conjugation of a benzenoid molecule can be gained.…”

Topological properties of altan-benzenoid hydrocarbons

“…As a direct consequence of this, some π-electron 1520 GUTMAN properties of annulenes 6,[22][23][24] are preserved also in altan-benzenoids. 15,[25][26][27] Another characteristic feature of the π-electron configuration of (4k)annulenes is the existence of a pair of non-bonding molecular orbitals (NBMOs). Of their properties, the most important may be that cyclic conjugation has a significant destabilizing energy effect.…”

A multidisciplinary study on magnesium

“…It would be more sensible to use the term quantum chemistry for investigations such a those carried out, e.g., by Gutman et al [50][51][52][53][54][55][56][57][58][59] However, in this case, a serious alternative to the name "quantum chemistry" would be "mathematical chemistry" or even something like "applied (mathematical) topology". It is only justified if one accepts the more historical than logical concept that molecules "belong" to chemistry, while atoms are a subject of physics.…”

“…The determination of the equilibrium composition is equivalent to finding the set of non-negative values of x i which minimize (59) (62), and form the expression analogous to (59), one obtains the optimal coefficients X = {x i , x 2 , …, x n } that lead to the condition ∂G(X) / ∂x i = 0 for all x i , by applying the iterative approach described in Supplement D. This algorithm has been used in numerous calculations of plasma composition. The determination of the equilibrium composition is equivalent to finding the set of non-negative values of x i which minimize (59) (62), and form the expression analogous to (59), one obtains the optimal coefficients X = {x i , x 2 , …, x n } that lead to the condition ∂G(X) / ∂x i = 0 for all x i , by applying the iterative approach described in Supplement D. This algorithm has been used in numerous calculations of plasma composition.…”