extinct 发表于 2025-3-26 23:13:37
,The distortive tendencies of delocalized π electronic systems. Benzene, cyclobutadiene and related dimers X. (e.g. H.), while X. may be stable if the X. bond is weak (e.g. Li.). According to this theory, the π systems of aromatic hydrocarbons are expected to be unstable in a regular geometry and to be more stable in an alternated one. To verify this prediction, the driving force responsible for t清楚 发表于 2025-3-27 04:34:28
The spin-coupled valence bond description of benzenoid aromatic molecules,non-orthogonal, singly-occupied orbitals. The characteristic properties of molecules such as benzene or naphthalene arise from a profoundly quantum mechanical phenomenon, namely the mode of coupling of the electron spins, rather than from any supposed delocalization of the orbitals. Other systems co使混合 发表于 2025-3-27 07:11:26
http://reply.papertrans.cn/16/1503/150266/150266_33.png昏暗 发表于 2025-3-27 11:28:07
Scaling properties of topological invariants, known approximate formulae for the total π-electron energy and the size extensivity of topological invariants are outlined. The scaling properties of the reduced topological invariants are introduced and the accuracy of various scaling functions is assessed. Finally, the stability index of benzenoiAesthete 发表于 2025-3-27 14:19:38
Molecular topology and chemical reactivity of polynuclear benzenoid hydrocarbons,elopments in the field of reactivity indices for polynuclear benzenoid hydrocarbons are reviewed. Reaction mechanisms and correlations of reactivity indices with rates of electrophilic substitution and Diels-Alder reactions, thermally induced polymerization, and biochemical transformations of benzendeface 发表于 2025-3-27 18:50:56
A periodic table for benzenoid hydrocarbons,mplished using an aufbau principle. This table complies to a sextet rule analogous to the octet rule for the periodic table of elements, and .. is analogous to the outer-shell electronic configuration and .. is analogous to the principle quantum number associated with the periodic table of elements.Notify 发表于 2025-3-27 22:21:05
http://reply.papertrans.cn/16/1503/150266/150266_37.pngJAUNT 发表于 2025-3-28 02:46:46
,The existence of Kekulé structures in a benzenoid system,dered as one of the most difficult open problems in this theory. Many investigations have been made in order to find necessary and sufficient conditions for the existence of Kekulé structures in a benzenoid system. Some fairly simple conditions which are both necessary and sufficient have been given食料 发表于 2025-3-28 09:57:34
Peak-valley path method on benzenoid and coronoid systems,is method has been greatly developed and has become one of the important approaches for investigating Kekulé structures of benzenoid hydrocarbons. The superiority of this method is its simplicity and visualization. According to the properties of the P-V path, some algorithmic approaches have been de抛媚眼 发表于 2025-3-28 11:44:32
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