cyclobutadiene and the cyclopentadiene cation are interesting in that they areunusually unstable.This is a property called “antiaromaticity”, which we will describe in some detail in the next post.
Aromaticity and Antiaromaticity A comprehensive review of the science of aromaticity, as well as its evolution, from benzene to atomic clusters In Aromaticity and Antiaromaticity: Concepts and Applications, a team of accomplished chemists delivers a comprehensive exploration of the evolution and ...
represent a chemical bonding pattern in terms of both Lewis bonding elements (lone pairs (1c–2e) and 2c–2e bonds) as well as delocalized bonding elements (such as nc–2e (n > 2) bonds), while the latter are usually associated with the concepts of aromaticity and antiaromaticity....
In the 2π systems, although the 4n+2 π electron count suggests aromaticity and hence diatropicity, the π orbital is magnetically inactive, as in the Al42− dianion. However, in the 4π formally antiaromatic systems, the π-like HOMO supports an additional paratropic current. ...
Pro-aromatic and anti-aromatic π-conjugated molecules: an irresistible wish to be diradicals Aromaticity is an important concept to understand the stability and physical properties of π-conjugated molecules. Recent studies on pro-aromatic and anti-aromatic molecules revealed their irresistible tendency...
In small and planar aromatic systems, simple semi-classical current loop models predict molecular magnetic properties surprisingly well. However, a full quantum chemical treatment is necessary to describe antiaromatic and more complex systems such as C 60 or Mbius annulenes. A particularly useful way...
Examples are given below – (image) Huckel’s Rule of Aromaticity:All compounds must obey Huckel’s Rule i.e. molecule must have 4n+2 pi-electrons where n is an integer (i.e. n= 0, 1, 2, 3, 4…etc.). For example, Benzene has 6 pi-electrons and (4×1)+2 = 6, thus it...
The aromaticity or antiaromaticity of mono- and polyphospha analogues of carbocyclic cations and anions, namely cyclopropenium, cyclopropenide, cyclopentad... R Gupta,RK Bansal - 《Computational & Theoretical Chemistry》 被引量: 2发表: 2016年 Antiaromaticity-promoted radical anion stability in α...
Give examples of a heterocyclic aromatic compound. Which heterocycles are aromatic? Classify the following compounds as aromatic, antiaromatic, or nonaromatic compounds. Explain your answer. Classify the following molecules as aromatic and antiaromatic: ...
The aromaticity or antiaromaticity of mono- and polyphospha analogues of carbocyclic cations and anions, namely cyclopropenium, cyclopropenide, cyclopentadienium and cyclopentadienide ions has been investigated at the DFT (B3LYP/6-31+G∗) level on the basis of bond lengths equalization, aromatic...