The C4H4 isomer cyclobutadiene (CBD) is the prime model for antiaromaticity and thus a molecule of considerable interest in chemistry. Because it highly reactive, can only be studied under isolated conditions. Its electronic structure characterized by pseudo-Jahn–Teller effect neutral E ⊗ β Jahn–Teller cation. As result, recording photoelectron spectra as well describing them theoretically has ...

Using natural bond orbital theory, aromatic stabilisation energies (NBO-ASEs) were calculated for neutral and cationic monoheterocyclic three-membered rings C2H2X(R)n (X = group 14-17 elements of rows 3-5; R F, H or SiH3; n 0-2). Generally, there was a decrease in the (anti)aromatic nature molecule moving down as either stabilizing overlap (aromaticity) destabilising interactions (antiaromatici...

In this work we explored the excited state reactivity of triplet chlorobenzenes with density functional theory and a cluster-continuum approach. We modeled two competing reactions: direct abstraction hydrogen from solvent molecule solvolysis via photo-SN2Ar. Electron donating (–OMe, –CH2SiMe3, –SiMe3) withdrawing (–CN) substituents not only have distinct effects on geometries, inducing structur...

This review summarizes the results on aromaticity of a series synthesized and hypothetical neutral heterocirculene molecules their double charged ions. The heterocirculenes is direct reflection electronic structure responsible for specific optoelectronic photophysical properties. We show how presence heteroatom in outer macrocycle affects hetero[8]circulenes. In addition, we also describe chang...

There is probably no other single molecule that has fascinated experimental and theoretical chemists so consistently over the past 40 years as has cyclobutadiene (CBD). On average, 16 publications which deal, in one form or another, with the parent compound C4H4 and 40 which deal with cyclobutdienes in general have appeared in every year of this time span, and there are probably many more on de...