The aryne [3 + 2] cycloaddition process with pyridinium imides breaks the aromaticity of the pyridine ring. By equipping the imide nitrogen with a sulfonyl group, the intermediate readily eliminates a sulfinate anion to restore the aromaticity, leading to the formation of pyrido[1,2-b]indazoles. The scope and limitation of this reaction are discussed. As an extension of this chemistry, N-tosyli...

Most dicyclopenta-fused polyacenes are predicted to be moderately aromatic and diatropic, although they have no (4n + 2)-site conjugated circuits. We applied our graph theory of aromaticity and magnetotropicity to these molecules and found that these anomalous properties arise from a set of non-conjugated circuits, which contribute collectively to aromaticity and diatropicity. This result indic...

The Baird-aromaticity of BN/CC cyclooctatetraene isosteres (azaboracyclooctatetraenes) in their lowest triplet states (T1) has been explored through computations various aromaticity indices that describe the different aspects (magnetic, electronic, energetic and geometric). While (COT) is aromatic its T1 state following Baird's 4n rule, we now reveal degrees vary with aspect considered. thermod...

In the free-electron model (FE) of cyclic polyenes the 7r-electrons are allowed to move freely in a ring. A modification of the FE-model (the MFE-model) is discussed in which the N-fold symmetry due to the N C-atoms of the ring is taken into account by an appropriate potential. The results of the MFE-model are compared with HMO-theory. The sequence of degenerate and non-degenerate levels which ...

In this study, an effort has been made to analyze the aromaticity of oligomers phenylenes and thiophenes, with presence absence linkers using Nucleus-Independent Chemical Shift (NICS) as a descriptor. The relation between HOMO–LUMO gaps, reorganization excitation energies respective NICS values employed develop structure-aromaticity-conjugation spectroscopy relationship (SACSR). Results show th...

This study analyzes the aromatic nature of cyanuric acid (hexahydrotriazine) and some of its derivatives, in terms of aromatic stabilization energy (ASE) and electronic behavior. The simplest molecule (C(3)N(3)O(3)H(3)) is the most aromatic item out of the entire set, but some of the others also display aromatic character. The structure of all the rings is analyzed considering their molecular o...

The unusual aromatic stability of cyclic bicalicene has been suggested to come from a tetraionic structure, where positive and negative charges are located on the cyclopropene and cyclopentadiene rings, respectively. Energetic, magnetic, geometric and electron delocalization analysis performed on a series of bicalicene derivatives, incorporating different electron donating and withdrawing group...