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...

It is demonstrated that there is a direct connection between aromaticity and the anisotropy of the π-electron density on planes parallel to the molecular ring. The electron density anisotropy on the plane is measured through the ratio of the in-plane Hessian eigenvalues associated with the eigenvectors lying in the plane. Computations on a wide-ranging set of well-characterized monocyclic syste...

In the combination of 5-fluorophenyl-1, 3, 7, 9-tetra methyl pyrido [2, 3, d, d, 5, 6 di pyrimidine -2, 4, 6, and 8 tetron, there are 4 rings, respectively, ring that is attached to the halogen ring A and, respectively, a ring The lower and the right to the left of the ring A are called C, B, and D. Calculations and studies show that the amount of aromatics in halogen-ring A in all cases has th...

The ring-current aromaticity of the bicalicene molecule arises, in spite of the 16 π carbon perimeter, from strong local diatropic circulations on the two pentagonal rings, as shown by current-density maps computed at the ipsocentric RHF/6-311G** and DFT/6-311G** levels of theory. Conjugated-circuit models cannot capture this pattern of circulation as it arises from 'ionic' contributions in a v...

Molecular aromaticity in the linear polyacenes is investigated using an atoms in molecules based six center index (SCI-AIM) which measures the electron delocalization. SCI-AIM values for the linear polyacenes indicate decreasing aromaticity going from outer to inner rings in the polyacene series. The SCI-AIM approach is compared to a Mulliken-like approach, and a critical comparison to the PDI ...

Aromaticity has been lately in the center of attention of chemists with books [1-3], journal special issues [4-10], reviews [11, 12], and publications (these are too numerous to cite). The discoveries of fullerenes, nanotubes, nanocones, and nanotori as well as the recent techniques for obtaining graphene sheets with monatomic thickness and astounding properties have enlarged our views about th...

Since its introduction by August Kekulé in 1865,1 the concept of aromaticity has been continuously conquering new territories in chemistry (refs 2-20 are only a small fraction of the published articles, reviews, books, and conference proceedings on this subject). Initially, aromaticity was developed for the following classes of organic compounds: (i) monocyclic planar conjugate hydrocarbons and...

Benzene represents the showcase of Hückel aromaticity. The silicon analog, hexasilabenzene, has consequently been targeted for decades. We now report an intensely green isomer of Si6R6 (R being 2,4,6-triisopropylphenyl) with a tricyclic structure in the solid state featuring silicon atoms with two, one, and no substituents outside the ring framework. The highly dispersed 29Si nuclear magnetic r...

NICS methodology has been applied to study the change in aromaticity in several aromatic rings (benzene, pyrrol, triazine, hexafluorobenzene) on complexation with several ions (Li, Na, K. F, Cl). For this purpose all the isolated and complexed rings have been optimized at the MP2/6-31++G(d,p) level of theory. Using GIAO method to calculate NICS values, the change in aromaticity on complexation ...