Based on the local Shannon entropy concept in information theory, a new measure of aromaticity is introduced. This index, which describes the probability of electronic charge distribution between atoms in a given ring, is called Shannon aromaticity (SA). Using B3LYP method and different basis sets (6-31G**, 6-31+G** and 6-311++G**), the SA values of some five-membered heterocycles, C(4)H(4)X, a...

Using suitable Density functional theory (DFT) methods and models of various sizes and symmetries, we have obtained the aromaticity pattern of infinite Graphene, which is an intrinsically collective effect, by a process of “spatial” evolution. Using a similar process backwards we obtain the distinct aromaticity pattern(s) of finite nanographenes, graphene dots, antidots, and graphene nanoribbon...

As compared to classical organic aromatic compounds, the evaluation of aromaticity in all-metal and semimetal clusters is much more complex. For a series of these clusters, it is frequently found that different methods used to discuss aromaticity lead to divergent conclusions. For this reason, there is a need to evaluate the reliability of the different descriptors of aromaticity to provide cor...

The degree of aromaticity of six-membered monoheterocycles with IV-VI group heteroatoms (C(6)H(5)X, where X = SiH, GeH, N, P, As, O(+), S(+), Se(+)) was analyzed using the results of ab initio calculations at the MP2/cc-pvtz level. Values of common aromaticity indices including those based on electronic delocalization properties, structural-dynamic features and magnetic properties all indicate ...

The influence of the substituent nature, as well as the number and position of the substituents, on the aromaticity/antiaromaticity of a comprehensive set of derivatives of cyclopentadienyl anion, cyclopentadiene and cyclopentadienyl cation has been analyzed. The aromaticity/antiaromaticity of substituted cyclopentadienyl derivatives has been measured using energetic, magnetic and structural cr...

The degree of aromaticity of mono-substituted derivatives of benzene has beeninvestigated using a new index based on electric field gradient index, by using two mechanicalquantum methods with Gaussian 03. Two different basis sets have applied to study and theresults compared. This strategy has demonstrated that, due to violation of symmetry in have pisystems,how the degree of aromaticity can ha...

In this work, the aromatic fluctuation index (FLU) that describes the fluctuation of electronic charge between adjacent atoms in a given ring is introduced as a new aromaticity measure. This new electronic criterion of aromaticity is based on the fact that aromaticity is related to the cyclic delocalized circulation of pi electrons. It is defined not only considering the amount of electron shar...

We have studied the topological and local aromaticity of BN-substituted benzene, pyrene, chrysene, triphenylene and tetracene molecules. The nucleus-independent chemical shielding (NICS), harmonic oscillator model of aromaticity (HOMA), para-delocalization index (PDI) and aromatic fluctuation index (FLU) have been calculated to quantify aromaticity in terms of magnetic and structural criteria. ...