Theoretical investigation on the aromaticity of mono-substituted benzene derivatives by using cyclic reference

The degree of aromaticity of mono-substituted derivatives of benzene has been investigated using a new index based on electric field gradient index, by using two mechanical quantum methods with Gaussian 03. Two different basis sets have applied to study and the results compared. This strategy has demonstrated that, due to violation of symmetry in have pisystems, how the degree of aromaticity can have been changed. A comparison of the values of our aromaticity index with other indices reveals a good correlation for these compounds