Quantitative Study on Local Aromaticity

Substituent Effect on Local Aromaticity has been studied in series of mono-and di-substituted biheterocycles (quinoline, isoquinoline, quinoxaline, quinazoline, 1H-Indole, 1H-Indazole, 1H- Benzo[d]imidazole). Electronically based indices (PDI, ATI and FLU) have been employed to investigate the substituent effect on the -electron delocalization in both heterocycle and benzenoid rings. Three typical substituents (Cl, OCH3 and CN) with different inductive and resonance effect have been selected. Generally, substituent causes a reduction in aromaticity irrespective of whether it is electron attracting or electron donating. Moreover, it is found that the substituent situation with respect to the heteroatom has a significant influence on the aromaticity, and irrespective of whether the two substituents form a meta or para isomer, they preferably choose the position which leads to the maximum aromaticity character. Also, influence of increasing the number of N as heteroatom and their sequences on -electron delocalization of aza derivatives of naphthalene and indole have been investigated by use of different quantitative descriptors including HOMA,NICS and electronic indices.

Autorentext

Dr. Mozhgan Shahamirian has obtained her PhD degree in Organic Chemistry in 2011 from Shiraz University.Her research interests are focused on Theoretical Studies on Organic Reactions & Important Properties of Organic Compounds such as Aromaticity. She is Assistant Professor at Islamic Azad University, Sarvestan Branch, Sarvestan, Fars, Iran.