Faride Ahmadi - Education Department, District ۱, Tehran, Iran.

In the combination of ۵-fluorophenyl-۱, ۳, ۷, ۹-tetra methyl pyrido [۲, ۳, d, d, ۵, ۶ di pyrimidine -۲, ۴, ۶, and ۸ tetron, there are ۴ 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 the highest amount. In the B and D loop, the predicted aromaticity level is low and close to zero, and there is a reduction in aromatics in the C loop than the A ring. In another stage of the study, with the replacement of the halogen ring A from F to I, the following trend was observed. In ring A, when halogens were changed, the increase in aromaticity in halogenated compounds was as follows:  F> Cl> Br> I.

NICS, aromaticity, halogenated compounds