Maryam Zaboli - Department of chemistry, University of Birjand, Birjand, Iran
Heidar Raissi - Department of chemistry, University of Birjand, Birjand, Iran
Farzaneh Farzad - Department of chemistry, University of Birjand, Birjand, Iran

The H-bonded complexes formed from interaction between DNA thymine base dimer and its various derivatives have been investigated by B3LYP method using 6-311++g** basis set in in the gas phase. Vibrational frequencies of the obtained compounds have been systematically explored. The natural bond orbital analysis is used to elucidate the interaction characteristics of the investigated complexes. The AIMtheory has been also used to examine the properties of the bond critical points: their electron densities and Laplacians. The following substituents have been taken into consideration: Br, CF3, CCl3, CHO, Cl, CN, F, NH2, OCH3, OH and SH

Thymine, intermolecular hydrogen bonding, density functional theory, AIM, NBO