Author/Authors :
Ebrahimi ، Ali نويسنده Undergraduate Student, Student Research Committee, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. , , Delarami، Hojat نويسنده Department of Chemistry, University of Sistan and Baluchestan, Zahedan, Iran , , Khorassani، Mostafa Habibi نويسنده Department of Chemistry, University of Sistan and Baluchestan, Zahedan, Iran , , Abedini، Somaye نويسنده Department of Chemistry, University of Sistan and Baluchestan, Zahedan, Iran , , Mostafavi ، Najmeh نويسنده Department of Chemistry, University of Sistan and Baluchestan, Zahedan, Iran ,
Abstract :
The effect of interactions of various Ia and IIa cations with two positions of the adenine-thymine (A-T) and guanine-cytosine (G-C) base
pairs on the geometries and individual hydrogen bond (HB) energies have been investigated by using the atoms in molecules (AIM) method at
the B3LYP/6-311++G(d,p) level of theory. The cations that possess higher charge/radius (q/rad) ratio make higher changes on the individual HB
energies and the total binding energies of G-C base pair, while no meaningful changes are observed for the A-T base pair. The effect of
coordination with cations on the H-bond energies of A-T type complexes, especially in the Xʹ-A-T derivatives, is slight and different from the GC
complexes. The changes of total binding energies are most important in the presence of bivalent cations. The estimated individual EHBs are in
good agreement with the results of natural bond orbital (NBO) analysis and also with the structural parameters of HBs.
