|
NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR) >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Chemistry -Section B (IJC-B) >
IJC-B Vol.48B [2009] >
IJC-B Vol.48B(10) [October 2009] >
| Title: | Study of [1,3] sigmatropic hydrogen migration in thymine, thymidine and thymidylic acid by AM1 method |
| Authors: | Rao, Bojja Rajeshwar |
| Keywords: | Frontier molecular orbital
AM1
[1, 3] sigmatropic rearrangement
tautomers
conformations |
| Issue Date: | Oct-2009 |
| Publisher: | CSIR |
| Abstract: | The geometry and electronic structures of thymine, thymidine and thymidylic acid involving [1,3] sigmatropic hydrogen migration in the formation of tautomers have been fully optimized and evaluated by semi-empirical molecular orbital AM1 method. In this connection, the heats of formation ( Hf°), dipole moments ( ), full atomic charges, and energies of frontier molecular orbitals (EHOMO and ELUMO) have been calculated and discussed. The mechanistic investigation of [1,3] sigmatropic rearrangement in thymine affected in the conformational changes of thymidine and thymidylic acid has been studied by the comparison of net charges of atoms in different positions of the molecule. All tautomers of thymine, thymidine and thymidylic acid exist within the energy of 28.054 kcal/mol, 20.889 kcal/mol, and 21.124 kcal/mol respectively. Furthermore, dipole moment and atomic charges of all tautomers indicated that the dipole-dipole interactions play a vital role during the hydrogen bonding with adenine. |
| Page(s): | 1411-1418 |
| ISSN: | 0975-0983(Online); 0376-4699(Print) |
| Source: | IJC-B Vol.48B(10) [October 2009]
|
|
