Theoretical investigations on the conformation of 1,5,N(4)-tetramethylcytosine

Abstract Theoretical investigations (Perturbative Configuration Interaction over Localized Orbitals (PCILO) and Intermediate Neglect of Differential Overlap (INDO) methods) of the conformation of tetramethylcystosine, an overcrowded molecule with planar struture, have carried out. The Physical features of rotational bending potentials of the dimethylamimo group are discussed. Particulary, the controversial problem concerning the planarity of the molecule is investigated. The obtained results show that the planarity of tetrathylcytosine is an intrinsic property of the molecule. Nevertheless, because of the repulsion between the methyl groups, the planar structure of tetramethylcytosine is slightly destabilized. Further, the functional dependence of the dipole moment of tetramethylcytosine on rotation and bending of the dimethylamino group has been analyzed.