Ground state intermolecular proton transfer in the supersystems thymine-(H2O)n and thymine-(CH3OH)n, n = 1,2: a theoretical study.
Twelve binary and eight ternary supersystems between thymine and methanol, and water were investigated in the ground state at the B3LYP and MP2 levels of theory using B3LYP/6-311 + + G(d,p) basis functions. The thermodynamics of complex formations and the mechanisms of intermolecular proton transfers were clarified in order to find out the most stable H-boned system. It was established that the energy barriers of the water/methanol-assisted proton transfers are several times lower than those of the intramolecular proton transfers in the DNA/RNA bases. The X-ray powder spectra of thymine, and this precrystallized from water and methanol showed that water molecules are incorporated in the crystal lattice of thymine forming H-bridges between thymine molecules.
Delchev
Vassil B
VB
Department Physical Chemistry, University of Plovdiv, Plovdiv, Bulgaria. vdelchev@uni-plovdiv.bg
Shterev
Ivan G
IG
D018360:Crystallography, X-Ray; D000432:Methanol / Q000737:chemistry*; D008956:Models, Chemical; D011522:Protons; D013941:Thymine / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D011522:Protons; D014867:Water; D013941:Thymine; D000432:Methanol