Protonation and deprotonation energies of uracil Implications for the uracil–water complex

• DOI: 10.1039/a708804c
• Publication Date: 2002-07-26T09:13:34Z
• Authors: Minh Tho Nguyen; Asit K. Chandra; The´rèse Zeegers-...
• Keywords: Lone pair; Uracil; Proton affinity; Affinities

The proton affinities PA(B) of the four oxygen lone pairs and two nitrogen atoms deprotonation energies PA(A-) NH bonds uracil are calculated by density functional theory (DFT) using 6-31G(d,p) 6-31G++(d,p) basis set. PAs also abinitio MO (MP4) for comparison. DFT/B3LYP frequency shifts ν(OH) stretching vibrations with 6-31++G(d,p) three cyclic structures uracil–water complexes. usual correlations between do not hold in case closed structures. most stable complex is formed at pair characterized lowest basicity bond highest acidity. energy decreases increasing value difference PA(A-)-PA(B).