Gas phase acidities of organic nitric acid derivatives: New opportunities in superacid chemistry

摘要

Density functional theory (DFT) calculations have been conducted on a new series of hybrid inorganic-organic acids. One of the oxygen double bonded to nitrogen in nitric acid has been systematically substituted with the different groups such as cyclopentadiene, indene, and borole motifs and the acidity of the compounds has been estimated via the DFT-B3LYP/6-311 + +G(d, p) method. The compounds 2b and 8 have the highest acidity, within the level of the superacids, with deprotonation enthalpies of 253 and 254 kcal/mol, respectively, which are more acidic than FSO3H, H2SO4, HNO3 and even CF3SO3H. Aromaticity indices of the designed compounds were analyzed along with their corresponding conjugate bases. C-H, O-H, and C=C=NH acids, were considered and their acidities were compared.