title: Barbituric and thiobarbituric acids: a conformational and spectroscopic study.
abstract: A conformational study on Barbituric (BA) and Thiobarbituric (TBA) acids was performed at ab initio MP2/6-31G** level on the neutral, protonated, mono- and di-anionic forms. Acid-base equilibria were studied by comparing the electronic transitions evaluated for the most stable conformations and the experimental spectra at different pH values. The electronic transitions were obtained through the ZINDO approach.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125 Catania, Italy. fzuccarello@dipchi.unict.it
authors.forename: Felice
authors.initials: F
authors.lastname: Zuccarello
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Buemi
authors.forename: Concetta
authors.initials: C
authors.lastname: Gandolfo
authors.forename: Annalinda
authors.initials: A
authors.lastname: Contino
mesh_terms: D001463:Barbiturates / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D013053:Spectrophotometry / Q000379:methods*; D013858:Thiobarbiturates / Q000032:analysis*; D014466:Ultraviolet Rays
chemical_list: D001463:Barbiturates; D013858:Thiobarbiturates; C029684:thiobarbituric acid; C032232:barbituric acid