title: Alloying barbituric and thiobarbituric acids: from solid solutions to a highly stable keto co-crystal form.
abstract: Alloying isomorphous crystals of barbituric acid (BA) and thiobarbituric acid (TBA) yields solid solutions of general formula BAxTBA1-x(x < 0.8); for x = 0.5 the stable co-crystal BA0.5TBA0.5, isomorphous with the parent keto forms, is observed, which melts at 265 °C, i.e. ca. 10 and 20 °C higher than the melting points of BA and TBA, respectively. While the BAxTBA1-xsolid solutions with x > 0.5 are stable, those with x < 0.5 convert, with time or temperature, to the BA0.5TBA0.5co-crystal.
authors.affiliation: Dipartimento di Chimica Giacomo Ciamician, Università degli Studi di Bologna, Via Selmi 2, 40126 Bologna, Italy. fabrizia.grepioni@unibo.it.
authors.forename: O
authors.initials: O
authors.lastname: Shemchuk
authors.affiliation: Dipartimento di Chimica Giacomo Ciamician, Università degli Studi di Bologna, Via Selmi 2, 40126 Bologna, Italy. fabrizia.grepioni@unibo.it.
authors.forename: D
authors.identifier: http://orcid.org/0000-0003-4162-4779
authors.initials: D
authors.lastname: Braga
authors.affiliation: Dipartimento di Chimica Giacomo Ciamician, Università degli Studi di Bologna, Via Selmi 2, 40126 Bologna, Italy. fabrizia.grepioni@unibo.it.
authors.forename: F
authors.identifier: http://orcid.org/0000-0003-3895-0979
authors.initials: F
authors.lastname: Grepioni