TY - JOUR
T1 - Cocrystals Help Break the "rules" of Isostructurality
T2 - Solid Solutions and Polymorphism in the Malic/Tartaric Acid System
AU - Cruz-Cabeza, Aurora J.
AU - Lestari, Monica
AU - Lusi, Matteo
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2018/2/7
Y1 - 2018/2/7
N2 - Crystalline solid solutions have the potential to afford tunable materials for pharmaceutical and technological applications. Unfortunately, these poorly understood phases are difficult to obtain and, hence, to study. In fact, commonly accepted empirical rules prescribe that only molecules of similar size and electron distribution are mutually soluble in the solid state. Here, despite the evident structural and electronic differences, the enantiomers of malic acid and tartaric acid are crystallized together in a variable stoichiometric ratio to produce both cocrystals and solid solutions. In some cases, physical mixtures are observed. The composition and polymorphism of the crystalline products are explained by DFT-d molecular substitution calculations for the cocrystallized molecules in different (known) structures. At the same time, from a crystal engineering perspective, the behavior of this complex system is rationalized thanks to the existence of intermediate cocrystal forms that merge the structural features of the pure molecular components.
AB - Crystalline solid solutions have the potential to afford tunable materials for pharmaceutical and technological applications. Unfortunately, these poorly understood phases are difficult to obtain and, hence, to study. In fact, commonly accepted empirical rules prescribe that only molecules of similar size and electron distribution are mutually soluble in the solid state. Here, despite the evident structural and electronic differences, the enantiomers of malic acid and tartaric acid are crystallized together in a variable stoichiometric ratio to produce both cocrystals and solid solutions. In some cases, physical mixtures are observed. The composition and polymorphism of the crystalline products are explained by DFT-d molecular substitution calculations for the cocrystallized molecules in different (known) structures. At the same time, from a crystal engineering perspective, the behavior of this complex system is rationalized thanks to the existence of intermediate cocrystal forms that merge the structural features of the pure molecular components.
UR - http://www.scopus.com/inward/record.url?scp=85041913550&partnerID=8YFLogxK
U2 - 10.1021/acs.cgd.7b01321
DO - 10.1021/acs.cgd.7b01321
M3 - Article
AN - SCOPUS:85041913550
SN - 1528-7483
VL - 18
SP - 855
EP - 863
JO - Crystal Growth and Design
JF - Crystal Growth and Design
IS - 2
ER -