Spontaneous cocrystal hydrate formation in the solid state: crystal structure aspects and kinetics

Influence of isomerism on recrystallization and cocrystallization induced by CO2 as an antisolvent

“…36 PXRD analysis (Fig. 38 The 10 | J. Furthermore, this pattern matched that of the reported 4-ASA:NCTA cocrystal evidencing the same 1:1 stoichiometry as well.…”

“…60 Solution of 4-ASA and NCTA in acetone was processed by the CO 2 -recrystallization technique using an equimolar mixture of 4-ASA and NCTA which is the reported cocrystal stoichiometry. 38 Presence of a cocrystal hydrate in the powder was detected, which was consistent with the ability of this cocrystal to spontaneously catch atmospheric water to form the hydrated cocrystal. 9) confirmed that a cocrystal was formed since the pattern exhibited specific peaks at 2θ values of 6°, 12°, 15.1° and 26.8° that were not in the patterns of single processed materials.…”

“…Hence, the variation of NH 2 position might prevent these interactions from occurring, giving thus opportunities for the chemical groups to interact with the coformer and form cocrystals. 36,38 Contrarily, 4-ASA did not form any cocrystal with 4-aminopyridine in DMSO or pyridine. 36 Incidentally, the formation of cocrystals with 4-ASA has been only recently screened and the preparation of 4-ASA:NCTA cocrystal and its hydrate by evaporation and co-grinding has been reported.…”

“…36,[38][39][40] No cocrystals of 5-or 3-ASA are yet described. 36,[38][39][40] No cocrystals of 5-or 3-ASA are yet described.…”

Spontaneous Solid-State Cocrystallization of Caffeine and Urea

“…[7][8][9][10] On the other hand it is known that solids with a low vapour pressure can spontaneously undergo solid-state reactions forming salts, solvates, or co-crystals. [11][12][13][14] Solid-state co-crystallization via manual grinding has been known for over a century. In 1893 Ling and Baker reacted an equimolar mixture of metadichloroquinone and metadichloroquinol to produce the metadichloroquinone-metadichloroquinol co-crystal.…”