0000000001302748
AUTHOR
Heike Lorenz
Single Enantiomer’s Urge to Crystallize in Centrosymmetric Space Groups: Solid Solutions of Phenylpiracetam
A detailed thermochemical and structural study of the phenylpiracetam enantiomer system was performed by characterizing the solid solutions, rationalizing the structural driving force for their formation, as well as identifying a common structural origin responsible for the formation of solid solutions of enantiomers. Enantiomerically pure phenylpiracetam forms two enantiotropically related polymorphs (enant–A and enant–B). The transition point (70(7) °C) was determined based on isobaric heat capacity measurements. Structural studies revealed that enant–A and enant–B crystallize in space groups P1 (Z′ = 4) and P212121 (Z′ = 2), respectively. However, pseudoinversion centers were present res…
A Maze of Solid Solutions of Pimobendan Enantiomers: An Extraordinary Case of Polymorph and Solvate Diversity
Over 10 polymorphs and solvatomorphs of the chiral pharmaceutically active ingredient pimobendan were found to lack enantioselectivity in the solid state, accordingly, forming solid solutions of enantiomers, which is reported to be a rare phenomenon. Solid form screening was performed on different enantiomeric composition samples to analyze obtained phases with powder X-ray diffraction and thermogravimetric differential scanning calorimetry. For nonsolvated forms, a melt phase diagram has been constructed convincingly showing the existence of stable and metastable solid solutions near the pure enantiomer and around the racemic composition regions. A crystal structure study combined with sol…
CCDC 1523462: Experimental Crystal Structure Determination
Related Article: Toms Rekis, Agris Be̅rziņš, Lia̅na Orola Tamás Holczbauer, Andris Actinš, Andreas Seidel-Morgenstern, Heike Lorenz|2017|Cryst.Growth Des.|17|1411|doi:10.1021/acs.cgd.6b01867
CCDC 1050684: Experimental Crystal Structure Determination
Related Article: Toms Rekis, Agris Be¯rzinš, Inese Sarcevica, Artis Kons, Ma¯rtinš Balodis, Lia¯na Orola, Heike Lorenz, Andris Actinš|2018|Cryst.Growth Des.|18|264|doi:10.1021/acs.cgd.7b01203
CCDC 1571124: Experimental Crystal Structure Determination
Related Article: Toms Rekis, Agris Be¯rzinš, Inese Sarcevica, Artis Kons, Ma¯rtinš Balodis, Lia¯na Orola, Heike Lorenz, Andris Actinš|2018|Cryst.Growth Des.|18|264|doi:10.1021/acs.cgd.7b01203
CCDC 1523460: Experimental Crystal Structure Determination
Related Article: Toms Rekis, Agris Be̅rziņš, Lia̅na Orola Tamás Holczbauer, Andris Actinš, Andreas Seidel-Morgenstern, Heike Lorenz|2017|Cryst.Growth Des.|17|1411|doi:10.1021/acs.cgd.6b01867
CCDC 1523461: Experimental Crystal Structure Determination
Related Article: Toms Rekis, Agris Be̅rziņš, Lia̅na Orola Tamás Holczbauer, Andris Actinš, Andreas Seidel-Morgenstern, Heike Lorenz|2017|Cryst.Growth Des.|17|1411|doi:10.1021/acs.cgd.6b01867