‘Quasi-isostructural polymorphism’ in molecular crystals: inputs from interaction hierarchy and energy frameworks

Abstract

The polymorphs of (Z)-2-fluoro-N'-phenyl benzamidamide with multiple Z' produce quasi-isostructural supramolecular architectures, wherein C-H···F interaction plays a significant role. The energy framework analysis indicates 2D structural similarities in the interaction topologies of these crystalline forms. The results point to a unique class of 'quasi-isostructural polymorphs' which are nearly equi-energetic crystal structures exhibiting high degrees of similarity in physical properties.

Comment on ‘Solution growth and thermal treatment of crystals lead to two new forms of 2-((2,6-dimethylphenyl)amino)benzoic acid’ by R. Hu, Y. Zhoujin, M. Liu, M. Zhang, S. Parkin, P. Zhou, J. Wang, F. Yu and S. Long, RSC Adv., 2018, 8, 15459

“…This piece of information refutes the possibility of quasiisoestrutural polymorphism 7 or any other phenomenon. Additional crystallographic data can be obtained in the Cambridge Crystallographic Data Centre under the number 1861886.…”

“…This indicated the possibility of being either the same crystalline structure (with a different renement) or the phenomenon of quasiisostructural polymorphism. 7 The rst step to assess this doubt was to attempt a new renement for the raw data reported by Kovala-Demertzi et al 2…”

Design, synthesis, and characterization of (1-(4-aryl)-1<em>H</em>-1,2,3-triazol-4-yl)methyl, substituted phenyl-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates against <em>Mycobacterium tuberculosis</em>

“…In addition, molecules form centrosymmetric dimers via N-H…N, C-H…N, C-H… π (Cg1) hydrogen bonds and weak π…π stacking interactions along the crystallographic b -axis wherein these dimers are linked with weak C-H…F (involving H20, F2) hydrogen bond and F…F (involving F1, F3) interactions (Figure 3B). Hence, it is noteworthy to mention that interactions involving fluorine atom are one of the important contributors to the overall packing 54–56. The list of all the intermolecular interactions is given in Table 4.…”

Toward an Understanding of the Formation and Desolvation of Methanol Solvate, and Structure of Methanolysis Product: A Case Study of Nicosulfuron

“…During these processes, the active pharmaceutical ingredient (API) is in close contact with the solvents, and the corresponding solvates may form under certain conditions. Due to the differences in the solvates' structure based on the packing arrangement [3], molecular conformation [4,5], and intermolecular interaction, they may give rise to great variation in physicochemical properties such as solubility, stability, dissolution, and bioavailability. It will further exert great influences on the processing of API into drug products [5,6].…”