Ejarque, DanielCalvet Pallàs, Maria TeresaFont Bardia, Ma. MercedesPons, Josefina2021-02-222021-02-222021-02-162073-4352https://hdl.handle.net/2445/174118The reactions of piperonylic acid (HPip) and cinnamic acid (HCinn) with 4,4'-bipyridine (4,4'-bipy) have been assayed using the same synthetic methodology, yielding two binary cocrystals with different acid:4,4'-bipy molar ratios, (HPip)(4,4'-bipy) (1) and (HCinn)2(4,4'-bipy) (2). The melting point (m.p.) of these cocrystals have been measured and a remarkable difference (DT 78 C) between them was observed. Moreover, the two cocrystals have been characterized by powder X-ray diffraction (PXRD), elemental analysis (EA), FTIR-ATR, 1H NMR spectroscopies, and single-crystal X-ray diffraction. The study of their structural packings via Hirshfeld surface analysis and energy frameworks revealed the important contribution of the pi..pi and C-H...pi interactions to the formation of different structural packing motifs, this being the main reason for the difference of m.p. between them. Moreover, it has been observed that 1 and 2 presented the same packing motifs as the crystal structure of their corresponding carboxylic acids, but 1 and 2 showed lower m.p. than those of the carboxylic acids, which could be related to the lower strength of the acid-pyridine heterosynthons respect to the acid-acid homosynthons in the crystal structures.16 p.application/pdfengcc-by (c) Ejarque, D. et al., 2021http://creativecommons.org/licenses/by/3.0/esCristallsEstructura cristal·lina (Sòlids)Lligands (Bioquímica)CrystalsLayer structure (Solids)Ligands (Biochemistry)info:eu-repo/semantics/article7072242021-02-22info:eu-repo/semantics/openAccess