On the issues of resolving a low melting combination as a definite eutectic or an elusive cocrystal: A critical evaluation

Cherukuvada, Suryanarayan (2016) On the issues of resolving a low melting combination as a definite eutectic or an elusive cocrystal: A critical evaluation. In: JOURNAL OF CHEMICAL SCIENCES, 128 (4). pp. 487-499.

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Abstract

Cocrystals and eutectics are different yet related crystalline multi-component adducts with diverse applications in pharmaceutical and materials fields. Recently, they were shown to be alternate products of cocrystallization experiments. Whereas a cocrystal shows distinct diffraction, spectroscopic and thermal signatures as compared to parent components, the hallmark of a eutectic is its low melting nature. However, in certain cases, there can be a problem when one resorts to design a cocrystal and assess its formation vis-A -vis a eutectic. In the absence of a gold standard method to make a cocrystal, it is often difficult to judge how exhaustive should the cocrystallization trials be to ensure the accomplishment of a desired/putative cocrystal. Further, a cocrystal can manifest with intermolecular interactions and/or crystal structure similar to that of its parent compounds such that the conventional diffraction and spectroscopic techniques will be of little help to conclusively infer the formation of cocrystal in the lack of single crystals. Such situations combined with low melting behavior of a combination brings the complication of resolving the combination as a cocrystal or eutectic since now both the adducts share common features. Based on the curious case of Caffeine-Benzoic acid combination, this study aims to unfold the intricate issues related to the design, formation and characterization of cocrystals and eutectics for a way forward. The utility of heteronuclear seeding methodology in establishing a given combination as a cocrystal-forming one or a eutectic-forming one in four known systems is appraised.

Item Type:	Journal Article
Publication:	JOURNAL OF CHEMICAL SCIENCES
Publisher:	INDIAN ACAD SCIENCES
Additional Information:	Copy right for this article belongs to the INDIAN ACAD SCIENCES, C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA
Keywords:	Cocrystal; eutectic; supramolecular compatibility; heteronuclear seeding; phase diagram
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	12 May 2016 05:45
Last Modified:	12 May 2016 05:45
URI:	http://eprints.iisc.ac.in/id/eprint/53815

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