Amani Direm

Bio: Amani Direm is an academic researcher. The author has contributed to research in topics: Hydrogen bond & Crystal structure. The author has an hindex of 5, co-authored 21 publications receiving 75 citations.

Cytosinium–hydrogen maleate–cytosine (1/1/1)

Abstract: The title organic salt, C4H6N3O+·C4H3O4−·C4H5N3O, was synthesized from cytosine base and maleic acid. An intra­molecular O—H⋯O hydrogen bond occurs in the hydrogen maleate anion. The crystal packing is stabilized by inter­molecular N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds, giving rise to a nearly planar two-dimensional network parallel to (101).

Anilinium hydrogen sulfate

Abstract: The asymmetric unit of the title compound, C6H8N+·HSO4−, contains two cations and two anions which are linked to each other through N—H⋯O hydrogen bonds, formed by all H atoms covalently bonded to the N atoms In addition, strong O—H⋯O anion–anion hydrogen-bond inter­actions are also observed

Intermolecular interactions of proton transfer compounds: synthesis, crystal structure and Hirshfeld surface analysis

Abstract: Three new proton transfer compounds, [2-ammonio-5-methylcarboxybenzene perchlorate (1), (C8H10NO2+·ClO4−), 4-(ammoniomethyl)carboxybenzene nitrate (2), (C8H10NO2+·NO3−), and 4-(ammoniomethyl)carboxybenzene perchlorate (3), (C8H10NO2+·ClO4−)], have been synthesized, their IR modes of vibrations have been assigned and their crystal structures studied by means of single-crystal X-ray diffraction. Their asymmetric units consist of one cation and one anion for both compounds (1) and (2). However, the crystal structure of compound (3) is based on a pair of cations and a pair of anions in its asymmetric unit. The three-dimensional Hirshfeld surface analysis and the two-dimensional fingerprint maps revealed that the three structures are dominated by H⋯O/O⋯H and H⋯H contacts. The strongest hydrogen-bonding interactions are associated with O—H⋯O and N—H⋯O constituting the highest fraction of approximately 50%, followed by those of the H⋯H type contributing 20%. Other close contacts are also present, including weak C⋯H/H⋯C contacts (with about 10%).

Co-crystallization and small molecule crystal form diversity: from pharmaceutical to materials applications

Abstract: Co-crystallization is the supramolecular phenomenon of aggregation of two or more different chemical entities in a crystalline lattice through non-covalent interactions. It encompasses the study of the manifestation of multi-component crystalline solids as well as their design. The chemistry community and the literature suggest cocrystals with reference to co-crystallization products and multi-component crystalline solids. Over the last decade cocrystals have become very popular as a potential new/alternate solid form of pharmaceuticals. However, there is no consensus on what exactly a cocrystal means and what it constitutes across academia, industry and regulatory bodies. On the other hand, cocrystals have been endorsed to the extent that the following facts have been obscured: (1) cocrystals are only one of the putative outcomes of co-crystallization, if at all, and (2) their application goes way beyond pharmaceuticals. Solvates, solid solutions, eutectics, salts, ionic liquids, solid dispersions, supramolecular gelators etc. are among the multifarious products of co-crystallization. The manifestation of these supramolecular/non-covalent crystalline adducts is controlled by the inherent nature of the system (the components involved) besides the surroundings (temperature, solvent, pH etc.); in effect it is a thermodynamic outcome. Each of these adducts, including cocrystals, are unique, exhibit varied physicochemical properties and are amenable to design and therefore have, and potentially find, manifold applications in diverse fields such as organic synthesis & separation, green chemistry, energy storage, solar cells, electronics, luminescent and smart materials, apart from pharmaceuticals. This article highlights the diversity of crystal forms and the utility of small molecule supramolecular combinations.

A Textbook of Biochemistry

Abstract: SOME justification is needed for producing another text-book of biochemistry; in this instance it is to be found in the array of authorities, both British and American, who have contributed to an advanced account of current biochemical knowledge. The book is, indeed, a kind of running ‘collective’ summary of the “Annual Review of Biochemistry”; some of the authors are common to both publications. A Textbook of Biochemistry Edited by Prof. Benjamin Harrow Dr. Carl P. Sherwin. Pp. 797. (Philadelphia and London: W. B. Saunders Co., 1935.) 25s. net.