engleski

Extensive Intramolecular and Intermolecular Interactions in Two Quaternary Salts of the Pyridoxal Oxime

Two derivatives of pyridoxal oxime (1) were prepared by quaternization of pyridoxal oxime with phenacyl bromide and 2-methoxyphenacyl bromide. The crystal structures of the 1-phenacyl-3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methylpyridinium bromide (2) and novel 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methyl-1-(2’-methoxyphenacyl) pyridinium bromide (3) have been determined by X-ray diffraction method. The conformation of these two pyridoxal oxime phenacyl derivatives is locked by numerous intramolecular hydrogen bonds. The O-H•••Br, C-H•••Br and C-H•••O hydrogen bonds in 2 and 3 form complex three-dimensional network. Supramolecular structure of 3 also contains C−H•••Pi and Pi•••Pi interactions which link neighbouring cations.

quaternary pyridinium salts; phenacyl bromides; pyridoxal oxime derivatives; X-ray diffraction; supramolecular assembling

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