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Updated: May 21, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Two dibenzodiazepinone molecules with dissimilar dimeric associations and apparent different tautomeric forms
Max Keller1, Mohan M Bhadbhade, Roger W Read
1School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
Abstract:
In two dibenzodiazepinones, viz. the tricyclic core structure, 5H-dibenzo[b,e]diazepin-11(10H)-one, C(13)H(10)N(2)O, and an acylated derivative, 1-(11-hydroxy-5H-dibenzo[b,e]diazepin-5-yl)-2-{4-[3-(1H-imidazol-1-yl)propyl]piperidin-1-yl}ethanone ethanol monosolvate, C(26)H(29)N(5)O(2)·C(2)H(5)OH, dimeric association via hydrogen-bond bridging between the cyclic amide entities is evident, but there are considerable differences between the parent compound and the amidated derivative. Highly consistent with reported structures of related tricyclic lactams, two molecules of the nonsubstituted compound are bridged through two N-H...O hydrogen bonds across a crystallographic centre of symmetry and the bond lengths of the cyclic amide entity correspond to the amino-oxo (lactam) tautomeric form. In contrast, the structure of the derivative shows two similar, but crystallographically unique, molecules hydrogen bonded into a dimeric unit exhibiting an approximate (noncrystallographic) C2 axis. The bond lengths of the two derivative cyclic amide groups support their potential presence in the hydroxyimine (lactim) tautomeric forms, with the resulting possibility of intermolecular tautomerism. Likely driving forces for the two extreme configurations are discussed.
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