Biomedical subjects
Publications and source records attributed to Danitza Vargas.
The structure of title compound, C6H16N+.C14H8N3O7S-, comprises discrete ions which are interconnected by N-H...O- and N-H+...O- hydrogen bonds, leading to a neutral one-dimensional network along [100]. These hydrogen bonds appear to complement the Coulombic interaction and help to stabilize the structure further.
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The surface properties of the supramolecular inclusion complex (IC) obtained from the threading of alpha-cyclodextrin (alpha-CD) onto poly(ethylene oxide) (PEO) free in solution are studied. The complexes were characterized by IR, (1)H NMR spectroscopy, and thermal analysis. The variation of the interfacial tension, gamma(int), with inclusion complex (IC) concentration and temperature were determined. The results were compared with those found for PEO under the same conditions. alpha-CD does not present surface activity. To quantify the adsorption process of IC and PEO in aqueous medium, the Gibbs equation was used. The driving force for adsorption of IC at the air/aqueous interface seems to arise from an enthalpic contribution. The wettability of the alpha-CD, PEO, and IC films with two liquids was determined by static contact angle measurements. The hydrophobicity degree was estimated. IC is more hydrophobic than PEO and alpha-CD.
The title compound, C27H19NO2S, contains chains of fused R(2)(2) (19) rings formed by intermolecular C-H...O=C hydrogen bonds and running along the [011] and [0-11] directions. These chains are linked through short intermolecular C-H...pi contacts, giving rise to sheets. The conformation of the title compound is dominated primarily by the nearly orthogonal lone-pair orbitals on the N and S atoms.