Solid‐State Structures and Solution Analyses of a Phenylpropylpyridine N‐Oxide and an N‐Methyl Phenylpropylpyridine

Abstract

The crystal structures of phenylpropylpyridine-N-oxide and N-methyl-phenylpropylpyridinium iodide are compared, revealing that hydrogen bonding with the solvent molecule plays an important role in the N-oxide compound, whilst electrostatic interactions are predominant in controlling the solid-state orientation of the N-methylated compound. Fluorescence spectroscopy and NOESY indicate that in contrast to the previously reported pyridinium iodide, the N-oxide is not subject to intramolecular pi-stacking, as judged by excimer emission and a lack of corresponding cross peaks, respectively.

Exploiting the Reversible Covalent Bonding of Boronic Acids: Recognition, Sensing, and Assembly

“…Recently, it has been demonstrated that pyridium cation−π interactions can be evaluated using fluorescence spectroscopy. − Since pyridinium boronic acids have already been used to prepare a saccharide sensor, the next logical step was to combine cation−π interactions and pyridinum boronic acids into one construct for diol detection. A simple propylene (Leonard Linker) linked phenyl alkyl pyridinium boronic acid showed characteristic cation−π stacking exciplex fluorescence .…”