Gradual transition from NH⋯-pyridyl hydrogen bonding to the NH⋯O tape synthon in pyridyl ureas

Peter Byrne, David R. Turner, Gareth O. Lloyd, Nigel Clarke, Jonathan W. Steed

Research output: Contribution to journalArticleResearchpeer-review

67 Citations (Scopus)


We report the synthesis and X-ray crystal structures of a series of pyridyl ureas of the type currently topical in anion binding and supramolecular gelation applications, along with their anion-binding ability in solution. The structures of the simple pyridyl ureas are dominated by urea ⋯ N(pyridyl) hydrogen bonding, because of steric congestion of the urea carbonyl by intramolecular CH⋯-O interations. However, introducing a further competing synthon in the form of alkenic or π-stacking interactions causes a gradual changeover, through a number of interesting intermediate hydrogen bonding motifs, to the urea α-tape arrangement.

Original languageEnglish
Pages (from-to)3335-3344
Number of pages10
JournalCrystal Growth and Design
Issue number9
Publication statusPublished - 1 Sep 2008

Cite this