Intramolecular O–H ⋯π hydrogen bond found in [2.2]metacyclophane systems: spectral properties and X-ray crystallographic analysis of 8-hydroxymethyl[2.2]metacyclophanes

Abstract

In 5-tert-butyl-8-hydroxymethyl[2.2]metacyclophanes 3b–h and meso-8,8′-(1,2-dihydroxyethane-1,2-diyl)bis(5-tert-butyl[2.2]metacyclophane)meso-4, the hydroxy group forms an intramolecular O–H ⋯π hydrogen bond with the opposing benzene ring as is indicated by IR spectroscopy. This is confirmed in the cases of the 13-tert-butyl derivative 3h and meso-4 by X-ray crystallographic analyses.