Complexation with Diol Host Compounds, 12. Synthesis and Solid‐State Inclusion Properties of Bis(diarylhydroxymethyl)1‐Substituted 1,1′‐Binaphthyls. Crystal Structures of a Host and Its Pyridine Clathrate

Abstract

A series of new clathrate host molecules 1 – 8 containing two bis(diarylhydroxymethyl) groups attached to different positions (2,2′ or 8,8′) of a 1,1′-binaphthyl frame have been synthesized. Their clathrate formation properties with organic guests including alcohols, amines, ketones, and other dipolar aprotic compounds or aromatic hydrocarbons are reported (74 examples of clathrates) together with the results of solvent competition experiments for the parent host compound. The inclusion formation and the clathrate stoichiometries depend on the structure of the host molecules in a systematic manner. The crystal structures of the free parent host 1 and its pyridine clathrate (1 : 3) have been determined by X-ray diffraction. The molecular structure of the host is similar in the two species involving an intramolecular hydrogen bond between the host hydroxyls. No other hydrogen bond is involved in the free host case while in the pyridine inclusion compound the second host hydroxyl forms a hydrogen bond with the nitrogen of one pyridine guest which is surrounded by two unbound pyridine species such as to form clusters of three pyridine guests enclosed in the cavities between the host molecules. Thermal analysis corresponds with the two binding states of the pyridine molecules in the clathrate.