SYNTHESIS AND INCLUSION PROPERTIES OF CARBONYL-BRIDGED ANALOGS OF ACYCLIC P-T-BUTYLPHENOL FORMALDEHYDE OLIGOMERS

A series of compounds in which a part or all of the methylene bridges of acyclic p-t-butylphenol-formaldehyde oligomers are replaced by C=O bridge(s) has been synthesized. The carbonyl-bridged tetramers, except for that with no methylene bridge, formed crystalline host-guest complexes with various organic compounds; those with two C=O bridges were superior regarding complexation, regardless of the position of the bridges. Exclusive guest selectivity of the tetramer with one terminal C=O bridge was observed for benzene and its methyl derivatives in a two-component system. The fully carbonyl-bridged dimer, trimer, tetramer, and pentamer had no complexing-capability. The thermal stability of benzene complexes (host: guest=2: 1) of the tetramers with one C=O bridge, as estimated from their thermal dissociation rates, are remarkably lower than that of the parent tetramer. Oximes derived from the tetramers with one C=O bridge were much more effective than the corresponding carbonyl-bridged ones regarding their complex-forming capability.