Synthesis and trans-β-carotenoid inclusion properties of a new class of water soluble calixarenes

The paper describes the synthesis of water soluble sulfonated calixarenes derived from p-benzylcalix[5,6,7,8]arenes and p-cumylcalix[4,6]arene along with their chlorosulfonyl derivatives. Inclusion phenomena of the sulfonated p-benzyl and p-phenyl calix[5,6]arenes towards carotenoids are also reported; 1H NMR, UV–VIS and light scattering experiments are consistent with a model in which the carotenoid is surrounded by two calixarenes and these supermolecules form large aggregates, 100–150 nm in diameter.