Topological Polymerization on Calixarene Template

Significance

The authors report a synthesis of tert-butylcalix[4]arenes with pendant diynyl groups (1). When 1 was exposed to UV radiation, no significant transformation took place. When ­hydroxyl groups were converted into urethanes (2 and 3), the compound exhibited color change from white to intense red upon a five-minute exposure to UV radiation. The authors exposed 2 to γ-radiation in order to achieve a more thorough transformation of the solid material. The resulting solid material was shown to have spectroscopic properties which suggest the presence of ene-yne conjugation of the expected product, 4.