The Conformation of Coumarin-Crown Ethers with Spin-Spin and Site Exchange Simulations

Abstract

The conformation of the fluorogenic host molecules of coumarin-15-crown-5 ethers were examined by 1H and 2D NMR. The gem. and vie. coupling constants were estimated to confirm the a, ±g, a unit conformations clearly. The proton site exchange rate simulations proved the rate of ± gauche interconvertions are not more then 800-1000 Hz which governed the role of molecular recognition.