EPR and NMR investigation on the interactions of nitroxide probes with resorcin[4]arene molecular capsules.

ABSTRACT

EPR experiments in water-saturated CH(2)Cl(2) solution clearly indicate that oxotempo is not included inside hexameric molecular capsules of resorcin[4]arene. In fact, the tumbling rate of oxotempo only experiences minor changes when resorcinarene is present in the solution. However, NMR spectroscopic data suggest that oxotempo engages in labile hydrogen-bonding interactions with water molecules interacting with the resorcinarene molecular capsules.