Inclusion Studies of 8-OH Quinoline with ?-Cyclodextrin

Cyclodexterins are well known for their ability to form inclusion complexes with molecules that can fit (completely or partially) into their central cavity. 8-Hydroxy Quinoline is a bifunctional hydrogen-bonding molecule, which in an alcoholic solution simultaneously acts as a H-donor at the OH site and an acceptor at the N-atom. Combination of these two entities was found to exhibit interesting photophysical properties. Host- Guest complexion studies between 8-OH Quinoline and ?-Cyclodextrin were carried out with the steady state absorption, fluorescence excitation and emission spectral analysis. A fascinating observation was made regarding the concentration dependence of the host-guest complex. Appreciable association constant was arrived numerically from the spectral values.