Resolution of d- and l-glucoses by chiral N-octyl-β-d-glycoside–Cu(II) complex adsorbed at the gas/liquid interface of small bubbles

A new technique of the jet drop method (JDM) was applied to a chiral molecular discrimination of optically active D- or L-glucose (guest) by chiral N-octyl-beta-D-glycoside (O beta DG)-Cu(II) complex (host) at the gas/liquid interface of small bubbles. The discrimination of glucoses as the guests is possible using O beta DG adsorbed at the gas/liquid interface of bubbles where it acts as the host, either in the presence or the absence of Cu(II) ions. In order to make clear the host-guest interaction at the gas/liquid interface, the composition 01 5000 top jet drops periodically collected onto a slide glass receiver was analyzed. The relative concentration (eta(i) - 1) and the surface excess amount Gamma(0)(i) of species i such as D- and L-glucoses, and O beta DG were determined as a function of bubble size, d(b) and bulk concentration C-b. The partition coefficient, Pi(i) = Gamma(0)(i)/C-b was also evaluated for each component. The adsorption of these materials either in the presence or absence of Cu(II) ions, was assigned to the Freundlich type, and the discrimination of D- and L-glucoses with O beta DG was evaluated in terms of the Freundlich constant, k(i) and 1/n. The discrimination ability of O beta DG was also evaluated by determining the equilibrium constants, K-c of complex formations for the respective glucoses in the presence and absence of Cu(II) ions. It was found that L-glucose can form a more stable complex with O beta DG-Cu(II). (C) 2010 Published by Elsevier B.V.