Synthesis and structural characterization of glucopyranosylamide films on gold.
Self-assembled monolayers (SAMs) of glucose derivatives on gold have been prepared from alpha- and beta-glucopyranosylamide derivatives. The glucosyl conjugates were synthesized stereoselectively via the in situ generation of glucosyl isoxazolines followed by treatment with thiopyridyl esters. The resulting film structures were characterized by atomic force microscopy, reflection Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The experimental data indicated that alpha- or beta-linked glucopyranosylamide derivatives with free hydroxyl groups attach to gold via the thiol linker. Both derivatives form monolayer films with high packing densities--comparable to those typically observed for alkanethiol monolayers on gold. Acetate analogues of these conjugates do not form SAMs on gold; they form multilayered films under identical deposition conditions.