The Formation of Self-Assembled Monolayers for Host-Guest Complex Systems

We have developed host-guest thin film systems for the creation of tunable surfaces. Self-assembled host-monolayers containing pre-existing cavities for guest inclusion have been prepared on Si (100) (Si/SiO₂) substrates via a stepwise reaction based on hydrolytic or silane chemistry. The cavities are formed via the introduction of a bulky organic group such as an anthracene-derivative. The resultant host-monolayers were characterized by contact angle measurements, Fourier Transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray specular reflectivity. Guest molecules consisting of a functional moiety and a long alkane tail can be inserted into the host film in order to form functionalized surfaces. Guest molecules can also be removed or exchanged by varying the solvent conditions – allowing for the modification or regeneration of a pre-existing film. The structural changes upon guest insertion and the kinetics of the guest exchange process are currently under investigation.