Abstract
The ccc stereoisomer-purified tert-butoxycarbonyloxy (t-Boc) protected calix[4]resorcinarene molecular resists blended with photoacid generator exhibit a non-uniform photoacid catalyzed reaction in thin films. The surface displays a reduced reaction extent, compared to the bulk, with average surface-layer thickness (7.0 ± 1.8) nm determined by neutron reflectivity with deuterium-labeled t-Boc groups. Ambient impurities (amines and organic bases) are known to quench surface reactions and contribute, but grazing incidence X-ray diffraction shows an additional effect that the protected molecular resist are preferentially oriented at the surface, while the bulk of the film displayed diffuse scattering representative of amorphous packing. The surface deprotection reaction and presence of photoacid was quantified by near-edge X-ray absorption fine structure measurements.
