A Si(100) surface featuring molecular recognition properties was obtained by covalent functionalization with a tetraphosphonate cavitand (Tiiii), able to complex positively charged species. Tiiii cavitand was grafted onto the Si by photochemical hydrosilylation together with 1-octene as a spatial spectator. The recognition properties of the Si-Tiii surface were demonstrated through two independent analytical techniques, namely XPS and fluorescence spectroscopy, during the course of reversible complexationguest exchange-clecomplexation cycles with specifically designed ammonium and pyridinium salts. Control experiments employing a Si(100) surface functionalized with a structurally similar, but complexation inactive, tetrathiophosphonate cavitand (TSiiii) demonstrated no recognition events. This provides evidence for the complexation properties of the Si-Tiiii surface, ruling out the possibility of nonspecific interactions between the substrate and the guests. The residual Si-O(-) terminations on the surface replace the guests' original counterions, thus stabilizing the complex ion pairs. These results represent a further step toward the control of self-assembly of complex supramolecular architectures on surfaces.
|Titolo:||Molecular Recognition on a Cavitand-Functionalized Silicon Surface|
|Data di pubblicazione:||2009|
|Citazione:||Molecular Recognition on a Cavitand-Functionalized Silicon Surface / Biavardi E; Favazza M; Motta A; Fragala IL; Massera C; Prodi L; Montalti M; Melegari M; Condorelli G; Dalcanale E. - 131:21(2009), pp. 7447-7455.|
|Appare nelle tipologie:||1.1 Articolo in rivista|