Synthesis and Characterization of Glyco‐Decorated Silsesquioxane‐Metallosalen Complexes

Abstract

Cube-octameric silsesquioxanes (COSS) present interesting opportunities in several applications due to their rigid inorganic and biocompatible silicate core combined with tunable, well-oriented corner functionalities. In the present study, multivalent mannose-decorated COSS-metallosalen complexes, as models combining potential catalytic activity and cell-targeting moieties in a single structure, were synthesized. The complexes proved to be hydrolytically stable, and their assembly was efficient between a slight excess of salicylaldehyde-derived mannose and an aminopropyl-modified COSS core, followed by complexation with metal ions. The complexes can adopt a D4h or an S4 geometry with zinc and copper ions, respectively, which affects the orientation of the mannose substituents and the availability of the catalytic metallosalen centers on the COSS core. Potential but modest ribonuclease activity of the complexes was observed. The hydrolytic stability and the efficient assembly of these well-organized complexes can be utilized for the synthesis of other glyco or biomolecule analogues.