Highlights on the binding of cobalta‐bis‐(dicarbollide) with glucose units

Metalla-bis-dicarbollides, such as the COSAN anion [Co(C 2 B 9 H 11 ) 2 ] - , have attracted much attention in biology but there is a lack of understanding of their interactions with cell-components. For this purpose, we studied the interactions of COSAN with carbohydrate moieties that are ubiquitous in biological processes in bulk media and at interfaces. Octyl-glucopyranoside surfactant (C8G1) has been chosen as a sugar based model that self-assembles into micelles creating a glucose covered interface with water. COSAN was found to adsorb onto C8G1 micelles at low COSAN contents and to disrupt C8G1 micelles into mixed COSAN-C8G1 aggregates at high COSAN contents. COSAN interact mainly through (i) the hydrophobic effect with C8G1 monomers and (ii) the superchaotropic effect, i.e. with a thermodynamically favorable dehydration of the sugar moieties and of the COSAN, with sugars in a collective manner at the micellar surface and with linear-oligosaccharides with possible di-hydrogen bond formation.