Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 52: Bioinspired Functional Materials, Biomaterials and Biopolymers (joint session CPP/BP)

CPP 52.6: Vortrag

Mittwoch, 14. März 2018, 16:15–16:30, PC 203

Self-consistent Hubbard-corrected DFT study of hole-polaron trapping in glucose-based bio-insulators: the Cyclodextrin case. — •Stefano Mensa and Gilberto Teobaldi — Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, L69 3BX Liverpool, United Kingdom

Using CyDs as an archetypal glucose-based bio-insulator, we use a self-consistent linear response DFT+U approach, as implemented in the linear-scaling ONETEP code, to explore hole-polaron relaxation both in vacuo and in the presence of different acidic, alkaline and ionic environments due to interacting H(+), OH(-), Na(+) and Cl(-) ions. Hole-polaron trapping in isolated CyDs or in CyDs interacting with H(+), Na(+) and Cl(-) ions is computed to be energetically disfavoured. However, hole-polaron trapping at terminal hydroxyl (-OH) groups becomes energetically favoured by up to -2 eV in the presence of alkaline conditions as a result of hydroxyl deprotonation by interacting OH(-) ions. Selective hole-polaron trapping at glycosidic (C-O-C) bridges between glucose monomers is found to be consistently disfavoured regardless of the presence of interacting ions. The computed stability of the CyD-backbone to direct oxidative depolymerisation, favourable hole-trapping at terminal CyDs hydroxyls, and well known CyDs capability of hosting both organic and inorganic contaminants altogether suggest that CyDs may be effective redox intermediates for the development of novel strategies for photocatalytic oxidation of hosted polluting agents in alkaline conditions.