Supramolecular complexes of spin-labelled cyclodextrins.
EPR spectra of cyclodextrins labelled with TEMPO derivatives (SL-CDs) are sensitive to complexation with large guest molecules. We used SL-CDs to explore the behaviour of concentrated PEG/PPG solutions. The relationship between rotational correlation times and solvent viscosity showed significant deviations from the Debye-Stokes-Einstein equation, probably due to self-aggregation of alkylene glycols in concentrated solutions. The data fit the fractional Debye-Stokes-Einstein equation well. We have also studied complexation of SL-CDs with adamantane-functionalised DAB dendrimers. The strength of binding increases with dendrimer generation; formation of supramolecular aggregates at high concentrations was observed with the generation 3 dendrimer.
Chechik
Victor
V
Department of Chemistry, University of York, Heslington, York, UK YO10 5DD. vc4@york.ac.uk
Ionita
Gabriela
G
D000218:Adamantane / Q000737:chemistry; D003505:Cyclodextrins / Q000737:chemistry*; D050091:Dendrimers / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D011092:Polyethylene Glycols / Q000737:chemistry; D019946:Propylene Glycol / Q000737:chemistry; D012399:Rotation; D012996:Solutions; D013113:Spin Labels
D003505:Cyclodextrins; D050091:Dendrimers; D012996:Solutions; D013113:Spin Labels; D011092:Polyethylene Glycols; D019946:Propylene Glycol; D000218:Adamantane