Phosphorescence Induction by Host-Guest Complexation with Cyclodextrins - The Role of Regioisomerism and Affinity.
Matthias HaydukTorsten SchallerFelix C NiemeyerKevin RudolphGuido H CleverFabio RizzoJens VoskuhlPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2022)
We present an in-depth investigation of cyclodextrin complexes with guest compounds featuring complexation-induced room temperature phosphorescence (RTP) in aqueous solution. Very interestingly, only the complexed regioisomers bearing lateral substituents on meta-position show RTP, whereas the stronger host-guest systems with para-substituted dyes show no RTP features. The reported systems were investigated regarding their complexation behavior in water using isothermal titration calorimetry and mass spectrometry. In the case of γ-CD very strong 1 : 1 inclusion complexes (K a up to 5.13×10 5 M -1 ) were unexpectedly observed. It was found that not only a strong binding to the cyclodextrin cavity is needed to restrict motion, inducing the emission, but also the conformation inside the cavity plays a pivotal role - as supported by an extensive NMR study and MD simulations.
Keyphrases
- room temperature
- capillary electrophoresis
- aqueous solution
- ionic liquid
- mass spectrometry
- high resolution
- molecular dynamics
- water soluble
- liquid chromatography
- magnetic resonance
- molecular docking
- optical coherence tomography
- solid state
- high performance liquid chromatography
- diabetic rats
- atomic force microscopy
- minimally invasive
- endothelial cells
- crystal structure
- ms ms
- solid phase extraction