Mass spectrometric titration experiments

Quantitative binding studies were performed in both cases by on-chip mass spectrometric titration experiments. 

XH NMR experiments show that the viologen residue interacts effectively with the CB7 host [53], Voltammetric and mass spectrometric data are also consistent with the formation of inclusion complexes between the dendronized viologens and CB7. As was the case with methylviologen, complexation by CB7 depresses the molar absorptivity coefficient for the viologen UV absorption band and this effect can be conveniently utilized to fit the absorbance data in titration experiments to 1 1 binding isotherms. From the optimization of these fittings we obtained the corresponding equilibrium association constants (Table 3). 

---