1H and 13C NMR spectra,protonation, deprotonation,and host-guest complexation-induced shifts of some fluorescence dyes

¹H and ¹³C NMR signal assignments for 8-anilinonaphthalenesulfonic acid (ANS) and dansyl amide (DNSA) are achieved using high-field spectra, decoupling, and two-dimensional NMR techniques as well as shift differences between conjugate acid and bases. Complexation of ANS and DNSA with a macrocyclic azoniacyclophane is measured by fluorescence and by NMR shift titration, furnishing an independent check for the equilibrium constant determination. The complexation-induced shifts (CIS) for ANS and DNSA are analyzed on the basis of aromatic ring current and linear electric field effect models. Comparison of equilibrium constants of the cyclophane and different substrates shows that, e.g., for ANS, lipophilic/hydrophobic binding dominates over electrostatic effects despite the presence of charges and the absence of a lipophilic cap or bottom on the receptor molecule.