Trifluoroacetyl-chlorin as a new chemosensor for alcohol/amine detection

Chlorophyll derivative possessing a trifluoroacetyl group at the 3-position was synthesized as a new chemosensor for alcohols and amines. Intense Qy peak of the trifluoroacetyl-chlorin (701 nm in CHCl3) showed blue shifts to 667 nm in MeOH and 665 nm in n-BuNH2 due to the formation of the corresponding hemiacetal and hemiaminal with visible color changes. Thermodynamic parameters for the complexation between trifluoroacetyl-chlorin and n-BuNH2 in CDCl3 were determined to be ΔH = −48 kJ mol−1 and ΔS = −147 J K−1 mol−1. Ratiometric fluorescence sensing of n-BuNH2 in THF was also demonstrated.