Fig. 2: Synthetic scheme and characterization of acac-FPA as a chelating ligand.

a Synthetic procedure for acac-FPA. b FT-IR spectra of acac-FPA films before and after being cross-linked. The red shade represents the presence of azide groups via the asymmetric stretching band νas (N3). c UV–visible absorption spectra of acac-FPA films before and after being cross-linked.