A new rhodamine based colorimetric 'off-on' fluorescence sensor selective for Pd2+ along with the first bound X-ray crystal structure

A new fluorescence rhodamine derivative bearing an 8-aminoquinoline moiety has been designed and synthesized for selective sensing of Pd2+ in the presence of other competing metal ions in aqueous media. Pd2+ induced spirolactam ring opening of rhodamine is confirmed for the first time by the X-ray crystal structure of the bound Pd2+-complex.