Colorimetric and Ratiometric Fluorescent Chemosensor with a Large Red-Shift in Emission:  Cu(II)-Only Sensing by Deprotonation of Secondary Amines as Receptor Conjugated to Naphthalimide Fluorophore

Abstract

[reaction: see text] A new fluorescent probe N-butyl-4,5-di[2-(phenylamino)ethylamino]-1,8-naphthalimide 1 senses only Cu(II) among heavy and transition metal (HTM) ions by means of a colorimetric (primrose yellow to pink) method with a large red-shift in emission (green to red) attributed to the deprotonation of the secondary amines as a receptor conjugated to the naphthalimide fluorophore.