New fluorescent chemodosimeter for Cu²⁺ based on Schiff base derived from 1-naphthylamine and 2-chlorobenzaldehyde

Abstract

1391-1396<span style="letter-spacing:-.2pt;mso-ansi-language: PT-BR" lang="PT-BR">On condensation of 1-naphthylamine with 2-chlorobenzaldehyde, the Schiff base (Z)-N-(2-chlorobenzylidene)naphthalene-1-amine (L) is formed which shows moderate fluorescence. L on interaction with Cu2+ hydrolyses back into fluorescent 1-naphthylamine and hence acts as fluorescent chemodosimeter for Cu2+ by “off-on” mode with an ca. 18 times enhancement in fluorescent intensity (detection limit is 10-5 M). The other hydrolysed product, 2-chlorobenzaldehyde, forms a tris chelate complex with Cu2+, as shown by UV/visible spectroscopy and cyclic voltammetry. The metal ions, Na+, K+, Ca2+, Mn2+, Fe2+, Co2+, Ni2+, Cd2+, Hg2+, Pb2+ and Ag+, do not interfere while in the case of Zn2+, moderate interference is observed. </span