Synthesis of a Dehydroabietyl Derivative Bearing a 2-(2′-Hydroxyphenyl)Benzimidazole Unit and Its Selective Cu(2+) Chemosensing

A dehydroabietyl derivative 2 bearing a 2-(2′-hydroxyphenyl)benzimidazole unit was synthesized and its sensing behaviors toward metal ions were investigated by UV-Vis and fluorescence spectroscopy methods. In THF solution, compound 2 exhibited excellent selectivity for Cu(II) over miscellaneous other metal ions including Cr(II), Mn(II), Co(II), Ni(II), Zn(II), Cd(II), Al(III), Mg(II), Pb(II), Hg(II), Na(I), Li(I) and K(I) evidenced through the quenching of the fluorescence of the benzimidazole fragment. The reaction between 2 and Cu(2+) was found to be stoichiometric with the formation of a 1:1 complex.