Syntheses, spectroscopic and structural characterizations and metal ion binding properties of Schiff bases derived from 4 '-aminobenzo-15-crown-5

Abstract

A series of benzyloxybenzaldehyde derivatives (1-4) were synthesized by the reactions of 4-(bromomethyl)benzonitrile with 4-hydroxy-3-methoxybenzaldehyde (vanillin), 2-hydroxy-3-methoxybenzaldehyde (o-vanillin), 2-hydroxy-4-methoxybenzaldehyde and 2-hydroxy-5-methoxybenzaldehyde. Condensation reactions among the new benzyloxybenzaldehyde derivatives (1-4) with 4'-aminobenzo-15-crown-5 yielded the new Schiff base compounds (5-8). Sodium complexes (5a-8a) and potassium complexes (5b-8b) were prepared with NaClO4 and KI, respectively. All of these synthesized compounds were characterized on the basis of FT-IR, H-1 and C-13 NMR, mass spectrometry and elemental analyses data. The solid state structures of compounds 8 and 5a were determined by X-ray crystallography. The extraction abilities of compounds 5-8 were also evaluated in CH2Cl2 by using several main group and transition metal picrates, such as Na+, K+, Pb2+, Cr3+, Ni2+, Cu2+ and Zn2+