Synthesis of unsaturated appended naphthalene macrocyclic ligands as chemosensor / Siti Nurwajihah Mohd Salleh

Macrocyclic ligand is defined as cyclic molecules that contain of heteroatoms and capable to bind substrates. Six new macrocyclic ligands were synthesized by the reaction of l,2-bis(2-carboxyaldehyde phenoxy)butane and various diamines. The macrocyclic ligands were synthesized involving two steps. The first step is the reaction of salicylaldehyde with 1,2-dibromoethane, 1,3-dibromopropane or 1,4-dibromobutane to produce precursor, then cyclisation were completed using Schiff base technique by adding diamines (naphthalene diamine). All ligands were characterized by using Elemental Analysis (EA), Fourier Transform Infrared (FT-IR) spectroscopy and proton Nuclear Magnetic Resonance (*H NMR) spectroscopy. The IR spectra of the precursor LI, L2, L3, L4 and L5 clearly demonstrated that the reaction was completed by the formation of u(C-O-C) peak and disappearance of u(OH) peak. The presence of u(C-O-C) band peak appear in the range of 1267.84- 1290.44 cm'1.