Summary: | Unsaturated macrocyclic molecules have got an interest due to their potential in catalysis, ion exchange and electron transfer. Salicaldehyde derivatives macrocyclic molecules have a broad range in synthesis. In this study, two unsaturated macrocyclic molecules (L1 and L2) have been synthesized. The preparation of unsaturated macrocyclic ligands involve two steps; the reaction of salicylaldehyde with 1,2-dibromoethane or 1,4-dibromobutane to produce precursor, then cyclisation were completed using schiff base technique by adding diamines (naphthalene diamine). The ligands were characterized spectroscopically. In FT-IR spectrums, the form of the ligands mainly can be observed on the disappearance of the carbonyl group of aldehyde at approximately 1650cm-1 that was readily assigned to C=O group of salicylaldehyde with the replacement of C=N peak at 1684.13cm-1. The success in producing macrocyclic ligands have been further characterized using fluorescence emission spectroscopy (FES) and revealed the typical emission of naphthalene at ∼430nm. Fluorescence changes of L1 and L2 showed high selectivity for Fe3+ and Cu2+ respectively in the presence of other common metal ions, such as Zn2+, Ni2+ and Co2+. Besides, the ligand was sensitive enough to detect the concentration of ferric ion with the detection limit down to 1.08 x 10-6 M and fluorescence change that was unaffected by the presence of other common coexisting metal ions. Complexation with Co(II) was also attempted. © Published under licence by IOP Publishing Ltd.
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