Synthesis and cation-binding property studies of macrocyclic schiff-base compounds

Abstract

In this research work, two macrocyclic Schiff-base compounds, 3,4,9,10-ditenzo- 1,12 -diaza-5,8-aioxacyclorentadeca.ne-1,11-diene; 0-en-N-tn and 3,4,10,11-dibenzo-1,13-dieza-5,9 -dioxacyclohexadecane-1,12-diene : 0-tn-N-tn were synthesized from cyclization reaction of dialdehydes with diamines. In addition, two corresponding open-chain Schiff-base compounds, Bis (salicylaldelyde) N, N’-ethylenedimine; Salen and Bis (Salicylaldehyde)N,N’- trimethylenediimine ; Saltn were also synthesized. The proposed structures of all compounds were confirmed by spectroscopic data and elemental analysis. Their cation binding abilities were investigated by solvent extraction method. It was found that Salen had a great affinity for copper ion in pH range of 4.5 to 7.2. The ratio of ligand to copper was 1:1 and 1:2 for open-chain and macrocyclic ligands respectively. Salen was selected in this study as being a reagent for the copper determination by measuring the absorbances of Cu(II)- Salen complex in chloroform at 562 nanometers. The calibration plot was found to be linear up to copper concentration of 55 ppm. The relative standard deviation at 12.00 ppm copper was 1.02 %, the molar absorptivity was 2.9 x 102 L mol-1 cm-1 limit of detection was 0.4 pm at absorbance 0.002. The coexisting ions, selected as Ca(II) and Mn(II), did not effect the analysis. The percent relative error was 1.50 %. The system was applied to the determination of copper in solder ingot sample. The results obtaining agreed well with the atomic absorption spectrophotometric method.