Molekul, Vol. 18. No. 1, March 2023: 50 – 58 50 MOLEKUL eISSN: 2503-0310 Articles https://doi.org/10.20884/1.jm.2023.18.1.5927 Synthesis of Ionophore from p-t-Butyl-(carboxymethoxy)calix[4]arene Substituted Amide Nasriadi Dali 1* , Seniwati Dali 2 , Armadi Chairunnas 3 , Hilda Ayu Melvi Amalia 4 , Sri Ayu Andini Puspitasari 5 1 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Halu Oleo University, Kendari 93232, Southeast Sulawesi, Indonesia 2 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Hasanuddin University, Makassar 90245, South Sulawesi, Indonesia 3 Department of Biology, Faculty of Mathematics and Natural Sciences, University of Nahdlatul Ulama Sulawesi Tenggara, Kendari 93563, Southeast Sulawesi, Indonesia 4 Study Program of Tadris Biology, Faculty of Tarbiyah and Teacher Training, Institut Agama Islam Negeri (IAIN), Kendari 93563, Southeast Sulawesi, Indonesia 5 Department of Public Health, Faculty of Public Health, Halu Oleo University, Kendari 93232, Southeast Sulawesi, Indonesia *Corresponding author email: nasriadidali@ymail.com Received June 04, 2022; Accepted October 20, 2022; Available online March 20, 2023 ABSTRACT. The ionophore has been successfully synthesized from p-t-butyl(carboxymethoxy)calix[4]arene subtituted amide. The ionophore was obtained in two steps of the synthesis reaction. The first step is the chlorination reaction of p-t- butyl(carboxymethoxy)calix[4]arene with thionyl chloride in dry benzene solvent. The product of the chlorination reaction is p- t-butyl(chloroacetylmethoxy)calix[4]arene in the form of the light brown viscous liquid with the rendemen of 78.25% and TLC (SiO2, CH3OH : CH2Cl2 = 1 : 1 v/v, Rf = 0.65). The second step is the amidation reaction of p-t-butyl(chloroacetylmethoxy) calix[4]arene with dimethylamine in dry tetrahydrofuran solvent. The product of the amidation reaction is p-t- butyl(dimethylcarbamoylmethoxy)-calix[4]arene or the DIMECAC4ND3 ionophore in the form of white solid with the rendemen of 60.75%, a melting point of 277-279 °C, and TLC (SiO2, CH3OH : CH2Cl2 = 1 : 1 v/v, Rf = 0.82). Keywords: amidation, calix[4]arene, chlorination, ionophore INTRODUCTION The separation of metal ions is an important process in analytical and industrial chemistry (Basset et al., 2014; Harrison, 2017; Lo et al., 2013). In the field of analytical chemistry, the purpose of separating metal ions is to remove or concentrate metal ions from a dilute solution before further analysis. In the industrial sector, metal ion separation aims to take, purify, and reduce the concentration of metal ions in liquid waste, especially heavy metal ions before being discharged into the environment. For the purpose of purification or retrieving metal ions from wastewater, a selective separation method is needed for metal ions to be separated. Industrial wastewater treatment involves the deposition of metals as hydroxides, salts, bases, and sulfides (Harrison, 2017). This method is not effective for wastewater with low dissolved metal ion concentration. One of the separation methods that can be applied for industrial wastewater treatment is liquid membrane transport. This method is favorable because it can be applied even though the dissolved metal ion concentration is low, can transport metal ions from low to high concentrations, uses little organic solvent, has simple operation, and requires low operating costs. In addition, the separation process takes place continuously (Mulder, 2016). In the liquid membrane transport method, metal ions are transported from the source phase to the target phase through an organic liquid membrane phase containing ion carrying molecules or ionophore. The success of this method is largely determined by stability of complex between metal ions and ionophore. The stability of complex is determined by the type of donor atom (active group), ring size, and branch length of the hydrophobic group of the ionophore (Bozkurt et al., 2015). Thus, the efficiency and selectivity of transport in various extraction techniques is heavily influenced by the ionophore in the liquid membrane (Qazi et al., 2012). Efforts to improve the performance of metal ion separation using the liquid membrane transport method continue to be carried out by researchers both from the synthesis aspect and its application to the separation of various metal ions (Suyanta, 2013; Tsurubou et al., 2015; Nijenhuis et al., 2012; Hwang