SINTESIS C-2-ETOKSIKARBONILMETOKSIFENIL KALIKS[4]RESORSINARENA BERBAHAN DASAR SALISILALDEHIDA DAN APLIKASINYA SEBAGAI ADSORBEN KATION LOGAM Pb(II)

PUTRI WIDYA MULYA, Prof. Dr. Jumina

2014 | Skripsi | KIMIA

Sintesis senyawa C-2-etoksikarbonilmetoksifenil kaliks[4]resorsinarena berbahan dasar salisilaldehid serta aplikasi senyawa tersebut sebagai adsorben kation logam Pb(II) telah dilakukan. Sintesis senyawa C-2-etoksikarbonilmetoksifenil kaliks[4]resorsinarena berbahan dasar salisilaldehid dilakukan melalui 3 tahap reaksi. Tahap pertama adalah sintesis etil 2-kloroasetat dengan metode esterifikasi Fischer. Ester yang diperoleh tidak berwarna, berbau khas dan memiliki rendemen sebesar 72,29%. Tahap kedua adalah sintesis senyawa 2-etoksikarbonilmetoksi benzaldehida dengan mereaksikan salisilaldehid dan etil 2-kloro asetat dengan katalis NaOEt. Produk yang dihasilkan berupa cairan berwarna oranye tua, berbau khas dengan rendemen sebesar 29,41%. Selanjutnya senyawa 2-etoksikarbonilmetoksi benzaldehida direaksikan dengan resorsinol dalam suasana asam menghasilkan senyawa C-2-etoksikarbonilmetoksifenil kaliks[4]resorsinarena. Hasil sintesis berupa padatan berwarna putih pucat dengan rendemen 16,46% dan titik leleh lebih dari 200 °C. Elusidasi struktur produk menggunakan spektrofotometer FTIR, 1H-NMR dan 13C-NMR. Adsorpsi dilakukan dengan variasi keasaman larutan, waktu interaksi dan konsentrasi awal larutan. Kinetika adsorpsi dipelajari dengan menggunakan kinetika Lagergren dan Ho, sedangkan isoterm adsorpsi dianalisis dengan persamaan Langmuir dan Freundlich. Data yang diperoleh menunjukkan bahwa kenaikan pH dan waktu interaksi meningkatkan jumlah logam teradsorpsi hingga mencapai kondisi optimum pada pH 5 dan waktu kontak 120 menit. Hasil kajian kinetika adsorpsi menunjukkan bahwa adsorpsi Pb(II) mengikuti model kinetika orde pseudo-dua Ho dengan laju adsorpsi (k) sebesar 2,85×10-1 g mg-1 menit-1. Kajian isoterm adsorpsi mengikuti isoterm adsorpsi Langmuir. Konstanta kesetimbangan (K), kapasitas maksimum serta energi adsorpsi Pb(II) pada adsorben tersebut berturut-turut sebesar 2,58×104 L mol-1; 1,57×10-4 mmol g-1 (32,71 mg g-1) dan 25,34 kJ mol-1.

Synthesis of C-2-ethoxycarbonylmethoxyphenyl calix[4]resorcinarene and its application for adsorption of Pb(II) metal cation have been carried out. The synthesis of C-2-ethoxycarbonylmethoxyphenyl calix[4]resorcinarene from salicyldehyde was conducted in three steps. The first step was synthesis of ethyl 2-chloro acetate by Fischer esterification. The ester product was obtained as liquid with characteristic odor in 72.29% yield. The second step was synthesis of 2-ethoxycarbonylmethoxy benzaldehyde from salicyldehyde and ethyl 2-chloro acetate using NaOEt catalyst. The product was obtained dark orange liquid with characteristic odor in 29.41% yield. The product was reacted with resorcinol in ethanol under acidic condition to produce C-2-ethoxycarbonylmethoxyphenyl calix[4]resorsinarene. This product was obtained as pale white solid in 16,46% yield having melting point more than 200 °C. The structure elucidation was perfomed by FTIR, 1H-NMR dan 13C-NMR spectrophotometers. Adsorption esperiments were carried out in batch system under variation of medium acidity, interaction time and initial metal concentration. Adsorption kinetic was studied using Lagergen and Ho equation, while adsorption isotherm was analyzed by Langmuir and Freundlinch equations. The results showed that the amount of absorbed metal increased with the increased of pH and interaction time until finally reached the optimum condition at pH 5 and interaction time of 120 minutes. The kinetic study showed that the adsorption of Pb(II) followed pseudo-second order of Ho with adsorption rate (k) of 2.85×10-1 g mg-1 minute-1. The isotherm study showed that the adsorption followed Langmuir model. The calculated equilibirium constant (K), maximum adsorption capacity and adsorption energy for the adsorption of Pb(II) on the adsorbent were 2.58×104 L mol-1; 1.57×10-4 mmol g-1 (32,71 mg g-1) and 25.34 kJ mol-1.

Kata Kunci : kaliks[4]resorsinarena, salisilaldehid, adsorpsi, Pb(II)