SINTESIS SENYAWA TURUNAN NITROVANILIN AZINA SEBAGAI KEMOSENSOR KOLORIMETRI UNTUK DETEKSI ANION SULFIDA

DIANA LESTARI, Drs. Bambang Purwono, M.Sc., Ph.D.

2022 | Tesis | MAGISTER KIMIA

Telah disintesis dan diuji senyawa nitrovanilin azina (NA) sebagai kemosensor kolorimetri anion berbahan dasar vanilin. Senyawa NA diperoleh melalui dua tahap reaksi. Vanilin dinitrasi menghasilkan 5-nitrovanilin (5-NV) dan dilanjutkan kondensasi Schiff base dengan hidrazin hidrat. Semua produk hasil sintesis dielusidasi menggunakan FT-IR, GC-MS, DI-MS, 1H-NMR, dan 13C-NMR. Uji aktivitas sebagai kemosensor kolorimetri dilakukan terhadap anion yaitu F-, Cl-, Br-, I-, S2-, CN-, AcO-, HCO3-, H2PO4-, N3-, NO2-, SCN-, ClO3-, dan NO3-. Hasil reaksi nitrasi terhadap vanilin dengan asam nitrat diperoleh rendemen sebesar 71,72%, sedang nitrovanilin azina (NA) diperoleh dengan rendemen sebesar 76,41%. Pendeteksian anion ditentukan berdasarkan studi spektofotometer UV-Vis dan pengamatan secara mata telanjang. Hasil uji ionokromik sebagai sensor anion menunjukkan bahwa kemosensor NA hanya selektif terhadap anion sulfida (S2-) dalam pelarut DMF:HBS (9:1, v/v, 10 mM, pH = 7,4) dari warna kuning muda menjadi hijau tua. Nilai limit deteksi (LOD) sulfida secara kolorimetri diperoleh sebesar 1,43x10-5 M (14,3 µM), sedangkan model interaksi host-guest (NA-S2-) yang terjadi melalui deprotonasi pada gugus -OH dengan rasio 1:1.

The compound nitrovanillin azine (NA) has been synthesized and tested as an anion colorimetric chemosensor based on vanillin. The NA compound was obtained through a two-step reaction. Vanillin was nitrated to yield 5-nitrovanillin (5-NV) and followed by condensation of Schiff base reaction with hydrazine hydrate. All synthesized products were elucidated using FT-IR, GC-MS, DI-MS, 1H-NMR, and 13C-NMR. Activity tests as colorimetric sensors were carried out on the anions, i.e., F-, Cl-, Br-, I-, S2-, CN-, AcO-, HCO3-, H2PO4-, N3-, NO2-, SCN-, ClO3-, and NO3-. The nitration of vanillin using nitric acid was obtained in 71.72% yield, while nitrovanillin azine (NA) was yielded in 76.41%. The anions detection were determined based on UV-Vis spectrophotometer studies and observations with the naked eyes. The results of the ionochromic test as an anion sensor showed that chemosensor NA was only selective for sulfide anion (S2-) in DMF:HBS (9:1, v/v, 10 mM, pH = 7.4) from light yellow to dark green. The detection of limit value (LOD) of sulfide was obtained by colorimetric at a concentration of 1.43x10-5 M (14.3 µM), while the host-guest interaction model (NA-S2-) occurs through deprotonation of the -OH group with a ratio of 1:1.

Kata Kunci : vanilin, 5-nitrovanilin, azina, kemosensor, kolorimetri, sulfida