Sintesis Senyawa Azina Asimetris Vanilin-p-Kloro-Benzaldehid sebagai Kemosensor Anion

Baiq Najwa, Prof. Drs. Bambang Purwono, M.Sc., Ph.D. ; Prof. Drs. Jumina, M.Sc., Ph.D.

2024 | Tesis | S2 Ilmu Kimia

Senyawa azina asimetris vanilin-p-kloro-benzaldehid (VAA) telah berhasil disintesis dari vanilin, hidrazin hidrat dan 4-kloro benzaldehid. Sintesis dilakukan dalam dua tahap reaksi. Pertama, vanilin direaksikan dengan hidrazin hidrat menghasilkan senyawa vanilin azina simetris. Senyawa turunan azina simetris tersebut kemudian didegradsi-kondensasi lebih lanjut dengan p-klorobenzaldehid untuk menghasilkan senyawa vanilin azina asimetris. Produk hasil sintesis dielusidasi menggunakan FT-IR, GC-MS, 1H-NMR, dan 13C-NMR. Uji aktivitas sebagai kemosensor kolorimetri dilakukan terhadap berbagai anion yaitu S2–, CN–, F–, Cl–, Br–, I–, N3–, NO3–, NO2–, SCN–, dan H2PO4–.

Sintesis vanilin azina simetris (VA) menghasilkan rendemen sebesar 48,17?n vanilin azina asimetris menghasilkan rendemen sebesar 70,60%. Keberhasilan sintesis senyawa VAA ditandai dengan karakterisasi GC-MS yang menunjukkan nilai m/z sebesar 288, dan munculnya 9 proton serta 13 karbon dari hasil karakterisasi menggunakan spektra NMR. Uji deteksi anion ditentukan secara kasat mata dan menggunakan spektrometri UV-Vis. Hasil uji anion menunjukkan bahwa kemosensor VAA selektif terhadap anion sianida (CN–) dan anion sulfida (S2–) dalam pelarut DMSO dengan terjadinya perubahan warna dari tidak berwarna menjadi kuning. Nilai limit deteksi (LOD) anion sianida sebesar 2,37×10-7 M dan anion sulfida sebesar 1,66×10-6 M. Aplikasi kemosensor VAA untuk analisis kuantitatif pada sampel air kran mampu mendeteksi anion S2– dengan % recovery lebih besar dari 90%, dan untuk analisis kualitatif menggunakan paper strips mampu mendeteksi anion CN– dan S2– dengan perubahan warna dari tidak berwarna menjadi kuning. 

The asymmetric azine compound vanillin-p-chloro-benzaldehyde (VAA) has been successfully synthesized from vanillin, hydrazine hydrate and 4-chloro benzaldehyde. Synthesis was carried out in two reaction stages. First, vanillin was reacted with hydrazine hydrate to produce a symmetric vanillin azine compound. The symmetric azine derivative compound was then further degraded-condensed with p-chlorobenzaldehyde to produce an asymmetric vanillin azine compound. The synthesized product was elucidated using FT-IR, GC-MS, 1H–NMR, and 13C–NMR spectrometers. Activity tests as colorimetric chemosensors were carried out on various anions, namely S2–, CN–, F–, Cl–, Br–, I–, N3–, NO3–, NO2–, SCN–, and H2PO4–.

The synthesis of symmetrical vanillin azine (VA) yielded 48.17%, while the asymmetrical vanillin azine yielded 70.60%. The successful synthesis of the VAA compound was confirmed by GC-MS characterization, which showed an m/z value of 288, and by NMR spectra, which revealed the presence of 9 protons and 13 carbons. The anion detection test was determined by the naked eye and using UV-Vis spectrometry. The results of the anion selectivity test showed that the VAA chemosensor was selective for cyanide anions (CN–) and sulfide anions (S2–) in DMSO solvent with a color change from colorless to yellow. The limit of detection (LOD) value for the cyanide anion was 2.37×10–7 M and the sulfide anion was 1.66×10–6 M. The application of the VAA chemosensor for quantitative analysis of tap water samples was able to detect the S2– anion with a recovery percentage greater than 90%, and for qualitative analysis using paper strips it was able to detect CN– and S2– anions with a color change from colorless to yellow.

Kata Kunci : azina asimetris, kemosensor, anion, paper strips