SINTESIS TURUNAN HIDRAZON DARI VANILIN SEBAGAI SENSOR KOLORIMETRI ANION; SYNTHESIS OF HYDRAZONE DERIVATIVES FROM VANILLIN AS COLORIMETRIC ANION SENSOR

Suharman, Bambang Purwono,

2014 | Disertasi | PROGRAM STUDI S2 ILMU KIMIA

Anion sensor based on hydrazone and azo-hydrazone derivatives from vanillin have been synthesized. The azo compound of 4-hydroxy-3-methoxy-5-(phenylazo)benzaldehyde was produced by diazotation reaction of vanillin (receptor 1). The azo-hydrazone compound 2-methoxy-6-(phenyldiazenyl)-4-(2-(2,4-dinitrophenyl)hydrazone)methyl)phenol (receptor 3) and 2-methoxy-6-(phenyldiazenyl)-4-(2-phenyhydrazone)methyl)phenol ( receptor 4) were synthe-sized by addition-elimination reaction of 4-hydroxy-3-methoxy-5-(phenylazo) benzaldehyde, while 4-((2-(2,4-dinitrophenyl)hydrazone)methyl)-2-methoxy-phenol (receptor 2) was synthesized by addition-elimination reaction of vanillin and 2,4-dinitrophenylhydrazine. Synthesis of azo 4-hydroxy-3-methoxy-5-(phenylazo)benzaldehyde, receptor 2, 3 and 4 resulted in yield 72; 79; 73 and 81% respectively. The test of receptors 2, 3 and 4 as anion sensor were carried out by addition F-, Cl-, Br-, I-, CN-, SO42-, CO32-, CH3COO- and H2PO42- anions. The test results as solvatochromic receptor 2, 3 and 4 showed the differences of ?max value: receptor 2 showed ?max at (DMSO = 400nm; CH3CN = 395 nm, ethanol = 397 nm); receptor 3 showed ?max at (DMSO = 355 nm; CH3CN = 390 nm); receptor 4 showed ?max at (DMSO = 355 nm; CH3CN = 347 nm; acetone = 348 nm; ethanol ; 351nm). The test results as anion sensors showed that receptor 2, 3 and 4 selective to cyanide anion in CH3CN solvent with ?max value 472, 555 and 510. Receptor 3 is more selective as cyanide anion sensor with a limit of detection 1 mM than receptor 2 (7 mM) and receptor 4 (4 mM).

Kata Kunci : vanillin, anion sensors, hydrazone, azo-hydrazone, addition-elimination, limit of detection