PENGARUH GUGUS NITRO PADA SINTESIS TURUNAN SENYAWA AZO DARI VANILIN SEBAGAI SENYAWA INDIKATOR ASAM-BASA DAN SENSOR ANION; THE INFLUENCE OF NITRO GROUP ON SYNTHESIS OF THE AZO COMPOUND DERIVATIVES FROM VANILLIN AS AN ACID-BASE INDICATOR AND ANION SENSORS

Tini Kaimudin, Bambang Purwono

2011 | Disertasi | PROGRAM STUDI S2 KIMIA

It has been researched the influence of nitro group on synthesis of the azo compound derivatives from vanillin 4-hydroxy-3-methoxy-5-(phenyldiazenil) benzaldehyde and 4-hydroxy-3-methoxy-5-(p-nitrophenyldiazenil) benzaldehyde as an indicator of acid-base and anion sensors compounds. Synthesis of 4-hydroxy-3- methoxy-5-(phenyldiazenil) benzaldehyde was carried out by reacting of benzenediazonium chloride salt with vanillin in sodium hydroxide solution and gave 40.28% yield. p-Nitrobenzenediazonium chloride salt reacted with vanillin in sodium hydroxide solution produced 4-hydroxy-3-methoxy-5-(p-nitrophenyldiazenil) benzaldehyde with 56.64% yield. The test results as halochromic and acidichromic compounds showed that the 4-hydroxy-3-methoxy-5-(p-nitrophenyldiazenil) benzaldehyde produced color changes more sharply than 4-hydroxy-3-methoxy-5- (phenyldiazenil) benzaldehyde. The 4-hydroxy-3-methoxy-5-(phenyldiazenil) benzaldehyde and 4-hydroxy-3-methoxy-5-(p-nitrophenyldiazenil) benzaldehyde can be used as an indicator titration of weak acid-strong base. The 4-hydroxy-3-methoxy- 5-(phenyldiazenil) benzaldehyde can also be used as a cyanide anion sensor with a detection limit of 1000 ppm, while 4-hydroxy-3-methoxy-5-(p-nitrophenyldiazenil) benzaldehyde can detect fluoride and cyanide anions with detection limits of 25 ppm and 0.5 ppm respectively.

Kata Kunci : vanilin, gugus nitro, indikator asam-basa, sensor anion, 4-hidroksi-3- metoksi-5-(fenildiazenil)benzaldehida, 4-hidroksi-3-metoksi-5- (p-nitrofenildiazenil)benzaldehida