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Dwi Siswanta
Chemistry Department, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta
Chemical Engineering, Chemistry & Bioengineering Chemistry

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SYNTHESIS OF THIOMETHYLATED CALIX[4]RESORCINARENE BASED ON FENNEL OIL VIA CHLOROMETHYLATION Suryadi Budi Utomo; Jumina Jumina; Dwi Siswanta; Mustofa Mustofa; Naresh Kumar
Indonesian Journal of Chemistry Vol 11, No 1 (2011)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (435.978 KB) | DOI: 10.22146/ijc.21411

Abstract

A research has been conducted to synthesize thiomethylated-C-4-methoxyphenylcalix[4]resorcinarene using fennel oil as a starting material. The synthesis was carried out in four steps i.e. (1) oxidation of anethole to yield p-anisaldehyde, (2) HCl-catalyzed condensation of p-anisaldehyde with resorcinol, (3) chloromethylation of C-4-methoxyphenylcalix[4]resorcinarene with paraformaldehyde and HCl in the presence of ZnCl2 to yield tetrakis-chloromethyl-C-4-methoxyphenylcalix[4]resorcinarene, and (4) reaction of tetrakis-chloromethyl-C-4-methoxyphenylcalix[4]resorcinarene with thiourea followed by hydrolysis with sodium hydroxide solution to yield tetrakis-thiomethyl-C-4-methoxyphenylcalix[4]resorcinarene. The prepared compounds were characterized based on melting point, FT-IR, and NMR spectrometers. According to the analysis of 1H-NMR spectrometer, C-4-methoxyphenylcalix[4]resorcinarene and tetrakis-chloromethyl-C-4-methoxyphenylcalix[4]resorcinarene were observed in the chair or flattened partial cone conformation, while tetrakis-thiomethyl-C-4-methoxyphenylcalix[4]resorcinarene tend to exist in the crown or cone conformation.
REDUCTION AND OXIDATION PROCESSES OF CHROMIUM IN HUMIC ACID SUBFRACTION-SENSITIZED PHOTOCATALYST Uripto Trisno Santoso; Herdiansyah Herdiansyah; Sri Juari Santosa; Dwi Siswanta
Indonesian Journal of Chemistry Vol 4, No 3 (2004)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (191.932 KB) | DOI: 10.22146/ijc.21848

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The process of reduction and oxidation of soluble chromium in humic acid subfraction-sensitized photocatalyst was studied. Humic acid was extracted from peat soil sampled in Gambut District, South Kalimantan. Humic acid (HA) was fractionated to humic acid subfraction (HAS) by centrifugation method. ZnO and TiO2 were applied as the photocatalysts produced by Merck, suspended in solution of 2 g/L. Two germicide UV lamps 30 watt (Philip®) was placed in a box at 20 cm above the samples. The results showed that HA or HAS sensitized the photoreduction of Cr(VI) by photocatalyst. The low molecular weight of HAS is more effective to act as sensitizer than the high molecular weight one. The yield of the photoreduction of Cr(VI) with photocatalysts enhanced both in the presence of Fe(II) ion and HAS. UV irradiation of the MnO4- solutions containing Cr(III) induced the photooxidation of Cr(III) to Cr(VI). The presence of Fe(III) or HAS doesn't inhibit significantly. The inhibition is enhanced by the present of both HAS and Fe(II) or HAS and Fe(III). This inhibition is enhanced more by the presence of ZnO or TiO2 photocalysts.
Co-Authors Herdiansyah Herdiansyah Jumina Jumina Mustofa Mustofa Naresh Kumar Sri Juari Santosa Suryadi Budi Utomo Uripto Trisno Santoso