Risfidian Mohadi
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Sriwijaya University, Kampus UNSRI Indralaya, Jl. Palembang Prabumulih Km 32 Ogan Ilir 30662, South Sumatera

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SINTESIS TRIS-(4-THIOANISIL)OKTILSILAN MELALUI REAKSI KOPLING ., Elfita; ., Eliza; Mohadi, Risfidian; Lesbani, Aldes
CHEMISTRY PROGRESS Vol 6, No 2 (2013)
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35799/cp.6.2.2013.3493

Abstract

Telah dilakukan sintesis tris-(4-thioanisil)oktilsilan (1) melalui reaksi kopling antara oktilsilan dengan 4-iodidathioanisol. Reaksi dilakukan menggunakan katalis paladium dalam kondisi atmosfir inert menggunakan pelarut tetrahidrofuran. Senyawa (1) diperoleh dalam bentuk cairan tak berwarna dengan rendemen 20% mempunyai tujuh puncak 1H NMR, tigabelas puncak 13C NMR dan memiliki nilai m/z 510.Synthesis of tris-(4-thioanisyl)octylsilane (1) by coupling reaction between octylsilane and 4-iodo thioanisole has been done. Reaction was carried out using palladium as catalyst in inert condition and tetrahydrofuran as solvent. Compound (1) was obtained in colorless oil with the yield 20% has seven peaks of 1H NMR, thirteen peaks of 13C NMR and m/z 501.
Catalytic Desulfurization of Benzothiophene Using Keggin Type Polyoxometalates as catalyst Lesbani, Aldes; Marpaung, Arianti; Verawaty, Marieska; Amalia, Hesti Rizki; Mohadi, Risfidian
The Journal of Pure and Applied Chemistry Research Vol 4, No 1 (2015)
Publisher : Chemistry Department, The University of Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (879.702 KB) | DOI: 10.21776/ub.jpacr.2015.004.01.202

Abstract

Performance of catalytic desulfurization of benzothiophen (BT) was studied using polyoxometalates as catalyst. Polyoxometalates H3[a-PW12O40] and  H4[a-SiW12O40], have different heteroatom in Keggin structure and catalytic activities. Polyoxometalates H3[a-PW12O40] and  H4[a-SiW12O40] have high crystallinity with homogeneous distribution particles. Desulfurization of BT using polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40] resulted % conversion up to 99% for 3 h reaction time and at temperature 40 oC. Application of polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40] for crude oil desulfurization showed % conversion of 4-88%. The main functional groups of polyoxometalates still retained after catalytic desulfurization indicated the stability of polyoxometalate compounds
STUDI KINETIKA DAN TERMODINAMIKA ADSORPSI TEMBAGA (II) MENGGUNAKAN ADSORBEN KITIN-SELULOSA HASIL IMPREGNASI Lesbani, Aldes; Agustina, Sherly; Hidayati, Nurlisa; Mohadi, Risfidian
Indonesian Journal of Chemical Science Vol 4 No 1 (2015)
Publisher : Indonesian Journal of Chemical Science

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Abstract

Telah dilakukan proses impregnasi kitin dari cangkang bekicot dan selulosa dari jerami padi menggunakan tiourea sebagai impregnan. Hasil impregnasi dikarakterisasi menggunakan spektrofotometer FTIR yang dibandingkan dengan spektra FTIR kitin maupun selulosa sebelum impregnasi. Selanjutnya hasil impregnasi kitin-selulosa digunakan sebagai adsorben pada adsorpsi tembaga(II). Proses adsorpsi dipelajari melalui parameter kinetika dan termodinamika dan dibandingkan dengan kitin dan selulosa sebelum impregnasi. Hasil penelitian menunjukkan bahwa proses impregnasi berhasil dilakukan yang ditunjukkan adanya bilangan gelombang baik untuk kitin maupun selulosa pada spektra FTIR. Hasil penentuan parameter kinetika menunjukkan proses adsorpsi mengikuti order laju reaksi adsorben hasil impregnasi (0,006 menit-1)  > kitin (0,005 menit-1) > selulosa (0,004 menit-1). Penentuan parameter termodinamika yang diamati dari kapasitas adsorpsi menunjukkan order kapasitas adsorpsi pada adsorben hasil impregnasi (5x10-4 mol/g) > kitin (2,5x10-4 mol/g) > selulosa (0,63x10-4 mol/g).
SINTESIS SATU LANGKAH ARILASI n-BUTIL SILIKA DENGAN ARIL IODIDA Lesbani, Aldes; Mohadi, Risfidian; Eliza, Eliza
Indonesian Journal of Chemical Science Vol 3 No 1 (2014)
Publisher : Indonesian Journal of Chemical Science

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Abstract

Telah disintesis tris(4-thioanisil)n-butil silan (1) dan tris(5-metil 2-thiophen)n-butil silan (2) melalui sintesis satu langkah dalam kondisi inert. Senyawa (1) dan (2) hasil sintesis diisolasi dengan kromatografi kolom menggunakan eluen etil asetat dan dikarakterisasi menggunakan kromatografi gas-spektrometer massa (GC-MS) dan spektrometer NMR 1H dan 13C. Hasil penelitian menunjukkan bahwa senyawa (1) dan (2) hasil sintesis diperoleh sebanyak 25% dan 35%. Hasil pengukuran dengan GC-MS menunjukkan puncak ion molekul m/z untuk senyawa (1) sebesar 454 dan senyawa (2) sebesar 376. Spektra 1H NMR senyawa (1) menunjukkan adanya delapan puncak proton ekivalen dimana senyawa (2) mempunyai tujuh puncak proton ekivalen. Pengukuran dengan 13C NMR menunjukkan baik senyawa (1) maupun (2) memiliki sembilan karbon ekivalen. Spektrum DEPT-135 bersesuaian dengan spektrum 13C NMR dan menunjukkan keberadaan karbon metilen dari gugus alifatik. Secara keseluruhan hasil analisis menunjukkan senyawa (1) dan (2) sesuai dengan struktur senyawa yang diusulkan.
TRIPEL ARILASI ORGANOSILIKA PRIMER DENGAN BEBERAPA ARIL IODIDA MENGGUNAKAN KATALIS PALADIUM Lesbani, Aldes; Mohadi, Risfidian
CHEMISTRY PROGRESS Vol 5, No 2 (2012)
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35799/cp.5.2.2012.768

Abstract

Telah dilakukan tripel arilasi senyawa organosilika primer dengan beberapa aril iodida menggunakan katalis paladium dengan teknik reaksi kopling. Reaksi dilakukan dalam kondisi atmosfir argon dengan 4-diazabicyclo[2,2,2]octane sebagai basa dalam pelarut tetrahidrofuran. Senyawa hasil sintesis yakni tris(5-metil-2-thiopen)fenil silan (1), tris(4-N,N-dimetil anilin) fenil silan (2), dan tris(2-thiopen)fenil silan (3) berhasil disintesis walaupun memilki persentase yield yang rendah yakni 27% untuk senyawa (1), 23% untuk senyawa (2) dan 17% untuk senyawa (3)The triple arylation between primary organosilica and several aryl iodides have been carried out using palladium catalyst by coupling reaction. Reaction was conducted in argon atmospheric with 4-diazabicyclo[2,2,2]octane as a base in tetrahydrofuran as a solvent. The products, which were tris(5-metil-2-thiopen)fenil silan (1), tris(4-N,N-dimetil anilin) fenil silan (2), and tris(2-thiopen)fenil silan (3), were successfully synthesized although with low yield. The yields of (1), (2), and (3) are 27%, 23%, and 17% respectively.
PREPARASI DAN KARAKTERISASI KALSIUM OKSIDA (CAO) DARI TULANG AYAM Susie, Yosine; Lesbani, Aldes; Mohadi, Risfidian
CHEMISTRY PROGRESS Vol 6, No 2 (2013)
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35799/cp.6.2.2013.3498

Abstract

Telah dilakukan preparasi kalsium oksida dari tulang ayam dengan proses dekomposisi selama 3 jam pada variasi temperatur 400oC, 500oC, 700oC, 800oC, 900oC, 1000oC, 1100oC. Karakterisasi CaO hasil dekomposisi dengan XRD menunjukkan pola difraksi CaO pada temperatur dekomposisi 1100°C mendekati difraksi CaO standar (JCPDS) yang memiliki nilai 2?: 34,2º, 37,3º, 58,3º, 64,1º dan 67,3º dengan struktur kristalin. Pita serapan pada spectra FTIR Ca-O dari tulang ayam terlihat pada daerah 354,90 cm-1 yang menunjukkan adanya vibrasi Ca-O hasil dekomposisi, diperkuat dengan munculnya puncak pada gelombang 870 cm-1. Kemudian persentase CaO di dalam sampel dikonfirmasi dengan data EDX yang menunjukkan persentase sebesar 56,28%.Preparation of calcium oxide from chicken bones has been carried out systematically by decomposition for 3 hours at various temperatures i.e. 400, 500, 700, 800, 900, 1000 and 1100 oC. Formation of calcium oxide from decomposition process was characterized using X-Ray diffractometer. The results showed that XRD pattern of materials obtained from decomposition of chicken bones at 1100 oC which has a values of 2?: 32.2º, 37.5º, 58.3º, and 64.1º with a crystalline structure is similar with XRD pattern of calcium oxide standard from Joint Committee on Powder Diffraction Standards (JCPDS) . The absorption bands in the FTIR spectra of the Ca-O shown at 354.90 cm-1 region indicated the presence of Ca-O vibration, reinforced by the emergence of a peak at 870 cm-1. The percentage of 56.28% of CaO in the sample was confirmed by EDX data.
Intercalation Zn/Cr Layered Double Hydroxides with K3[𝛼-PW12O40]nH2O and K4[𝛼-SiW12O40]nH2O as Adsorbent of Rhodamine-B Ramadhan, Jeri; palapa, neza rahayu; Taher, Tarmizi; Lesbani, Aldes; Mohadi, Risfidian
Science and Technology Indonesia Vol 4 No 4 (2019): October
Publisher : ARTS Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2019.4.4.109-114

Abstract

Synthesis of Zn-Cr layered double hydroxide intercalated with polyoxometalate K3[?-PW12O40]nH2O and K4[?- SiW12O40]nH2O was conducted successfully. The characterization of layered double hydroxide intercalated was performed using XRD and FT-IR analyses. After that layered double hydroxide intercalated used as an adsorbent of rhodamine B (RhB) dye. The results show Rhodamine-B (RhB) more effective adsorbed using the Zn-Cr adsorbent K3[?-PW12O40]nH2O than using an intercalated adsorbent K4[?-SiW12O40]nH2O because the distance between the layers is smaller. Study of kinetics showed that the adsorption process is more fits with PSO than PFO based on coefficients correlation. The adsorption process described by Langmuir isotherm models for all adsorbent. The value of enthalpy and entropy shows that the adsorption process was endothermic and negative free energy value was indicated that the process was spontaneous.
Removal of Anionic Direct Dye Using Zn/Al, Zn/Fe and Zn/Cr Layered Double Hydroxides Toward Interlayer Distance Palapa, Neza Rahayu; Taher, Tarmizi; Mohadi, Risfidian; Lesbani, Aldes
Science and Technology Indonesia Vol 4 No 3 (2019): July
Publisher : ARTS Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1299.16 KB) | DOI: 10.26554/sti.2019.4.3.70-76

Abstract

In order to minimize harmful effect of synthetic dye (direct yellow and direct violet) the capacity of Zn/Al, Zn/Cr and Zn/Fe layered double hydroxides of these contaminant was studied in this work. Batch adsorption experiment was conduct to investigate the effect of various operating parameters such as contact time, initial dye concentration and adsorption temperature in order to provide optimal condition in removal synthetic dye. Based on result, the sorption of direct dye onto LDHs followed pseudo-second-order rate model. The equilibrium adsorption data for both direct dye was fitted Freundlich isotherm model
Synthesis and Characterization of Zn/Al, Zn/Fe, and Zn/Cr Layered Double Hydroxides: Effect of M3+ ions Toward Layer Formation Palapa, Neza Rahayu; Saria, Yosi; Taher, Tarmizi; Mohadi, Risfidian; Lesbani, Aldes
Science and Technology Indonesia Vol 4 No 2 (2019): April
Publisher : ARTS Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1267.749 KB) | DOI: 10.26554/sti.2019.4.2.36-39

Abstract

Layered double hydroxides are composed by substitution of metal cation divalent and trivalent. Metal cation divalent and trivalent can be changed. In this work, effect metal cation trivalent (M3+) toward layer formation were studied. Synthesis of LDHs has used co-precipitation methods with molar ratio 3:1 and kept pH at 10. The result of synthesis was characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FT-IR) analyses.
INTERCALATION ZN/CR LAYERED DOUBLE HYDROXIDES WITH K3[𝛼-PW12O40]NH2O AND K4[𝛼-SIW12O40]NH2O AS ADSORBENT OF RHODAMINE-B Ramadhan, Jeri; Palapa, Neza Rahayu; Taher, Tarmizi; Mohadi, Risfidian; Lesbani, Aldes
Science and Technology Indonesia Vol 4 No 4 (2019): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2019.4.4.109-114

Abstract

Synthesis of Zn-Cr layered double hydroxide intercalated with polyoxometalate K3[?-PW12O40]nH2O and K4[?- SiW12O40]nH2O was conducted successfully. The characterization of layered double hydroxide intercalated was performed using XRD and FT-IR analyses. After that layered double hydroxide intercalated used as an adsorbent of rhodamine B (RhB) dye. The results show Rhodamine-B (RhB) more effective adsorbed using the Zn-Cr adsorbent K3[?-PW12O40]nH2O than using an intercalated adsorbent K4[?-SiW12O40]nH2O because the distance between the layers is smaller. Study of kinetics showed that the adsorption process is more fits with PSO than PFO based on coefficients correlation. The adsorption process described by Langmuir isotherm models for all adsorbent. The value of enthalpy and entropy shows that the adsorption process was endothermic and negative free energy value was indicated that the process was spontaneous.