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All Journal CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry) Bulletin of Chemical Reaction Engineering & Catalysis Indonesian Journal of Chemistry
Muhamad Abdulkadir Martoprawiro
Inorganic and Physical Chemistry Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung 40132, Indonesia
Chemical Engineering, Chemistry & Bioengineering Chemistry Electrical & Electronics Engineering

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DFT Study on the Reaction Mechanism of Cyclization of 2-Hydroxy Chalcone Catalyzed by Bronsted Acid with M06-2X Functional Suci Zulaikha Hildayani; Muhamad Abdulkadir Martoprawiro; Yana Maolana Syah
Bulletin of Chemical Reaction Engineering & Catalysis 2021: BCREC Volume 16 Issue 4 Year 2021 (December 2021)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.16.4.11487.796-803

Abstract

Flavanones are one of the flavonoid group that has wide variety of applications such as a precursors in drug discovery. In the laboratory, flavanone is often synthesized from chalcone compounds. The conversion of chalcone to flavanone can be catalyzed by bronsted acid. The reaction mechanism for this process is proposed through the Michael addition reaction, however, the energetic details and the rate determining step for this reaction is not certainly known. This research aimed to investigate the reaction mechanism for chalcone-flavanone conversion with the present of bronsted acid as catalyst and also studied the effect of the solvent on the reaction energy profile with computational method. In this study, the modeling of the reaction mechanism for the said reaction was carried out using the DFT computational method with M06-2X functional. The computation was done both in the gas phase and in present of the solvent effect using the PCM models. The results showed that the mechanism of chalcone-flavanone conversion occurred in three steps which are protonation, cyclization, and then tautomerization. Based on these calculations, the rate determining step was the tautomerization reaction, which exhibited the same results with or without the solvent effects. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Density Functional Theory (DFT) and Natural Bond Orbital (NBO) Analysis of Intermolecular Hydrogen Bond Interaction in "Phosphorylated Nata De Coco - Water" Sitti Rahmawati; Cynthia Linaya Radiman; Muhamad Abdulkadir Martoprawiro
Indonesian Journal of Chemistry Vol 18, No 1 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (502.91 KB) | DOI: 10.22146/ijc.25170

Abstract

This study aims to study the conformation, the hydrogen bond network, and the stabilities of all the possible intermolecular interactions in phosphorylated nata de coco membrane with water (NDCF-(H2O)n, n = 1-5). Analysis of natural bond orbital (NBO) was performed to measure the relative strength of the hydrogen bonding interactions, charge transfer, particularly the interactions of n-σ * O-H and to take into account the effect on the stabilities of the molecular structure. All calculation were performed using density functional theory (DFT) method, at B3LYP functional level of theory and 6-311 G** basis set. The charge transfer between the lone pair of a proton acceptor to the anti-bonding orbital of the proton donor provides the substantial to the stabilization of the hydrogen bonds. Interaction between NDCF and (H2O)5 was strongest with the stabilization energy of 37.73 kcal/mol, that indicate the ease of donating lone pair electrons. The contributions of each hydrogen bond to the stability of the complex have been analyzed.
Highest Ionic Conductivity of BIMEVOX (ME = 10% Cu, 10% Ga, 20% Ta): Computational Modeling and Simulation Akram La Kilo; Alberto Costanzo; Daniele Mazza; Muhamad Abdulkadir Martoprawiro; Bambang Prijamboedi; Ismunandar Ismunandar
Indonesian Journal of Chemistry Vol 20, No 3 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (486.073 KB) | DOI: 10.22146/ijc.42635

Abstract

BIMEVOX had the potential to play an important role in solid oxide fuel cell, especially as the electrolyte due to their high ionic conductivity. In this work, oxide ion migrations of γ-Bi2VO5.5 and BIMEVOX were simulated using density function theory (DFT), Mott-Littleton method, and molecular dynamic simulation. In γ-Bi2VO5.5, there were oxygen vacancies at the equatorial position in the vanadate layers. These vacancies could facilitate oxide ions migration. The Enthalpy of the oxide migration for γ-Bi2VO5.5 based on DFT calculation was 0.38 eV, which was in a good agreement with experimental results. The γ-Bi2VO5.5 can be stabilized by partial substitution of V5+ with Cu2+, Ga3+, and Ta5+. Defect simulation results using the Mott-Littleton method showed that the total maximum energies of region II were achieved at concentrations of 10, 10, and 20%, respectively for Cu2+, Ga3+, and Ta5+. The calculated concentration of Cu2+, Ga3+, and Ta5+ were in a good agreement with those of experiment results, where the highest ionic conductivity obtained. The results of the molecular dynamics simulation showed that the activation energies of oxide ion migration in γ-Bi2VO5.5 and BIMEVOX (ME = Cu and Ta) respectively were 0.19, 0.21, and 0.10 eV, close to experimental values.
PENGARUH ADITIF SELULOSA TERHADAP KARAKTERISTIK OKSIDA TIMAH YANG DIPEROLEH MENGGUNAKAN METODE HIDROTERMAL M. Rofif Nurfaizi; Muhamad Abdulkadir Martoprawiro; I Putu Mahendra
CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry) Vol 10 No 1 (2022): Cakra Kimia (Indonesian E-Journal of Applied Chemistry)
Publisher : Graduate Program of Applied Chemistry, Udayana University, Bali-INDONESIA

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Abstract

ABSTRAK: Material semikonduktor SnO2 merupakan oksida logam yang memiliki banyak keunggulan sehingga dapat dimanfaatkan di berbagai bidang seperti fotokatalis, sensor gas, dan bahan baku film transparan. Pada penelitian ini, SnO2 disintesis dengan menggunakan metode hidrotermal. Prekursor yang digunakan adalah SnCl2.2H2O. Tujuan dari penelitian ini adalah mengevaluasi pengaruh penambahan aditif selulosa terhadap karakteristik SnO2 yang diperoleh. Tahapan sintesis SnO2 diawali dengan melarutkan 0,9026 gram SnCl2.2H2O dalam larutan etanol air (1:2 v/v). Selulosa ditambahkan dengan perbandingan massa terhadap Sn (II) masing-masing sebesar 1:1, 2:1 dan 3:1. pH suspensi Sn (II) diatur menjadi 2,6 dengan penambahan NaOH 5 M. Proses hidrotermal dilakukan pada suhu 150°C selama 12 jam. Pengamatan secara kasat mata terhadap hasil sintesis tanpa aditif menunjukkan keberadaan serbuk hitam (SnO). Berbeda dengan hasil sintesis dengan aditif selulosa yang menunjukkan hanya serbuk warna putih kekuningan (SnO2). Perbedaan jenis oksida yang diperoleh pada proses sintesis didukung oleh hasil karakterisasi menggunakan X-ray Difraction. Analisis Scanning Electron Microscope menunjukkan perbedaan morfologi pada oksida timah yang disintesis dengan menggunakan dan tanpa aditif. ABSTRACT: SnO2 semiconductor material is a metal oxide with many advantages, it can be used in various fields such as photocatalysts, gas sensors, and transparent film raw materials. In this study, SnO2 was synthesized using the hydrothermal method, with SnCl2.2H2O as the precursor. The purpose of this study is to evaluate the effect of cellulose additive to the characteristics of the obtained SnO2. The SnO2 synthesis was begun by dissolving 0.9026 grams of SnCl2.2H2O in an aqueous-ethanol solution (2:1 V/V). The tin oxide was prepared in the presence of additives, 1:1, 2:1, and 3:1 with the ratio additives to Sn (II). The pH of the Sn (II) suspension was adjusted to 2.6 with the addition of NaOH 5 M. The hydrothermal process was carried out at 150°C for 12 hours. Observation with the naked eye on the results of the synthesis without additives showed the presence of black powder (SnO). In contrast to the results of the synthesis with cellulose addition which showed only yellowish white powder (SnO2). The different types of oxides obtained in the synthesis process are supported by the results of characterization using x-ray diffraction. Scanning electron microscope analysis showed morphological differences in the synthesized tin oxide with and without additives.
Co-Authors Akram La Kilo Alberto Costanzo Bambang Prijamboedi Cynthia Linaya Radiman Daniele Mazza I Putu Mahendra Ismunandar Ismunandar M. Rofif Nurfaizi Suci Zulaikha Hildayani Yana Maolana Syah