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Catalytic efficacy of metal-based catalysts can be significantly enhanced by doping graphene or its derivatives in the catalytic protocol. In continuation of previous work regarding the catalytic properties of highly-reduced graphene oxide (HRG), graphene-oxide (GO) doped mixed metal oxide-based nanocomposites, herein we report a simple, straightforward and solventless mechanochemical preparation of N-doped graphene (NDG)/mixed metal oxide-based nanocomposites of ZnO–MnCO3 (i.e., ZnO–MnCO3/(X%-NDG)), wherein N-doped graphene (NDG) is employed as a dopant. The nanocomposites were prepared by physical milling of separately fabricated NDG and ZnO–MnCO3 calcined at 300 °C through eco-friendly ball mill procedure. The as-obtained samples were characterized via X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), Raman, Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX) and surface area analysis techniques. To explore the effectiveness of the obtained materials, liquid-phase dehydrogenation of benzyl alcohol (BOH) to benzaldehyde (BH) was chosen as a benchmark reaction using eco-friendly oxidant (O2) without adding any harmful surfactants or additives. During the systematic investigation of reaction, it was revealed that the ZnO–MnCO3/NDG catalyst exhibited very distinct specific-activity (80 mmol/h.g) with a 100% BOH conversion and <99% selectivity towards BH in a very short time. The mechanochemically synthesized NDG-based nanocomposite showed remarkable enhancement in the catalytic performance and increased surface area compared with the catalyst without graphene (i.e., ZnO–MnCO3). Under the optimum catalytic conditions, the catalyst successfully transformed various aromatic, heterocyclic, allylic, primary, secondary and aliphatic alcohols to their respective ketones and aldehydes with high selectively and convertibility without over-oxidation to acids. In addition, the ZnO–MnCO3/NDG was also recycled up to six times with no apparent loss in its efficacy.
Mujeeb Khan; Syed Adil; Mohamed Assal; Abdulrahman Alharthi; Mohammed Shaik; Mufsir Kuniyil; Abdulrahman Al-Warthan; Aslam Khan; Zeeshan Nawaz; Hamid Shaikh; Mohammed Siddiqui. Solventless Mechanochemical Fabrication of ZnO–MnCO3/N-Doped Graphene Nanocomposite: Efficacious and Recoverable Catalyst for Selective Aerobic Dehydrogenation of Alcohols under Alkali-Free Conditions. Catalysts 2021, 11, 760 .
AMA StyleMujeeb Khan, Syed Adil, Mohamed Assal, Abdulrahman Alharthi, Mohammed Shaik, Mufsir Kuniyil, Abdulrahman Al-Warthan, Aslam Khan, Zeeshan Nawaz, Hamid Shaikh, Mohammed Siddiqui. Solventless Mechanochemical Fabrication of ZnO–MnCO3/N-Doped Graphene Nanocomposite: Efficacious and Recoverable Catalyst for Selective Aerobic Dehydrogenation of Alcohols under Alkali-Free Conditions. Catalysts. 2021; 11 (7):760.
Chicago/Turabian StyleMujeeb Khan; Syed Adil; Mohamed Assal; Abdulrahman Alharthi; Mohammed Shaik; Mufsir Kuniyil; Abdulrahman Al-Warthan; Aslam Khan; Zeeshan Nawaz; Hamid Shaikh; Mohammed Siddiqui. 2021. "Solventless Mechanochemical Fabrication of ZnO–MnCO3/N-Doped Graphene Nanocomposite: Efficacious and Recoverable Catalyst for Selective Aerobic Dehydrogenation of Alcohols under Alkali-Free Conditions." Catalysts 11, no. 7: 760.
The conventional physical and chemical synthetic methods for the preparation of metal nanoparticles have disadvantages as they use expensive equipment and hazardous chemicals which limit their applications for biomedical purposes, and are not environment friendly. However, for the synthesis of biocompatible nanomaterials, plant-based techniques are eco-friendly and easy to handle. Herein a simple, single-step biosynthesis of gold nanoparticles using aqueous extracts of Nigella sativa (NSE) and Zingiber officinale (GE) as a reducing and capping agent has been demonstrated. The formation of gold nanoparticles (Au NPs) was confirmed by X-ray diffraction, UV-Vis, and EDS spectroscopies. Spectroscopic and chromatographic analysis of GE and NSE revealed the presence of bioactive phytochemical constituents, such as gingerol, thymoquinone, etc., which successfully conjugated the surface of resulting Au NPs. TEM analysis indicated the formation of smaller-sized, less-aggregated, spherical-shaped Au NPs both in the case of GE (~9 nm) and NSE (~11 nm). To study the effect of the concentration of the extracts on the quality of resulting NPs and their anticancer properties, three different samples of Au NPs were prepared from each extract by varying the concentration of extracts while keeping the amount of precursor constant. In both cases, high-quality, spherical-shaped NPs were obtained, only at a high concentration of the extract, whereas at lower concentrations, larger-sized, irregular-shaped NPs were formed. Furthermore, the as-prepared Au NPs were evaluated for the anticancer properties against two different cell lines including MDA-MB-231 (breast cancer) and HCT 116 (colorectal cancer) cell lines. GE-conjugated Au NPs obtained by using a high concentration of the extract demonstrated superior anticancer properties when compared to NSE-conjugated counterparts.
Alaa Alkhathlan; Hessah Al-Abdulkarim; Merajuddin Khan; Mujeeb Khan; Musaed Alkholief; Aws Alshamsan; Aliyah Almomen; Norah Albekairi; Hamad Alkhathlan; M. Siddiqui. Evaluation of the Anticancer Activity of Phytomolecules Conjugated Gold Nanoparticles Synthesized by Aqueous Extracts of Zingiber officinale (Ginger) and Nigella sativa L. Seeds (Black Cumin). Materials 2021, 14, 3368 .
AMA StyleAlaa Alkhathlan, Hessah Al-Abdulkarim, Merajuddin Khan, Mujeeb Khan, Musaed Alkholief, Aws Alshamsan, Aliyah Almomen, Norah Albekairi, Hamad Alkhathlan, M. Siddiqui. Evaluation of the Anticancer Activity of Phytomolecules Conjugated Gold Nanoparticles Synthesized by Aqueous Extracts of Zingiber officinale (Ginger) and Nigella sativa L. Seeds (Black Cumin). Materials. 2021; 14 (12):3368.
Chicago/Turabian StyleAlaa Alkhathlan; Hessah Al-Abdulkarim; Merajuddin Khan; Mujeeb Khan; Musaed Alkholief; Aws Alshamsan; Aliyah Almomen; Norah Albekairi; Hamad Alkhathlan; M. Siddiqui. 2021. "Evaluation of the Anticancer Activity of Phytomolecules Conjugated Gold Nanoparticles Synthesized by Aqueous Extracts of Zingiber officinale (Ginger) and Nigella sativa L. Seeds (Black Cumin)." Materials 14, no. 12: 3368.
Graphene nanocomposites have gained significant interest in a variety of biological applications due to their unique properties. Herein, we have studied the apoptosis-inducing ability and anticancer properties of functionalized highly reduced graphene oxide (HRG) and gold nanoparticles (Au NPs)-based nanocomposites (AP-HRG-Au). Samples were prepared under facile conditions via simple stirring and ultrasonication. All the samples were tested for their anticancer properties against different human cancer cell lines including lung (A549), liver (HepG2), and breast (MCF-7) cancer cells using doxorubicin as a positive control. In order to enhance the solubility and bioavailability of the sample, HRG was functionalized with 1-aminopyrene (1-AP) as a stabilizing ligand. The ligand also facilitated the homogeneous growth of Au NPs on the surface of HRG by offering chemically specific binding sites. The synthesis of nanocomposites and the surface functionalization of HRG were confirmed by UV–Vis, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The structure and morphology of the as-prepared nanocomposites were established by high-resolution transmission electron microscopy. Because of the functionalization, the AP-HRG-Au nanocomposite exhibited enhanced physical stability and high dispersibility. A comparative anticancer study of pristine HRG, nonfunctionalized HRG-Au, and 1-AP-functionalized AP-HRG-Au nanocomposites revealed the enhanced apoptosis ability of functionalized nanocomposites compared to the nonfunctionalized sample, whereas the pristine HRG did not show any anticancer ability against all tested cell lines. Both HRG-Au and AP-HRG-Au have induced a concentration-dependent reduction in cell viability in all tested cell lines after 48 h of exposure, with a significantly higher response in MCF-7 cells compared to the remaining cells. Therefore, MCF-7 cells were selected to perform detailed investigations using apoptosis assay, cell cycle analysis, and reactive oxygen species measurements. These results suggest that AP-HRG-Au induces enhanced apoptosis in human breast cancer cells.
Syed Farooq Adil; Mohammed Rafi Shaik; Fahd A. Nasr; Ali S. Alqahtani; Mohammad Z. Ahmed; Wajhul Qamar; Mufsir Kuniyil; Adibah Almutairi; Abdulrahman Alwarthan; Mohammed Rafiq H. Siddiqui; Mohammad Rafe Hatshan; Mujeeb Khan. Enhanced Apoptosis by Functionalized Highly Reduced Graphene Oxide and Gold Nanocomposites in MCF-7 Breast Cancer Cells. ACS Omega 2021, 6, 15147 -15155.
AMA StyleSyed Farooq Adil, Mohammed Rafi Shaik, Fahd A. Nasr, Ali S. Alqahtani, Mohammad Z. Ahmed, Wajhul Qamar, Mufsir Kuniyil, Adibah Almutairi, Abdulrahman Alwarthan, Mohammed Rafiq H. Siddiqui, Mohammad Rafe Hatshan, Mujeeb Khan. Enhanced Apoptosis by Functionalized Highly Reduced Graphene Oxide and Gold Nanocomposites in MCF-7 Breast Cancer Cells. ACS Omega. 2021; 6 (23):15147-15155.
Chicago/Turabian StyleSyed Farooq Adil; Mohammed Rafi Shaik; Fahd A. Nasr; Ali S. Alqahtani; Mohammad Z. Ahmed; Wajhul Qamar; Mufsir Kuniyil; Adibah Almutairi; Abdulrahman Alwarthan; Mohammed Rafiq H. Siddiqui; Mohammad Rafe Hatshan; Mujeeb Khan. 2021. "Enhanced Apoptosis by Functionalized Highly Reduced Graphene Oxide and Gold Nanocomposites in MCF-7 Breast Cancer Cells." ACS Omega 6, no. 23: 15147-15155.
Oxidation is an important organic transformation, and several catalysts have been reported for this conversion. In this study, we report the synthesis of mixed metal oxide Cu x Zn y O, which is prepared by a coprecipitation method by varying the molar ratio of Cu and Zn in the catalytic system. The prepared mixed metal oxide Cu x Zn y O was evaluated for catalytic performance for toluene oxidation. Various parameters of the catalytic evaluation were studied in order to ascertain the optimum condition for the best catalytic performance. The results indicate that aging time, calcination temperature, reaction temperature, and feed rate influence catalytic performance. It was found that the catalyst interfaces apparently enhanced catalytic activity for toluene oxidation. The XRD diffractograms reveal the crystalline nature of the mixed metal oxide formed and also confirm the coexistence of hexagonal and monoclinic crystalline phases. The catalyst prepared by aging for 4 h and calcined at 450 °C was found to be the best for the conversion of toluene to benzaldehyde while the reactor temperature was maintained at 250 °C with toluene fed into the reactor at 0.01 mL/min. The catalyst was active for about 13 h.
Khadijah Alharbi; Ali Alsalme; Ahmed Aloumi; Mohammed Siddiqui. Selective Catalytic Oxidation of Toluene to Benzaldehyde: Effect of Aging Time and Calcination Temperature Using CuxZnyO Mixed Metal Oxide Nanoparticles. Catalysts 2021, 11, 354 .
AMA StyleKhadijah Alharbi, Ali Alsalme, Ahmed Aloumi, Mohammed Siddiqui. Selective Catalytic Oxidation of Toluene to Benzaldehyde: Effect of Aging Time and Calcination Temperature Using CuxZnyO Mixed Metal Oxide Nanoparticles. Catalysts. 2021; 11 (3):354.
Chicago/Turabian StyleKhadijah Alharbi; Ali Alsalme; Ahmed Aloumi; Mohammed Siddiqui. 2021. "Selective Catalytic Oxidation of Toluene to Benzaldehyde: Effect of Aging Time and Calcination Temperature Using CuxZnyO Mixed Metal Oxide Nanoparticles." Catalysts 11, no. 3: 354.
Applications of chemical synthetic methods for the preparation of metal nanoparticles involve toxic reagents, which are hazardous to both humans and the environment. On the other hand, ecofriendly plant-based techniques offer rapid, non-toxic, and suitable alternatives to the traditional methods. Herein, we report an eco-friendly method for the preparation of silver nanoparticles (Ag NPs) using two different aqueous extracts of Zingiber officinale (ginger) and Nigella sativa L. seeds (black cumin). Successful preparation of Ag NPs was confirmed by X-ray diffraction, ultraviolet–visible (UV-Vis) spectroscopy, and energy dispersive spectroscopy (EDX). Transmission electron microscopy (TEM) analysis revealed that Nigella sativa L. seed extract (NSE) produced a smaller size of NPs (~8 nm), whereas the ginger extract (GE) led to the formation of slightly larger Ag NPs (~12 nm). In addition, to study the effect of concentration of the extract on the quality of resulting NPs, two different samples were prepared from each extract by increasing the concentrations of the extracts while using a fixed amount of precursor (AgNO3). In both cases, a high concentration of extract delivered less agglomerated and smaller-sized Ag NPs. Furthermore, the antibacterial properties of as-prepared Ag NPs were tested against different bacterial strains. Notably, despite the slightly better quality of Ag NPs obtained from NSE (NSE-Ag), NPs prepared by using GE (GE-Ag) demonstrated superior antibacterial properties. In case of the plant-extract-based synthesis of nanoparticles, it is widely reported that during the preparation, the residual phytomolecules remain on the surface of resulting NPs as stabilizing agents. Therefore, in this case, the high antibacterial properties of GE-Ag can be attributed to the contributing or synergetic effect of residual phytomolecules of GE extract on the surface of Ag NPs, since the aqueous extract of GE has been known to possess higher intrinsic bactericidal properties when compared to the aqueous NSE extract.
Alaa Alkhathlan; Hessah Al-Abdulkarim; Mujeeb Khan; Merajuddin Khan; Abdullah AlDobiy; Musaed Alkholief; Aws Alshamsan; Hamad Alkhathlan; M. Siddiqui. Ecofriendly Synthesis of Silver Nanoparticles Using Aqueous Extracts of Zingiber officinale (Ginger) and Nigella sativa L. Seeds (Black Cumin) and Comparison of Their Antibacterial Potential. Sustainability 2020, 12, 10523 .
AMA StyleAlaa Alkhathlan, Hessah Al-Abdulkarim, Mujeeb Khan, Merajuddin Khan, Abdullah AlDobiy, Musaed Alkholief, Aws Alshamsan, Hamad Alkhathlan, M. Siddiqui. Ecofriendly Synthesis of Silver Nanoparticles Using Aqueous Extracts of Zingiber officinale (Ginger) and Nigella sativa L. Seeds (Black Cumin) and Comparison of Their Antibacterial Potential. Sustainability. 2020; 12 (24):10523.
Chicago/Turabian StyleAlaa Alkhathlan; Hessah Al-Abdulkarim; Mujeeb Khan; Merajuddin Khan; Abdullah AlDobiy; Musaed Alkholief; Aws Alshamsan; Hamad Alkhathlan; M. Siddiqui. 2020. "Ecofriendly Synthesis of Silver Nanoparticles Using Aqueous Extracts of Zingiber officinale (Ginger) and Nigella sativa L. Seeds (Black Cumin) and Comparison of Their Antibacterial Potential." Sustainability 12, no. 24: 10523.
Citronellol is one of the most widely used fragrances for bouquetting purposes and it is a starting material for synthesis of several other terpenoids. Nevertheless, few data have been reported on citronellol selective oxidation. Accordingly, we report our findings on the selective oxidation of citronellol with hydrogen peroxide using a set of titanosilicate catalysts with different morphologies and textural properties—conventional titanium silicalite 1 (TS-1), mesoporous TS-1, layered TS-1 and silica-titania pillared TS-1 and also studying the effect of the solvent used. Epoxidation of C6=C7 double bond was the main primary reaction in this system and trace signals of C5 allylic oxidation products were observed without formation of citronellal. Due to the presence of post-synthesis introduced additional Ti sites, the silica-titania pillared TS-1 (TS-1-PITi) provided the highest conversion among the tested catalysts; nevertheless, citronellol was oxidized over all the studied catalysts including conventional TS-1; therefore, showing that it penetrates even into MFI micropores (0.55 nm in diameter). When using acetonitrile as a solvent, the conversion was proportional to the titanium content of the catalyst. When studying the effect of the solvent, acetonitrile provided the highest epoxide selectivity (55%) while in methanol, 2-propanol and 1,4-dioxane, ring opening reactions caused epoxide decomposition.
Daifallah Aldhayan; Květa Kalíková; Mohammed Rafi Shaik; Mohammed Rafiq H. Siddiqui; Jan Přech. Selective Oxidation of Citronellol over Titanosilicate Catalysts. Catalysts 2020, 10, 1284 .
AMA StyleDaifallah Aldhayan, Květa Kalíková, Mohammed Rafi Shaik, Mohammed Rafiq H. Siddiqui, Jan Přech. Selective Oxidation of Citronellol over Titanosilicate Catalysts. Catalysts. 2020; 10 (11):1284.
Chicago/Turabian StyleDaifallah Aldhayan; Květa Kalíková; Mohammed Rafi Shaik; Mohammed Rafiq H. Siddiqui; Jan Přech. 2020. "Selective Oxidation of Citronellol over Titanosilicate Catalysts." Catalysts 10, no. 11: 1284.
The newly synthesized dinuclear uranyl salen coordination compound showed excellent photocatalytic reduction of CO2 to methanol.
Mohammad Azam; Umesh Kumar; Joshua O. Olowoyo; Saud I. Al-Resayes; Agata Trzesowska-Kruszynska; Rafal Kruszynski; Mohammadd Shahidul Islam; Mohammad Rizwan Khan; Syed Farooq Adil; Mohammad Rafique Siddiqui; Fahad Ahmed Al-Harthi; Abdul Karim Alinzi; Saikh Mohammad Wabaidur; Masoom Raza Siddiqui; Mohammed Rafi Shaik; Suman L. Jain; M. Amin Farkhondehfal; Simelys Hernàndez. Dinuclear uranium(vi) salen coordination compound: an efficient visible-light-active catalyst for selective reduction of CO2 to methanol. Dalton Transactions 2020, 49, 17243 -17251.
AMA StyleMohammad Azam, Umesh Kumar, Joshua O. Olowoyo, Saud I. Al-Resayes, Agata Trzesowska-Kruszynska, Rafal Kruszynski, Mohammadd Shahidul Islam, Mohammad Rizwan Khan, Syed Farooq Adil, Mohammad Rafique Siddiqui, Fahad Ahmed Al-Harthi, Abdul Karim Alinzi, Saikh Mohammad Wabaidur, Masoom Raza Siddiqui, Mohammed Rafi Shaik, Suman L. Jain, M. Amin Farkhondehfal, Simelys Hernàndez. Dinuclear uranium(vi) salen coordination compound: an efficient visible-light-active catalyst for selective reduction of CO2 to methanol. Dalton Transactions. 2020; 49 (47):17243-17251.
Chicago/Turabian StyleMohammad Azam; Umesh Kumar; Joshua O. Olowoyo; Saud I. Al-Resayes; Agata Trzesowska-Kruszynska; Rafal Kruszynski; Mohammadd Shahidul Islam; Mohammad Rizwan Khan; Syed Farooq Adil; Mohammad Rafique Siddiqui; Fahad Ahmed Al-Harthi; Abdul Karim Alinzi; Saikh Mohammad Wabaidur; Masoom Raza Siddiqui; Mohammed Rafi Shaik; Suman L. Jain; M. Amin Farkhondehfal; Simelys Hernàndez. 2020. "Dinuclear uranium(vi) salen coordination compound: an efficient visible-light-active catalyst for selective reduction of CO2 to methanol." Dalton Transactions 49, no. 47: 17243-17251.
Catalysts of 10% Ni, supported on promoted alumina, were used to accomplish the partial oxidation of methane. The alumina support was doped with oxides of Mo, Mg, Ti and Y. An incipient wetness impregnation technique was used to synthesize the catalysts. The physicochemical properties of the catalysts were described by XRD, H2-TPR (temperature programmed reduction), BET, TGA, CO2-TPD (temperature-programmed desorption) and Raman. The characterization results denoted that Ni has a strong interaction with the support. The TGA investigation of spent catalysts displayed the anticoking enhancement of the promoters. The impact of the support promoters on the catalyst stability, methane conversion and H2 yield was inspected. Stability tests were done for 460 min. The H2 yields were 76 and 60% and the CH4 conversions were 67 and 92%, respectively, over Ni/Al2O3+Mg, when the reaction temperatures were 550 and 650 °C, respectively. The performance of the present work was compared to relevant findings in the literature.
Ahmed A. Ibrahim; Wasim U. Khan; Fahad Al-Mubaddel; Ahmed S. Al-Fatesh; Samsudeen O. Kasim; Sofiu L. Mahmud; Ateyah A. Al-Zahrani; M. Rafiq H. Siddiqui; Anis H. Fakeeha. Study of Partial Oxidation of Methane by Ni/Al2O3 Catalyst: Effect of Support Oxides of Mg, Mo, Ti and Y as Promoters. Molecules 2020, 25, 5029 .
AMA StyleAhmed A. Ibrahim, Wasim U. Khan, Fahad Al-Mubaddel, Ahmed S. Al-Fatesh, Samsudeen O. Kasim, Sofiu L. Mahmud, Ateyah A. Al-Zahrani, M. Rafiq H. Siddiqui, Anis H. Fakeeha. Study of Partial Oxidation of Methane by Ni/Al2O3 Catalyst: Effect of Support Oxides of Mg, Mo, Ti and Y as Promoters. Molecules. 2020; 25 (21):5029.
Chicago/Turabian StyleAhmed A. Ibrahim; Wasim U. Khan; Fahad Al-Mubaddel; Ahmed S. Al-Fatesh; Samsudeen O. Kasim; Sofiu L. Mahmud; Ateyah A. Al-Zahrani; M. Rafiq H. Siddiqui; Anis H. Fakeeha. 2020. "Study of Partial Oxidation of Methane by Ni/Al2O3 Catalyst: Effect of Support Oxides of Mg, Mo, Ti and Y as Promoters." Molecules 25, no. 21: 5029.
In recent years, the development of green mechanochemical processes for the synthesis of new catalysts with higher catalytic efficacy and selectivity has received manifest interest. In continuation of our previous study, in which graphene oxide (GRO) and highly reduced graphene oxide (HRG) based nanocomposites were prepared and assessed, herein, we have explored a facile and solvent-less mechanochemical approach for the synthesis of N-doped graphene (NDG)/mixed metal oxide (MnCO3–ZrO2) ((X%)NDG/MnCO3–ZrO2), as the (X%)NDG/MnCO3–ZrO2 nano-composite was synthesized using physical grinding of separately synthesized NDG and pre-calcined (300 °C) MnCO3–ZrO2 via green milling method. The structures of the prepared materials were characterized in detail using X-ray powder diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-Ray Analysis (EDX), Fourier-transform infrared spectroscopy (FTIR), Raman, Thermogravimetric analysis (TGA), and N2 adsorption-desorption isotherm analysis. Besides, the obtained nanocomposites were employed as heterogeneous oxidation catalyst for the alcohol oxidation using green oxidant O2 without involving any surfactants or bases. The reaction factors were systematically studied during the oxidation of benzyl alcohol (PhCH2OH) as the model reactant to benzaldehyde (PhCHO). The NDG/MnCO3–ZrO2 exhibits premium specific activity (66.7 mmol·g−1·h−1) with 100% conversion of PhCH2OH and > 99.9% selectivity to PhCHO after only 6 min. The mechanochemically prepared NDG based nanocomposite exhibited notable improvement in the catalytic efficacy as well as the surface area compared to the pristine MnCO3–ZrO2. Under the optimal circumstances, the NDG/MnCO3–ZrO2 catalyst could selectively catalyze the aerobic oxidation of a broad array of alcohols to carbonyls with full convertibility without over-oxidized side products like acids. The NDG/MnCO3–ZrO2 catalyst were efficiently reused for six subsequent recycling reactions with a marginal decline in performance and selectivity.
Mufsir Kuniyil; J. V. Shanmukha Kumar; Syed Farooq Adil; Mohamed E. Assal; Mohammed Rafi Shaik; Mujeeb Khan; Abdulrahman Al-Warthan; Mohammed Rafiq H. Siddiqui; Aslam Khan; Muhammad Bilal; Hafiz M. N. Iqbal; Waheed A. Al-Masry. Eco-Friendly and Solvent-Less Mechanochemical Synthesis of ZrO2–MnCO3/N-Doped Graphene Nanocomposites: A Highly Efficacious Catalyst for Base-Free Aerobic Oxidation of Various Types of Alcohols. Catalysts 2020, 10, 1136 .
AMA StyleMufsir Kuniyil, J. V. Shanmukha Kumar, Syed Farooq Adil, Mohamed E. Assal, Mohammed Rafi Shaik, Mujeeb Khan, Abdulrahman Al-Warthan, Mohammed Rafiq H. Siddiqui, Aslam Khan, Muhammad Bilal, Hafiz M. N. Iqbal, Waheed A. Al-Masry. Eco-Friendly and Solvent-Less Mechanochemical Synthesis of ZrO2–MnCO3/N-Doped Graphene Nanocomposites: A Highly Efficacious Catalyst for Base-Free Aerobic Oxidation of Various Types of Alcohols. Catalysts. 2020; 10 (10):1136.
Chicago/Turabian StyleMufsir Kuniyil; J. V. Shanmukha Kumar; Syed Farooq Adil; Mohamed E. Assal; Mohammed Rafi Shaik; Mujeeb Khan; Abdulrahman Al-Warthan; Mohammed Rafiq H. Siddiqui; Aslam Khan; Muhammad Bilal; Hafiz M. N. Iqbal; Waheed A. Al-Masry. 2020. "Eco-Friendly and Solvent-Less Mechanochemical Synthesis of ZrO2–MnCO3/N-Doped Graphene Nanocomposites: A Highly Efficacious Catalyst for Base-Free Aerobic Oxidation of Various Types of Alcohols." Catalysts 10, no. 10: 1136.
Plant extract of Pulicaria undulata (L.) was used as both reducing agent and stabilizing ligand for the rapid and green synthesis of gold (Au), silver (Ag), and gold–silver (Au–Ag) bimetallic (phase segregated/alloy) nanoparticles (NPs). These nanoparticles with different morphologies were prepared in two hours by stirring corresponding metal precursors in the aqueous solution of the plant extracts at ambient temperature. To infer the role of concentration of plant extract on the composition and morphology of NPs, we designed two different sets of experiments, namely (i) low concentration (LC) and (ii) high concentration (HC) of plant extract. In the case of using low concentration of the plant extract, irregular shaped Au, Ag, or phase segregated Au–Ag bimetallic NPs were obtained, whereas the use of higher concentrations of the plant extract resulted in the formation of spherical Au, Ag, and Au–Ag alloy NPs. The as-prepared Au, Ag, and Au–Ag bimetallic NPs showed morphology and composition dependent catalytic activity for the reduction of 4-nitrophenol (4-NPh) to 4-aminophenol (4-APh) in the presence of NaBH4. The bimetallic Au–Ag alloy NPs showed the highest catalytic activity compared to all other NPs.
Merajuddin Khan; Khaleel Al-Hamoud; Zainab Liaqat; Mohammed Rafi Shaik; Syed Farooq Adil; Mufsir Kuniyil; Hamad Z. Alkhathlan; Abdulrahman Al-Warthan; Mohammed Rafiq H. Siddiqui; Mihail Mondeshki; Wolfgang Tremel; Mujeeb Khan; Muhammad Nawaz Tahir. Synthesis of Au, Ag, and Au–Ag Bimetallic Nanoparticles Using Pulicaria undulata Extract and Their Catalytic Activity for the Reduction of 4-Nitrophenol. Nanomaterials 2020, 10, 1885 .
AMA StyleMerajuddin Khan, Khaleel Al-Hamoud, Zainab Liaqat, Mohammed Rafi Shaik, Syed Farooq Adil, Mufsir Kuniyil, Hamad Z. Alkhathlan, Abdulrahman Al-Warthan, Mohammed Rafiq H. Siddiqui, Mihail Mondeshki, Wolfgang Tremel, Mujeeb Khan, Muhammad Nawaz Tahir. Synthesis of Au, Ag, and Au–Ag Bimetallic Nanoparticles Using Pulicaria undulata Extract and Their Catalytic Activity for the Reduction of 4-Nitrophenol. Nanomaterials. 2020; 10 (9):1885.
Chicago/Turabian StyleMerajuddin Khan; Khaleel Al-Hamoud; Zainab Liaqat; Mohammed Rafi Shaik; Syed Farooq Adil; Mufsir Kuniyil; Hamad Z. Alkhathlan; Abdulrahman Al-Warthan; Mohammed Rafiq H. Siddiqui; Mihail Mondeshki; Wolfgang Tremel; Mujeeb Khan; Muhammad Nawaz Tahir. 2020. "Synthesis of Au, Ag, and Au–Ag Bimetallic Nanoparticles Using Pulicaria undulata Extract and Their Catalytic Activity for the Reduction of 4-Nitrophenol." Nanomaterials 10, no. 9: 1885.
An efficient metal-free domino reaction leading to structural/electronically divergent 1,2-dihydropyridines from easily accessible propargyl vinyl anilines via N-phenyl 3-aza-Cope sigmatropic rearrangement is reported with good to excellent yields using 1,2-dichlorobenzene as solvent under thermal conditions. Spirocyclic substitution is also tolerated under the present optimized conditions.
Osamah Alduhaish; Ravi Varala; Syed Farooq Adil; Mujeeb Khan; Mohammed Rafiq H. Siddiqui; Abdulrhman Alwarthan; M. Mujahid Alam. Synthesis of 1,2-Dihydro-Substituted Aniline Analogues Involving N-Phenyl-3-aza-Cope Rearrangement Using a Metal-Free Catalytic Approach. Journal of Chemistry 2020, 2020, 1 -8.
AMA StyleOsamah Alduhaish, Ravi Varala, Syed Farooq Adil, Mujeeb Khan, Mohammed Rafiq H. Siddiqui, Abdulrhman Alwarthan, M. Mujahid Alam. Synthesis of 1,2-Dihydro-Substituted Aniline Analogues Involving N-Phenyl-3-aza-Cope Rearrangement Using a Metal-Free Catalytic Approach. Journal of Chemistry. 2020; 2020 ():1-8.
Chicago/Turabian StyleOsamah Alduhaish; Ravi Varala; Syed Farooq Adil; Mujeeb Khan; Mohammed Rafiq H. Siddiqui; Abdulrhman Alwarthan; M. Mujahid Alam. 2020. "Synthesis of 1,2-Dihydro-Substituted Aniline Analogues Involving N-Phenyl-3-aza-Cope Rearrangement Using a Metal-Free Catalytic Approach." Journal of Chemistry 2020, no. : 1-8.
CoxOy–manganese carbonate (X%)(CoxOy–MnCO3 catalysts (X = 1–7)) were synthesized via a straightforward co-precipitation strategy followed by calcination at 300 °C. Upon calcination at 500 °C, these were transformed to CoxOy–dimanganese trioxide i.e., (X%)CoxOy–Mn2O3. A relative catalytic evaluation was conducted to compare the catalytic efficiency of the two prepared catalysts for aerial oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) using O2 molecule as a clean oxidant without utilizing any additives or alkalis. Amongst the different percentages of doping with CoxOy (0–7% wt./wt.) on MnCO3 support, the (1%)CoxOy–MnCO3 catalyst exhibited the highest catalytic activity. The influence of catalyst loading, calcination temperature, reaction time, and temperature and catalyst dosage was thoroughly assessed to find the optimum conditions of oxidation of benzyl alcohol (BzOH) for getting the highest catalytic efficiency. The (1%)CoxOy–MnCO3 catalyst which calcined at 300 °C displayed the best effectiveness and possessed the largest specific surface area i.e., 108.4 m2/g, which suggested that the calcination process and specific surface area play a vital role in this transformation. A 100% conversion of BzOH along with BzH selectivity >99% was achieved after just 20 min. Notably, the attained specific activity was found to be considerably larger than the previously-reported cobalt-containing catalysts for this transformation. The scope of this oxidation reaction was expanded to various alcohols containing aromatic, aliphatic, allylic, and heterocyclic alcohols without any further oxidation i.e., carboxylic acid formation. The scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET) specific surface area analytical techniques were used to characterize the prepared catalysts. The obtained catalyst could be easily regenerated and reused for six consecutive runs without substantial decline in its efficiency.
Osamah Alduhaish; Syed Farooq Adil; Mohamed E. Assal; Mohammed Rafi Shaik; Mufsir Kuniyil; Khalid M. Manqari; Doumbia Sekou; Mujeeb Khan; Aslam Khan; Ahmed Z. Dewidar; Abdulrahman Al-Warthan; Mohammed Rafiq H. Siddiqui. Synthesis and Characterization of CoxOy–MnCO3 and CoxOy–Mn2O3 Catalysts: A Comparative Catalytic Assessment Towards the Aerial Oxidation of Various Kinds of Alcohols. Processes 2020, 8, 910 .
AMA StyleOsamah Alduhaish, Syed Farooq Adil, Mohamed E. Assal, Mohammed Rafi Shaik, Mufsir Kuniyil, Khalid M. Manqari, Doumbia Sekou, Mujeeb Khan, Aslam Khan, Ahmed Z. Dewidar, Abdulrahman Al-Warthan, Mohammed Rafiq H. Siddiqui. Synthesis and Characterization of CoxOy–MnCO3 and CoxOy–Mn2O3 Catalysts: A Comparative Catalytic Assessment Towards the Aerial Oxidation of Various Kinds of Alcohols. Processes. 2020; 8 (8):910.
Chicago/Turabian StyleOsamah Alduhaish; Syed Farooq Adil; Mohamed E. Assal; Mohammed Rafi Shaik; Mufsir Kuniyil; Khalid M. Manqari; Doumbia Sekou; Mujeeb Khan; Aslam Khan; Ahmed Z. Dewidar; Abdulrahman Al-Warthan; Mohammed Rafiq H. Siddiqui. 2020. "Synthesis and Characterization of CoxOy–MnCO3 and CoxOy–Mn2O3 Catalysts: A Comparative Catalytic Assessment Towards the Aerial Oxidation of Various Kinds of Alcohols." Processes 8, no. 8: 910.
In this study, we reported the eco-friendly fabrication of Ag2O–MnO2/GRO nanocomposites by the solid-state mixing of separately prepared GRO and Ag2O–MnO2 NPs using ball milling method, a mechanochemical approach. The prepared material was studied for the catalytic effect of GRO in the system for the aerial oxidation of a variety of alcohols. It was found that the (1%)Ag2O–MnO2/(5 wt.%)GRO nanocatalyst demonstrated a high conversion ability (~100%) and excellent selectivity in the presence of O2 as a clean oxidant. The higher catalytic properties of the nanocomposite were attributed to the presence of GRO, which exhibited extraordinary catalytic properties like improved surface area, excellent chemical compatibility, and stability, as well as the introduction of several defects in the obtained nanocomposite that enhance the catalytic performance. The specific activity of 13.3 mmol·g−1·h−1 is obtained for the catalyst i.e. (1%)Ag2O–MnO2/(5 wt.%)GRO, which is reportedly superior to the various other catalysts previously reported in the literature for the same conversion reaction. Our catalytic strategy was highly selective, producing only desired products with no over-oxygenation to carboxylic acids. The merits of our catalytic methodology were: (a) facile process, (b) inexpensive and clean oxidant, (c) no surfactants or nitrogenous bases were required, (d) mild catalytic conditions, (e) cost-effective recoverable catalyst, (f) complete convertibility, (g) full selectivity, (h) rapid process, and (i) applicable to virtually all types of alcohols. So, these highlights made this catalytic strategy to be highly applicable in the industrial applications for manufacturing of carbonyls. To the best of our knowledge, this was the first study of utilizing Ag2O–MnO2/GRO composite as a catalyst for the oxidation of alcohols, highlighting the catalytic efficiency of GRO.
Syed Adil; Mujeeb Khan; Mohammed Rafi Shaik; Mufsir Kuniyil; M Rafiq Siddiqui; Abdulrahman Alwarthan. Ag2O–MnO2/Graphene Oxide Nanocomposite. 2020, 1 .
AMA StyleSyed Adil, Mujeeb Khan, Mohammed Rafi Shaik, Mufsir Kuniyil, M Rafiq Siddiqui, Abdulrahman Alwarthan. Ag2O–MnO2/Graphene Oxide Nanocomposite. . 2020; ():1.
Chicago/Turabian StyleSyed Adil; Mujeeb Khan; Mohammed Rafi Shaik; Mufsir Kuniyil; M Rafiq Siddiqui; Abdulrahman Alwarthan. 2020. "Ag2O–MnO2/Graphene Oxide Nanocomposite." , no. : 1.
Graphene–metal nanocomposites have been found to remarkably enhance the catalytic performance of metal nanoparticle‐based catalysts. In continuation of our previous report, in which highly reduced graphene oxide (HRG)‐based nanocomposites were synthesized and evaluated, we present nanocomposites of graphene oxide (GRO) and ZnO nanoparticle‐doped MnCO3 ([ZnO–MnCO3/(1%)GRO]) synthesized via a facile, straightforward co‐precipitation technique. Interestingly, it was noticed that the incorporation of GRO in the catalytic system could noticeably improve the catalytic efficiency compared to a catalyst (ZnO–MnCO3) without GRO, for aerial oxidation of benzyl alcohol (BzOH) employing O2 as a nature‐friendly oxidant under base‐free conditions. The impacts of various reaction factors were thoroughly explored to optimize reaction conditions using oxidation of BzOH to benzaldehyde (BzH) as a model substrate. The catalysts were characterized using X‐ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, field‐emission scanning electron microscopy, Energy dispersive X‐ray spectroscopy (EDX), Brunauer‐Emmett‐Teller (BET), and Raman spectroscopy. The (1%)ZnO–MnCO3/(1%)GRO exhibited significant specific activity (67 mmol.g−1.hr−1) with full convversion of BzOH and >99% BzH selectivity within just 6 min. The catalytic efficiency of the (1%)ZnO–MnCO3/(1%)GRO nanocomposite was significantly better than the (1%)ZnO–MnCO3/(1%)HRG and (1%)ZnO–MnCO3 catalysts, presumably due to the existence of oxygen‐possessing groups on the GRO surface and as well as a very high surface area that could have been instrumental in uniformly dispersing the active sites of the catalyst, i.e., ZnO–MnCO3. Under optimum circumstances, various kinds of alcohols were selectively transformed to respective carbonyls with full convertibility over the (1%)ZnO–MnCO3/(1%)GRO catalyst. Furthermore, the highly effective (1%)ZnO–MnCO3/(1%)GRO catalyst could be successfully reused and recycled over five consecutive runs with a marginal reduction in its performance and selectivity.
Syed Farooq Adil; Mohamed E. Assal; Mohammed Rafi Shaik; Mufsir Kuniyil; Azhar Hashmi; Mujeeb Khan; Aslam Khan; Muhammad Nawaz Tahir; Abdulrahman Al‐Warthan; Mohammed Rafiq H. Siddiqui. Efficient aerial oxidation of different types of alcohols using ZnO nanoparticle–MnCO 3 ‐graphene oxide composites. Applied Organometallic Chemistry 2020, 34, 1 .
AMA StyleSyed Farooq Adil, Mohamed E. Assal, Mohammed Rafi Shaik, Mufsir Kuniyil, Azhar Hashmi, Mujeeb Khan, Aslam Khan, Muhammad Nawaz Tahir, Abdulrahman Al‐Warthan, Mohammed Rafiq H. Siddiqui. Efficient aerial oxidation of different types of alcohols using ZnO nanoparticle–MnCO 3 ‐graphene oxide composites. Applied Organometallic Chemistry. 2020; 34 (8):1.
Chicago/Turabian StyleSyed Farooq Adil; Mohamed E. Assal; Mohammed Rafi Shaik; Mufsir Kuniyil; Azhar Hashmi; Mujeeb Khan; Aslam Khan; Muhammad Nawaz Tahir; Abdulrahman Al‐Warthan; Mohammed Rafiq H. Siddiqui. 2020. "Efficient aerial oxidation of different types of alcohols using ZnO nanoparticle–MnCO 3 ‐graphene oxide composites." Applied Organometallic Chemistry 34, no. 8: 1.
A series of 3-aryl indazoles and 1-methyl-3-aryl indazole derivatives are prepared with exceptional yields by coupling with several arylboronic acids and methylation by two dissimilar approaches. The as-prepared indazole derivatives (3a–3j) and their N-methyl derivatives (5a–5j) are evaluated for in vitro anticancer activity against two cancer cell lines, HCT-116 and MDA-MB-231. The results reveal that the indazole derivatives tested display mild to moderate anticancer activities against the cell lines tested.
Jagan Mohana Rao Saketi; S. N. Murthy Boddapati; Raghuram M.; Syed Farooq Adil; Mohammed Rafi Shaik; Osamah Alduhaish; Mohammed Rafiq H. Siddiqui; Hari Babu Bollikolla. Pd(PPh3)4 Catalyzed Synthesis of Indazole Derivatives as Potent Anticancer Drug. Applied Sciences 2020, 10, 3792 .
AMA StyleJagan Mohana Rao Saketi, S. N. Murthy Boddapati, Raghuram M., Syed Farooq Adil, Mohammed Rafi Shaik, Osamah Alduhaish, Mohammed Rafiq H. Siddiqui, Hari Babu Bollikolla. Pd(PPh3)4 Catalyzed Synthesis of Indazole Derivatives as Potent Anticancer Drug. Applied Sciences. 2020; 10 (11):3792.
Chicago/Turabian StyleJagan Mohana Rao Saketi; S. N. Murthy Boddapati; Raghuram M.; Syed Farooq Adil; Mohammed Rafi Shaik; Osamah Alduhaish; Mohammed Rafiq H. Siddiqui; Hari Babu Bollikolla. 2020. "Pd(PPh3)4 Catalyzed Synthesis of Indazole Derivatives as Potent Anticancer Drug." Applied Sciences 10, no. 11: 3792.
Bee pollens are rich source of essential amino acids and are often considered as complete food for human beings. Herein, we exploited the potential reducing abilities of Bee pollens extract for the eco-friendly preparation of silver nanoparticles (AgNPs-G). The resulting NPs were characterized using a combination of microscopic and spectroscopic techniques. The analyses confirm the formation of spherical Ag NPs. AgNPs-G obtained from the aqueous extract of bee pollens was used to study their antibacterial properties against Gram-positive and Gram-negative microbes using the Minimum Inhibitory Concentration 50 (MIC50) method. The antibacterial properties of AgNPs-G were compared to the properties of chemically synthesized Ag NPs (AgNPs-C) using sodium borohydride as a reducing agent. The green synthesized nanoparticles (AgNPs-G) exhibited a better antibacterial activity against most of the studied strains when compared to the chemically synthesized Ag NPs (AgNPs-C). In addition, the anti-cancer activity of Ag NPs was also studied against human liver and breast carcinoma cell lines by applying MTT-assay. The Ag NPs demonstrated considerable anticancer activity against the studied cell lines and exhibited high IC50 values in both MCF-7 and HepG2 cell lines.
Hanan M. Al-Yousef; Musarat Amina; Ali S. Alqahtani; Mohammed S. Alqahtani; Abdul Malik; Mohammad Rafe Hatshan; Mohammed Rafiq H. Siddiqui; Mujeeb Khan; Mohammed Rafi Shaik; Mohammad Shamsul Ola; Rabbani Syed. Pollen Bee Aqueous Extract-Based Synthesis of Silver Nanoparticles and Evaluation of Their Anti-Cancer and Anti-Bacterial Activities. Processes 2020, 8, 524 .
AMA StyleHanan M. Al-Yousef, Musarat Amina, Ali S. Alqahtani, Mohammed S. Alqahtani, Abdul Malik, Mohammad Rafe Hatshan, Mohammed Rafiq H. Siddiqui, Mujeeb Khan, Mohammed Rafi Shaik, Mohammad Shamsul Ola, Rabbani Syed. Pollen Bee Aqueous Extract-Based Synthesis of Silver Nanoparticles and Evaluation of Their Anti-Cancer and Anti-Bacterial Activities. Processes. 2020; 8 (5):524.
Chicago/Turabian StyleHanan M. Al-Yousef; Musarat Amina; Ali S. Alqahtani; Mohammed S. Alqahtani; Abdul Malik; Mohammad Rafe Hatshan; Mohammed Rafiq H. Siddiqui; Mujeeb Khan; Mohammed Rafi Shaik; Mohammad Shamsul Ola; Rabbani Syed. 2020. "Pollen Bee Aqueous Extract-Based Synthesis of Silver Nanoparticles and Evaluation of Their Anti-Cancer and Anti-Bacterial Activities." Processes 8, no. 5: 524.
A facile, one-pot, and proficient method was developed for the production of various 2-arylaminobenzimidazoles. This methodology is based for the first time on a copper catalyst promoted domino C–N cross-coupling reaction for the generation of 2-arylaminobenzimidazoles. Mechanistic investigations revealed that the synthetic pathway involves a copper-based desulphurization/nucleophilic substitution and a subsequent domino intra and intermolecular C–N cross-coupling reactions. Some of the issues typically encountered during the synthesis of 2-arylaminobezimidazoles, including the use of expensive catalytic systems and the low reactivity of bromo precursors, were addressed using this newly developed copper-catalyzed method. The reaction procedure is simple, generally with excellent substrate tolerance, and provides good to high yields of the desired products.
S. N. Murthy Boddapati; Ramana Tamminana; Ravi Kumar Gollapudi; Sharmila Nurbasha; Mohamed E. Assal; Osamah Alduhaish; Mohammed Rafiq H. Siddiqui; Hari Babu Bollikolla; Syed Farooq Adil. Copper-Promoted One-Pot Approach: Synthesis of Benzimidazoles. Molecules 2020, 25, 1788 .
AMA StyleS. N. Murthy Boddapati, Ramana Tamminana, Ravi Kumar Gollapudi, Sharmila Nurbasha, Mohamed E. Assal, Osamah Alduhaish, Mohammed Rafiq H. Siddiqui, Hari Babu Bollikolla, Syed Farooq Adil. Copper-Promoted One-Pot Approach: Synthesis of Benzimidazoles. Molecules. 2020; 25 (8):1788.
Chicago/Turabian StyleS. N. Murthy Boddapati; Ramana Tamminana; Ravi Kumar Gollapudi; Sharmila Nurbasha; Mohamed E. Assal; Osamah Alduhaish; Mohammed Rafiq H. Siddiqui; Hari Babu Bollikolla; Syed Farooq Adil. 2020. "Copper-Promoted One-Pot Approach: Synthesis of Benzimidazoles." Molecules 25, no. 8: 1788.
A series of (E)-3-(2-((5-(benzylideneamino)-1,3,4-thiadiazol-2-yl)thio) acetyl)-2H-chromen-2-one and its derivatives (4a-h) have been obtained using a one-pot multicomponent reaction with good yields. The compounds have been synthesized from 3-(2-bromoacetyl)chromen-2-ones (1), 5-amino-1,3,4-thiadiazole-2-thiol (2), and substituted benzaldehydes (3) in anhydrous ethanol and conc. H2SO4. Subsequently, all the synthesized compounds have been screened for their antimicrobial activity and characterized by analytical and spectral data.
Shivanand Merugu; Vijaya Kumar Ponnamaneni; Ravi Varala; Syed Farooq Adil; Mujeeb Khan; Mohammed Rafiq H. Siddiqui; Ravikumar Vemula. Metal-free Catalyzed One-Pot Multicomponent Synthesis of (E)-3-(2-((5-(Benzylideneamino)-1,3,4-thiadiazol-2-yl)thio) Acetyl)-2H-chromen-2-one Derivatives and Their Biological Evaluation. Journal of Chemistry 2020, 2020, 1 -7.
AMA StyleShivanand Merugu, Vijaya Kumar Ponnamaneni, Ravi Varala, Syed Farooq Adil, Mujeeb Khan, Mohammed Rafiq H. Siddiqui, Ravikumar Vemula. Metal-free Catalyzed One-Pot Multicomponent Synthesis of (E)-3-(2-((5-(Benzylideneamino)-1,3,4-thiadiazol-2-yl)thio) Acetyl)-2H-chromen-2-one Derivatives and Their Biological Evaluation. Journal of Chemistry. 2020; 2020 ():1-7.
Chicago/Turabian StyleShivanand Merugu; Vijaya Kumar Ponnamaneni; Ravi Varala; Syed Farooq Adil; Mujeeb Khan; Mohammed Rafiq H. Siddiqui; Ravikumar Vemula. 2020. "Metal-free Catalyzed One-Pot Multicomponent Synthesis of (E)-3-(2-((5-(Benzylideneamino)-1,3,4-thiadiazol-2-yl)thio) Acetyl)-2H-chromen-2-one Derivatives and Their Biological Evaluation." Journal of Chemistry 2020, no. : 1-7.
Herein, different types of metal-containing ionic liquid (IL) complexes and various metal oxide-based nanocatalysts have been successfully prepared (from ionic liquids) and applied for the oxidative desulfurization (ODS) of dibenzothiophene (DBT). The ILs complexes are comprised of N,N′-dialkylimidazolium salts of the type [RMIM-Cl]2[MCln], where [RMIM+] = 1 alkyl-3-methylimidazolium and M = Mn(II)/Fe(II)/Ni(II)/Co(II). These complexes were prepared using an easy synthetic route by refluxing the methanolic solutions of imidazolium chloride and metal chlorides under facile conditions. The as-prepared complexes were further used as precursors during the ionothermal and chemical synthesis of various metal oxide-based nanocatalysts. The resulting ILs salts and metal oxides NPs have been characterized by FT-IR, TGA, XRD, SEM, and TEM analysis. The results indicate that thermal and chemical treatment of ILs based precursor has produced different phases of metal oxide NPs. The calcination produced α-Fe2O3, Mn3O4, and Co3O4, NPs, whereas the chemical treatment of the ILs salts have led to the production of Fe3O4, Mn2O3, and α-Co(OH)2. All the as-prepared salts and metal oxide-based nanocatalysts were used as catalysts towards ODS of dibenzothiophene. The oxidation of dibenzothiophene was performed at atmospheric conditions using hydrogen peroxide as the oxygen donor. Among various catalysts, the thermally obtained metal oxide NPs such as α-Fe2O3, Mn3O4, and Co3O4, have demonstrated relatively superior catalytic activities compared to the other materials. For example, among these nanocatalysts, α-Fe2O3 has exhibited a maximum conversion (∼99%) of dibenzothiophene (DBT) to dibenzothiophene sulfone (DBTO2).
Bader Alenazi; Ali Alsalme; Saad G. Alshammari; Rais Khan; Mohammed Rafiq H. Siddiqui. Ionothermal Synthesis of Metal Oxide-Based Nanocatalysts and Their Application towards the Oxidative Desulfurization of Dibenzothiophene. Journal of Chemistry 2020, 2020, 1 -11.
AMA StyleBader Alenazi, Ali Alsalme, Saad G. Alshammari, Rais Khan, Mohammed Rafiq H. Siddiqui. Ionothermal Synthesis of Metal Oxide-Based Nanocatalysts and Their Application towards the Oxidative Desulfurization of Dibenzothiophene. Journal of Chemistry. 2020; 2020 ():1-11.
Chicago/Turabian StyleBader Alenazi; Ali Alsalme; Saad G. Alshammari; Rais Khan; Mohammed Rafiq H. Siddiqui. 2020. "Ionothermal Synthesis of Metal Oxide-Based Nanocatalysts and Their Application towards the Oxidative Desulfurization of Dibenzothiophene." Journal of Chemistry 2020, no. : 1-11.
Recently, the development of eco-friendly mechanochemical approaches for the preparation of novel catalysts with enhanced activity and selectivity has gained considerable attention. Herein, we developed a rapid and solvent-less mechanochemical method for the preparation of mixed metal oxide (Ag2O–MnO2) decorated graphene oxide (GRO)-based nanocomposites (Ag2O–MnO2/(X wt.%)GRO), as the Ag2O–MnO2/(X wt.%)GRO nanocomposite was fabricated by the physical grinding of freshly prepared GRO and pre-annealed (300 °C) mixed metal oxide nanoparticles (NPs) (Ag2O–MnO2) using an eco-friendly milling procedure. The as-prepared nanocatalysts were characterized by using various techniques. Furthermore, the nanocomposites were applied as a heterogeneous catalyst for the oxidation of alcohol by employing gaseous O2 as an eco-friendly oxidant under base-free conditions. The mechanochemically obtained GRO-based composite exhibited noticeable enhancement in the surface area and catalytic performance compared to the pristine Ag2O–MnO2. The results revealed that (1%)Ag2O–MnO2/(5 wt.%)GRO catalyst exhibited higher specific performance (13.3 mmol·g−1·h−1) with a 100% conversion of benzyl alcohol (BnOH) and >99% selectivity towards benzaldehyde (BnH) within 30 min. The enhancement of the activity and selectivity of GRO-based nanocatalyst was attributed to the presence of various oxygen-containing functional groups, a large number of defects, and a high specific surface area of GRO. In addition, the as-prepared nanocatalyst also demonstrated excellent catalytic activity towards the conversion of a variety of other alcohols to respective carbonyls under optimal conditions. Besides, the catalyst ((1%)Ag2O–MnO2/(5 wt.%)GRO) could be efficiently recycled six times with no noticeable loss in its performance and selectivity.
Syed Farooq Adil; Mohamed E. Assal; Mujeeb Khan; Mohammed Rafi Shaik; Mufsir Kuniyil; Doumbia Sekou; Ahmed Z. Dewidar; Abdulrahman Al-Warthan; Mohammed Rafiq H. Siddiqui. Eco-Friendly Mechanochemical Preparation of Ag2O–MnO2/Graphene Oxide Nanocomposite: An Efficient and Reusable Catalyst for the Base-Free, Aerial Oxidation of Alcohols. Catalysts 2020, 10, 281 .
AMA StyleSyed Farooq Adil, Mohamed E. Assal, Mujeeb Khan, Mohammed Rafi Shaik, Mufsir Kuniyil, Doumbia Sekou, Ahmed Z. Dewidar, Abdulrahman Al-Warthan, Mohammed Rafiq H. Siddiqui. Eco-Friendly Mechanochemical Preparation of Ag2O–MnO2/Graphene Oxide Nanocomposite: An Efficient and Reusable Catalyst for the Base-Free, Aerial Oxidation of Alcohols. Catalysts. 2020; 10 (3):281.
Chicago/Turabian StyleSyed Farooq Adil; Mohamed E. Assal; Mujeeb Khan; Mohammed Rafi Shaik; Mufsir Kuniyil; Doumbia Sekou; Ahmed Z. Dewidar; Abdulrahman Al-Warthan; Mohammed Rafiq H. Siddiqui. 2020. "Eco-Friendly Mechanochemical Preparation of Ag2O–MnO2/Graphene Oxide Nanocomposite: An Efficient and Reusable Catalyst for the Base-Free, Aerial Oxidation of Alcohols." Catalysts 10, no. 3: 281.