1
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Ywaya DO, Ibrahim H, Friedrich HB, Bala MD, Soobramoney L, Daniels A, Singh M. Chemotherapeutic Activities of New η 6- p-Cymene Ruthenium(II) and Osmium(II) Complexes with Chelating SS and Tridentate SNS Ligands. Molecules 2024; 29:944. [PMID: 38474456 DOI: 10.3390/molecules29050944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/16/2024] [Accepted: 02/17/2024] [Indexed: 03/14/2024] Open
Abstract
A series of new chelating bidentate (SS) alkylimidazole-2-thione-Ru(II)/Os(II) complexes (3ai, 3aii, 3aiii, 3bii/4aiii, 4bi, 4bii), and the tridentate (SNS) pyridine-2,6-diylimidazole-2-thione-Ru(II)/Os(II) complexes (5bi, 5civ/6bi, 6ci, 6civ) in the forms [MII(cym)(L)Cl]PF6 and [MII(cym)(L)]PF6 (M = Ru or Os, cym = η6-p-cymene, and L = heterocyclic derivatives of thiourea) respectively, were successfully synthesized. Spectroscopic and analytical methods were used to characterize the complexes and their ligands. Solid-state single-crystal X-ray diffraction analyses revealed a "piano-stool" geometry around the Ru(II) or Os(II) centers in the respective complexes. The complexes were investigated for in vitro chemotherapeutic activities against human cervical carcinoma (HeLa) and the non-cancerous cell line (Hek293) using the MTT assay. The compounds 3aii, 5civ, 5bi, 4aiii, 6ci, 6civ, and the reference drug, 5-fluorouracil were found to be selective toward the tumor cells; the compounds 3ai, 3aiii, 3bii, 4bi, 4bii, and 6bi, which were found not to be selective between normal and tumor cell lines. The IC50 value of the tridentate half-sandwich complex 5bi (86 ± 9 μM) showed comparable anti-proliferative activity with the referenced commercial anti-cancer drug, 5-fluorouracil (87 ± 15 μM). The pincer (SNS) osmium complexes 6ci (36 ± 10 μM) and 6civ (40 ± 4 μM) were twice as effective as the reference drug 5-fluorouracil at the respective dose concentrations. However, the analogous pincer (SNS) ruthenium complex 5civ was ineffective and did not show anti-proliferative activity, even at a higher concentration of 147 ± 1 μM. These findings imply that the higher stability of the chelating (SS) and the pincer (SNS) ligand architectures in the complexes improves the biological (anti-proliferative) activity of the complexes by reducing the chance of ligand dissociation under physiological conditions. In general, the pincer (SNS) osmium complexes were found to be more cytotoxic than their ruthenium analogues, suggesting that the anti-proliferative activity of the imidazole-2-thione-Ru/Os complexes depends on the ligand's spatial coordination, the nature of the metal center, and the charge of the metal complex ions.
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Affiliation(s)
- David O Ywaya
- School of Chemistry and Physics, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Halliru Ibrahim
- School of Chemistry and Physics, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Holger B Friedrich
- School of Chemistry and Physics, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Muhammad D Bala
- School of Chemistry and Physics, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Lynette Soobramoney
- School of Chemistry and Physics, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Aliscia Daniels
- Nano-Gene and Drug Delivery Group, Discipline of Biochemistry, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Moganavelli Singh
- Nano-Gene and Drug Delivery Group, Discipline of Biochemistry, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
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2
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Damoyi NE, Friedrich HB, Kruger GH, Willock DJ. A DFT study of the catalytic ODH of n-hexane over a cluster model of vanadium oxide. Molecular Catalysis 2023. [DOI: 10.1016/j.mcat.2023.113078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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3
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Anyanwu VO, Friedrich HB, Mahomed AS, Singh S, Moyo T. Phase Transition of High-Surface-Area Glycol-Thermal Synthesized Lanthanum Manganite. Materials (Basel) 2023; 16:1274. [PMID: 36770280 PMCID: PMC9920577 DOI: 10.3390/ma16031274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/28/2022] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
Cubic and rhombohedral phases of lanthanum manganite were synthesized in a high-pressure reactor. A mixture of La and Mn nitrates with ethylene glycol at a synthesis temperature of 200 °C and a calcination temperature of up to 1000 °C, resulted in a single-phase perovskite, LaMnO3 validated using X-ray diffraction. Significant changes in unit cell volumes from 58 to 353 Å3 were observed associated with structural transformation from the cubic to the rhombohedral phase. This was confirmed using structure calculations and resistivity measurements. Transmission electron microscopy analyses showed small particle sizes of approximately 19, 39, 45, and 90 nm (depending on calcination temperature), no agglomeration, and good crystallinity. The particle characteristics, high purity, and high surface area (up to 33.1 m2/g) of the material owed to the inherent PAAR reactor pressure, are suitable for important technological applications, that include the synthesis of perovskite oxides. Characteristics of the synthesized LaMnO3 at different calcination temperatures are compared, and first-principles calculations suggest a geometric optimization of the cubic and rhombohedral perovskite structures.
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Ntola P, Friedrich HB, Singh S, Olivier EJ, Farahani M, Mahomed AS. Effect of the fuel on the surface VOx concentration, speciation and physico-chemical characteristics of solution combustion synthesised VOx/MgO catalysts for n-octane activation. CATAL COMMUN 2022. [DOI: 10.1016/j.catcom.2022.106571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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5
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Farahani MD, Moodley C, Mahomed AS, Friedrich HB. Morphology, oxygen vacancies and other factors affecting the performance of supported bimetallic ceria catalysts. iScience 2022; 25:105560. [DOI: 10.1016/j.isci.2022.105560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 10/20/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
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6
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Gichumbi JM, Zamisa SJ, Friedrich HB. Crystal structure of chlorido-( η
6-toluene)(5,5′-dimethyl-2,2′-bipyridine-κ 2
N, N′)ruthenium(II) hexafluoridophosphate(V) ─ acetone (1/1) C 22H 26ClN 2ORuPF 6. Z KRIST-NEW CRYST ST 2022. [DOI: 10.1515/ncrs-2022-0219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C22H26ClN2ORuPF6, triclinic, P
1
‾
$\overline{1}$
(no. 2), a = 10.2106(4) Å, b = 10.8139(4) Å, c = 11.1963(4) Å, α = 93.765(2)°, β = 90.418(1)°, γ = 94.324(2)°, V = 1229.98(8) Å3, Z = 2, R
gt
(F) = 0.0251, wR
ref
(F
2) = 0.0683, T = 100 K.
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Affiliation(s)
- Joel M. Gichumbi
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville, 4000 , Durban , South Africa
| | - Sizwe J. Zamisa
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville, 4000 , Durban , South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville, 4000 , Durban , South Africa
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7
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Ibrahim H, Bala MD, Friedrich HB. Poly-functional imino-N-heterocyclic carbene ligands: Synthesis, complexation, and catalytic applications. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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8
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Naicker L, Schörner M, Kremitzl D, Friedrich HB, Haumann M, Wasserscheid P. Influencing the Product Distribution in Citral Hydrogenation Using Ionic Liquid Modified Cu Catalysts. ChemCatChem 2022. [DOI: 10.1002/cctc.202200388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Letisha Naicker
- Catalysis Research Group School of Chemistry and Physics University of KwaZulu-Natal Durban 4000 South Africa
| | - Markus Schörner
- Lehrstuhl für Chemische Reaktionstechnik (CRT) Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Egerlandstr. 3 91058 Erlangen Germany
| | - Daniel Kremitzl
- Lehrstuhl für Chemische Reaktionstechnik (CRT) Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Egerlandstr. 3 91058 Erlangen Germany
| | - Holger B. Friedrich
- Catalysis Research Group School of Chemistry and Physics University of KwaZulu-Natal Durban 4000 South Africa
| | - Marco Haumann
- Lehrstuhl für Chemische Reaktionstechnik (CRT) Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Egerlandstr. 3 91058 Erlangen Germany
- Research Centre for Synthesis and Catalysis Department of Chemistry University of Johannesburg P.O. Box 524 Auckland Park 2006 South Africa
| | - Peter Wasserscheid
- Lehrstuhl für Chemische Reaktionstechnik (CRT) Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Egerlandstr. 3 91058 Erlangen Germany
- Forschungszentrum Jülich GmbH Helmholtz-Institut Erlangen-Nürnberg for Renewable Energy (IEK-11) Egerlandstr. 3 91058 Erlangen Germany
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Gichumbi JM, Zamisa SJ, Friedrich HB. Crystal structure of chlorido-( η
6-toluene)(2,2′-bipyridine-κ 2
N, N′)ruthenium(II) hexafluorophosphate, C 17H 16ClN 2RuPF 6. Z KRIST-NEW CRYST ST 2022. [DOI: 10.1515/ncrs-2022-0210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C17H16ClN2RuPF6, monoclinic, P21/c (no. 14), a = 14.4426(9) Å, b = 8.3311(5) Å, c = 16.413(1) Å, β = 109.2690°, V = 1864.2(2) Å3, Z = 4, R
gt
(F) = 0.0309, wR
ref
(F
2) = 0.0697, T = 173 K.
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Affiliation(s)
- Joel M. Gichumbi
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus, Westville, 4000 , Durban , South Africa
| | - Sizwe J. Zamisa
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus, Westville, 4000 , Durban , South Africa
| | - Holger B. Friedrich
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus, Westville, 4000 , Durban , South Africa
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10
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Naicker D, Alapour S, Zamisa SJ, Friedrich HB. New Ru PNP complexes as in situ Ru-oxo precursors in styrene and octane oxidation. J COORD CHEM 2022. [DOI: 10.1080/00958972.2022.2110867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Dunesha Naicker
- Catalysis Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Saba Alapour
- Catalysis Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Sizwe J. Zamisa
- Catalysis Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Holger B. Friedrich
- Catalysis Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
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11
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Chanerika R, Shozi ML, Prato M, Friedrich HB. The effect of organic modifiers on Ag/Al2O3 catalysts for the sequential hydrogenation of 1-octyne vs 1-octene. Molecular Catalysis 2022. [DOI: 10.1016/j.mcat.2022.112344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Ywaya DO, Friedrich HB, Bala MD, Soobramoney L, Ibrahim H. Crystal structure of 3,3′-(pyridine-2,6-diylbis(methylene))bis(1-propyl-1 H-imidazol-3-ium) ditetrafluoroborate, C 19H 27B 2F 8N 5. Z KRIST-NEW CRYST ST 2022. [DOI: 10.1515/ncrs-2022-0078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C19H27N5, orthorhombic Pbca (no. 61), a = 9.8515(12) Å, b = 16.508(2) Å, c = 29.817(3) Å, β = 90°, V = 4849.3(10) Å3, Z = 8, R
gt
(F) = 0.0409, wR
ref(F
2) = 0.1082.
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Affiliation(s)
- David O. Ywaya
- School of Chemistry, University of Kwazulu-Natal , Private Bag X54001 , Durban 4001 , South Africa
| | - Holger B. Friedrich
- School of Chemistry, University of Kwazulu-Natal , Private Bag X54001 , Durban 4001 , South Africa
| | - Muhammad D. Bala
- School of Chemistry, University of Kwazulu-Natal , Private Bag X54001 , Durban 4001 , South Africa
| | - Lynette Soobramoney
- School of Chemistry, University of Kwazulu-Natal , Private Bag X54001 , Durban 4001 , South Africa
| | - Halliru Ibrahim
- School of Chemistry, University of Kwazulu-Natal , Private Bag X54001 , Durban 4001 , South Africa
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13
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Chanerika R, Shozi ML, Friedrich HB. Synthesis and Characterization of Ag/Al 2O 3 Catalysts for the Hydrogenation of 1-Octyne and the Preferential Hydrogenation of 1-Octyne vs 1-Octene. ACS Omega 2022; 7:4026-4040. [PMID: 35155897 PMCID: PMC8829924 DOI: 10.1021/acsomega.1c05231] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/19/2021] [Indexed: 06/14/2023]
Abstract
Catalysts featuring 2, 5, and 10 wt % silver supported on alumina were prepared by the deposition precipitation method and activated under hydrogen. All catalysts were characterized by Brunauer-Emmett-Teller (BET) measurements, inductively coupled plasma-optical emission spectrometry (ICP-OES), backscattered electron scanning electron microscopy (BSE-SEM), high-resolution transmission electron microscopy (HR-TEM), hydrogen-temperature-programmed reduction (H2-TPR), H2-chemisorption, thermogravimetric analysis (TGA), infrared (IR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, and isopropylamine (IPA) TPD and evaluated in a continuous plug flow fixed-bed reactor. Metal nanoparticles with average sizes of 4.5, 11.5, and 21.1 nm were identified by HR-TEM for the 2, 5, and 10 wt % Ag/Al2O3 catalysts, respectively. A conversion of 99% was observed for 1-octyne over particles between 10 and 15 nm in size, with stable operation up to 24 h (decreasing thereafter) at a temperature of 140 °C and a pressure of 30 bar in the competitive hydrogenation reaction. No conversion of 1-octene was noted in competitive reactions (mixed 1-octyne and 1-octene feed) but rather a gain of 1-octene throughout the 72 h time-on-stream. The performance of all catalysts was influenced by both the metal and support, where the latter impacted the overall acidity of the catalysts, thus affecting their long-term stability.
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14
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Shozi ML, Zulu X, Friedrich HB. Synthesis and characterization of amine-functionalized supported phosphine catalysts and their application in ethylene oligomerization. S Afr j chem 2022. [DOI: 10.17159/0379-4350/2022/v76a02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
ABSTRACT A series of phosphorus and nitrogen-based ethylene oligomerization ligands of the type Ph2PN(X)PPh2 where X = i-propyl, n-butyl, ethylbenzene and cyclohexyl substituents are reported. These ligands were functionalized to enable tethering on amino-silica. The free ligands, amino-silica and the tethered ligands were characterized by BET, XRD, IR, TGA and NMR. The catalysts were tested for ethylene oligomerization using Cr(acac)3 (acac = acetylacetonate) as the precursor and MMAO (modified methylaluminoxane) as the activator. The activity and selectivity of these catalysts to 1-octene was monitored at 45 bar ethylene in the temperature range of45-100 °C. The activity of the supported catalysts was comparable to their homogeneous counterparts, surpassing them in some cases and selectivities to 1-octene in the C8 products were as high as 99 wt%. The steric effect of the substituent on the ligand as well as that of the support was found to influence the activity and product distribution. Keywords: 1-hexene, 1-octene, ethylene oligomerization, phosphine ligands, silica, supported catalysts
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15
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Ibrahim H, Zamisa SJ, Bala MD, Friedrich HB. A new polymorph of 1-(4-nitrophenyl)-1H-benzimidazole (C13H9N3O2). Z KRIST-NEW CRYST ST 2021. [DOI: 10.1515/ncrs-2021-0360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C13H9N3O2, monoclinic, P21/c (no. 14), a = 3.7375(1) Å, b = 27.9680(6) Å, c = 10.2595(2) Å, β = 95.5120(10)°, V = 1067.47(4) Å3, Z = 4, R
gt
(F) = 0.0370, wR
ref
(F
2) = 0.0975, T = 100 K.
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Affiliation(s)
- Halliru Ibrahim
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville, 4000 Durban , South Africa
| | - Sizwe J. Zamisa
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville, 4000 Durban , South Africa
| | - Muhammad D. Bala
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville, 4000 Durban , South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville, 4000 Durban , South Africa
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16
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Soobramoney L, Bala MD, Friedrich HB. Flexible pincer backbone revisited: CuSNS complexes as efficient catalysts in paraffin oxidation. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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17
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Naicker L, Valand J, Govender A, Xaba BM, Friedrich HB. Impact of the impregnation sequence on the surface characteristics on Cu-Ag supported on γ-Alumina towards the liquid phase competitive hydrogenation of octanal in the presence of octene. Molecular Catalysis 2021. [DOI: 10.1016/j.mcat.2021.111879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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18
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Singh NK, Soobramoney L, Shozi ML, Friedrich HB, Zamisa SJ. Crystal structure of bis{(2-pyridinyl)-1-phenyl-1-isopropylmethanolato-κ 2
N,O}nickel, C 30H 32N 2NiO 2. Z KRIST-NEW CRYST ST 2021. [DOI: 10.1515/ncrs-2021-0064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C30H32N2NiO2, monoclinic,
P
2
1
/
c
$P{2}_{1}/c$
(no. 14), a = 12.1250(4) Å, b = 13.6413(4) Å, c = 8.1152(3) Å, β = 108.348(2)°, V = 1274.02(7) Å3, Z = 2, R
gt
(F) = 0.0285, wR
ref
(F
2) = 0.0711, T = 100 K.
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Affiliation(s)
- Nijal K. Singh
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville , 4000 Durban , South Africa
| | - Lynette Soobramoney
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville , 4000 Durban , South Africa
| | - Mzamo L. Shozi
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville , 4000 Durban , South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville , 4000 Durban , South Africa
| | - Sizwe J. Zamisa
- School of Chemistry and Physics, University of KwaZulu-Natal , Private Bag X54001, Westville Campus, Westville , 4000 Durban , South Africa
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19
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Buthelezi S, Ibrahim H, Bala MD, Friedrich HB. Crystal structure of 4- tert-butyl-2- N-(2-pyridylmethyl)aminophenol, C 16H 20N 2O. Z KRIST-NEW CRYST ST 2021. [DOI: 10.1515/ncrs-2021-0065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C16H20N2O, monoclinic,
P
2
1
/
c
$P{2}_{1}/c$
(no. 14), a = 9.7933(2) Å, b = 17.5290(3) Å, c = 17.1148(3) Å, β = 101.242(1)°, V = 2881.67(9) Å3, Z = 8, R
gt(F) = 0.0402, wR
ref(F
2) = 0.1106, T = 150(2) K.
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Affiliation(s)
- Sipho Buthelezi
- School of Chemistry and Physics , University of KwaZulu-Natal , Westville Campus, Private Bag X54001 , Durban 4000, South Africa
| | - Halliru Ibrahim
- School of Chemistry and Physics , University of KwaZulu-Natal , Westville Campus, Private Bag X54001 , Durban 4000, South Africa
| | - Muhammad D. Bala
- School of Chemistry and Physics , University of KwaZulu-Natal , Westville Campus, Private Bag X54001 , Durban 4000, South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics , University of KwaZulu-Natal , Westville Campus, Private Bag X54001 , Durban 4000, South Africa
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20
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Ndlela SS, Friedrich HB, Cele MN. Faujasite silicalites for oxidative dehydrogenation of n-octane: Influence of alkali metals, gallium, and boron on catalyst activity. Molecular Catalysis 2021. [DOI: 10.1016/j.mcat.2021.111393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Farahani MD, Fadlalla MI, Ezekiel IP, Osman NSE, Moyo T, Claeys M, Friedrich HB. Nb 2O 5 as a radical modulator during oxidative dehydrogenation and as a Lewis acid promoter in CO 2 assisted dehydrogenation of octane over confined 2D engineered NiO–Nb 2O 5–Al 2O 3. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00550b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Ordered mesoporous 2D NiO–Nb2O5–Al2O3 nano-composites were used for CO2 assisted dehydrogenation of n-octane; and the close proximity of Ni and Nb2O5 in the optimised catalyst promoted CO2 dissociation and substantially prolonged alkane activation.
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Affiliation(s)
- Majid D. Farahani
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban 4000
- South Africa
| | - Mohamed I. Fadlalla
- Catalysis Institute, Department of Chemical Engineering
- University of Cape Town
- South Africa
- DST-NRF Centre of Excellence in Catalysis
- c*change
| | | | - Nadir S. E. Osman
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban 4000
- South Africa
| | - Thomas Moyo
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban 4000
- South Africa
| | - Michael Claeys
- Catalysis Institute, Department of Chemical Engineering
- University of Cape Town
- South Africa
- DST-NRF Centre of Excellence in Catalysis
- c*change
| | - Holger B. Friedrich
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban 4000
- South Africa
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22
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Catalysts C, Shozi ML, Zulu X, Friedrich HB. Ethylene Trimerization over Supported SNS and PNP. S Afr j chem 2021. [DOI: 10.17159/0379-4350/2021/v75a5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
ABSTRACT Chromium(III) complexes with sulphur, nitrogen and phosphorus tridentate ligands were synthesized and characterized. These complexes were supported on SiO2 and characterized by BET surface area measurements, XRF, SEM-EDX and FTIR. The complexes were tested for activity and selectivity in the trimerization of ethylene. The substituent's effect and influence on the sulphur on the supported catalysts were studied using the ethyl and the decyl substituted catalysts. The influence of temperature on catalytic performance was evaluated using the PPP supported system. The most active supported catalyst, the decyl substituted SNS catalyst, showed good activity of up to 19 500 g/g Cr h-1 and selectivity of 97.3 % to C6 products (98.2 % 1-hexene). This activity and selectivity were comparable to the homogeneous counterpart's performance that achieved 22 000 g/g Cr h-1 and 98.2 % C6 products (96.7 % 1-hexene), which surpassed the ethyl substituted catalyst, which was not supported, under the same reaction conditions. The supported PPP catalyst activities showed it was sensitive to higher temperatures, but this depends on the supporting technique. Keywords: Ethylene trimerization, sulfanyl ligands, phosphine ligands, supported catalysts.
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23
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Naicker D, Alapour S, Friedrich HB. The effects of metals and ligands on the oxidation of n-octane using iridium and rhodium “PNP” aminodiphosphine complexes. Journal of Chemical Research 2020. [DOI: 10.1177/1747519820967245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ir and Rh “PNP” complexes with different ligands are utilized for the oxidation of n-octane. Based on the obtained conversion, selectivity, and the characterized recovered catalysts, it is found that the combination of Ir and the studied ligands does not promote the redox mechanism that is known to result in selective formation of oxo and peroxo compounds [desired species for C(1) activation]. Instead, they support a deeper oxidation mechanism, and thus higher selectivity for ketones and acids is obtained. In contrast, these ligands seem to tune the electron density around the Rh (in the Rh-PNP complexes), and thus result in a higher n-octane conversion and improved selectivity for the C(1) activated products, with minimized deeper oxidation, in comparison to Ir-PNP catalysts.
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Affiliation(s)
- Dunesha Naicker
- Catalysis Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Saba Alapour
- Catalysis Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Holger B Friedrich
- Catalysis Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
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24
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Farahani MD, Wolf M, P.O. Mkhwanazi T, Claeys M, Friedrich HB. Operando experimental evidence on the central role of oxygen vacancies during methane combustion. J Catal 2020. [DOI: 10.1016/j.jcat.2020.07.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Marimuthu T, Alapour S, Friedrich HB. Microwave-assisted oxidation reaction of primary alcohols with sensitive functional groups to aldehydes using ruthenium diphosphorus complexes. ARKIVOC 2020. [DOI: 10.24820/ark.5550190.p011.197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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26
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Gichumbi JM, Friedrich HB, Omondi B, Chenia HY. Synthesis, characterization, and antimicrobial studies of half-sandwich η 6-toluene ruthenium complexes with N,N′-bidentate ligands. J COORD CHEM 2020. [DOI: 10.1080/00958972.2020.1795146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | - Holger B. Friedrich
- School of Chemistry, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Bernard Omondi
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Scottsville, South Africa
| | - Hafizah Y. Chenia
- School of Life Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
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27
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Gichumbi JM, Omondi B, Friedrich HB. Crystal structure of chlorido-( η
6- p-cymene)-( N-(2-fluorophenyl)-1-(pyridin-2-yl)methanimine- κ
2
N, N′)ruthenium(II) – acetone (1/1), C 22H 23ClN 2F 7OPRu. Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2019-0793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C22H23ClN2F7OPRu, monoclinic, P21/c (no. 14), a = 7.30480(10) Å, b = 12.9540(3) Å, c = 28.7076(6) Å, β = 96.6990(10)°, V = 2697.95(9) Å3, Z = 4, R
gt(F) = 0.0196, wR
ref(F
2) = 0.0479, T = 100(2) K.
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Affiliation(s)
- Joel M. Gichumbi
- Chuka University , Department Of Physical Sciences , P.O. Box 109-60400 , Chuka , Kenya
| | - Bernard Omondi
- University of KwaZulu-Natal, School of Chemistry and Physics , P.O. Box X01, Pietermaritzburg Campus , Scottsville, Pietermaritzburg 3209 , South Africa
| | - Holger B. Friedrich
- University of KwaZulu-Natal, School of Chemistry and Physics , P.O. Box X54001, Westville Campus, Westville , 4000 Durban , South Africa
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28
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Mncwabe Z, Farahani MD, Friedrich HB. Switching Between Oxidation Types Using Molybdenum Phosphate Catalysts for Paraffin Activation Using Doped Fe as Surface Acidity Modifier and MoOx as an Oxygen Insertion Tool. Catal Letters 2020. [DOI: 10.1007/s10562-019-02943-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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29
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Gichumbi JM, Zamisa SJ, Friedrich HB. Crystal structure of chlorido-( η
5-pentamethylcyclopentadienyl)-((bis-pyrazol-1-yl)methane-κ 2
N, N′) rhodium(III) hexafluorophosphate. (C 17H 23ClN 4RhF 6P). Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2019-0692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C17H23ClN4RhF6P, monoclinic, P21/c (no. 14), a = 10.6954(2) Å, b = 15.3868(3) Å, c = 12.6130(2) Å, β = 90.5590(10)°, V = 2075.60(7) Å3, Z = 4, R
gt(F) = 0.0296, wR
ref(F
2) = 0.0727, T = 100(2) K.
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Affiliation(s)
- Joel M. Gichumbi
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus, Westville , 4000 Durban , South Africa
| | - Sizwe J. Zamisa
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus, Westville , 4000 Durban , South Africa
| | - Holger B. Friedrich
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus, Westville , 4000 Durban , South Africa
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30
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Nyalungu N, Alapour S, Friedrich HB, Bala MD. Crystal structure of (2,7-dihexyl-9,9-dimethyl-9 H-xanthene-4,5-diyl)bis(diphenylphosphane), C 51H 56OP 2. Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2019-0769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C51H56OP2, monoclinic, C2/c (no. 15), a = 20.1788(4) Å, b = 13.0247(4) Å, c = 18.0172(5) Å, β = 119.874(2)°, V = 4106.1(2) Å3, Z = 4, R
gt(F) = 0.0363, wR
ref(F
2) = 0.0981, T = 173(2) K.
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Affiliation(s)
- Nonjabulo Nyalungu
- University of KwaZulu-Natal, School of Chemistry and Physics , PO Box X54001, Westville Campus , Westville , Durban
| | - Saba Alapour
- University of KwaZulu-Natal, School of Chemistry and Physics , PO Box X54001, Westville Campus , Westville , Durban
| | - Holger B. Friedrich
- University of KwaZulu-Natal, School of Chemistry and Physics , PO Box X54001, Westville Campus , Westville , Durban
| | - Muhammad D. Bala
- University of KwaZulu-Natal, School of Chemistry and Physics , PO Box X54001, Westville Campus , Westville , Durban
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31
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Gichumbi JM, Omondi B, Friedrich HB. Crystal structure of η 6- p-cymene-iodido-( N-isopropyl-1-(pyridin-2-yl)methanimine-κ 2
N, N′)ruthenium(II) hexafluorophosphate(V), C 19H 26IN 2F 6Ru. Z KRIST-NEW CRYST ST 2020. [DOI: 10.1515/ncrs-2019-0786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C19H26IN2F6Ru, triclinic, P1̄ (no. 2), a = 9.240(2) Å, b = 10.019(3) Å, c = 12.689(3) Å, α = 78.921°, β = 81.596(10)°, γ = 83.654°, V = 1136.30(5) Å3, Z = 2, R
gt(F) = 0.0174, wR
ref(F
2) = 0.0440, T = 173 K.
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Affiliation(s)
- Joel M. Gichumbi
- Chuka University , Department of Physical Sciences , P.O. Box 109-60400, Chuka , Kenya
| | - Bernard Omondi
- University of KwaZulu-Natal, School of Chemistry and Physics , P.O. Box X01, Pietermaritzburg Campus , Scottsville, Pietermaritzburg 3209, South Africa
| | - Holger B. Friedrich
- University of KwaZulu-Natal , School of Chemistry and Physics , PO Box X54001, Westville Campus , Westville 4000, Durban, South Africa
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32
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Chanerika R, Friedrich HB, Shozi ML. Application of new Ru (II) pyridine‐based complexes in the partial oxidation of
n‐
octane. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Revana Chanerika
- School of Chemistry and PhysicsUniversity of KwaZulu‐Natal Durban South Africa
| | - Holger B. Friedrich
- School of Chemistry and PhysicsUniversity of KwaZulu‐Natal Durban South Africa
| | - Mzamo L. Shozi
- School of Chemistry and PhysicsUniversity of KwaZulu‐Natal Durban South Africa
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33
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Affiliation(s)
- Drushan Padayachee
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Abdul S. Mahomed
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Sooboo Singh
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000, South Africa
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34
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Dasireddy VDBC, Khan FB, Bharuth-Ram K, Singh S, Friedrich HB. Non oxidative and oxidative dehydrogenation of n-octane using FePO 4: effect of different FePO 4 phases on the product selectivity. Catal Sci Technol 2020. [DOI: 10.1039/d0cy01585g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The activation of n-octane with O2 has been investigated over different phases of FePO4 which were formed under dehydrogenation and oxidative dehydrogenation (ODH) conditions.
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Affiliation(s)
| | - Faiza B. Khan
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban
- South Africa
| | - K. Bharuth-Ram
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban
- South Africa
- Department of Physics
| | - Sooboo Singh
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban
- South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban
- South Africa
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35
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Elkhalifa EA, Friedrich HB. Oxidative dehydrogenation of n-octane over a vanadium–magnesium oxide catalyst: Influence of the gas hourly space velocity. ARAB J CHEM 2019. [DOI: 10.1016/j.arabjc.2015.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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36
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Chetty T, Dasireddy VDBC, Friedrich HB. The Continuous Flow Ag/γ-Al2O3 Catalysed Preferential Hydrogenation of Octanal in an Octanal/Octene Mixture. Catal Letters 2019. [DOI: 10.1007/s10562-019-02812-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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37
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Abstract
Abstract
C12H9ClN2, monoclinic, P21/c (no. 14), a = 19.0184(3) Å, b = 4.81220(10) Å, c = 11.3896(2) Å, β = 107.388(1)°, Z = 4, V = 994.75(3) Å3, R
gt(F) = 0.0284, wR
ref(F
2) = 0.0800, T = 100(2) K.
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Affiliation(s)
- Nyameka Diko
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus , Durban 4000 , South Africa
| | - Sizwe J. Zamisa
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus , Durban 4000 , South Africa , e-mail:
| | - Holger B. Friedrich
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus , Durban 4000 , South Africa
| | - Mzamo L. Shozi
- University of KwaZulu-Natal, School of Chemistry and Physics , Private Bag X54001, Westville Campus , Durban 4000 , South Africa
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38
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Chanerika R, Friedrich HB, Shozi ML. Synthesis of Co(II) NNN-pyridine based complexes and their activity in the partial oxidation of n-octane. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2019.118992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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39
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Soobramoney L, Bala MD, Friedrich HB, Pillay MN. Flexible SNS pincer complexes of copper: Synthesis, structural characterisation and application in n-octane oxidation. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.02.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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40
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Riley C, De La Riva A, Zhou S, Wan Q, Peterson E, Artyushkova K, Farahani MD, Friedrich HB, Burkemper L, Atudorei N, Lin S, Guo H, Datye A. Synthesis of Nickel‐Doped Ceria Catalysts for Selective Acetylene Hydrogenation. ChemCatChem 2019. [DOI: 10.1002/cctc.201801976] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Christopher Riley
- Department of Chemical and Biological Engineering and Center for Microengineered Materials University of New Mexico Albuquerque, New Mexico 87131 USA
| | - Andrew De La Riva
- Department of Chemical and Biological Engineering and Center for Microengineered Materials University of New Mexico Albuquerque, New Mexico 87131 USA
| | - Shulan Zhou
- Department of Chemistry and Chemical Biology University of New Mexico Albuquerque, New Mexico 87131 USA
- Department of Material Science and Engineering Jingdezhen Ceramic Institute Jingdezhen 333403 China
| | - Qiang Wan
- State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou University Fuzhou 350002 China
| | - Eric Peterson
- Department of Chemical and Biological Engineering and Center for Microengineered Materials University of New Mexico Albuquerque, New Mexico 87131 USA
| | - Kateryna Artyushkova
- Department of Chemical and Biological Engineering and Center for Microengineered Materials University of New Mexico Albuquerque, New Mexico 87131 USA
| | - Majid D. Farahani
- Catalysis Research Group, School of Chemistry and Physics Westville Campus University of KwaZulu-Natal Durban 4000 South Africa
| | - Holger B. Friedrich
- Catalysis Research Group, School of Chemistry and Physics Westville Campus University of KwaZulu-Natal Durban 4000 South Africa
| | - Laura Burkemper
- Center for Stable Isotopes University of New Mexico Albuquerque, New Mexico 87131 USA
| | - Nicu‐Viorel Atudorei
- Center for Stable Isotopes University of New Mexico Albuquerque, New Mexico 87131 USA
| | - Sen Lin
- State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou University Fuzhou 350002 China
| | - Hua Guo
- Department of Chemistry and Chemical Biology University of New Mexico Albuquerque, New Mexico 87131 USA
| | - Abhaya Datye
- Department of Chemical and Biological Engineering and Center for Microengineered Materials University of New Mexico Albuquerque, New Mexico 87131 USA
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41
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Pansuriya PB, Maguire GE, Friedrich HB. Structural Characterization and Thermal Properties of the Anti-malarial Drug: Lumefantrine. S Afr j chem 2019. [DOI: 10.17159/0379-4350/2019/v72a33] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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42
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Gichumbi JM, Friedrich HB, Omondi B. Synthesis and characterization of water-soluble arene-ruthenium complexes and their application in biphasic olefin oxidation. J COORD CHEM 2018. [DOI: 10.1080/00958972.2018.1548702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Joel M. Gichumbi
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Bernard Omondi
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
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43
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Fadlalla MI, Farahani MD, Friedrich HB. Three inter-linked active sites in the dehydrogenation of n-octane over magnesium molybdate based catalysts and their influences on coking and cracking side reactions. Molecular Catalysis 2018. [DOI: 10.1016/j.mcat.2018.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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44
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45
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Thangavel S, Paulpandi M, Friedrich HB, Sukesh K, Skelton AA. New Ru(II) half sandwich complexes bearing the N,N′ bidentate 9-ethyl-N-(pyridin-2-ylmethylene)9H-carbazole-3-amine ligand: Effects of halogen (Cl−, Br− and I−) leaving groups versus in vitro activity on HepG2 cancer cells, cell cycle, fluorescence study, cellular accumulation and DFT study. Polyhedron 2018. [DOI: 10.1016/j.poly.2018.05.060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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46
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Chetty T, Dasireddy VDBC, Callanan LH, Friedrich HB. Continuous Flow Preferential Hydrogenation of an Octanal/Octene Mixture Using Cu/Al 2O 3 Catalysts. ACS Omega 2018; 3:7911-7924. [PMID: 31458932 PMCID: PMC6644744 DOI: 10.1021/acsomega.7b01993] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/23/2018] [Indexed: 06/10/2023]
Abstract
γ-Alumina-supported catalysts with varying copper loadings (5-25 wt %) were prepared by incipient wet impregnation and characterized by various characterization techniques. These catalysts were tested for the selective hydrogenation of octanal in a mixture containing 10 wt % octanal and 2 wt % octene diluted in octanol. The reactions were carried out in a continuous flow fixed-bed reactor in a down flow mode with varying pressures, liquid hourly space velocities, and hydrogen (H2)-to-aldehyde molar ratios. The catalyst activities were assessed over a temperature range between 100 and 180 °C using hydrogen gas as the hydrogen source. The results obtained showed that under these experimental conditions, copper preferentially hydrogenates the aldehyde and the copper content exhibited no significant influence on the catalyst activity or product selectivity. Kinetic modeling revealed that both octanal and octene hydrogenation were first-order reactions, although octene conversion was very low until octanal conversion had reached a significant level. The activation energy for octanal hydrogenation is higher than the octene hydrogenation. A maximum octanal conversion of >99% was obtained at 160 °C, and the best selectivity toward octanol of 99% was achieved at 100 °C (53% conversion). The pressure played a small role with regards to octanal conversion and selectivity toward octanol, whereas it exhibited a significant influence on the octene conversion. Increasing the hydrogen-to-aldehyde ratio was found to have a direct influence on both octanal and octene conversion.
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Affiliation(s)
- Thashini Chetty
- Catalysis
Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Venkata D. B. C. Dasireddy
- Catalysis
Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Linda H. Callanan
- Department
of Process Engineering, Stellenbosch University, Stellenbosch 7602, South Africa
| | - Holger B. Friedrich
- Catalysis
Research Group, School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
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47
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Thakar AS, Pansuriya PB, Friedrich HB, Maguire GEM. Crystal structure of methyl (1-phenylethyl)carbamate, C 10H 13NO 2. Z KRIST-NEW CRYST ST 2018. [DOI: 10.1515/ncrs-2017-0320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C10H13NO2, monoclinic, P21 (no. 14), a = 9.9882(7) Å, b = 8.5202(6) Å, c = 23.1403(18) Å, β = 91.010(2)°, V = 1969.0(2) Å3, Z = 8, R
gt(F) = 0.0387, wR
ref(F
2) = 0.0919, T = 173(2)K.
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Affiliation(s)
- Amit S. Thakar
- School of Chemistry and Physics , University of KwaZulu-Natal , Durban, 4000 , South Africa
| | - Pramod B. Pansuriya
- School of Chemistry and Physics , University of KwaZulu-Natal , Durban, 4000 , South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics , University of KwaZulu-Natal , Durban, 4000 , South Africa
| | - Glenn E. M. Maguire
- School of Chemistry and Physics , University of KwaZulu-Natal , Durban, 4000 , South Africa
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Gichumbi JM, Friedrich HB. Half-sandwich complexes of platinum group metals (Ir, Rh, Ru and Os) and some recent biological and catalytic applications. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2018.04.021] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Damoyi NE, Friedrich HB, Kruger GH, Willock D. A DFT mechanistic study of the ODH of n-hexane over isolated H3VO4. Molecular Catalysis 2018. [DOI: 10.1016/j.mcat.2018.03.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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