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Azarkamanzad Z, Farzaneh F, Abbasi A, Ghiasi M. Synthesis, characterization, Hirshfeld surface analysis and DFT study of a new ionic Co(II) complex with 2,4,6-tris(2-pyridyl)-1,3,5-triazine. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2022.134386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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2
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Curley JB, Townsend TM, Bernskoetter WH, Hazari N, Mercado BQ. Iron, Cobalt, and Nickel Complexes Supported by a iPrPNPhP Pincer Ligand. Organometallics 2022. [DOI: 10.1021/acs.organomet.1c00646] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Julia B. Curley
- The Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
| | - Tanya M. Townsend
- The Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
| | - Wesley H. Bernskoetter
- The Department of Chemistry, The University of Missouri, Columbia, Missouri 65211, United States
| | - Nilay Hazari
- The Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
| | - Brandon Q. Mercado
- The Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
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3
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Curley JB, Hert C, Bernskoetter WH, Hazari N, Mercado BQ. Control of Catalyst Isomers Using an N-Phenyl-Substituted RN(CH 2CH 2P iPr 2) 2 Pincer Ligand in CO 2 Hydrogenation and Formic Acid Dehydrogenation. Inorg Chem 2021; 61:643-656. [PMID: 34955015 DOI: 10.1021/acs.inorgchem.1c03372] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A novel pincer ligand, iPrPNPhP [PhN(CH2CH2PiPr2)2], which is an analogue of the versatile MACHO ligand, iPrPNHP [HN(CH2CH2PiPr2)2], was synthesized and characterized. The ligand was coordinated to ruthenium, and a series of hydride-containing complexes were isolated and characterized by NMR and IR spectroscopies, as well as X-ray diffraction. Comparisons to previously published analogues ligated by iPrPNHP and iPrPNMeP [CH3N(CH2CH2PiPr2)2] illustrate that there are large changes in the coordination chemistry that occur when the nitrogen substituent of the pincer ligand is altered. For example, ruthenium hydrides supported by the iPrPNPhP ligand always form the syn isomer (where syn/anti refer to the relative orientation of the group on nitrogen and the hydride ligand on ruthenium), whereas complexes supported by iPrPNHP form the anti isomer and complexes supported by iPrPNMeP form a mixture of syn and anti isomers. We evaluated the impact of the nitrogen substituent of the pincer ligand in catalysis by comparing a series of iPrPNRP (R = H, Me, Ph)-ligated ruthenium hydride complexes as catalysts for formic acid dehydrogenation and carbon dioxide (CO2) hydrogenation to formate. The iPrPNPhP-ligated species is the most active for formic acid dehydrogenation, and mechanistic studies suggest that this is likely because there are kinetic advantages for catalysts that operate via the syn isomer. In CO2 hydrogenation, the iPrPNPhP-ligated species is again the most active under our optimal conditions, and we report some of the highest turnover frequencies for homogeneous catalysts. Experimental and theoretical insights into the turnover-limiting step of catalysis provide a basis for the observed trends in catalytic activity. Additionally, the stability of our complexes enabled us to detect a previously unobserved autocatalytic effect involving the base that is added to drive the reaction. Overall, by modifying the nitrogen substituent on the MACHO ligand, we have developed highly active catalysts for formic acid dehydrogenation and CO2 hydrogenation and also provided a framework for future catalyst development.
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Affiliation(s)
- Julia B Curley
- The Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
| | - Clayton Hert
- The Department of Chemistry, The University of Missouri, Columbia, Missouri 65211, United States
| | - Wesley H Bernskoetter
- The Department of Chemistry, The University of Missouri, Columbia, Missouri 65211, United States
| | - Nilay Hazari
- The Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
| | - Brandon Q Mercado
- The Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
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4
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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5
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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] [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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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] [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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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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8
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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10
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Soobramoney L, Bala MD, Friedrich HB. Utilisation of new NiSNS pincer complexes in paraffin oxidation. Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2018.04.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Kadwa E, Friedrich HB, Bala MD. Base metal Schiff base complexes applied as catalysts for the oxidation of n -octane. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2017.04.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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12
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Stereoselective Alkane Oxidation with meta-Chloroperoxybenzoic Acid (MCPBA) Catalyzed by Organometallic Cobalt Complexes. Molecules 2016; 21:molecules21111593. [PMID: 27879680 PMCID: PMC6273550 DOI: 10.3390/molecules21111593] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 11/15/2016] [Accepted: 11/16/2016] [Indexed: 01/21/2023] Open
Abstract
Cobalt pi-complexes, previously described in the literature and specially synthesized and characterized in this work, were used as catalysts in homogeneous oxidation of organic compounds with peroxides. These complexes contain pi-butadienyl and pi-cyclopentadienyl ligands: [(tetramethylcyclobutadiene)(benzene)cobalt] hexafluorophosphate, [(C4Me4)Co(C6H6)]PF6 (1); diiodo(carbonyl)(pentamethylcyclopentadienyl)cobalt, Cp*Co(CO)I2 (2); diiodo(carbonyl)(cyclopentadienyl)cobalt, CpCo(CO)I2 (3); (tetramethylcyclobutadiene)(dicarbonyl)(iodo)cobalt, (C4Me4)Co(CO)2I (4); [(tetramethylcyclobutadiene)(acetonitrile)(2,2′-bipyridyl)cobalt] hexafluorophosphate, [(C4Me4)Co(bipy)(MeCN)]PF6 (5); bis[dicarbonyl(B-cyclohexylborole)]cobalt, [(C4H4BCy)Co(CO)2]2 (6); [(pentamethylcyclopentadienyl)(iodo)(1,10-phenanthroline)cobalt] hexafluorophosphate, [Cp*Co(phen)I]PF6 (7); diiodo(cyclopentadienyl)cobalt, [CpCoI2]2 (8); [(cyclopentadienyl)(iodo)(2,2′-bipyridyl)cobalt] hexafluorophosphate, [CpCo(bipy)I]PF6 (9); and [(pentamethylcyclopentadienyl)(iodo)(2,2′-bipyridyl)cobalt] hexafluorophosphate, [Cp*Co(bipy)I]PF6 (10). Complexes 1 and 2 catalyze very efficient and stereoselective oxygenation of tertiary C–H bonds in isomeric dimethylcyclohexanes with MCBA: cyclohexanols are produced in 39 and 53% yields and with the trans/cis ratio (of isomers with mutual trans- or cis-configuration of two methyl groups) 0.05 and 0.06, respectively. Addition of nitric acid as co-catalyst dramatically enhances both the yield of oxygenates and stereoselectivity parameter. In contrast to compounds 1 and 2, complexes 9 and 10 turned out to be very poor catalysts (the yields of oxygenates in the reaction with cis-1,2-dimethylcyclohexane were only 5%–7% and trans/cis ratio 0.8 indicated that the oxidation is not stereoselective). The chromatograms of the reaction mixture obtained before and after reduction with PPh3 are very similar, which testifies that alkyl hydroperoxides are not formed in this oxidation. It can be thus concluded that the interaction of the alkanes with MCPBA occurs without the formation of free radicals. The complexes catalyze oxidation of alcohols with tert-butylhydroperoxide (TBHP). For example, tert-BuOOH efficiently oxidizes 1-phenylethanol to acetophenone in 98% yield if compound 1 is used as a catalyst.
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Naicker D, Pansuriya PB, Friedrich HB. Crystal structure of N, N-bis(diphenylphosphanyl)cyclohexylamine, C 30H 31NP 2. Z KRIST-NEW CRYST ST 2016. [DOI: 10.1515/ncrs-2015-0231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C30H31NP2, monoclinic, P21/n, a = 15.8251(19) Å, b = 10.3667(12) Å, c = 15.900(2) Å, β = 107.225(3)°, V = 2491.5(5) Å3, Z = 4, R
gt
(F) = 0.0390, wR
ref
(F
2
) = 0.0935, T = 163 K.
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Affiliation(s)
- Dunesha Naicker
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville campus, Durban 4000, South Africa
| | - Pramod B. Pansuriya
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville campus, Durban 4000, South Africa
| | - Holger B. Friedrich
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville campus, Durban 4000, South Africa
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Naicker D, Friedrich HB, Pansuriya PB. Iridium and rhodium “PNP” aminodiphosphine complexes used as catalysts in the oxidation of styrene. RSC Adv 2016. [DOI: 10.1039/c6ra01276k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
New Ir and Rh “PNP” aminodiphosphine complexes are effective catalysts in styrene oxidation withtert-butyl hydroperoxide as the oxidant. The Ir catalysts were more active than the Rh catalysts with high yields to benzaldehyde in comparison to styrene oxide.
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Affiliation(s)
- Dunesha Naicker
- 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
| | - Pramod B. Pansuriya
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban
- South Africa
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