0000000000042490

AUTHOR

Michael G. Richmond

0000-0001-6641-866x

Chalcogenide-capped triiron clusters [Fe3(CO)9(μ3-E)2], [Fe3(CO)7(μ3-CO)(μ3-E)(μ-dppm)] and [Fe3(CO)7(μ3-E)2(μ-dppm)] (E = S, Se) as proton-reduction catalysts

Chalcogenide-capped triiron clusters [Fe3(CO)7(μ3-CO)(μ3-E)(μ-dppm)] and [Fe3(CO)7(μ3-E)2(μ-dppm)] (E = S, Se) have been examined as proton-reduction catalysts. Protonation studies show that [Fe3(CO)9(μ3-E)2] are unaffected by strong acids. Mono-capped [Fe3(CO)7(μ3-CO)(μ3-E)(μ-dppm)] react with HBF4.Et2O but changes in IR spectra are attributed to BF3 binding to the face-capping carbonyl, while bicapped [Fe3(CO)7(μ3-E)2(μ-dppm)] are protonated but in a process that is not catalytically important. DFT calculations are presented to support these protonation studies. Cyclic voltammetry shows that [Fe3(CO)9(μ3-Se)2] exhibits two reduction waves, and upon addition of strong acids, proton-reducti…

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Oxygen Atom Transfer Catalysis by Dioxidomolybdenum(VI) Complexes of Pyridyl Aminophenolate Ligands

A series of new cationic dioxidomolybdenum(VI) complexes [MoO2(Ln)]PF6 (2-5) with the tripodal tetradentate pyridyl aminophenolate ligands HL2-HL5 have been synthesized and characterized. Ligands HL2-HL4 carry substituents in the 4-position of the phenolate ring, viz. Cl, Br and NO2, respectively, whereas the ligand HL5, N-(2-hydroxy-3,5-di-tert-butylbenzyl)-N,N-bis(2-pyridylmethyl)amine, is a derivative of 3,5-di-tert-butylsalicylaldehyde. X-ray crystal structures of complexes 2, 3 and 5 reveal that they have a distorted octahedral geometry with the bonding parameters around the metal centres being practically similar. Stoichiometric oxygen atom transfer (OAT) properties of 5 with PPh3 wer…

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Proton reduction by phosphinidene-capped triiron clusters

Bis(phosphinidene)-capped triiron carbonyl clusters, including electron rich derivatives formed by substitution with chelating diphosphines, have been prepared and examined as proton reduction catalysts. Treatment of the known cluster [Fe3(CO)9(µ3-PPh)2] (1) with various diphosphines in refluxing THF (for 5, refluxing toluene) afforded the new clusters [Fe3(CO)7(µ3-PPh)2(κ2-dppb)] (2), [Fe3(CO)7(µ3-PPh)2(κ2-dppv)] (3), [Fe3(CO)7(µ3-PPh)2(κ2-dppe)] (4) and [Fe3(CO)7(µ3-PPh)2(µ-κ2-dppf)] (5) in moderate yields, together with small amounts of the corresponding [Fe3(CO)8(µ3-PPh)2(κ1-Ph2PxPPh2)] cluster (x = -C4H6-, -C2H2-, -C2H4-, -C3H6-, -C5H4FeC5H4-). The molecular structures of complexes 3 a…

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Nonheme Fe(IV) Oxo Complexes of Two New Pentadentate Ligands and Their Hydrogen-Atom and Oxygen-Atom Transfer Reactions.

Two new pentadentate {N5} donor ligands based on the N4Py (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) framework have been synthesized, viz. [N-(1-methyl-2-benzimidazolyl)methyl-N-(2-pyridyl)methyl-N-(bis-2-pyridyl methyl)amine] (L1) and [N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine] (L2), where one or two pyridyl arms of N4Py have been replaced by corresponding (N-methyl)benzimidazolyl-containing arms. The complexes [FeII(CH3CN)(L)]2+ (L = L1 (1); L2 (2)) were synthesized, and reaction of these ferrous complexes with iodosylbenzene led to the formation of the ferryl complexes [FeIV(O)(L)]2+ (L = L1 (3); L2 (4)), which were characterized by UV–vis spe…

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Asymmetric hydrogenation of an α-unsaturated carboxylic acid catalyzed by intact chiral transition metal carbonyl clusters – diastereomeric control of enantioselectivity

Twenty clusters of the general formula [(μ-H)2Ru3(μ3-S)(CO)7(μ-P–P*)] (P–P* = chiral diphosphine of the ferrocene-based Walphos or Josiphos families) have been synthesised and characterised. The clusters have been tested as catalysts for asymmetric hydrogenation of tiglic acid [trans-2-methyl-2-butenoic acid]. The observed enantioselectivities and conversion rates strongly support catalysis by intact Ru3 clusters. A catalytic mechanism involving an active Ru3 catalyst generated by CO loss from [(μ-H)2Ru3(μ3-S)(CO)7(μ-P–P*)] has been investigated by DFT calculations. peerReviewed

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Diastereomeric control of enantioselectivity: evidence for metal cluster catalysis

Enantioselective hydrogenation of tiglic acid effected by diastereomers of the general formula [(μ-H)2Ru3(μ3-S)(CO)7(μ-P–P*)] (P–P* = chiral Walphos diphosphine ligand) strongly supports catalysis by intact Ru3 clusters. A catalytic mechanism involving Ru3 clusters has been established by DFT calculations. peerReviewed

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Oxygen atom transfer catalysis by dioxidomolybdenum(VI) complexes of pyridyl aminophenolate ligands

Abstract A series of new cationic dioxidomolybdenum(VI) complexes [MoO2(Ln)]PF6 (2–5) with the tripodal tetradentate pyridyl aminophenolate ligands HL2-HL5 have been synthesized and characterized. Ligands HL2-HL4 carry substituents in the 4-position of the phenolate ring, viz. Cl, Br and NO2, respectively, whereas the ligand HL5, N-(2-hydroxy-3,5-di-tert-butylbenzyl)-N,N-bis(2-pyridylmethyl)amine, is a derivative of 3,5-di-tert-butylsalicylaldehyde. X-ray crystal structures of complexes 2, 3 and 5 reveal that they have a distorted octahedral geometry with the bonding parameters around the metal centres being practically similar. Stoichiometric oxygen atom transfer (OAT) properties of 5 with…

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Cis- and trans molybdenum oxo complexes of a prochiral tetradentate aminophenolate ligand : Synthesis, characterization and oxotransfer activity

Abstract Reaction of [MoO2Cl2(dmso)2] with the tetradentate O2N2 donor ligand papy [H2papy = N-(2-hydroxybenzyl)-N-(2-picolyl)glycine] leads to formation of the dioxomolybdenum(VI) complex [MoO2(papy)] (1) as a mixture of cis and trans isomers. Recrystallization from methanol furnishes solid cis-1, whereas the use of a dichloromethane-hexane mixture allows for the isolation of the trans-1 isomer. Both isomers have been structurally characterized by X-ray crystallography and the energy difference between the isomeric pair has been investigated by electronic structure calculations. Optimization of two configurational isomers in the gas phase predicts the trans isomer to lie 2.5 kcal/mol lower…

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Syntheses and catalytic oxotransfer activities of oxo molybdenum(vi) complexes of a new aminoalcohol phenolate ligand.

The new aminoalcohol phenol 2,4-di-tert-butyl-6-(((2-hydroxy-2-phenylethyl)amino)methyl)phenol (H2L) was prepared by a facile solvent-free synthesis and used as a tridentate ligand for new cis-dioxomolybdenum(vi)(L) complexes. In the presence of a coordinating solvent (DMSO, MeOH, pyridine), the complexes crystallise as monomeric solvent adducts while in the absence of such molecules, a trimer with asymmetric Mo[double bond, length as m-dash]O→Mo bridges crystallises. The complexes can catalyse epoxidation of cis-cyclooctene and sulfoxidation of methyl-p-tolylsulfide, using tert-butyl hydroperoxide as oxidant.

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CCDC 1043618: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 1502861: Experimental Crystal Structure Determination

Related Article: Md. Kamal Hossain, Anja Köhntopp, Matti Haukka, Michael G. Richmond, Ari Lehtonen, Ebbe Nordlander|2020|Polyhedron|178|114312|doi:10.1016/j.poly.2019.114312

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CCDC 2044571: Experimental Crystal Structure Determination

Related Article: Md Kamal Hossain, Jörg A. Schachner, Matti Haukka, Michael G. Richmond, Nadia C. Mösch-Zanetti, Ari Lehtonen, Ebbe Nordlander|2021|Polyhedron|205|115234|doi:10.1016/j.poly.2021.115234

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CCDC 1418388: Experimental Crystal Structure Determination

Related Article: Mainak Mitra , Hassan Nimir , Serhiy Demeshko , Satish S. Bhat , Sergey O. Malinkin , Matti Haukka , Julio Lloret-Fillol , George C. Lisensky , Franc Meyer , Albert A. Shteinman , Wesley R. Browne , David A. Hrovat , Michael G.Richmond , Miquel Costas , Ebbe Nordlander|2015|Inorg.Chem.|54|7152|doi:10.1021/ic5029564

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CCDC 1962572: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 1033835: Experimental Crystal Structure Determination

Related Article: Mainak Mitra , Hassan Nimir , Serhiy Demeshko , Satish S. Bhat , Sergey O. Malinkin , Matti Haukka , Julio Lloret-Fillol , George C. Lisensky , Franc Meyer , Albert A. Shteinman , Wesley R. Browne , David A. Hrovat , Michael G.Richmond , Miquel Costas , Ebbe Nordlander|2015|Inorg.Chem.|54|7152|doi:10.1021/ic5029564

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CCDC 1962571: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 2044573: Experimental Crystal Structure Determination

Related Article: Md Kamal Hossain, Jörg A. Schachner, Matti Haukka, Michael G. Richmond, Nadia C. Mösch-Zanetti, Ari Lehtonen, Ebbe Nordlander|2021|Polyhedron|205|115234|doi:10.1016/j.poly.2021.115234

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CCDC 2044572: Experimental Crystal Structure Determination

Related Article: Md Kamal Hossain, Jörg A. Schachner, Matti Haukka, Michael G. Richmond, Nadia C. Mösch-Zanetti, Ari Lehtonen, Ebbe Nordlander|2021|Polyhedron|205|115234|doi:10.1016/j.poly.2021.115234

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CCDC 1962575: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 993899: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Amrendra K. Singh, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2014|Chem.Commun.|50|7705|doi:10.1039/C4CC02319F

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CCDC 1981159: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 1896756: Experimental Crystal Structure Determination

Related Article: Ahibur Rahaman, George C. Lisensky, Matti Haukka, Derek A. Tocher, Michael G. Richmond, Stephen B. Colbran, Ebbe Nordlander|2021|J.Organomet.Chem.|943|121816|doi:10.1016/j.jorganchem.2021.121816

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CCDC 1502862: Experimental Crystal Structure Determination

Related Article: Md. Kamal Hossain, Anja Köhntopp, Matti Haukka, Michael G. Richmond, Ari Lehtonen, Ebbe Nordlander|2020|Polyhedron|178|114312|doi:10.1016/j.poly.2019.114312

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CCDC 1962574: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 1502863: Experimental Crystal Structure Determination

Related Article: Md. Kamal Hossain, Anja Köhntopp, Matti Haukka, Michael G. Richmond, Ari Lehtonen, Ebbe Nordlander|2020|Polyhedron|178|114312|doi:10.1016/j.poly.2019.114312

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CCDC 1043620: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 1043617: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 993900: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Amrendra K. Singh, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2014|Chem.Commun.|50|7705|doi:10.1039/C4CC02319F

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CCDC 1473054: Experimental Crystal Structure Determination

Related Article: Ahibur Rahaman, Shishir Ghosh, Sucharita Basak-Modi, Ahmed F. Abdel-Magied, Shariff E. Kabir, Matti Haukka, Michael G. Richmond, George C. Lisensky, Ebbe Nordlander, Graeme Hogarth|2019|J.Organomet.Chem.|880|213|doi:10.1016/j.jorganchem.2018.10.018

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CCDC 1962573: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 1473051: Experimental Crystal Structure Determination

Related Article: Ahibur Rahaman, Shishir Ghosh, Sucharita Basak-Modi, Ahmed F. Abdel-Magied, Shariff E. Kabir, Matti Haukka, Michael G. Richmond, George C. Lisensky, Ebbe Nordlander, Graeme Hogarth|2019|J.Organomet.Chem.|880|213|doi:10.1016/j.jorganchem.2018.10.018

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CCDC 1043616: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

research product

CCDC 1981173: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 1896754: Experimental Crystal Structure Determination

Related Article: Ahibur Rahaman, George C. Lisensky, Matti Haukka, Derek A. Tocher, Michael G. Richmond, Stephen B. Colbran, Ebbe Nordlander|2021|J.Organomet.Chem.|943|121816|doi:10.1016/j.jorganchem.2021.121816

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CCDC 1043619: Experimental Crystal Structure Determination

Related Article: Ahmed F. Abdel-Magied, Yusuf Theibich, Amrendra K. Singh, Ahibur Rahaman, Isa Doverbratt, Arun K. Raha, Matti Haukka, Michael G. Richmond, Ebbe Nordlander|2020|Dalton Trans.|49|4244|doi:10.1039/C9DT04799A

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CCDC 2044570: Experimental Crystal Structure Determination

Related Article: Md Kamal Hossain, Jörg A. Schachner, Matti Haukka, Michael G. Richmond, Nadia C. Mösch-Zanetti, Ari Lehtonen, Ebbe Nordlander|2021|Polyhedron|205|115234|doi:10.1016/j.poly.2021.115234

research product

CCDC 1896755: Experimental Crystal Structure Determination

Related Article: Ahibur Rahaman, George C. Lisensky, Matti Haukka, Derek A. Tocher, Michael G. Richmond, Stephen B. Colbran, Ebbe Nordlander|2021|J.Organomet.Chem.|943|121816|doi:10.1016/j.jorganchem.2021.121816

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CCDC 994961: Experimental Crystal Structure Determination

Related Article: Mainak Mitra , Hassan Nimir , Serhiy Demeshko , Satish S. Bhat , Sergey O. Malinkin , Matti Haukka , Julio Lloret-Fillol , George C. Lisensky , Franc Meyer , Albert A. Shteinman , Wesley R. Browne , David A. Hrovat , Michael G.Richmond , Miquel Costas , Ebbe Nordlander|2015|Inorg.Chem.|54|7152|doi:10.1021/ic5029564

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