TY  - JOUR
AU  - Steen, Jorn D.
AU  - Stepanović, Stepan
AU  - Parvizian, Mahsa
AU  - de Boer, Johannes W.
AU  - Hage, Ronald
AU  - Chen, Juan
AU  - Swart, Marcel
AU  - Gruden-Pavlović, Maja
AU  - Browne, Wesley R.
PY  - 2019
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3691
AB  - Lewis acid (LA) activation by coordination to metal oxido species has emerged as a new strategy in catalytic oxidations. Despite the many reports of enhancement of performance in oxidation catalysis, direct evidence for LA-catalyst interactions under catalytically relevant conditions is lacking. Here, we show, using the oxidation of alkenes with H2O2 and the catalyst [Mn2(μ-O)3(tmtacn)2](PF6)2 (1), that Lewis acids commonly used to enhance catalytic activity, e.g., Sc(OTf)3, in fact undergo hydrolysis with adventitious water to release a strong Brønsted acid. The formation of Brønsted acids in situ is demonstrated using a combination of resonance Raman, UV/vis absorption spectroscopy, cyclic voltammetry, isotope labeling, and DFT calculations. The involvement of Brønsted acids in LA enhanced systems shown here holds implications for the conclusions reached in regard to the relevance of direct LA-metal oxido interactions under catalytic conditions.
PB  - American Chemical Society
T2  - Inorganic Chemistry
T1  - Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation
VL  - 58
IS  - 21
SP  - 14924
EP  - 14930
DO  - 10.1021/acs.inorgchem.9b02737
ER  - 

@article{
author = "Steen, Jorn D. and Stepanović, Stepan and Parvizian, Mahsa and de Boer, Johannes W. and Hage, Ronald and Chen, Juan and Swart, Marcel and Gruden-Pavlović, Maja and Browne, Wesley R.",
year = "2019",
abstract = "Lewis acid (LA) activation by coordination to metal oxido species has emerged as a new strategy in catalytic oxidations. Despite the many reports of enhancement of performance in oxidation catalysis, direct evidence for LA-catalyst interactions under catalytically relevant conditions is lacking. Here, we show, using the oxidation of alkenes with H2O2 and the catalyst [Mn2(μ-O)3(tmtacn)2](PF6)2 (1), that Lewis acids commonly used to enhance catalytic activity, e.g., Sc(OTf)3, in fact undergo hydrolysis with adventitious water to release a strong Brønsted acid. The formation of Brønsted acids in situ is demonstrated using a combination of resonance Raman, UV/vis absorption spectroscopy, cyclic voltammetry, isotope labeling, and DFT calculations. The involvement of Brønsted acids in LA enhanced systems shown here holds implications for the conclusions reached in regard to the relevance of direct LA-metal oxido interactions under catalytic conditions.",
publisher = "American Chemical Society",
journal = "Inorganic Chemistry",
title = "Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation",
volume = "58",
number = "21",
pages = "14924-14930",
doi = "10.1021/acs.inorgchem.9b02737"
}

Steen, J. D., Stepanović, S., Parvizian, M., de Boer, J. W., Hage, R., Chen, J., Swart, M., Gruden-Pavlović, M.,& Browne, W. R.. (2019). Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. in Inorganic Chemistry
American Chemical Society., 58(21), 14924-14930.
https://doi.org/10.1021/acs.inorgchem.9b02737

Steen JD, Stepanović S, Parvizian M, de Boer JW, Hage R, Chen J, Swart M, Gruden-Pavlović M, Browne WR. Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. in Inorganic Chemistry. 2019;58(21):14924-14930.
doi:10.1021/acs.inorgchem.9b02737 .

Steen, Jorn D., Stepanović, Stepan, Parvizian, Mahsa, de Boer, Johannes W., Hage, Ronald, Chen, Juan, Swart, Marcel, Gruden-Pavlović, Maja, Browne, Wesley R., "Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation" in Inorganic Chemistry, 58, no. 21 (2019):14924-14930,
https://doi.org/10.1021/acs.inorgchem.9b02737 . .

TY  - DATA
AU  - Steen, Jorn D.
AU  - Stepanović, Stepan
AU  - Parvizian, Mahsa
AU  - de Boer, Johannes W.
AU  - Hage, Ronald
AU  - Chen, Juan
AU  - Swart, Marcel
AU  - Gruden-Pavlović, Maja
AU  - Browne, Wesley R.
PY  - 2019
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3692
PB  - American Chemical Society
T2  - Inorganic Chemistry
T1  - Supplementary data for the article: Steen, J. D.; Stepanovic, S.; Parvizian, M.; De Boer, J. W.; Hage, R.; Chen, J.; Swart, M.; Gruden, M.; Browne, W. R. Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. Inorganic Chemistry 2019, 58 (21), 14924–14930. https://doi.org/10.1021/acs.inorgchem.9b02737
UR  - https://hdl.handle.net/21.15107/rcub_cherry_3692
ER  - 

@misc{
author = "Steen, Jorn D. and Stepanović, Stepan and Parvizian, Mahsa and de Boer, Johannes W. and Hage, Ronald and Chen, Juan and Swart, Marcel and Gruden-Pavlović, Maja and Browne, Wesley R.",
year = "2019",
publisher = "American Chemical Society",
journal = "Inorganic Chemistry",
title = "Supplementary data for the article: Steen, J. D.; Stepanovic, S.; Parvizian, M.; De Boer, J. W.; Hage, R.; Chen, J.; Swart, M.; Gruden, M.; Browne, W. R. Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. Inorganic Chemistry 2019, 58 (21), 14924–14930. https://doi.org/10.1021/acs.inorgchem.9b02737",
url = "https://hdl.handle.net/21.15107/rcub_cherry_3692"
}

Steen, J. D., Stepanović, S., Parvizian, M., de Boer, J. W., Hage, R., Chen, J., Swart, M., Gruden-Pavlović, M.,& Browne, W. R.. (2019). Supplementary data for the article: Steen, J. D.; Stepanovic, S.; Parvizian, M.; De Boer, J. W.; Hage, R.; Chen, J.; Swart, M.; Gruden, M.; Browne, W. R. Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. Inorganic Chemistry 2019, 58 (21), 14924–14930. https://doi.org/10.1021/acs.inorgchem.9b02737. in Inorganic Chemistry
American Chemical Society..
https://hdl.handle.net/21.15107/rcub_cherry_3692

Steen JD, Stepanović S, Parvizian M, de Boer JW, Hage R, Chen J, Swart M, Gruden-Pavlović M, Browne WR. Supplementary data for the article: Steen, J. D.; Stepanovic, S.; Parvizian, M.; De Boer, J. W.; Hage, R.; Chen, J.; Swart, M.; Gruden, M.; Browne, W. R. Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. Inorganic Chemistry 2019, 58 (21), 14924–14930. https://doi.org/10.1021/acs.inorgchem.9b02737. in Inorganic Chemistry. 2019;.
https://hdl.handle.net/21.15107/rcub_cherry_3692 .

Steen, Jorn D., Stepanović, Stepan, Parvizian, Mahsa, de Boer, Johannes W., Hage, Ronald, Chen, Juan, Swart, Marcel, Gruden-Pavlović, Maja, Browne, Wesley R., "Supplementary data for the article: Steen, J. D.; Stepanovic, S.; Parvizian, M.; De Boer, J. W.; Hage, R.; Chen, J.; Swart, M.; Gruden, M.; Browne, W. R. Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. Inorganic Chemistry 2019, 58 (21), 14924–14930. https://doi.org/10.1021/acs.inorgchem.9b02737" in Inorganic Chemistry (2019),
https://hdl.handle.net/21.15107/rcub_cherry_3692 .

TY  - JOUR
AU  - Chen, Juan
AU  - Stepanović, Stepan
AU  - Draksharapu, Apparao
AU  - Gruden-Pavlović, Maja
AU  - Browne, Wesley R.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2104
AB  - Non-heme (L)Fe-III and (L)Fe-III-O-Fe-III(L) complexes (L=1,1-di(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)-ethan-1-amine) underwent reduction under irradiation to the Fe-II state with concomitant oxidation of methanol to methanal, without the need for a secondary photosensitizer. Spectroscopic and DFT studies support a mechanism in which irradiation results in charge-transfer excitation of a Fe-III-mu-O-Fe-III complex to generate [(L)Fe-IV=O](2+) (observed transiently during irradiation in acetonitrile), and an equivalent of (L)Fe-II. Under aerobic conditions, irradiation accelerates reoxidation from the Fe-II to the Fe-III state with O-2, thus closing the cycle of methanol oxidation to methanal.
PB  - Wiley-V C H Verlag Gmbh, Weinheim
T2  - Angewandte Chemie (International Edition)
T1  - A Non-Heme Iron Photocatalyst for Light-Driven Aerobic Oxidation of Methanol
VL  - 57
IS  - 12
SP  - 3207
EP  - 3211
DO  - 10.1002/anie.201712678
ER  - 

@article{
author = "Chen, Juan and Stepanović, Stepan and Draksharapu, Apparao and Gruden-Pavlović, Maja and Browne, Wesley R.",
year = "2018",
abstract = "Non-heme (L)Fe-III and (L)Fe-III-O-Fe-III(L) complexes (L=1,1-di(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)-ethan-1-amine) underwent reduction under irradiation to the Fe-II state with concomitant oxidation of methanol to methanal, without the need for a secondary photosensitizer. Spectroscopic and DFT studies support a mechanism in which irradiation results in charge-transfer excitation of a Fe-III-mu-O-Fe-III complex to generate [(L)Fe-IV=O](2+) (observed transiently during irradiation in acetonitrile), and an equivalent of (L)Fe-II. Under aerobic conditions, irradiation accelerates reoxidation from the Fe-II to the Fe-III state with O-2, thus closing the cycle of methanol oxidation to methanal.",
publisher = "Wiley-V C H Verlag Gmbh, Weinheim",
journal = "Angewandte Chemie (International Edition)",
title = "A Non-Heme Iron Photocatalyst for Light-Driven Aerobic Oxidation of Methanol",
volume = "57",
number = "12",
pages = "3207-3211",
doi = "10.1002/anie.201712678"
}

Chen, J., Stepanović, S., Draksharapu, A., Gruden-Pavlović, M.,& Browne, W. R.. (2018). A Non-Heme Iron Photocatalyst for Light-Driven Aerobic Oxidation of Methanol. in Angewandte Chemie (International Edition)
Wiley-V C H Verlag Gmbh, Weinheim., 57(12), 3207-3211.
https://doi.org/10.1002/anie.201712678

Chen J, Stepanović S, Draksharapu A, Gruden-Pavlović M, Browne WR. A Non-Heme Iron Photocatalyst for Light-Driven Aerobic Oxidation of Methanol. in Angewandte Chemie (International Edition). 2018;57(12):3207-3211.
doi:10.1002/anie.201712678 .

Chen, Juan, Stepanović, Stepan, Draksharapu, Apparao, Gruden-Pavlović, Maja, Browne, Wesley R., "A Non-Heme Iron Photocatalyst for Light-Driven Aerobic Oxidation of Methanol" in Angewandte Chemie (International Edition), 57, no. 12 (2018):3207-3211,
https://doi.org/10.1002/anie.201712678 . .

TY  - JOUR
AU  - Chen, Juan
AU  - Unjaroen, Duenpen
AU  - Stepanović, Stepan
AU  - van Dam, Annie
AU  - Gruden-Pavlović, Maja
AU  - Browne, Wesley R.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2131
AB  - Non-heme iron(II) complexes of pentadentate N4Py (N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) type ligands undergo visible light-driven oxidation to their iron(III) state in the presence of O-2 without ligand degradation. Under mildly basic conditions, however, highly selective base catalyzed ligand degradation with O-2, to form a well-defined pyridyl-imine iron(II) complex and an iron(III) picolinate complex, is accelerated photochemically. Specifically, a pyridyl-CH2 moiety is lost from the ligand, yielding a potentially N4 coordinating ligand containing an imine motif. The involvement of reactive oxygen species other than O-2 is excluded; instead, deprotonation at the benzylic positions to generate an amine radical is proposed as the rate determining step. The selective nature of the transformation holds implications for efforts to increase catalyst robustness through ligand design.
PB  - Amer Chemical Soc, Washington
T2  - Inorganic Chemistry
T1  - Selective Photo-Induced Oxidation with O-2 of a Non-Heme Iron(III) Complex to a Bis(imine-pyridyl)iron(II) Complex
VL  - 57
IS  - 8
SP  - 4510
EP  - 4515
DO  - 10.1021/acs.inorgchem.8b00187
ER  - 

@article{
author = "Chen, Juan and Unjaroen, Duenpen and Stepanović, Stepan and van Dam, Annie and Gruden-Pavlović, Maja and Browne, Wesley R.",
year = "2018",
abstract = "Non-heme iron(II) complexes of pentadentate N4Py (N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) type ligands undergo visible light-driven oxidation to their iron(III) state in the presence of O-2 without ligand degradation. Under mildly basic conditions, however, highly selective base catalyzed ligand degradation with O-2, to form a well-defined pyridyl-imine iron(II) complex and an iron(III) picolinate complex, is accelerated photochemically. Specifically, a pyridyl-CH2 moiety is lost from the ligand, yielding a potentially N4 coordinating ligand containing an imine motif. The involvement of reactive oxygen species other than O-2 is excluded; instead, deprotonation at the benzylic positions to generate an amine radical is proposed as the rate determining step. The selective nature of the transformation holds implications for efforts to increase catalyst robustness through ligand design.",
publisher = "Amer Chemical Soc, Washington",
journal = "Inorganic Chemistry",
title = "Selective Photo-Induced Oxidation with O-2 of a Non-Heme Iron(III) Complex to a Bis(imine-pyridyl)iron(II) Complex",
volume = "57",
number = "8",
pages = "4510-4515",
doi = "10.1021/acs.inorgchem.8b00187"
}

Chen, J., Unjaroen, D., Stepanović, S., van Dam, A., Gruden-Pavlović, M.,& Browne, W. R.. (2018). Selective Photo-Induced Oxidation with O-2 of a Non-Heme Iron(III) Complex to a Bis(imine-pyridyl)iron(II) Complex. in Inorganic Chemistry
Amer Chemical Soc, Washington., 57(8), 4510-4515.
https://doi.org/10.1021/acs.inorgchem.8b00187

Chen J, Unjaroen D, Stepanović S, van Dam A, Gruden-Pavlović M, Browne WR. Selective Photo-Induced Oxidation with O-2 of a Non-Heme Iron(III) Complex to a Bis(imine-pyridyl)iron(II) Complex. in Inorganic Chemistry. 2018;57(8):4510-4515.
doi:10.1021/acs.inorgchem.8b00187 .

Chen, Juan, Unjaroen, Duenpen, Stepanović, Stepan, van Dam, Annie, Gruden-Pavlović, Maja, Browne, Wesley R., "Selective Photo-Induced Oxidation with O-2 of a Non-Heme Iron(III) Complex to a Bis(imine-pyridyl)iron(II) Complex" in Inorganic Chemistry, 57, no. 8 (2018):4510-4515,
https://doi.org/10.1021/acs.inorgchem.8b00187 . .

TY  - DATA
AU  - Chen, Juan
AU  - Unjaroen, Duenpen
AU  - Stepanović, Stepan
AU  - van Dam, Annie
AU  - Gruden-Pavlović, Maja
AU  - Browne, Wesley R.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2984
PB  - Amer Chemical Soc, Washington
T2  - Inorganic Chemistry
T1  - Supplementary material for the article: Chen, J.; Unjaroen, D.; Stepanovic, S.; Van Dam, A.; Gruden, M.; Browne, W. R. Selective  Photo-Induced Oxidation with O 2 of a Non-Heme Iron(III) Complex to a Bis(Imine Pyridyl)Iron(II) Complex. Inorganic Chemistry 2018, 57 (8), 4510–4515. https://doi.org/10.1021/acs.inorgchem.8b00187
UR  - https://hdl.handle.net/21.15107/rcub_cherry_2984
ER  - 

@misc{
author = "Chen, Juan and Unjaroen, Duenpen and Stepanović, Stepan and van Dam, Annie and Gruden-Pavlović, Maja and Browne, Wesley R.",
year = "2018",
publisher = "Amer Chemical Soc, Washington",
journal = "Inorganic Chemistry",
title = "Supplementary material for the article: Chen, J.; Unjaroen, D.; Stepanovic, S.; Van Dam, A.; Gruden, M.; Browne, W. R. Selective  Photo-Induced Oxidation with O 2 of a Non-Heme Iron(III) Complex to a Bis(Imine Pyridyl)Iron(II) Complex. Inorganic Chemistry 2018, 57 (8), 4510–4515. https://doi.org/10.1021/acs.inorgchem.8b00187",
url = "https://hdl.handle.net/21.15107/rcub_cherry_2984"
}

Chen, J., Unjaroen, D., Stepanović, S., van Dam, A., Gruden-Pavlović, M.,& Browne, W. R.. (2018). Supplementary material for the article: Chen, J.; Unjaroen, D.; Stepanovic, S.; Van Dam, A.; Gruden, M.; Browne, W. R. Selective  Photo-Induced Oxidation with O 2 of a Non-Heme Iron(III) Complex to a Bis(Imine Pyridyl)Iron(II) Complex. Inorganic Chemistry 2018, 57 (8), 4510–4515. https://doi.org/10.1021/acs.inorgchem.8b00187. in Inorganic Chemistry
Amer Chemical Soc, Washington..
https://hdl.handle.net/21.15107/rcub_cherry_2984

Chen J, Unjaroen D, Stepanović S, van Dam A, Gruden-Pavlović M, Browne WR. Supplementary material for the article: Chen, J.; Unjaroen, D.; Stepanovic, S.; Van Dam, A.; Gruden, M.; Browne, W. R. Selective  Photo-Induced Oxidation with O 2 of a Non-Heme Iron(III) Complex to a Bis(Imine Pyridyl)Iron(II) Complex. Inorganic Chemistry 2018, 57 (8), 4510–4515. https://doi.org/10.1021/acs.inorgchem.8b00187. in Inorganic Chemistry. 2018;.
https://hdl.handle.net/21.15107/rcub_cherry_2984 .

Chen, Juan, Unjaroen, Duenpen, Stepanović, Stepan, van Dam, Annie, Gruden-Pavlović, Maja, Browne, Wesley R., "Supplementary material for the article: Chen, J.; Unjaroen, D.; Stepanovic, S.; Van Dam, A.; Gruden, M.; Browne, W. R. Selective  Photo-Induced Oxidation with O 2 of a Non-Heme Iron(III) Complex to a Bis(Imine Pyridyl)Iron(II) Complex. Inorganic Chemistry 2018, 57 (8), 4510–4515. https://doi.org/10.1021/acs.inorgchem.8b00187" in Inorganic Chemistry (2018),
https://hdl.handle.net/21.15107/rcub_cherry_2984 .

TY  - DATA
AU  - Chen, Juan
AU  - Stepanović, Stepan
AU  - Draksharapu, Apparao
AU  - Gruden-Pavlović, Maja
AU  - Browne, Wesley R.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3148
PB  - Wiley-V C H Verlag Gmbh, Weinheim
T2  - Angewandte Chemie (International Edition)
T1  - Supplementary material for the article: Chen, J.; Stepanovic, S.; Draksharapu, A.; Gruden, M.; Browne, W. R. A Non-Heme Iron  Photocatalyst for Light-Driven Aerobic Oxidation of Methanol. Angewandte Chemie -  International Edition 2018, 57 (12), 3207–3211. https://doi.org/10.1002/anie.201712678
UR  - https://hdl.handle.net/21.15107/rcub_cherry_3148
ER  - 

@misc{
author = "Chen, Juan and Stepanović, Stepan and Draksharapu, Apparao and Gruden-Pavlović, Maja and Browne, Wesley R.",
year = "2018",
publisher = "Wiley-V C H Verlag Gmbh, Weinheim",
journal = "Angewandte Chemie (International Edition)",
title = "Supplementary material for the article: Chen, J.; Stepanovic, S.; Draksharapu, A.; Gruden, M.; Browne, W. R. A Non-Heme Iron  Photocatalyst for Light-Driven Aerobic Oxidation of Methanol. Angewandte Chemie -  International Edition 2018, 57 (12), 3207–3211. https://doi.org/10.1002/anie.201712678",
url = "https://hdl.handle.net/21.15107/rcub_cherry_3148"
}

Chen, J., Stepanović, S., Draksharapu, A., Gruden-Pavlović, M.,& Browne, W. R.. (2018). Supplementary material for the article: Chen, J.; Stepanovic, S.; Draksharapu, A.; Gruden, M.; Browne, W. R. A Non-Heme Iron  Photocatalyst for Light-Driven Aerobic Oxidation of Methanol. Angewandte Chemie -  International Edition 2018, 57 (12), 3207–3211. https://doi.org/10.1002/anie.201712678. in Angewandte Chemie (International Edition)
Wiley-V C H Verlag Gmbh, Weinheim..
https://hdl.handle.net/21.15107/rcub_cherry_3148

Chen J, Stepanović S, Draksharapu A, Gruden-Pavlović M, Browne WR. Supplementary material for the article: Chen, J.; Stepanovic, S.; Draksharapu, A.; Gruden, M.; Browne, W. R. A Non-Heme Iron  Photocatalyst for Light-Driven Aerobic Oxidation of Methanol. Angewandte Chemie -  International Edition 2018, 57 (12), 3207–3211. https://doi.org/10.1002/anie.201712678. in Angewandte Chemie (International Edition). 2018;.
https://hdl.handle.net/21.15107/rcub_cherry_3148 .

Chen, Juan, Stepanović, Stepan, Draksharapu, Apparao, Gruden-Pavlović, Maja, Browne, Wesley R., "Supplementary material for the article: Chen, J.; Stepanovic, S.; Draksharapu, A.; Gruden, M.; Browne, W. R. A Non-Heme Iron  Photocatalyst for Light-Driven Aerobic Oxidation of Methanol. Angewandte Chemie -  International Edition 2018, 57 (12), 3207–3211. https://doi.org/10.1002/anie.201712678" in Angewandte Chemie (International Edition) (2018),
https://hdl.handle.net/21.15107/rcub_cherry_3148 .