Substrate-Gated Transformation of a Pre-Catalyst into an Iron-Hydride Intermediate [(NO)2(CO)Fe(μ-H)Fe(CO)(NO)2]- for Catalytic Dehydrogenation of Dimethylamine Borane

Yu-Ting Tseng; Vladimir Pelmenschikov; Linda Iffland-Mühlhaus; Donato Calabrese; Yu-Che Chang; Konstantin Laun; Chih-Wen Pao; Ilya Sergueev; Yoshitaka Yoda; Wen-Feng Liaw; Chien-Hong Chen; I-Jui Hsu; Ulf-Peter Apfel; Giorgio Caserta; Lars Lauterbach; Tsai-Te Lu

doi:10.1021/acs.inorgchem.2c03278

Substrate-Gated Transformation of a Pre-Catalyst into an Iron-Hydride Intermediate [(NO)₂(CO)Fe(μ-H)Fe(CO)(NO)₂]^- for Catalytic Dehydrogenation of Dimethylamine Borane

Inorg Chem. 2023 Jan 16;62(2):769-781. doi: 10.1021/acs.inorgchem.2c03278. Epub 2022 Dec 29.

Authors

Yu-Ting Tseng^{1

2}, Vladimir Pelmenschikov³, Linda Iffland-Mühlhaus⁴, Donato Calabrese⁵, Yu-Che Chang², Konstantin Laun³, Chih-Wen Pao⁶, Ilya Sergueev⁷, Yoshitaka Yoda⁸, Wen-Feng Liaw¹, Chien-Hong Chen⁹, I-Jui Hsu¹⁰, Ulf-Peter Apfel^{4

11}, Giorgio Caserta³, Lars Lauterbach⁵, Tsai-Te Lu^{1

2}

Affiliations

¹ Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
² Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
³ Institut für Chemie, Technische Universität Berlin, Berlin 10623, Germany.
⁴ Department of Chemistry and Biochemistry, Inorganic Chemistry Ι, Ruhr-Universität Bochum, Bochum 44801, Germany.
⁵ Institute of Applied Microbiology, RWTH Aachen University, Aachen 52074, Germany.
⁶ National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
⁷ Deutsches Elektronen-Synchrotron DESY, Hamburg D-22607, Germany.
⁸ JASRI, SPring-8, Sayo-gun, Hyogo 679-5198, Japan.
⁹ Department of Medical Applied Chemistry, Chung Shan Medical University and Department of Medical Education, Chung Shan Medical University Hospital, Taichung 40201, Taiwan.
¹⁰ Department of Molecular Science and Engineering, Research and Development Center of Smart Textile Technology, National Taipei University of Technology, Taipei 10608, Taiwan.
¹¹ Department for Electrosynthesis, Fraunhofer UMSICHT, Oberhausen 46047, Germany.

PMID: 36580657
DOI: 10.1021/acs.inorgchem.2c03278

Abstract

Continued efforts are made on the development of earth-abundant metal catalysts for dehydrogenation/hydrolysis of amine boranes. In this study, complex [K-18-crown-6-ether][(NO)₂Fe(μ-^MePyr)(μ-CO)Fe(NO)₂] (3-K-crown, ^MePyr = 3-methylpyrazolate) was explored as a pre-catalyst for the dehydrogenation of dimethylamine borane (DMAB). Upon evolution of H_2(g) from DMAB triggered by 3-K-crown, parallel conversion of 3-K-crown into [(NO)₂Fe(N,N'-^MePyrBH₂NMe₂)]^- (5) and an iron-hydride intermediate [(NO)₂(CO)Fe(μ-H)Fe(CO)(NO)₂]^- (A) was evidenced by X-ray diffraction/nuclear magnetic resonance/infrared/nuclear resonance vibrational spectroscopy experiments and supported by density functional theory calculations. Subsequent transformation of A into complex [(NO)₂Fe(μ-CO)₂Fe(NO)₂]^- (6) is synchronized with the deactivated generation of H_2(g). Through reaction of complex [Na-18-crown-6-ether][(NO)₂Fe(η²-BH₄)] (4-Na-crown) with CO_(g) as an alternative synthetic route, isolated intermediate [Na-18-crown-6-ether][(NO)₂(CO)Fe(μ-H)Fe(CO)(NO)₂] (A-Na-crown) featuring catalytic reactivity toward dehydrogenation of DMAB supports a substrate-gated transformation of a pre-catalyst [(NO)₂Fe(μ-^MePyr)(μ-CO)Fe(NO)₂]^- (3) into the iron-hydride species A as an intermediate during the generation of H_2(g).