Silicon vacancy containing two hydrogen atoms studied with electron paramagnetic resonance and infrared absorption spectroscopy

2002 ◽  
Vol 66 (23) ◽  
Author(s):  
P. Johannesen ◽  
R. Jakobsen ◽  
P. Stallinga ◽  
B. Bech Nielsen ◽  
J. R. Byberg
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Absorption Spectroscopy ◽  
Infrared Absorption ◽  
Infrared Absorption Spectroscopy ◽  
Hydrogen Atoms ◽  
Paramagnetic Resonance ◽  
Silicon Vacancy ◽  
Electron Paramagnetic

scholarly journals [FeFe]-Hydrogenase Maturation: H-Cluster Assembly Intermediates Tracked by Electron Paramagnetic Resonance, Infrared, and X-Ray Absorption Spectroscopy

2020 ◽  
Author(s):  
Brigitta Németh ◽  
Moritz Senger ◽  
Holly J. Redman ◽  
Pierre Ceccaldi ◽  
Joan Broderick ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Absorption Spectroscopy ◽  
Cluster Assembly ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Hydrogenase Maturation ◽  
Catalytically Active ◽  
X Ray Absorption ◽  
Electron Paramagnetic

[FeFe]-hydrogenase enzymes employ a unique organometallic cofactor for efficient and reversible hydrogen conversion. This so-called H-cluster consists of a [4Fe-4S] cubane cysteine-linked to a diiron complex coordinated by carbon monoxide and cyanide ligands and an azadithiolate ligand (adt = NH(CH2S)2). [FeFe]-hydrogenase apo-protein binding only the [4Fe-4S] sub-complex can be fully activated in vitro by the addition of a synthetic diiron site precursor complex ([2Fe]adt,). Elucidation of the mechanism of cofactor assembly will aid in the design of improved hydrogen processing synthetic catalysts. We combined in situ electron paramagnetic resonance, Fourier-transform infrared, and X-ray absorption spectroscopy to characterize intermediates of H-cluster assembly as initiated by mixing of the apo-protein (HydA1) from the green alga Chlamydomonas reinhardtii with [2Fe]adt. The three methods consistently show rapid formation of a complete H-cluster in the oxidized, CO-inhibited state (Hox-CO) already within seconds after the mixing. Moreover, FTIR spectroscopy support a model in which Hox-CO formation is preceded by a short-lived Hred´-CO like intermediate. Accumulation of Hox-CO was followed by CO release resulting in the slower conversion to the catalytically active state (Hox) as well as formation of reduced states of the H-cluster.

scholarly journals Ethanol–ethylene conversion mechanism on hydrogen boride sheets probed by in situ infrared absorption spectroscopy

2021 ◽  
Author(s):  
Asahi Fujino ◽  
Shin-ichi Ito ◽  
Taiga Goto ◽  
Ryota Ishibiki ◽  
Ryota Osuga ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Infrared Absorption ◽  
Infrared Absorption Spectroscopy ◽  
Dehydration Process ◽  
Ethanol Dehydration ◽  
Hydrogen Atoms ◽  
Ethylene Conversion

The catalytic ethanol dehydration process on hydrogen boride (HB) sheets are found to involve the hydrogen atoms of the HB sheets.

Sign in / Sign up

Export Citation Format

Share Document