Paramagnetic bridging hydrides of relevance to catalytic hydrogen evolution at metallosulfur centers.
Paramagnetic hydrides are likely intermediates in hydrogen-evolving enzymic and molecular systems. Herein we report the first spectroscopic characterization of well-defined paramagnetic bridging hydrides. Time-resolved FTIR spectroelectrochemical experiments on a subsecond time scale revealed that single-electron transfer to the μ-hydride di-iron dithiolate complex 1 generates a 37-electron valence-delocalized species with no gross structural reorganization of the coordination sphere. DFT calculations support and (1)H and (2)H EPR measurements confirmed the formation an S = ½ paramagnetic complex (g = 2.0066) in which the unpaired spin density is essentially symmetrically distributed over the two iron atoms with strong hyperfine coupling to the bridging hydride (A(iso) = -75.8 MHz).
Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
Aušra
A
Jablonskytė
Joseph A
JA
Wright
Shirley A
SA
Fairhurst
Jamie N T
JN
Peck
Saad K
SK
Ibrahim
Vasily S
VS
Oganesyan
Christopher J
CJ
Pickett
D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008280:Magnetics; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013455:Sulfur / Q000737:chemistry*
D009942:Organometallic Compounds; D013455:Sulfur; D006859:Hydrogen; D007501:Iron