Vibrational characterization of a diiron bridging hydride complex – a model for hydrogen catalysis
Leland B. Gee, Vladimir Pelmenschikov, Hongxin Wang, Nakul Mishra, Yu‐Chiao Liu, Yoshitaka Yoda, Kenji Tamasaku, Ming‐Hsi Chiang, Stephen P. Cramer
Abstract
Fe-NRVS. Our combined approach demonstrates an asymmetric sharing of the hydride between the two iron sites that yields two nondegenerate Fe-μH/D stretching vibrations. The studied complex provides an important model relevant to biological hydrogen catalysis intermediates. The complex mimics proposals for the binuclear metal sites in [FeFe] and [NiFe] hydrogenases. It is also an appealing prototype for the 'Janus intermediate' of nitrogenase, which has been proposed to contain two bridging Fe-H-Fe hydrides and two protonated sulfurs at the FeMo-cofactor. The significance of observing indirect effects of the bridging hydride, as well as obstacles in its direct observation, is discussed in the context of biological hydrogen intermediates.