Hydrogen Production From Model Complexes of the [iron-Iron]- and [nickel-Iron]-Hydrogenase Active Sites

Unlike the [FeFe]-hydrogenases, model complexes for the [NiFe]-hydrogenases were unknown prior to the crystal structure in 1996. However, most synthetic efforts focused on structural models for the active site, and neglected the catalytically imperative hydride ligand. Thus, we sought a nickel-iron hydride complex to explore the relevant reactivity of the first (mu-H)Ni(mu-SR) 2Fe complex. We found that the previously reported (dppe)Ni(mu-pdt)Fe(CO) 3, a Ni(I)Fe(I) complex, reacted with acid to provide [(dppe)Ni(mu-H)(mu-pdt)Fe(CO) 3]+, the first nickel-iron hydride. After protonation, the hydride complex is amenable to substitution chemistry at the Fe(CO) 3 subunit. Further derivatives altering the Ni(diphosphine)(SR) 2 subunit have been achieved through an alternative synthetic procedure to the Ni(I)Fe(I) complex. All nickel-iron hydrides investigated are active catalysts for the reduction of protons. As the catalytic mechanism of [NiFe]-hydrogenase is widely speculative, the reactivity of this new class of nickel-iron hydrides offers powerful insights into Nature's catalytic mechanism. (Abstract shortened by UMI.).

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Barton, Bryan E.

Contributors dc:contributor

• Rauchfuss, Thomas B.

• Chemistry, Inorganic

Language dc:language

eng

Identifier

(MiAaPQ)AAI3455686

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84354