Comparison of cobalt and nickel complexes with sterically demanding cyclic diphosphine ligands: Electrocatalytic H2 production by [Co(P tBu2NPh2)(CH3CN) 3](BF4)2

Eric S. Wiedner, Jenny Y. Yang, William G. Dougherty, W. Scott Kassel, R. Morris Bullock, M. Rakowski Dubois, Daniel L. Dubois

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The cyclic diphosphine ligands PtBu2N Ph2 and PtBu2N Bz2 have been synthesized and used to prepare new complexes of Co(II) and Ni(II) with the formula [M(Pt Bu2NR2)(CH3CN) n](BF4)2 (n = 2, 3). The products have been characterized by variable-temperature NMR data, X-ray diffraction studies, and cyclic voltammetry, and properties of the new complexes have been compared with those of previously studied complexes containing PPh 2NR2 ligands. The variation of either phosphorus or nitrogen substituents in these ligands can result in significant differences in the structure, electrochemistry, and reactivity of the metal complexes. [Co(PtBu2NPh 2)(CH3CN)3](BF4)2 is found to be an effective electrocatalyst for the formation of hydrogen using bromoanilinium tetrafluoroborate as the acid, with a turnover frequency of 160 s-1 and an overpotential of 160 mV. These cobalt derivatives are a promising class of catalysts for further study and optimization.

Original languageEnglish
Pages (from-to)5390-5401
Number of pages12
Issue number21
Publication statusPublished - Nov 8 2010


ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

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