Our recent progress in understanding the function-determining photoinduced reaction steps in Ruthenium-polypyridin based dinuclear complexes for the photocatalytic hydrogen production is discussed. The work combines Resonance-Raman-scattering with electrochemistry, theoretical chemistry, X-ray absorption spectroscopy and time-resolved spectroscopy.The photoinduced electron transfer processes within Bis-(4,4'-di-tert-butyl-2,2'-bipyridine) ruthenium(II)-� (tetrapyrido [3,2-a:2',3'c:3'',2'',-h:2''',3'''-j]phenazine)dichloro-palladium(II)Ru-tpphz-Pd  (RuPd  ) and Ru-tpphz-Pt  are characterized in detail by resonance Raman1 and ultrafast time-resolved absorption spectroscopy. By comparing the photophysics of the complexes to model complexes the individual electron transfer steps are assigned to kinetic components and their solvent dependence is discussed.2 The resonance Raman data reveal that the initial excitation of the molecular ensemble is spread over the terminal tbbpy (4,4'-Di-tert-butyl-2,2'-bipyridine) and the tpphz (tetrapyrido[3,2-a:2',3'c:3'',2'',-h:2''',3'''-j]phenazine) ligands.3To decipher the electronic structure of long lived intermediates within the catalytic cycle, resonance Raman-spectroelectrochemistry is employed.4 The results reveal a distinct influence of the second metal ion, i.e. Pd or Pt, on the electrochemical properties of the complexes and � hence � on the nature of the intermediates formed. Furthermore, X-ray absorption measurements indicate the nature of the catalytically active species to be different in RuPd  and RuPt . The comprehensive spectroscopic approach enables to watch the individual steps of the catalytic function of the dinuclear complexes and infer design strategies for the photocatalyst.This work was financially supported by the Studienstiftung des deutschen Volkes, the Fonds der Chemischen Industrie and the Th�ringer Ministerium f�r Bildung, Wissenschaft und Kultur.References: [1] M. W�chtler et al. Coordination Chemistry Reviews 2012  , 256, 1479.[2] (a) S. Tschierlei et al. Chemistry, European Journal 2009  , 15, 7678; (b) C. Kuhnt et al. Physical Chemistry Chemical Physics 2010  , 12, 1357.[3] S. Tschierlei et al. Angew. Chem. Int. Ed. 2010  , 49, 3981.[4] L. Zedler et al. Journal of Physical Chemistry C 2013  , 117, 6669.

Watching a photocatalyst function: Spectroscopic implications for the design of supramolecular photocatalysts for the production of H<sub>2</sub>

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Watching a photocatalyst function: Spectroscopic implications for the design of supramolecular photocatalysts for the production of H2

Watching a photocatalyst function: Spectroscopic implications for the design of supramolecular photocatalysts for the production of H₂