title: Carbene based photochemical molecular assemblies for solar driven hydrogen generation.
abstract: Novel photocatalysts based on ruthenium complexes with NHC (N-heterocyclic carbene)-type bridging ligands have been prepared and structurally and photophysically characterised. The identity of the NHC-unit of the bridging ligand was established unambiguously by means of X-ray structural analysis of a heterodinuclear ruthenium-silver complex. The photophysical data indicate ultrafast intersystem crossing into an emissive and a non-emissive triplet excited state after excitation of the ruthenium centre. Exceptionally high luminescence quantum yields of up to 39% and long lifetimes of up to 2 μs are some of the triplet excited state characteristics. Preliminary studies into the visible light driven photocatalytic hydrogen formation show no induction phase and constant turnover frequencies that are independent on the concentration of the photocatalyst. In conclusion this supports the notion of a stable assembly under photocatalytic conditions.
authors.affiliation: Friedrich-Alexander-Universität Erlangen-Nürnberg, Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Egerlandstrasse 3, 91058 Erlangen, Germany. dirk.guldi@chemie.uni-erlangen.de.
authors.forename: Katrin
authors.initials: K
authors.lastname: Peuntinger
authors.forename: T David
authors.initials: TD
authors.lastname: Pilz
authors.forename: Robert
authors.initials: R
authors.lastname: Staehle
authors.forename: Markus
authors.initials: M
authors.lastname: Schaub
authors.forename: Simon
authors.initials: S
authors.lastname: Kaufhold
authors.forename: Lydia
authors.initials: L
authors.lastname: Petermann
authors.forename: Markus
authors.initials: M
authors.lastname: Wunderlin
authors.forename: Helmar
authors.initials: H
authors.lastname: Görls
authors.forename: Frank W
authors.initials: FW
authors.lastname: Heinemann
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Thomas
authors.initials: T
authors.lastname: Drewello
authors.forename: Johannes G
authors.initials: JG
authors.lastname: Vos
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Sven
authors.initials: S
authors.lastname: Rau
mesh_terms: D002384:Catalysis; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry; D055664:Electrochemical Techniques; D006571:Heterocyclic Compounds / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D008024:Ligands; D008027:Light; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008968:Molecular Conformation; D011725:Pyridines / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013053:Spectrophotometry
chemical_list: D056831:Coordination Complexes; D006571:Heterocyclic Compounds; D008024:Ligands; D011725:Pyridines; C030011:carbene; D012834:Silver; D012428:Ruthenium; D006859:Hydrogen; D008697:Methane