title: Luminescence quenching by photoinduced charge transfer between metal complexes in peptide nucleic acids.
abstract: A new scaffold for studying photoinduced charge transfer has been constructed by connecting a [Ru(Bpy)3](2+) donor to a bis(8-hydroxyquinolinate)2 copper [CuQ2] acceptor through a peptide nucleic acid (PNA) bridge. The luminescence of the [Ru(Bpy)3](2+*) donor is quenched by electron transfer to the [CuQ2] acceptor. Photoluminescence studies of these donor-bridge-acceptor systems reveal a dependence of the charge transfer on the length and sequence of the PNA bridge and on the position of the donor and acceptor in the PNA. In cases where the [Ru(Bpy)3](2+) can access the π base stack at the terminus of the duplex, the luminescence decay is described well by a single exponential; but if the donor is sterically hindered from accessing the π base stack of the PNA duplex, a distribution of luminescence lifetimes for the donor [Ru(Bpy)3](2+*) is observed. Molecular dynamics simulations are used to explore the donor-PNA-acceptor structure and the resulting conformational distribution provides a possible explanation for the distribution of electron transfer rates.
authors: Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
authors: Xing
authors: X
authors: Yin
authors: Jing
authors: J
authors: Kong
authors: Arnie
authors: A
authors: De Leon
authors: Yongle
authors: Y
authors: Li
authors: Zhijie
authors: Z
authors: Ma
authors: Emil
authors: E
authors: Wierzbinski
authors: Catalina
authors: C
authors: Achim
authors: David H
authors: DH
authors: Waldeck
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D004583:Electrons; D049449:Luminescence; D008163:Luminescent Measurements; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D020135:Peptide Nucleic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D055668:Photochemical Processes; D017378:Quinolinic Acid / Q000138:chemical synthesis / Q000737:chemistry*; D044366:Transition Temperature
chemical_list: C477453:6-hydroxyquinolinic acid; D009942:Organometallic Compounds; D020135:Peptide Nucleic Acids; C103599:bis(bipyridyl)ruthenium(II); D015082:2,2'-Dipyridyl; D003300:Copper; D017378:Quinolinic Acid