title: Sequential energy and electron transfer in polyisocyanopeptide-based multichromophoric arrays.
abstract: We report on the synthesis and detailed photo-physical investigation of four model chromophore side chain polyisocyanopeptides: two homopolymers of platinum-porphyrin functionalized polyisocyanopeptides (Pt-porphyrin-PIC) and perylene-bis(dicarboximide) functionalized polyisocyanopeptides (PDI-PIC), and two statistical copolymers with different ratios of Pt-porphyrin and PDI molecules attached to a rigid, helical polyisocyanopeptide backbone. (1)H NMR and circular dichroism measurements confirm that our model compounds retain a chiral architecture in the presence of the chromophores. The combination of Pt-porphyrin and PDI chromophores allows charge- and/or energy transfer to happen. We observe the excitation and relaxation pathways for selective excitation of the Pt-porphyrin and PDI chromophores. Studies of photoluminescence and transient absorption on nanosecond and picosecond scales upon excitation of Pt-porphyrin chromophores in our multichromophoric assemblies show similar photophysical features to those of the Pt-porphyrin monomers. In contrast, excitation of perylene chromophores results in a series of energy and charge transfer processes with the Pt-porphyrin group and forms additional charge-transfer states, which behave as an intermediate state that facilitates electronic coupling in these multichromophoric systems.
authors.affiliation: Optoelectronics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom. ysh21@cam.ac.uk
authors.forename: Ya-Shih
authors.initials: YS
authors.lastname: Huang
authors.forename: Xudong
authors.initials: X
authors.lastname: Yang
authors.forename: Erik
authors.initials: E
authors.lastname: Schwartz
authors.forename: Li Ping
authors.initials: LP
authors.lastname: Lu
authors.forename: Sebastian
authors.initials: S
authors.lastname: Albert-Seifried
authors.forename: Chris E
authors.initials: CE
authors.lastname: Finlayson
authors.forename: Matthieu
authors.initials: M
authors.lastname: Koepf
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Kitto
authors.forename: Burak
authors.initials: B
authors.lastname: Ulgut
authors.forename: Matthijs B J
authors.initials: MB
authors.lastname: Otten
authors.forename: Jeroen J L M
authors.initials: JJ
authors.lastname: Cornelissen
authors.forename: Roeland J M
authors.initials: RJ
authors.lastname: Nolte
authors.forename: Alan E
authors.initials: AE
authors.lastname: Rowan
authors.forename: Richard H
authors.initials: RH
authors.lastname: Friend
mesh_terms: D004583:Electrons; D004735:Energy Transfer; D017953:Isocyanates / Q000138:chemical synthesis / Q000737:chemistry*; D009944:Organoplatinum Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D055668:Photochemical Processes; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D017953:Isocyanates; D009944:Organoplatinum Compounds; D010455:Peptides; D011108:Polymers