title: Multichromophoric Perylenediimide-Silicon Phthalocyanine-C60System as an Artificial Photosynthetic Analogue.
abstract: Sequential photoinduced energy transfer followed by electron transfer and the formation of charge-separated states, which are primary events of natural photosynthesis, have been demonstrated in a newly synthesized multichromophoric covalently linked triad, PDI-SiPc-C60. The triad comprises a perylenediimide (PDI), which primarily fulfils antenna and electron-acceptor functionalities, silicon phthalocyanine (SiPc) as an electron donor, and fulleropyrrolidine (C60) as a second electron acceptor. The multi-step convergent synthetic procedure developed here produced good yields of the triad and control dyads, PDI-SiPc and SiPc-C60. The structures and geometries of the newly synthesized donor-acceptor systems have been established from spectral, computational, and electrochemical studies with reference to appropriate control compounds. Ultrafast energy transfer from1PDI* to SiPc in the case of PDI-SiPc and PDI-SiPc-C60was witnessed. An energy-level diagram established from spectral and electrochemical data suggested the formation of two types of charge-separated states, that is, PDI-SiPc.+-C60.-and PDI.--SiPc.+-C60from the1SiPc* in the triad, with generation of the latter being energetically more favorable. However, photochemical studies involving femtosecond transient spectroscopy revealed the formation of PDI-SiPc.+-C60.-as a major charge-separated product. This observation may be rationalized in terms of the closer spatial proximity to SiPc of C60compared to PDI in the triad. The charge-separated state persisted for a few nanoseconds prior to populating the3SiPc* state during charge recombination.
authors.affiliation: División de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. de la Universidad s/n, 03203, Elche, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Martín-Gomis
authors.affiliation: División de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. de la Universidad s/n, 03203, Elche, Spain.
authors.forename: Francisco
authors.identifier: http://orcid.org/0000-0003-3268-9335
authors.initials: F
authors.lastname: Peralta-Ruiz
authors.affiliation: Department of Chemistry, University of North Texas at Denton, 1155 Union Circle, #305070, Denton, TX, 76203-5017, USA.
authors.forename: Michael B
authors.identifier: http://orcid.org/0000-0003-1461-5594
authors.initials: MB
authors.lastname: Thomas
authors.affiliation: División de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. de la Universidad s/n, 03203, Elche, Spain.
authors.forename: Fernando
authors.identifier: http://orcid.org/0000-0002-4598-6024
authors.initials: F
authors.lastname: Fernández-Lázaro
authors.affiliation: Department of Chemistry, University of North Texas at Denton, 1155 Union Circle, #305070, Denton, TX, 76203-5017, USA.
authors.forename: Francis
authors.identifier: http://orcid.org/0000-0003-3815-8949
authors.initials: F
authors.lastname: D'Souza
authors.affiliation: División de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. de la Universidad s/n, 03203, Elche, Spain.
authors.forename: Ángela
authors.identifier: http://orcid.org/0000-0002-8835-2486
authors.initials: Á
authors.lastname: Sastre-Santos
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry*; D004579:Electron Transport; D004735:Energy Transfer; D037741:Fullerenes / Q000737:chemistry*; D007094:Imides / Q000138:chemical synthesis / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010569:Perylene / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D011759:Pyrrolidines / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D037741:Fullerenes; D007094:Imides; D007211:Indoles; D017646:Organosilicon Compounds; D045322:Photosynthetic Reaction Center Complex Proteins; D011759:Pyrrolidines; C521332:perylenediimide; C082854:silicon phthalocyanine; D010569:Perylene; C032519:pyrrolidine; C069837:fullerene C60
keywords: charge separation; excitation transfer; fullerenes; perylenediimide; phthalocyanines