title: Ultrafast energy and electron transfers in structurally well addressable BODIPY-porphyrin-fullerene polyads.
abstract: Two electron transfer polyads built upon [C60]-[ZnP]-[BODIPY] (1) and [ZnP]-[ZnP](-[BODIPY])(-[C60]) (2), where [C60] = N-methyl-2-phenyl-3,4-fulleropyrrolidine, [BODIPY] = boron dipyrromethane, and [ZnP] = zinc(ii) porphyrin, were synthesized along with their corresponding energy transfer polyads [ZnP]-[BODIPY] (1a) and [ZnP]-[ZnP]-[BODIPY] (2a) as well as relevant models. These polyads were studied using cyclic voltammetry, DFT computations, steady state and time-resolved fluorescence spectroscopy, and fs transient absorption spectroscopy. The rates for energy transfer, kET, [BODIPY]* → [ZnP] are ∼2.8 × 1010s-1for both 1a and 2a, with an efficiency of 99%. Concurrently, the fast appearance of the [C60]-˙ anion for 1 and 2 indicates that the charge separation occurs on the 20-30 ps timescale with the rates of electron transfer, ket, [ZnP]*/[C60] → [ZnP]+˙/[C60]-˙ of ∼0.9 × 1010to ∼3.8 × 1010s-1. The latter value is among the fastest for these types of polyads. Conversely, the charge recombination operates on the ns timescale. These rates are comparable to or faster than those reported for other more flexible [C60]-[ZnP]-[BODIPY] polyads, which can be rationalized by the donor-acceptor separations.
authors.affiliation: Departement de chimie, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada. Pierre.Harvey@Usherbrooke.ca.
authors.forename: Di
authors.identifier: http://orcid.org/0000-0002-3777-6350
authors.initials: D
authors.lastname: Gao
authors.affiliation: Departement de chimie, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada. Pierre.Harvey@Usherbrooke.ca.
authors.forename: Shawkat M
authors.initials: SM
authors.lastname: Aly
authors.affiliation: Departement de chimie, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada. Pierre.Harvey@Usherbrooke.ca.
authors.forename: Paul-Ludovic
authors.initials: PL
authors.lastname: Karsenti
authors.affiliation: Departement de chimie, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada. Pierre.Harvey@Usherbrooke.ca.
authors.forename: Gessie
authors.initials: G
authors.lastname: Brisard
authors.affiliation: Departement de chimie, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada. Pierre.Harvey@Usherbrooke.ca.
authors.forename: Pierre D
authors.initials: PD
authors.lastname: Harvey