Upon slow admission of MeOH, the enantiomerically pure form of chiral amphiphilic porphyrin-fullerene dyad 1 in CH(2)Cl(2) self-assembles at 25 degrees C into nanofibers with a built-in donor/acceptor heterojunction, while its racemic form, under identical conditions, self-assembles into submicrometer-sized spheres with a donor/acceptor arrangement essentially different from that in the nanofiber assembly. Although a cast film of the latter hardly shows a photoconducting profile on micrometer-gap electrodes, the former sample clearly displays photoconduction with an ambipolar charge-transporting character. The electron and hole mobilities under zero electric field, as estimated from time-of-flight profiles, are 0.14 and 0.10 cm(2) V(-1) s(-1), respectively, which are comparable to or even better than those reported for top-class organic materials with a donor/acceptor heterojunction.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ja1014713 | DOI Listing |
J Phys Chem B
June 2022
Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1205 Geneva, Switzerland.
The excited-state properties of an amphiphilic porphyrin-fullerene dyad and of its porphyrin analogue adsorbed at the dodecane/water interface are investigated by using surface second-harmonic generation. Although the porphyrin is formally centrosymmetric, the second-harmonic spectra of both compounds are dominated by the intense Soret band of the porphyrin. Polarization-selective measurements and molecular dynamics simulations suggest an angle of about 45° between the donor-acceptor axis and the interfacial plane, with the porphyrin interacting mostly with the nonpolar phase.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2022
Institute for Problems of Chemical Physics of Russian Academy of Sciences,Semenov av. 1, Chernogolovka, Moscow Region 142432, Russia.
Photo-switchable organic field-effect transistors (OFETs) represent an important platform for designing memory devices for a diverse array of products including security (brand-protection, copy-protection, keyless entry, etc.), credit cards, tickets, and multiple wearable organic electronics applications. Herein, we present a new concept by introducing self-assembled monolayers of donor-acceptor porphyrin-fullerene dyads as light-responsive triggers modulating the electrical characteristics of OFETs and thus pave the way to the development of advanced nonvolatile optical memory.
View Article and Find Full Text PDFPhys Chem Chem Phys
November 2020
Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilova str. 38, 119991 Moscow, Russia.
Photoinduced intra- and interlayer electron transfer (ET) of doubly bridged donor-acceptor molecule, porphyrin-fullerene dyad (PF), was studied in single- and multi-layered Langmuir-Schäfer (LS) films and in LS films, where PF and an efficient electron donating polymer polyhexyltiophene (PHT) formed a bilayer PHT/PF and multi-layered PHT/PF structures. The ET through layers were investigated by a method, which measures the photovoltaic (PV) response proportional to the number of charge-separated (CS) states and to the CS distance between the electrons and holes formed in pulsed photo-excitation. Primary conclusions were, that ET starts as formations of CS dyads (PF) in single-layers, continues as long-range intra-layer charge migrations following interlayer CS between two adjacent monolayers.
View Article and Find Full Text PDFJ Phys Chem B
December 2020
Faculty of Engineering and Natural Science, Tampere University, P.O. Box 541, Tampere 33101, Finland.
Porphyrin-fullerene dyads were intensively studied as molecular donor-acceptor systems providing efficient photoinduced charge separation (CS). A practical advantage of the dyads is the possibility to tune its CS process by the porphyrin periphery modification, which allows one to optimize the dyad for particular applications. However, this tuning process is typically composed of a series of trial stages involving the development of complex synthetic schemes.
View Article and Find Full Text PDFChem Commun (Camb)
June 2020
Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, TX 76203-5017, USA.
The formation of a high-energy, long-lived radical ion-pair by electron transfer exclusively from the triplet excited state, is demonstrated in a newly synthesized platinum porphyrin-fullerene dyad, in which the porphyrin ring is modified with three electron rich triphenylamine entities. The spin selectivity of the electron transfer leading to the formation of the radical ion-pair is demonstrated using time-resolved optical and EPR spectroscopic techniques.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!