Synthesis and Photophysics of Coaxial Threaded Molecular Wires: Polyrotaxanes with Triarylamine Jackets
Artikel i vetenskaplig tidskrift, 2014

Conjugated polyrotaxanes jacketed with hole-transport groups have been synthesized from water-soluble polyrotaxanes consisting of a polyfluorene-alt-biphenylene (PFBP) conjugated polymer threaded through beta-cyclodextrin macrocycles. The hydroxyl groups of the oligosaccharides were efficiently functionalized with triphenylamine (TPA) so that every polyrotaxane molecule carries a coat of about 200 TPA units, forming a supramolecular coaxial structure. This architecture was characterized using a range of techniques, including small-angle X-ray scattering. Absorption of light by the TPA units results in excitation energy transfer (EET) and photoinduced electron transfer (ET) to the inner conjugated polymer core. These energy- and charge-transfer processes were explored by steady-state and time-resolved fluorescence spectroscopy, femtosecond transient absorption spectroscopy, and molecular modeling. The time-resolved measurements yielded insights into the heterogeneity of the TPA coat: those TPA units which are close to the central polymer core tend to undergo ET, whereas those on the outer surface of the polyrotaxane, far from the core, undergo EET. Sections of the backbone that are excited indirectly via EET tend to be more remote from the TPA units and thus are less susceptible to electron-transfer quenching. The rate of EET from the TPA units to the PFBP core was effectively modeled by taking account of the heterogeneity in the TPA-PFBP distance, using a distributed monopole approach. This work represents a new strategy for building and studying well-defined arrays of >100 covalently linked chromophores.

WHITE

P55

1995

P269

ANNALEN DER PHYSIK

ATOM FORCE-FIELD

CONJUGATED POLYROTAXANES

CYCLODEXTRIN

ARCHIVES OF MICROBIOLOGY

NATURE

BINARY BLENDS

V119

1978

PHOTOSYNTHETIC BACTERIA

CHARGE-TRANSPORT

DERMOTT G

ELECTROLUMINESCENCE

V2

P517

ELECTRON-TRANSFER

1948

AEHELIN LA

ENERGY-TRANSFER

RSTER T

V374

SUPRAMOLECULAR CONTROL

Författare

G. Sforazzini

University of Oxford

Axel Kahnt

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Michael Wykes

Université de Mons

Johannes K. Sprafke

University of Oxford

S. Brovelli

University College London (UCL)

Universita' degli Studi di Milano-Bicocca

D. Montarnal

University of California

F. Meinardi

Universita' degli Studi di Milano-Bicocca

F. Cacialli

University College London (UCL)

David Beljonne

Université de Mons

Bo Albinsson

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Harry L. Anderson

University of Oxford

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 118 4553-4566

Ämneskategorier

Fysikalisk kemi

DOI

10.1021/jp500624q