Search results for "Donor-Acceptor ensembles"

Topological effects of a rigid chiral spacer on the electronic interactions in donor-acceptor ensembles

2005

Two triads (donor-spacer-acceptor), etTTF-BN-C 6 0 (6) and ZnP-BN-C 6 0 (7), in which electron donors (i.e., exTTF or ZnP) are covalently linked to C 6 0 through a chiral binaphthyl bridge (BN), have been prepared in a multistep synthetic procedure starting from a highly soluble enantiomerically pure binaphthyl building block (1). Unlike other oligomeric bridges, with hinaphthyl bridges, the conjugation between the donor and the acceptor units is broken and geometric conformational changes are facilitated. Consequently, distances and electronic interactions between the donor and C 6 0 are drastically changed. Both donor-spacer-acceptor (D-s-A) systems (i.e., 6 and 7) exhibit redox processes…

Solid film versus solution-phase charge-recombination dynamics of exTTF-bridge-C60 dyads.

2005

The charge-recombination dynamics of two exTTF-C 6 0 dyads (exTTF=9,10-bis(l,3-dithiol-2-ylidene)-9,10-dihydroanthracene), observed after photoinduced charge separation, are compared in solution and in the solid state. The dyads differ only in the degree of conjugation of the bridge between the donor (exTTF) and the acceptor (C 6 0 ) moieties. In solution, photoexcitation of the nonconjugated dyad C 6 0 -BN-exTTF (1) (BN=1,1'-binaphthyl) shows slower charge-recombination dynamics compared with the conjugated dyad C 6 0 -TVB-exTTF (2) (TVB = bisthienylvinylenebenzene) (lifetimes of 24 and 0.6 μs, respectively), consistent with the expected stronger electronic coupling in the conjugated dyad.…

Probing molecular wire: synthesis of donor-acceptor ensembles exhibiting long range electron transfer

2005

A series of donor–acceptor arrays (C60–oligo-PPV–exTTF; 16–20) incorporating p-conjugated oligo(phenylenevinylene) wires (oligo-PPV) of different length between p-extended tetrathiafulvalene (exTTF) as electron donor and C60 as electron acceptor has been prepared by multistep convergent synthetic approaches. The electronic interactions between the three electroactive species present in 16–20 were investigated by UV-visible spectroscopy and cyclic voltammetry (CV). Our studies clearly show that, although the C60 units are connected to the exTTF donors through a p-conjugated oligo- PPV framework, no significant electronic interactions are observed in the ground state. Interestingly, photoindu…

Molecular wires - long range electron tunneling and hopping in novel donor-acceptor ensembles

2004