Triazole Bridges as Versatile Linkers in Electron Donor–Acceptor Conjugates

Abstract

Aromatic triazoles have been frequently used as π-conjugated linkers in intramolecular electron transfer processes. To gain a deeper understanding of the electron mediating function of triazoles, we have synthesized a family of new triazole-based electron donor-acceptor conjugates. We have connected porphyrins and fullerenes through a central triazole moiety – (ZnP-Tri-C60) – each with a single change in their connection through the linker. An extensive photophysical and computational investigation reveals that the electron transfer dynamics – charge separation and charge recombination – in the different ZnP-Tri-C60 conjugates reflect a significant influence of the connectivity at the triazole linker. Except for m4m-ZnP-Tri-C60 17, the conjugates exhibit through-bond electron transfer with varying rate constants. Since the through-bond distance is nearly equal in the ZnP-Tri-C60 conjugates, the variation in charge separation and charge recombination dynamics is mainly associated with the electronic properties of the conjugates, including orbital energies, electron affinity, and the energies of the excited states. The changes of the electronic couplings are, in turn, a consequence of the different connectivity patterns at the triazole moieties.

“Click”-reaction: An alternative tool for new architectures of porphyrin based derivatives

“…In a following report, photoactive, multicomponent supermolecules 13 and 14 ( Figure 5) were synthesized where a porphyrin unit is covalently linked to a Dawsontype heteropolyphosphotungstate (POM) [83]. The connection has been made via a Guldi and coworkers synthesized artificial photosynthetic systems 15-17 ( Figure 6) incorporated of an electron donor, an electron acceptor and a bridging unit [84]. In this research the donor is a porphyrin, the acceptor a C 60 molecule and the bridge is a triazole unit.…”

Light‐Harvesting Materials for Organic Electronics

“…De Miguel et al [10] have recently prepared a series of porphyrin-fullerene dyads (1), connected through different triazole-containing linking bridges by means of click chemistry reactions ( Fig. 9.2).…”

Microwave‐Assisted Cycloaddition Reactions

“…The pure m,4,p-ZnP-triazole-benzaldehyde (11) Interestingly,Özçubukçu et al [14] developed an efficient method for the preparation of 1,4-disubstituted-1,2,3-triazoles (14) by one-pot azide formation plus MW-irradiated CuAAC reaction using the new catalyst 3·CuCl. Taking into account the interest in avoiding storage and manipulation of organyl azides, the use of 3·CuCl in a one pot process involving the in situ formation of a benzyl-or alkylazides generated from the corresponding bromides (13) The duplex stability of modified oligonucleotides was also studied by Kocalka et al [17], who used a one-pot azidation procedure under MW irradiation to form different 2 -deoxyuridines substituted at the 5-position by a 1,2,3-triazole ring. The nucleoside analogs 20 were then introduced into nonamer oligonucleotides by phosphoramidite chemistry (Scheme 17.2).…”