Synergy of Electrostatic and π–π Interactions in the Realization of Nanoscale Artificial Photosynthetic Model Systems

Abstract

In the scientific race to build up photoactive electron donor-acceptor systems with increasing efficiencies,l ittle is knowna bout the interplay of their building blocks when integrated into supramolecular nanoscale arrays,p articularly in aqueous environments.Here,wedescribe an aqueous donoracceptor ensemble whose emergence as an anoscale material renders it remarkably stable and efficient. We have focused on at etracationic zinc phthalocyanine (ZnPc) featuring pyrenes, which shows an unprecedented mode of aggregation, driven by subtle cooperation between electrostatic and p-p interactions. Our studies demonstrate monocrystalline growth in solution and as ymmetry-breaking intermolecular charge transfer between adjacent ZnPcs upon photoexcitation. Immobilizing an egatively charged fullerene (C 60)a se lectron acceptor onto the monocrystalline ZnPc assemblies was found to enhance the overall stability,a nd to suppress the energy-wasting charge recombination found in the absence of C 60 .O verall, the resulting artificial photosynthetic model system exhibits ahigh degree of preorganization, which facilitates efficient charge separation and subsequent charge transport.

A Janus-Type Phthalocyanine for the Assembly of Photoactive DNA Origami Coatings

“…This effect can be explained by agglomeration or crowding of 1 caused by the higher ionic strength of 1x PBS. A similar effect was observed with pyrene-substituted cationic ZnPcs . The molecules are close enough to undergo exciton coupling, while the chemical design hinders cofacial aggregation or H-type stacking.…”

“…A similar effect was observed with pyrene-substituted cationic ZnPcs. 40 The molecules are close enough to undergo exciton coupling, while the chemical design hinders cofacial aggregation or H-type stacking.…”

Peripherally Crowded Cationic Phthalocyanines as Efficient Photosensitizers for Photodynamic Therapy

“…Similar observations have been reported for extremely bulky phenoxy-substituted Pcs and were ascribed to the formation of atypical aggregates that do not differ from monomers in the shape of the absorption spectrum. 19,26,27 The absorption spectra of quaternized Pcs 1Me and 2Me in PBS, in turn, were also characteristic of the monomeric form and perfectly overlapped the spectra in DMF. In contrast to Pc 2, a strong fluorescence emission was preserved this case.…”

A bioinspired hollow g-C3N4–CuPc heterostructure with remarkable SERS enhancement and photosynthesis-mimicking properties for theranostic applications

“…18,19 In combination with photosensitive Raman reporters such as metallophthalocyanine (MPc) acting as a photosynthetic pigment graed on the surface, the CM-SERS substrate-molecule system is prominent to mimic natural photosynthesis. 20 Similar to the photosynthetic thylakoid membrane incorporated with a water-oxidation centre and carbon dioxide-reduction centre, efficient energy transfer and photon conversions in a nanosized substratemolecule biomimetic system could proceed for optical and catalytic performances. 21 Particularly, inspired by thylakoids, a hollow organic semiconductor is a promising optical nanogenerator allowing for the direct generation of reactive electrons and holes on the shell with sufficient energy for redox chemistry.…”