title: Interactions in single wall carbon nanotubes/pyrene/porphyrin nanohybrids.
abstract: This work provides an in-depth look at a range of physicochemical aspects of (i) single wall carbon nanotubes (SWNT), (ii) pyrene derivatives (pyrene(+)), (iii) porphyrin derivatives (ZnP(8)()(-)() and H(2)()P(8)()(-)()), (iv) poly(sodium 4-styrenesulfonate), and (v) their combinations. Implicit in their supramolecular combinations is the hierarchical integration of SWNT (as electron acceptors), together with ZnP(8)()(-)() or H(2)()P(8)()(-)() (as electron donors), in an aqueous environment mediated through pyrene(+). This supramolecular approach yields novel electron donor-acceptor nanohybrids (SWNT/pyrene(+)/ZnP(8)()(-)() or SWNT/pyrene(+)/H(2)()P(8)()(-)()). In particular, we report on electrochemical and photophysical investigations that as a whole suggest sizeable and appreciable interactions between the individual components. The key step to form SWNT/pyrene(+)()/ZnP(8)()(-)() or SWNT/pyrene(+)()/H(2)()P(8)()(-)() hybrids is pi-pi interactions between SWNT and pyrene(+), for which we have developed for the first time a sensitive marker. The marker is the monomeric pyrene fluorescence, which although quenched is (i) only present in SWNT/pyrene(+) and (ii) completely lacking in just pyrene(+). Electrostatic interactions help to immobilize ZnP(8)()(-)() or H(2)()P(8)()(-)() onto SWNT/pyrene(+) to yield the final electron donor-acceptor nanohybrids. A series of photochemical experiments confirm that long-lived radical ion pairs are formed as a product of a rapid excited-state deactivation of ZnP(8)()(-)() or H(2)()P(8)()(-)(). This formation is fully rationalized on the basis of the properties of the individual moieties. Additional modeling shows that the data are likely to be relevant to the SWNTs present in the sample, which possess wider diameters.
authors.affiliation: Institute for Physical and Theoretical Chemistry, Egerlandstrasse 3, 91058 Erlangen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Ehli
authors.forename: G M Aminur
authors.initials: GM
authors.lastname: Rahman
authors.forename: Norbert
authors.initials: N
authors.lastname: Jux
authors.forename: Domenico
authors.initials: D
authors.lastname: Balbinot
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Francesco
authors.initials: F
authors.lastname: Paolucci
authors.forename: Massimo
authors.initials: M
authors.lastname: Marcaccio
authors.forename: Demis
authors.initials: D
authors.lastname: Paolucci
authors.forename: Manuel
authors.initials: M
authors.lastname: Melle-Franco
authors.forename: Francesco
authors.initials: F
authors.lastname: Zerbetto
authors.forename: Stéphane
authors.initials: S
authors.lastname: Campidelli
authors.forename: Maurizio
authors.initials: M
authors.lastname: Prato
mesh_terms: D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon; D011166:Porphyrins / Q000737:chemistry*; D011721:Pyrenes / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D037742:Nanotubes, Carbon; D011166:Porphyrins; D011721:Pyrenes