title: [2,2']paracyclophane-based π-conjugated molecular wires reveal molecular-junction behavior.
abstract: The electronic coupling as well as the attenuation factor (β), which depends primarily on the nature of the molecular bridge and is used as a benchmark to test the molecular wire behavior, have been determined in a systematic study carried out on a series of ZnP/C(60) conjugates connected through a [2,2']paracyclophane-oligophenylenevinylene (pCp-oPPV). The convergent synthesis involves a series of Horner-Emmons olefination reactions or double palladium-catalized Heck-type reactions. ZnP-pCp-C(60) conjugates were finally obtained by the 1,3-dipolar cycloaddition reaction of the in situ-generated azomethyne ylide containing the ZnP-pCp moiety to the [60]fullerene using Prato conditions. Experimental (UV-vis, fluorescence, transient absorption spectroscopy, and solution electrochemistry) and theoretical studies revealed that the pCps act as molecular junctions. If hole transfer is assumed to be the dominant charge transfer (CT) mechanism, CT is facilitated in one direction (from C(60) to ZnP via pCp) but disfavored in the other direction (from ZnP to C(60) via pCp).
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, Madrid, Spain.
authors.forename: Agustín
authors.initials: A
authors.lastname: Molina-Ontoria
authors.forename: Mateusz
authors.initials: M
authors.lastname: Wielopolski
authors.forename: Julian
authors.initials: J
authors.lastname: Gebhardt
authors.forename: Andreas
authors.initials: A
authors.lastname: Gouloumis
authors.forename: Timothy
authors.initials: T
authors.lastname: Clark
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín
mesh_terms: D002384:Catalysis; D003500:Cyclization; D037741:Fullerenes / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D011083:Polycyclic Compounds / Q000737:chemistry*; D011524:Protoporphyrins / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D037741:Fullerenes; D011083:Polycyclic Compounds; D011524:Protoporphyrins; C515344:(2.2)paracyclophane; C017803:zinc protoporphyrin; D010165:Palladium; C069837:fullerene C60