Stereoselective photopolymerization of tetraphenylporphyrin derivatives on Ag(110) at the sub-monolayer level.

We explore a photochemical approach to achieve an ordered polymeric structure at the sub-monolayer level on a metal substrate. In particular, a tetraphenylporphyrin derivative carrying para-amino-phenyl functional groups is used to obtain extended and highly ordered molecular wires on Ag(110). Scanning tunneling microscopy and density functional theory calculations reveal that porphyrin building blocks are joined through azo bridges, mainly as cis isomers.

Chromium wheels quasi-hexagonal 2D assembling by direct UHV sublimation.

Chromium(III)-based wheels close-pack on the Ag(110) surface forming a quasi-hexagonal 2D network following direct sublimation in ultra high vacuum (UHV). Wheels organization and chemical integrity have been proved through in situ Scanning Tunneling Microscopy (STM) and X-ray Photoelectron Spectroscopy (XPS) studies.

Fullerene/porphyrin multicomponent nanostructures on Ag(110): from supramolecular self-assembly to extended copolymers.

A novel two-step bottom-up approach to construct a 2D long-range ordered, covalently bonded fullerene/porphyrin binary nanostructure is presented: in the first place, reversible supramolecular interactions between C60 and 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin are exploited to obtain large domains of an ordered binary network, subsequently a reaction between fullerene molecules and the amino-groups residing on porphyrin units, triggered by thermal treatment, is used to freeze the supramolecular nanostructure with covalent bonds. The resulting nanostructure resists high temperature treatments as expected for an extended covalent network, whereas very similar fullerene/porphyrin nanostructures held together only by weak interactions are disrupted upon annealing at the same or at lower temperatures.