The Role of the Laser-Induced Oxide Layer in the Formation of Laser-Induced Periodic Surface Structures.

Laser-induced periodic surface structures (LIPSS) are often present when processing solid targets with linearly polarized ultrashort laser pulses. The different irradiation parameters to produce them on metals, semiconductors and dielectrics have been studied extensively, identifying suitable regimes to tailor its properties for applications in the fields of optics, medicine, fluidics and tribology, to name a few. One important parameter widely present when exposing the samples to the high intensities provided by these laser pulses in air environment, that generally is not considered, is the formation of a superficial laser-induced oxide layer.

Femtosecond Laser Texturing of Surfaces for Tribological Applications.

Laser texturing is an emerging technology for generating surface functionalities on basis of optical, mechanical, or chemical properties. Taking benefit of laser sources with ultrashort (fs) pulse durations features outstanding precision of machining and negligible rims or burrs surrounding the laser-irradiation zone. Consequently, additional mechanical or chemical post-processing steps are usually not required for fs-laser surface texturing (fs-LST).

Multistep energy and electron transfer processes in novel rotaxane donor-acceptor hybrids generating microsecond-lived charge separated states.

A new set of [Cu(phen)] based rotaxanes, featuring [60]-fullerene as an electron acceptor and a variety of electron donating moieties, namely zinc porphyrin (ZnP), zinc phthalocyanine (ZnPc) and ferrocene (Fc), has been synthesized and fully characterized with respect to electrochemical and photophysical properties. The assembly of the rotaxanes has been achieved using a slight variation of our previously reported synthetic strategy that combines the Cu(i)-catalyzed azide-alkyne cycloaddition reaction (the "click" or CuAAC reaction) with Sauvage's metal-template protocol. To underline our results, complementary model rotaxanes and catenanes have been prepared using the same strategy and their electrochemistry and photo-induced processes have been investigated.

On-off switch of charge-separated states of pyridine-vinylene-linked porphyrin-C conjugates detected by EPR.

The design, synthesis, and electronic properties of a new series of D-π-A conjugates consisting of free base (HP) and zinc porphyrins (ZnP) as electron donors and a fullerene (C) as electron acceptor, in which the two electroactive entities are covalently linked through pyridine-vinylene spacers of different lengths, are described. Electronic interactions in the ground state were characterized by electrochemical and absorption measurements, which were further supported with theoretical calculations. Most importantly, charge-transfer bands were observed in the absorption spectra, indicating a strong - behavior.

Synthesis and photophysical properties of new catenated electron donor-acceptor materials with magnesium and free base porphyrins as donors and C60 as the acceptor.

A new series of nanoscale electron donor-acceptor systems with [2]catenane architectures has been synthesized, incorporating magnesium porphyrin (MgP) or free base porphyrin (H2P) as electron donor and C60 as electron acceptor, surrounding a central tetrahedral Cu(I)-1,10-phenanthroline (phen) complex. Model catenated compounds incorporating only one or none of these photoactive moieties were also prepared. The synthesis involved the use of Sauvage's metal template protocol in combination with the 1,3-dipolar cycloaddition of azides and alkynes ("click chemistry"), as in other recent reports from our laboratories.

25th anniversary article: 25 years of fullerene research in electron transfer chemistry.

The past 25 years have served as a test bed for exploring the chemistry and physics, in general, and the electron transfer chemistry, in particular, of low-dimensional carbon. Nevertheless, the new realm started with the advent of fullerenes, followed in chronological order by carbon nanotubes, and, more recently, by graphene. The major thrust of this Review article is to historically recap the versatility of fullerenes regarding the design, the synthesis, and the tests as an electroactive building block in photosynthetic reaction mimics, photovoltaics, and catalysis.