Excited-State Charge Distribution of a Donor-π-Acceptor Zn Porphyrin Probed by N K-Edge Transient Absorption Spectroscopy.

Zinc porphyrin solar cell dyes with donor-π-acceptor architectures combine light absorber (π), electron-donor, and electron-acceptor moieties inside a single molecule with atomic precision. The donor-π-acceptor design promotes the separation of charge carriers following optical excitation. Here, we probe the excited-state electronic structure within such molecules by combining time-resolved X-ray absorption spectroscopy at the N K-edge with first-principles time-dependent density functional theory (TD-DFT) calculations.

Fundamentals of the NEA Thermochemical Database and its influence over national nuclear programs on the performance assessment of deep geological repositories.

For the last 30 years, the NEA Thermochemical Database (TDB) Project (www.oecd-nea.org/dbtdb/) has been developing a chemical thermodynamic database for elements relevant to the safety of radioactive waste repositories, providing data that are vital to support the geochemical modeling of such systems.

New generation solar cells: concepts, trends and perspectives.

Organic, dye-sensitized and perovskite solar cell technologies have triggered widespread interest in recent years due to their very promising potential towards a high solar electricity future. A number of important milestones have marked the roadmap of each sector on the way to today's outstanding performances, but there still remains plenty of scope for further improvement. The most influential landmarks, together with basic concepts and future perspectives, are unraveled in this review.

Modern synthetic tools toward the preparation of sophisticated phthalocyanine-based photoactive systems.

Phthalocyanines are ideal components in a variety of electronic applications due to their extraordinary photophysical characteristics combined with their synthetic versatility and robustness. They have attracted substantial attention in recent decades and are now established building blocks of sophisticated molecular materials. Synthetically, a great deal of this progress is attributed to the use of modern synthetic tools, which gave rise to phthalocyanine-based systems that could not have been envisaged in the past.

Sterically hindered phthalocyanines for dye-sensitized solar cells: influence of the distance between the aromatic core and the anchoring group.

A new phthalocyanine (Pc) bearing bulky peripheral substituents and a carboxylic anchoring group directly attached to the macrocycle has been prepared and used as a sensitizer in DSSCs, reaching 5.57% power conversion efficiency. In addition, an enhanced performance for the TT40 dye, previously reported by us, was achieved in optimized devices, obtaining a new record efficiency with Pc-sensitized cells.

Electron-donating behavior of few-layer graphene in covalent ensembles with electron-accepting phthalocyanines.

We describe herein the first example of highly exfoliated graphene covalently linked to electron accepting phthalocyanines. The functionalization of the nanocarbon surface with alkylsulfonyl phthalocyanines was attained by means of a "click" chemistry protocol. The new ensemble was fully characterized (thermogravimetric analysis, atomic force microscopy, transmission electron microscopy and Raman, as well as ground-state absorption) and was studied in terms of electron donor-acceptor interactions in the ground and in the excited state.

Linking photo- and redoxactive phthalocyanines covalently to graphene.

"Green" graphene: For the first time, the covalent attachment of a light-harvesting and electron-donating phthalocyanine to the basal plane of few-layer graphene is reported. Physicochemical characterizations reveal an ultrafast charge separation from the photoexcited phthalocyanine to few-layer graphene followed by a slower charge recombination.

Synthesis, in silico docking experiments of new 2-pyrrolidinone derivatives and study of their anti-inflammatory activity.

A new class of 2-pyrrolidinone derivatives was designed, synthesized, and tested for their antioxidant and anti-inflammatory activities. The compounds were evaluated for their inhibitory activity against LOX. The most potent among them, 14d [IC(50) 0.

Stereoselective synthesis of 2,4,5-trisubstituted piperidines via radical cyclization.

A novel approach to 2,4,5-trisubstituted piperidines is reported, involving the 6-exo cyclization of stabilized radicals onto α,β-unsaturated esters. Only two of the four possible diastereoisomers are observed, with diastereomeric ratios ranging from 3:2 to 40:1 when the radical stabilizing group is vinyl or phenyl. Cyclization of a (triethylsilyl)vinyl-stabilized radical gives the corresponding piperidine radical as a single diastereoisomer that may either be trapped by tributyltin hydride to afford the 2,4,5-trisubstituted piperidine or undergo a second 5-endo cyclization onto the (triethylsilyl)vinyl substituent to produce the 3,5,7-trisubstituted octahydro[2]pyrindene as a single diastereoisomer.

Alpha-carboxy-6-nitroveratryl: a photolabile protecting group for carboxylic acids.

The synthesis of a new photolabile protecting group for carboxylic acids, alpha-carboxy-6-nitroveratryl (alphaCNV), is described. Bromide 3, prepared in four steps from 3,4-dimethoxyphenylacetic acid, was used to alkylate carboxylic acids under mild conditions in good yield. Palladium-catalyzed deallylation afforded the acids 4a-h, which underwent rapid and quantitative photolysis at wavelengths longer than 300 nm to liberate the carboxylic acid in good to quantitative yield.