Reversible light-driven redox switching of multifunctional dipolar ruthenium(III/II) pentaammine(4,4'-bipyridinium) complexes

We report the first example of a molecular switch of multifunctional dipolar ruthenium(III/II) pentaammine-N-methyl-(4,4'-bipyridinium) complexes, exclusively driven by light. This is achieved by using a two-phase (water/benzene) system in which RuIII/II complexes are soluble only in the water phase. The reversible redox switching is triggered by the selective irradiation of the water and the benzene compartments with 254 and 528 nm light, respectively.     

Nitrophenyl derivatives of pyrrole 2,5-diamides: structural behaviour,anion binding and colour change signalled deprotonation

Two new pyrrole 2,5-diamide clefts have been synthesized containing 4-nitrophenyl or 3,5-dinitrophenyl groups appended to the amide positions. The 3,5-dinitrophenyl derivative has been shown to deprotonate in the presence of fluoride, which in acetonitrile solution, gives rise to a deep blue colour.     

Generation and intramolecular reactivity of acyl radicals from alkynylthiol esters under reducing tin-free conditions

[reaction: see text] The radical chain reaction of benzenethiol with alkynylthiol esters provides a new, valuable protocol for the tin-free generation of acyl radicals that arise from intramolecular substitution at sulfur by the initial sulfanylvinyl radicals.     

Ettore Majorana’s Course on Theoretical Physics: A Recent Discovery

We analyze in some detail the course that Ettore Majorana gave on theoretical physics at the University of Naples between January and March 1938, just prior to his mysterious disappearance. We discuss, in particular, the recently discovered Moreno Lecture Notes, in which all of Majorana’s lectures are recorded, six of which are not present in those that are preserved in the Domus Galilaeana in Pisa, Italy. Antonino Drago is a retired professor of history of physics at the University of Naples “Federico II.” Salvatore Esposito is a researcher on theoretical physics and history of physics at the University of Naples “Federico II.”     

Nickel nanostructured materials from liquid phase photodeposition

Liquid Phase Photo-Deposition (LPPD) technique has been used to obtain both colloidal particles and thin films of metallic and chloride nickel from solutions of only precursor Ni(acac)₂ (acac=2,4-pentandionato). Metallic nickel was obtained from ethanol solutions by direct nickel(II) photoreduction at 254 nm and by acetone sensitised reaction at 300 nm. In this latter process the rate was higher than in the first one. NiCl₂ was formed from CCl₄ solution by a solvent-initiated reaction. TEM analysis, performed on colloidal particles of nickel, showed that their dimensions are in the range 2–4 nm. The films did not present carbon contamination and were characterized by AFM, XPS and GIXRD. Metallic films consisted of particles of 20–40 nm that are the result of the aggregation of smaller crystallites (4–5 nm). Larger agglomerations (around 200 nm) have been observed for NiCl₂ films.     

Deposition and properties of high-carbon iron films

Thin high-carbon iron films were deposited by pulsed laser deposition onto grids for transmission electron microscopy using pre-combined carbon/iron targets with equal area ratio. The deposited films of about 20 nm in thickness were directly characterized by transmission electron microscopy. The films showed a variety of phases, surprisingly also including the NaCl-type FeC phase, which was theoretically predicted in the literature. For comparison, thin high-carbon stainless-steel films were deposited onto oxidized Si wafers with different carbon ratios in the targets (10, 20, 40 and 50 at.%). These films were characterized by means of Mössbauer Spectroscopy, the magneto-optical Kerr-effect, grazing incidence X-ray diffraction and Rutherford backscattering spectrometry. With these methods clearly defined multilayer-structures were observed which could lead to interesting magneto-resistance phenomena if the thickness of the multilayers can be controlled by the processing parameters.     

A Combined Theoretical and Experimental Approach to the Study of the Structural and Electronic Properties of Curcumin as a Function of the Solvent

Curcumin, a chemical compound present in the well-known Indian spice turmeric, has uses in many different fields ranging from medicinal chemistry to the dye industry. Its poor water solubility, though, makes Curcumin difficult to handle, making it less appealing for potential uses. The principal aim of this work is to perform a computational study of the structural and electronic properties of Curcumin {IUPAC name: 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione} in several solvents, and a comparison with experimental data. Rotameric equilibria, vibrational and thermochemical analysis, and electronic absorption spectra (with ab initio and semi-empirical methodologies) have been studied, both in vacuum and in three selected solvents. Different computational techniques have been applied and the results compared. Combined approaches resulted in very satisfactory results. Interesting results have emerged, which suggest subsequent investigations about the nature of the excited states and potential derivatives of Curcumin that possibly have non-linear optical applications, as a π-core for innovative materials in laser engineering and photonics.