Trapped molecular species in N-doped TiO<Subscript>2</Subscript>

Nitrogen-doped TiO₂, a novel photocatalyst active in the decomposition of organic pollutants using visible light, contains several different types of paramagnetic centers. These are molecular species, such as NO and NO₂ radicals and other species, deeply interacting with the TiO₂ structure. All or part of these species is related to specific properties of the solid. Electron paramagnetic resonance has been employed to characterize the N-containing paramagnetic species present in N-doped anatase TiO₂ powders obtained via sol-gel synthesis. In the present work attention is focused on molecular species generated during the synthesis process and segregated in cavities of the TiO₂ structure.     

Electronic structure of a metal-organic copper spin-1/2 molecule: bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II)

The metal-organic molecule bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II) (Cu(CNdpm)2) (C24H36N2O4Cu, Cu(II)) is a copper spin-1/2 system with a magnetic moment of 1.05 +/- 0.04 muB/molecule, slightly smaller than the 1.215+/-0.02 muB/molecule for the larger size copper spin-1/2 system C36H48N4O4Cu.C4H8O (bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II) 4,4'-bipyridylethene-THF). There is generally good agreement between photoemission from vapor-deposited thin films of the C24H36N2O4Cu on Cu(111) and Co(111) and model calculations. Although this molecule is expected to have a gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, the molecule remains surprisingly well screened in the photoemission final state.     

The ales laboratory automation system

A systenm for the automation of the analytical activities of a chemical laboratory is described. The system dieals with investigations of physical and chemical characteristics of telecommunication materials for prototype development and quality control. The architecture, software development and interfacing of different analytical instruments (mainly for calorimetry, spectroscopy, electrochemistry, chromatography and mechanics) for the ALES (Automatzione del Laboratorio Elettrochimico SIP) system are discussed in terms of analytical and management performance.     

Ionic wind generator derived from a liquid filled capillary pin. Application to particle capture

A new fluid pin-based ionic wind generator applied to airborne pathogen collection combines the processes of air flow generation by ionic wind, electrospray and electrostatic particle collection. This new concept brings a breakthrough in integration as it combines these three phenomena with a single driving force in order to perform the four functions of an airborne pathogen sampler, namely air flow production, particle capture, sample phase transfer and collecting electrode decontamination. The characterizations presented in this article led to a proof of concept and demonstrated the device's performance for a compact and portable airborne pathogen collection system.     

ChemInform Abstract: A Route Toward the Generation of Thermally Stable Au Cluster Anions Supported on the MgO Surface.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

C2‐Symmetric Zirconocenes in the Polymerization of Conjugated Diolefins

C₂‐symmetric zirconocenes activated by methylaluminoxane were utilized as catalysts in the polymerization of 1,3‐diolefins. The results indicate that the most crowded catalytic precursor rac[CH₂(3‐tert‐butyl‐1‐indenyl)₂]ZrCl₂ ( 1 ) is also the most active one, giving 1,4‐polymerization of 1,3‐butadiene and (Z)‐1,3‐pentadiene and 1,2‐polymerization of (E)‐1,3‐pentadiene and 4‐methyl‐1,3‐pentadiene. Probably, the different behavior of 1 with respect to other C₂‐symmetric zirconocenes utilized is due to the different stability of the bond between the last inserted monomer unit and the metal, as well as to the coordination of incoming monomer.