Cristina Hofmann

Magnetic−Plasmonic Core−Shell Nanoparticles

Nanoparticles composed of magnetic cores with continuous Au shell layers simultaneously possess both magnetic and plasmonic properties. Faceted and tetracubic nanocrystals consisting of wustite with magnetite-rich corners and edges retain magnetic properties when coated with a Au shell layer, with the composite nanostructures showing ferrimagnetic behavior. The plasmonic properties are profoundly influenced by the high dielectric constant of the mixed iron oxide nanocrystalline core. A comprehensive theoretical analysis that examines the geometric plasmon tunability over a range of core permittivities enables us to identify the dielectric properties of the mixed oxide magnetic core directly from the plasmonic behavior of the core-shell nanoparticle.

TiO2 nanoparticles as a soft x-ray molecular probe

This communication reports the development of a TiO2-streptavidin nanoconjugate as a new biological label for X-ray bio-imaging applications; this new probe, used in conjunction with the nanogold probe, will make it possible to obtain quantitative, high-resolution information about the location of proteins using X-ray microscopy.

Addition of thianthrene cation radical to non-conjugated dienes—Part II: Addition to two double bonds

Reaction of thianthrene cation radical tetrafluoroborate with 1,5-hexadiene, 1,7-octadiene, 1,8-nonadiene and 1,9-decadiene in the molar ratio 4:1 caused addition to occur to one and both of each diene’s double bonds. A mixture of four adducts was thus obtained, namely a bisadduct (12a–d), a monoadduct (13a–d), a di(bis)adduct (14a–d) and a di(mono)adduct (15a–d). The di(mono)adducts (15b–d) were isolated and characterized with 1H and 13C NMR spectroscopy. Under the same condition of excess of cation radical, addition occurred to only one double bond of 1,4-cyclohexadiene and 1,5-cyclooctadiene. Addition to both double bonds was not observed. The bisadduct (16) of 1,4-cyclohexadiene was characterized with 1H and 13C NMR spectroscopy and X-ray crystallography. On activated alumina, 15b–d underwent fast opening of dicationic rings to form mixtures of (E, E) – (17b–d) and (E, Z)-di(5-thianthreniumyl)diene (18b–d) in which the (E, E)-isomer was dominant and was characterized with 1H and 13C NMR spectroscopy.

Mononuclear Iron Carbonyls without Hydrocarbon Ligands

This chapter is dedicated to mononuclear iron carbonyls without hydrocarbon ligands. Beginning with the simple mononuclear iron carbonyls, iron carbonyl hydrides and iron carbonyls with group 13, 14, and 15 ligands are treated in detail. In addition, the oxygen, sulfur, selenium, and tellurium donor ligands are discussed. The chapter also covers the fluoride, chloride, bromide, and iodide complexes.