Bernd Speiser

  • Citations Per Year
Learn More
The synthesis of Stöber silica particles as basis for redox modifications is optimized for desired properties, in particular diameter in a wide sub-micrometer range, spherical shape, monodispersity, the absence of porosity, and aggregation free isolability for characterization and later covalent modification. The materials are characterized by SEM, DLS,(More)
Nonporous spherical silica nanoparticles resulting from a controlled Stöber process are covalently surface modified with redox-active molecules. Ferrocene, a ruthenium(II) complex with an N2P2Cl2 ligand set, and a sterically hindered biphenylamine are used as modifiers. The resulting materials are characterized by physical, spectroscopic, electrochemical,(More)
A general method for the functionalization of silica surfaces with silicon hydride (Si-H) groups is described for four different preparations of silica. The silica surface is reduced in a two-step chlorination-reduction procedure within a simple gas-flow system at high temperatures. After initial dehydroxylation of the silica surface, silicon chloride(More)
Silicon hydride terminated silica surfaces were prepared at high temperatures by a chlorination-reduction sequence. SiH groups are desired for further surface modification as an alternative to the native silanol groups which are unfavorable for RPLC applications. Only few silanol groups remain in these materials and mostly SiH moieties with the highest(More)
Two in a row: A pentacene dimer in which both units are covalently linked through a [2.2]paracyclophane bridge, has been synthesized. The electronic properties of the molecule were elucidated by a combination of experimental and computational methods. Such molecules could lead to materials with improved charge-transport properties.
We describe a modeling software component Ecco, implemented in the C++ programming language. It assists in the formulation of physicochemical systems including, in particular, electrochemical processes within general geometries. Ecco's kinetic part then translates any user defined reaction mechanism into an object-oriented representation and generates the(More)
The boron-nitrogen-boron (BNB) zigzag edged benzo[fg]tetracene is accessible from 4-butyl-2,6-diphenylaniline in four steps in good yields. The two mesityl groups stabilize the boron centers toward nucleophilic attack and result in two enantiomeric forms in the solid state. The title compound has a large optical gap, shows blue fluorescence, and is quite(More)
Sulfur-bridged binuclear structures [2M-2S] play a pivotal role in a variety of chemical processes such as bond breaking and formation and electron transfer. In general, structural persistence is deemed essential to the respective function but due to the lack of a suitable molecular model system current understanding of the factors that control(More)