David Vonlanthen

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In Europe, the compound 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy, Adam), in addition to cannabis, is the most abused illicit drug at all-night "techno" parties. Methods for the determination of MDMA and its metabolites, 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-dihydroxy-methamphetamine (HHMA), 3,4-methylenedioxyamphetamine (MDA),(More)
The conductance of a family of biphenyl-dithiol derivatives with conformationally fixed torsion angle was measured using the scanning tunneling microscopy (STM)-break-junction method. We found that it depends on the torsion angle phi between two phenyl rings; twisting the biphenyl system from flat (phi = 0 degrees ) to perpendicular (phi = 90 degrees )(More)
We present a combined experimental and theoretical study of the electronic transport through single-molecule junctions based on nitrile-terminated biphenyl derivatives. Using a scanning tunneling microscope-based break-junction technique, we show that the nitrile-terminated compounds give rise to well-defined peaks in the conductance histograms resulting(More)
In situ gap-mode Raman spectra were acquired in an electrochemical environment on a single-crystal gold electrode employing a Au(100)|4,4'-biphenyldithiol (BPDT)|Au-NP(55 nm) sandwich assembly. This geometry enabled an investigation of the influence of an applied electrochemical gate field on the conformational changes in nanojunctions, such as the torsion(More)
The influence of electron donors and electron acceptors of variable strength in the 4 and 4' position of 2 and 2' propyl-bridged axial chiral biphenyl cyclophanes on their atropisomerization process was studied. Estimated free energies ΔG(‡)(T) of the rotation around the central biphenyl bond which were obtained from (1)H-NMR coalescence measurements were(More)
A series of dicyanobiphenylcyclophanes 1-6 with various π-backbone conformations and characteristic n-type semiconductor properties is presented. Their synthesis, optical, structural, electrochemical, spectroelectrochemical, and packing properties are investigated. The X-ray crystal structures of all n-type rods allow the systematic correlation of(More)
The thermodynamics of the atropisomerisation of torsion angle restricted, axial chiral biphenyl-based push-pull cyclophanes were studied. Using (1)H NMR coalescence measurements the rotation barrier around the central C-C bond was determined to be 50 kJ mol(-1) for the propyl-bridged biphenyl derivative 1b, displaying only a negligible solvent dependence.(More)
OBJECTIVE The pharmacokinetics and pharmacodynamics of high-dose intravenous (i.v.), oral and rectal diacetylmorphine (diamorphine, heroin, DAM) preparations were compared. METHOD Two heroin-dependent patients participating in a heroin-assisted treatment program received single or repeated doses of 200 - 690 mg DAM i.v., orally (capsules,(More)
M. Bürkle,1,2 J. K. Viljas,3,4 D. Vonlanthen,5 A. Mishchenko,6 G. Schön,1,2,7 M. Mayor,2,5,7,* T. Wandlowski,6,† and F. Pauly1,2,8,‡ 1Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany 2Center for Functional Nanostructures, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany 3Low Temperature(More)
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