The determination of an inhomogeneous linewidth for a strongly coupled adsorbate system

We present a set of experiments that provide a complete mapping of coherent and incoherent vibrational relaxation times for a molecule on a metal surface, CO/Ir{111}. Included is the first detection of a midinfrared photon echo from a metallic surface, some 15 years after the analogous measurement on a semiconductor surface, which sets a precedent for the ability to manipulate and rephase polarization on a subpicosecond time scale on surfaces. For the C-O stretch in a strongly dipole-coupled CO layer we obtain a total linewidth of 5.6 cm-1, composed of a homogeneous width of 2.7 cm-1 and an inhomogeneous contribution of 3.0 cm-1. Pure dephasing is negligible at liquid nitrogen temperatures, making CO/Ir{111} an attractive model system for quantum computing.     

Synthesis,crystal structures and magnetic properties of three Ni(II) complexes having NiN4 core with argentocyanide,terephthalate and dicyanamide ions: From discrete molecule to a helical network

This work describes the synthesis and X-ray crystallographic characterization of three nickel(II) complexes [Ni(3,2,3-tet){Ag(CN)₂}₂] (1), [Ni(3,2,3-tet)(μ-tp)]_n · 1.5nH₂O (2) and {[Ni(3,2,3-tet)(μ_1,5-dca)](ClO₄)}_n (3) where 3,2,3-tet = N,N′-bis(3-aminopropyl)-1,2-ethylenediamine, tp = terephthalate and dca = dicyanamide. Compound 1 is a heterotrinuclear discrete distorted octahedral molecule whereas compound 2 forms a 1D polymeric network and an extended 2D network is formed by intermolecular hydrogen bonding. Interestingly, two adjacent 1D chains execute a novel double-helical network constructed by Ni(II) and the bridging dca ligand in compound 3. The variable temperature magnetic susceptibility measurements for compounds 2 and 3 were also carried out.     

ZUR EXISTENZ VON “H3PS” UND SEINES RADIKALKATIONS IN DER GASPHASE

Abstract

Radialkationen der Zusammensetzung [H₃PS]⁺ (m/z66) entstehen beim EI-Zerfall (70eV) von ionisiertem Diethylphosphinsulfid Et₂HP(S). Aus der Analyse des Stoßaktivierungs(CA)-Massenspektrums der Ionen m/z 66 und aus thermochemischen Daten sowie den Ergebnissen semiempirischer MO-Rechnungen (MNDO) ergibt sich, daß bei ihnen die Struktur [H₂P-SH]^+. (C_s) gegenüber [H₃PS]^+. (C_3v) bzw. [HPSH₂]^+. (C_s) bevorzugt ist. Mittels der jüngeren Technik der Neutralisations-Reionisations-Massenspektrometrie (NRMS) konnte gezeigt werden, daß Ionen der Struktur [H₂PSH]^+. durch Neutralisation in Neutralmoleküle H₂P-SH übergeführt werden können, die in der verdünnten Gasphase stabil sind.     

Elucidating the Role of Dissolution in CeO2 Nanoparticle Plant Uptake by Smart Radiolabeling

The identification of major uptake pathways in plants is an important factor when evaluating the fate of manufactured nanoparticles in the environment and the associated risks. Using different radiolabeling techniques we were able to show a predominantly particulate uptake for CeO₂ nanoparticles in contrast to a possible uptake in the form of ionic cerium.     

An inverse eigenvalue problem and an associated approximation problem for generalized K-centrohermitian matrices

A partially described inverse eigenvalue problem and an associated optimal approximation problem for generalized K-centrohermitian matrices are considered. It is shown under which conditions the inverse eigenproblem has a solution. An expression of its general solution is given. In case a solution of the inverse eigenproblem exists, the optimal approximation problem can be solved. The formula of its unique solution is given.