Tetrahydroquinoline and tetrahydroisoquinoline mixed ligand rhenium complexes with the SNS/S donor atom set

New oxorhenium complexes with 3‐methylazapentane‐1,5‐dithiolate (SNMeS) and thiol functionalized monodentate tetrahydroquinolyl and tetrahydroisoquinolyl derivatives have been synthesized by simultaneous reaction of [PPh₃]₂[Re(O)Cl₃] with tridentate HSNMeSH and the corresponding N‐heterocycle containing thiol. The characterization of complexes involved elemental analysis, IR, ¹H and ¹³C NMR spectroscopy and X‐ray crystallographic analysis. The nature of the heterocycle in monodentate ligand, even situated at the distance of two methylene group length, has been found to have a significant influence on the molecular conformation. Metal complexes were found to be active in psychotropic in vivo and cytotoxicity in vitro screening. Copyright © 2007 John Wiley & Sons, Ltd.     

Recombination experiments at CRYRING

Recent advances in studies of electron-ion recombination processes at low relative energies with the electron cooler of the heavy-ion storage ring CRYRING are shown. Through the use of an adiabatically expanded electron beam, collisions down to 10^-4eV relative energies were measured with highly charged ions stored in the ring at around 15 MeV/amu energies. Examples of recombination measurements for bare ions of D⁺, He²⁺, N⁷⁺, Ne¹⁰⁺ and Si¹⁴⁺ are presented. Further on, results of an experiment measuring laser-induced recombination (LIR) into n=3 states of deuterium with polarized laser light are shown. This revised version was published online in July 2006 with corrections to the Cover Date.     

Recombination measurements at low energies with Ar16+ and Ar18+ ions in a dense, cold electron target

Recombination of multiply charged ions with electrons at very low relative energies has become a major topic of interest, due to the observation of rates which are enhanced beyond the expectations for radiative recombination. We present results for Ar¹⁶⁺ and Ar¹⁸⁺ ions from systematic measurements along the argon isonuclear sequence using a high density cold electron beam target (n_e = 7 × 10⁹ cm^-3) at the UNILAC of GSI. The transverse and longitudinal temperatures of the electron beam were determined from DR resonance features observed with metastable Ar¹⁶⁺ (2³S) ions. The rate at E_rel = 0 for radiative recombination of completely stripped Ar¹⁸⁺ calculated with electron beam temperatures kT_∥ = 0.002 eV, kT_⊥ = 0.2 eV amounts to α = 10^-9 cm³ s^-1. This is exceeded by nearly a factor of 10 by the rate measured in experiments with Ar¹⁸⁺ ions. This revised version was published online in August 2006 with corrections to the Cover Date.     

Recent dielectronic recombination experiments

New recombination experiments with merged cold beams of electrons and atomic ions have been carried out at the storage ring facilities TSR in Heidelberg, ESR in Darmstadt, and CRYRING in Stockholm. A brief overview is given on the recent activities in which the Giessen group was engaged. Topics of this research were dielectronic recombination (DR) of astrophysically relevant ions, recombination of highly charged ions with respect to cooling losses in storage rings, field effects on DR, search for interference effects in photorecombination of ions, correlation effects in DR of low-Z ions, spectroscopy of high-Z ions by DR, and lifetimes of metastable states deduced from DR experiments. This revised version was published online in July 2006 with corrections to the Cover Date.     

Efficient absorbing boundary conditions for Biot's equations in time-harmonic finite element applications

Absorbing boundary conditions for two phase media previously presented by Zerfa and Loret [Earthquake Eng. Struct. Dyn. 33, 89-110 (2004)] have been improved by considering additionally absorbing waves with auxiliary angles of incidence. These angles are defined at each point on the boundaries, so one can easily implement tensor impedances as analogous to those defined by Krenk and Kirkegaard for isotropic, nonporous media [J. Sound Vib. 247, 875-896 (2001)]. The boundary conditions have been tested and validated in two-dimensional frequency domain simulations.