Synthesis and structural features of the first thallium(I) selenoether derivatives

The first evidence for thallium(I) complexes involving selenoether ligands is presented, together with the structure determinations for the 1D chain species [T1[MeSe(CH2)3SeMe]]PF6 and the 3D network species [T1[MeSe(CH2)2SeMe]]PF6.     

Peak Effect and the Phase Diagram of Moving Vortices in FexNi1-xZr2 Superconducting Glasses

In the mixed state of type II superconductors, vortices penetrate the sample and form a correlated system due to the screening of supercurrents around them. Interestingly, we can study this correlated system as a function of density and driving force. The density, for instance, is controlled by the magnetic field B, whereas a current density j acts as a driving force F=j x B on all vortices. To minimize the pinning strength, we study a superconducting glass in which the depinning current is 10 to 1000 times smaller than in previous studies, which enables us to map out the complete phase diagram in this new regime. The diagram is obtained as a function of B, driving current, and temperature, and leads to a remarkable set of new results, which includes a huge peak effect, an additional reentrant depinning phase, and a driving force induced pinning phase.     

A dicoordinate palladium(0) complex with an unusual intramolecular eta(1)-arene coordination

The reaction of (tmeda)PdMe2 with dcpBiph gives (dcpBiph)2Pd in high yield. The solid-state structure of (dcpBiph)2Pd reveals a bent P-Pd-P framework and an unusual eta1-arene interaction between the palladium and the distal ring of one of the biphenyl substituents. In solution, an additional conformer exists which does not show a pi-interaction with a biphenyl ring. The low-coordinate complex, (dcpBiph)2Pd, undergoes C-X oxidative addition reactions with PhX (X = I, Br, Cl). A minor product resulting from metalation of the biphenyl ring is also observed.     

Level crossing resonance detection of a muonic radical in sulphur

Detection of a level crossing resonance establishes that a molecular radical is created in elemental sulphur following the implantation of positive muons. Formally this is the product of the reaction of atomic muonium with the S₈ rings and must serve as a model for the fate of interstitial atomic hydrogen in this element. The isotropic component of the muon-electron hyperfine interaction is determined to be 233 ± 5 MHz. Preliminary data for the temperature dependence of the resonance linewidth indicates a substantial motional narrowing of the anisotropic components.     

Why ALC μSR is superior for gas‐phase radical spectroscopy

ALC μSR spectra of the muonated ethyl and cyclohexadienyl radicals in the gas phase are reported. They have surprisingly narrow lines for a magnetic resonance type technique under conditions near ambient temperature and near 1 atmosphere pressure. The main reason for this behaviour is the dramatic reduction of electron spin relaxation in high magnetic fields. This revised version was published online in August 2006 with corrections to the Cover Date.     

Residual polarization of negative muons implanted in C60 and K3C60

Negative muons captured by atoms with zero nuclear spin usually retain about 1/6 of their initial spin polarization P_0 after cascading down to their lowest Bohr orbital. This is particularly observed for μ^- implanted into graphite and diamond. However, μ^- implanted into a powder of the fullerene C₆₀ are found to show essentially zero residual polarization. A residual polarization of \sim P_0/6 is again seen in metallic K₃C₆₀. We speculate that these results are to be explained on the basis of hyperfine effects after completion of the muonic cascade. This revised version was published online in August 2006 with corrections to the Cover Date.     

Submillimetre laser and interferometric spectroscopy of the alkyl alcohols

The far-infrared power absorption of a series of alkyl alcohols has been measured with interferometry and laser spectroscopy. The two techniques are complementary and in good agreement. The vibrational COH torsion and O...H stretch have been analysed, particularly for methanol in dilute solutions.