The influence of the skin effect on gamma detected pulsed NMRON signals

The influence of the skin effect on single and triple (spin echo) gamma detected pulsed NMRON signals is calculated using a density matrix approach within a pure Zeeman manifold. For single pulse NMRON the turn angle dependences of the signals for uniform and exponential profiles of the resonant nuclei are presented for a typical inhomogeneous broadening applicable to intermediate mass impurities in ferromagnetic hosts. For triple pulse NMRON the baseline and principal spin echo amplitudes for equal resonant rf pulses are presented for the same inhomogeneous broadening. It is found that the skin effect leads to the form of pulsed NMRON signals that are in accord with experiment.     

Aerodynamic interference between high-speed slender bodies

Under supersonic flow conditions, slender bodies in close proximity induce aerodynamic interference effects. This paper aims to quantify the magnitude of the resulting interference loads and to understand the underlying flow-physics mechanisms that cause them. A pair of identical slender bodies are investigated through a series of wind-tunnel experiments and supporting computational fluid dynamics (CFD) predictions. The bodies induce a complex interference flowfield, which tends to be bespoke to each configuration. The flow features include impinging shock and expansion waves, conical shock reflections, strong skewing of the boundary-layer flows and shock diffraction. The effects of axial stagger, lateral separation and the strength of the primary disturbance flow field are evaluated. The interference loads are found to be most sensitive to the initial location of the primary disturbance but are also affected by its strength. In addition, maximum interference loads which equate to an effective incidence of up to 6° are observed. Finally, very good agreement is found between the measurements and the CFD predicted normal force and pitching moment.     

Nuclear magnetic resonance of thermally oriented nuclei

The more recent developments in the spectroscopy of Nuclear Magnetic Resonance on Oriented Nuclei (NMRON) are reviewed; both theoretical and experimental advances are summarised with applications to On-Line and Off-Line determination of magnetic dipole and electric quadrupole hyperfine parameters. Some emphasis is provided on solid state considerations with indications of where likely enhancements in technique will lead in conventional hyperfine studies.     

Tuning the [L2Rh···H3B·NR3]+ interaction using phosphine bite angle. Demonstration by the catalytic formation of polyaminoboranes

Efficient catalysts for the dehydrocoupling or dehydropolymerisation of H(3)B·NMe(x)H((3-x)) (x = 1, 2) have been developed by variation of the P-Rh-P angle in {Rh(Ph(2)P(CH(2))(n)PPh(2))}(+) fragments (n = 2-5).     

Domain effects near the order-disorder and order-order ferromagnetic transitions in Gd and Dy

The technique of transient enhancement of the ac initial susceptibility χ has been used to compare domain effects in the ferromagnetic-paramagnetic transition of Gd and the ferromagnetic-antiferromagnetic transition of Dy. The temperature hysteresis in both χ and enhanced χ in the AF region of Dy indicates the existence of domains. The results for Dy support the suggestion that the transition from ferromagnetic to antiferromagnetic order upon warming in the vicinity of the Curie temperature takes place via an intermediate, moment-bearing domain structure.     

Gold(I) and platinum(II) complexes with a new diphosphine ligand based on the cyclotriphosphazene platform

A new diphosphine ligand assembled on the cyclotriphosphazene platform forms linear chelate and dimetallic bridged complexes with Au(I) and a cis-chelate complex with Pt(II).     

Rhodium(I) Pincer Complexes of Nitrous Oxide

The synthesis of two well‐defined rhodium(I) complexes of nitrous oxide (N₂O) is reported. These normally elusive adducts are stable in the solid state and persist in solution at ambient temperature, enabling comprehensive structural interrogation by ¹⁵N NMR and IR spectroscopy, and single‐crystal X‐ray diffraction. These methods evidence coordination of N₂O through the terminal nitrogen atom in a linear fashion and are supplemented by a computational energy decomposition analysis, which provides further insights into the nature of the Rh–N₂O interaction.     

One‐Electron Oxidation of [M(PtBu3)2] (M=Pd,Pt): Isolation of Monomeric [Pd(PtBu3)2]+ and Redox‐Promoted C−H Bond Cyclometalation

Oxidation of zero‐valent phosphine complexes [M(P^tBu₃)₂] (M=Pd, Pt) has been investigated in 1,2‐difluorobenzene solution using cyclic voltammetry and subsequently using the ferrocenium cation as a chemical redox agent. In the case of palladium, a mononuclear paramagnetic Pd^I derivative was readily isolated from solution and fully characterized (EPR, X‐ray crystallography). While in situ electrochemical measurements are consistent with initial one‐electron oxidation, the heavier congener undergoes C−H bond cyclometalation and ultimately affords the 14 valence‐electron Pt^II complex [Pt(κ²_PC‐P^tBu₂CMe₂CH₂)(P^tBu₃)]⁺ with concomitant formation of [Pt(P^tBu₃)₂H]⁺.