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.     

Implantation of the 111In/Cd Probe as InO− Ion for Radioisotope Tracer Studies

A radioisotope ion implanter has been developed using a cesium-sputtering, negative ion source, which offers versatility and sustained operation. Employing the molecular ¹¹¹In¹⁶O⁻ ion, μCi activities of the radioisotope probe ¹¹¹In/Cd have been implanted into different material hosts. The implanted tracer activity has been shown to be sufficient for LTNO, NMRON and PAC. A new NMRON resonance for ¹¹¹InAg was observed at 75.08 MHz. In₂O₃ powder performed well as the radioisotope carrier in the ion source, with the ratio of radioisotope and parasitic ion current being typically 4 × 10⁻⁴.     

Hydroboration of an alkene by amine-boranes catalysed by a [Rh(PR3)2]+ fragment. Mechanistic insight and tandem hydroboration/dehydrogenation

The catalytic hydroboration of tert-butylethene using H(3)B·NMe(3) gives RH(2)B·NMe(3). With H(3)B·NMe(2)H tandem hydroboration under mild conditions/dehydrocoupling occurs that produces R(2)B=NMe(2) (R = H, CH(2)CH(2)(t)Bu).     

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]⁺.