D2 Atmosphere Research Articles

Cationic Hydrogen Complexes of Rhenium. 2. Synthesis, Reactivity, and Competition Studies

Cationic rhenium dihydrogen complexes, [Re(H2)(PR3)2(CO)3]B(Ar‘)4 (PR3 = PCy3, PiPr3, PiPrPh2, PPh3; Ar‘ = 3,5-(CF3)2C6H3), have been prepared by the protonation of ReX(PR3)2(CO)3 (X = H, CH3) with [H(Et2O)2]B(Ar‘)4 under a hydrogen atmosphere. Deuterium is incorporated into the H2 ligand when placed under a D2 atmosphere and large JHD values (30−33 Hz) are consistent with a dihydrogen formulation. Relaxation data indicate very short T1min for these complexes. These complexes are susceptible to heterolytic cleavage of dihydrogen, and the reactivity with several bases has been investigated. Under vacuum or argon atmosphere the complexes readily lose hydrogen to form 16-electron complexes. In the solid state, [Re(PCy3)2(CO)3]B(Ar‘)4 exhibits an agostic interaction to a β C−H bond of the phosphine ligand. Variable-temperature 31P{1H} NMR spectra of [Re(PCy3)2(CO)3]B(Ar‘)4 indicate a dynamic process involving hindered rotation about the Re−P bond. Competition studies have been conducted, and the hydrogen bind...

Measurement of neutron emission from LiNbO3 fracture process in D2 and H2 atmosphere

We reproduced neutron emission in D2 atmosphere from a crushing process of lithium-niobate (LiNbO3) single crystal which was reported previously. The neutron rate was 1 count/h with a confidence level of 92% in D2 atmosphere; on the other hand no neutron was found in H2 atmosphere.

Thermal Extraction Behavior of He and D from He+-Implanted Yttrium Iron Garnet Annealed in D2

Thermal extraction behavior of He and D from He+-implanted yttrium iron garnet (Y3Fe5O12 or YIG) thin films annealed in D2 and activation energies of He and D in each trapping state have been investigated by means of a thermal desorption mass spectrometric (TDS) technique in order to clarify the effect of hydrogen on the effective anisotropy field change induced by ion implantation followed by D2 annealing. Four trapping states of He in He+-implanted YIG were observed when it was annealed under Ta=320°C at a constant pressure of 760 Torr. The residual He atoms shifted to stabler states when it was annealed at above Ta=350°C. Two trapping states of diffused D atoms which were extracted as a form of D2O were observed for two kinds of YIG samples annealed in D2 atmosphere. The relationship between effective anisotropy field change induced by ion implantation and the thermal extraction behavior of He and D was discussed against the annealing temperature.