γ-irradiated [(CH3)4N]2SiF6 single crystal investigation by electron paramagnetic resonance technique
摘要:
In this study, gamma-irradiation damage centers in [(CH3)(4)N](2)SiF6 single crystal has been investigated by electron paramagnetic resonance spectroscopy (EPR) at room temperature. It has been found that gamma-irradiation produces the (CH3)<(N)overdot(+) radicals in this compound. The g factor and the hyperfine constant for H atoms, measured as 28.7 G, were found to be isotropic. The hyperfine coupling constant of the N nucleus, observed (CH3)(3)< (N)overdot >(+) hole radical in [(CH3)(4)N](2)SiF6 was found to be anisotropic with A(//) = 15 and A(perpendicular to) = 23 G, respectively. This means that each methyl groups rotate around the C-3 nu-axis and they also rotate around the C-3 nu-axis of (CH3)(3)<(N)over dot >(+) radical. These results were compared with the earlier studies in (CH3)(3)(N) over circle (+)radical and discussed. (c) 2006 Elsevier B.V. All rights reserved.
Direct syntheses of tetramethylammonium salts of complex fluoroanions
作者:R.Z. Gnann、R.I. Wagner、K.O. Christe
DOI:10.1016/s0022-1139(97)00022-5
日期:1997.7
The tetramethylammonium salts of BF4-, PF6-, SiF5-, SiF62-, GeF5- and GeF62- were prepared in high yields by direct synthesis from N(CH3)(3), CH3F and the corresponding Lewis acid at elevated temperature and pressure. Attempts to prepare anhydrous N(CH3)(4)F directly from N(CH3)(3) and CH3F at elevated temperature and pressure or by pyrolysis of some of the above tetramethylammonium complex fluoroanion salts were unsuccessful. (C) 1997 Elsevier Science S.A.