1H NMR study of proton dynamics in (NH4)1-zRbz3H(SO4)2(z=0.54)

摘要：

Proton dynamics in (NH4)1-xRbx3H(SO4)2 with x=0.54 has been studied by means of 1H solid-state NMR. The 1H magic-angle-spinning (MAS) NMR spectra were traced at room temperature (RT), and 1H static NMR spectra and spin-lattice relaxation times (T1) were measured in the range of 296-490 K. The 1H chemical shift for the acidic proton (15.4 ppm) indicates hydrogen bonds of intermediate strength between (NH4)3H (SO4)2 and Rb3H(SO4)2. In phase II, a very fast local and anisotropic motion of the acidic protons takes place and NH4+ions start to diffuse translationally just below the transition temperature. In phase I, both NH4+ions and the acidic protons diffuse translationally. The acidic protons diffuse with an activation energy of 29 kJ mol-1 and the inverse of a frequency factor of 6.0×10-13 s. No proton exchange is observed between NH4+ions and the acidic protons in both phases.

关键词： Proton dynamics Proton diffusion Inorganic solid acid Nuclear magnetic resonance Solid state NMR

作者: Hironori Omi Koh-ichi Suzuki Shigenobu Hayashi

作者单位: Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan

会议类型: 国际会议

会议名称: The 16th International Conference on Solid State Ionics(第十六届国际固态离子学会议)

会议地点: 上海

会议语种:英文

页码: 842-846

在线出版日期: 2007-07-01（万方平台首次上网日期，不代表论文的发表时间）