revisittohydrogenexchangebetweenammoniumandwaterdiffusionindependentchemicalexchange
文献类型：期刊论文
| 作者 | Zhang Yonghong; Mao Xian |
| 刊名 | 波谱学杂志
 |
| 出版日期 | 2002 |
| 卷号 | 19期号:3页码:235 |
| ISSN号 | 1000-4556 |
| 英文摘要 | Hydrogen exchange between ammonium and water is revisited. Exchange rate constants, diffusion coefficients and relaxation times for solutions with varied pH, temperature and concentration of a coexisting salt are measured using NMR spectroscopy. It is demonstrated that the hydrogen exchange in ammonium solutions is independent of apparent diffusion. The mechanism involves chemical-bond/hydrogen-bond exchange. In solutions, water molecules, with the help of hydrogen bonding, serve as a bridge to connect the ammonium with its base partner ammonia. During hydrogen exchange, the ammonia accepts a hydrogen from water while the ammonium donates a hydrogen to water, or a hydrogen jumps from water to ammonium and at the same time another hydrogen jumps back from ammonium to water. There is no net hydrogen transfer between ammonium and water. At lower pH, the concentration of ammonia becomes lower and less ammonium-water-ammonia complex is formed. As a result, the probability of the hydrogen exchange is reduced. This explains why at lower pH hydrogen exchange is slow, a common phenomenon observed in biological hydrogen exchange systems. |
| 语种 | 英语 |
| 源URL | [http://ir.wipm.ac.cn/handle/112942/20348]  |
| 专题 | 中国科学院武汉物理与数学研究所 |
| 作者单位 | 中国科学院武汉物理与数学研究所 |
| 推荐引用方式 GB/T 7714 | Zhang Yonghong,Mao Xian. revisittohydrogenexchangebetweenammoniumandwaterdiffusionindependentchemicalexchange[J]. 波谱学杂志,2002,19(3):235. |
| APA | Zhang Yonghong,&Mao Xian.(2002).revisittohydrogenexchangebetweenammoniumandwaterdiffusionindependentchemicalexchange.波谱学杂志,19(3),235. |
| MLA | Zhang Yonghong,et al."revisittohydrogenexchangebetweenammoniumandwaterdiffusionindependentchemicalexchange".波谱学杂志 19.3(2002):235. |
入库方式： OAI收割
来源：武汉物理与数学研究所
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