...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Heavy Water Reactions with Atomic Transition-Metal and Main-Group Cations: Gas Phase Room-Temperature Kinetics and Periodicities in Reactivity
【24h】

Heavy Water Reactions with Atomic Transition-Metal and Main-Group Cations: Gas Phase Room-Temperature Kinetics and Periodicities in Reactivity

机译：具有原子过渡金属和主族阳离子的重水反应：气相室温动力学和反应性周期性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Reactions of heavy water, D2O, have been measured with 46 atomic metal cations at room temperature in a helium bath gas at 0.35 Torr using an inductively coupled plasma/selected ion flow tube tandem mass spectrometer. The atomic cations were produced at ca. 5500 K in an ICP source and were allowed to decay radiatively and thermalize by collisions with Ar and He atoms prior to reaction. Rate coefficients and product distributions are reported for the reactions of fourth-row atomic cations from K~+ to Se~+, of fifth-row atomic cations from Rb~+ to Te~+ (excluding Tc~+), and of sixth-row atomic cations from Cs~+ to Bi~+. Primary reaction channels were observed leading to O-atom transfer, OD transfer, and D2O addition. O-Atom transfer occurs almost exclusively (>90%) in the reactions with most early transition-metal cations (Sc~+, Ti~+, V~+, Y~+, Zr~+, Nb~+, Mo~+, Hf~+, Ta~+, and W~+) and to a minor extent (10%) with one main-group cation (As~+). OD transfer is observed to occur only with three cations (Sr~+, Ba~+, and La~+). Other cations, including most late transition and main-group cations, were observed to react with D2O exclusively and slowly by D2O addition or not at all. O-Atom transfer proceeds with rate coefficients in the range of 8.1 X 10~(-13) (As~+) to 9.5 X 10~(-10) (Y~+) cm~3 molecule~(-1) s~(-1) and with efficiencies below 0.1 and even below 0.01 for the fourth-row atomic cations V~+ (0.0032) and As~+ (0.0036). These low efficiencies can be understood in terms of the change in spin required to proceed from the reactant to the product potential energy surfaces. Higher order reactions are also measured. The primary products, NbO~+, TaO~+, MoO~+, and WO~+, are observed to react further with D2O by O-atom transfer, and ZrO~+ and HfO~+ react further through OD group abstraction. Up to five D2O molecules were observed to add sequentially to selected M~+ and MO~+ as well as MO_2~+ cations and four to MO_2D~+. Equilibrium measurements for sequential D2O addition to M~+ are also reported. The periodic variation in the efficiency {k/k_c) of the first addition of D2O appears to be similar to the periodic variation in the standard free energy (DELTA G deg) of hydration.
机译：使用电感耦合等离子体/选定离子流管串联质谱仪，已在室温下于0.35托的氦浴气体中与46种原子金属阳离子测量了重水D2O的反应。原子阳离子在约70℃下产生。在ICP源中5500 K，并在反应之前通过与Ar和He原子的碰撞而辐射衰减并热化。报告了第四行原子阳离子从K〜+到Se〜+，第五行原子阳离子从Rb〜+到Te〜+（不包括Tc〜+）和第六行原子阳离子的速率系数和产物分布。从Cs〜+到Bi〜+排列原子阳离子。观察到主要反应通道导致O原子转移，OD转移和D2O添加。 O-原子转移几乎全部（> 90％）发生在与大多数早期过渡金属阳离子（Sc〜+，Ti〜+，V〜+，Y〜+，Zr〜+，Nb〜+，Mo〜+ ，Hf〜+，Ta〜+和W〜+），并在很小的程度上（10％）带有一个主阳离子（As〜+）。观察到只有三个阳离子（Sr〜+，Ba〜+和La〜+）才发生OD转移。观察到其他阳离子，包括大多数后期跃迁和主族阳离子，仅通过添加D2O即可与D2O缓慢反应，甚至完全不与D2O反应。 O-原子转移的速率系数范围为8.1 X 10〜（-13）（As〜+）至9.5 X 10〜（-10）（Y〜+）cm〜3分子〜（-1）s〜 （-1），第四行原子阳离子V〜+（0.0032）和As〜+（0.0036）的效率低于0.1甚至低于0.01。这些低效率可以根据从反应物到产物势能表面进行旋转所需的自旋变化来理解。还测量了更高阶的反应。观察到主要产物NbO〜+，TaO〜+，MoO〜+和WO〜+通过O原子转移与D2O进一步反应，ZrO〜+和HfO〜+通过OD基团抽象进一步反应。观察到最多五个D2O分子依次添加到选定的M〜+和MO〜+以及MO_2〜+阳离子上，四个添加到MO_2D〜+。还报道了D2O连续添加到M〜+中的平衡测量。首次添加D2O的效率（k / k_c）的周期性变化似乎类似于水合标准自由能（ΔG度）的周期性变化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号