• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>other >Synthetic Models for the FeFe-Hydrogenase: Catalytic Proton Reduction and the Structure of the Doubly Protonated Intermediate
【2h】

Synthetic Models for the FeFe-Hydrogenase: Catalytic Proton Reduction and the Structure of the Doubly Protonated Intermediate

机译：催化质子还原和双质子化中间产物的结构：对于FEFE -Hydrogenase合成模型

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This report compares biomimetic HER catalysts with and without the amine cofactor (adtNH): Fe2(adtNH)(CO)2(dppv)2 (>1NH) and Fe2(pdt)(CO)2(dppv)2 (>2; (adtNH)2− = (HN(CH2S)22−, pdt2− = 1,3-(CH2)3S22−). These compounds are spectroscopically, structurally, and stereodynamically very similar but exhibit very different catalytic properties. Protonation of >1NH and >2 each give three isomeric hydrides beginning with the kinetically favored terminal hydride, which converts sequentially to sym and unsym isomers of the bridging hydrides. In the case of the amine, the corresponding ammonium-hydrides are also observed. In the case of the terminal amine hydride [t-H>1NH]BF4, the ammonium/amine-hydride equilibrium is sensitive to counteranions and solvent. The species [t-H>1NH2](BF4)2 represents the first example of a crystallographically characterized terminal hydride produced by protonation. The NH--HFe distance of 1.88(7) Å indicates dihydrogen bonding. The bridging hydrides [µ-H>1NH]+ and [µ-H>2]+ reduce near −1.8 V, about 150 mV more negative than the reductions of the terminal hydride [t-H>1NH]+ and [t-H>2]+ at −1.65 V. Reductions of the amine hydrides [t-H>1NH]+ and [t-H>1NH2]2+ are irreversible. For the pdt analog, the [t-H>2]+/0 couple is unaffected by weak acids (pKaMeCN 15.3) but exhibits catalysis with HBF4•Et2O, albeit with a TOF around 4 s−1 and an overpotential greater than 1 V. The voltammetry of [t-H>1NH]+ is strongly affected by relatively weak acids and proceeds at 5000 s−1 with an overpotential of 0.7 V. The ammonium-hydride [t-H>1NH2]2+ is a faster catalyst with an estimated TOF of 58,000 s−1 and an overpotential of 0.5 V.
机译：该报告比较了有和没有胺辅助因子（adt NH ）的仿生HER催化剂：Fe2（adt NH ）（CO）2（dppv）2（> 1 < sup> NH ）和Fe2（pdt）（CO）2（dppv）2（> 2 ;（adt NH ） 2 − =（HN（CH2S）2 2-，pdt 2- = 1,3-（CH2）3S2 2- ）。这些化合物在光谱，结构和立体动力学上非常相似，但表现出非常不同的催化性能，> 1 NH 和> 2 的质子化分别产生三个异构体氢化物从动力学上受好评的末端氢化物开始，后者依次转变为桥接氢化物的对称和不对称异构体；在胺的情况下，还观察到相应的氢化铵；在末端胺的氢化物[tH < strong> 1 NH ] BF4，铵/胺-氢化物平衡对抗衡阴离子和溶剂敏感，种类为[tH > 1 NH2 ]（BF4）2代表由质子化产生的晶体学表征的末端氢化物的第一个例子。 NH-HFe距离为1.88（7）Å表示二氢键合。桥接氢化物[µ-H > 1 NH ] + 和[µ-H > 2 ] + 减小-1.8 V附近的电压，比末端氢化物[tH > 1 NH ] + 的减小多150 mV的负电压， [tH > 2 ] + 在-1.65 V处。胺氢化物的还原[tH > 1 NH ] + 和[tH > 1 NH2 ] 2 + 是不可逆的。对于pdt类似物，[tH > 2 ] + / 0 对不受弱酸（pKa MeCN 15.3）的影响，但具有HBF4催化作用•Et 2 O，尽管TOF约为4 s -1 ，且超电势大于1V。[tH > 1 NH < / sup> ] + 受相对弱酸的强烈影响，并且在5000 s -1 下进行，超电势为0.7V。氢化铵[tH > 1 NH2 ] 2 + 是更快的催化剂，估计TOF为58,000 s -1 ，且超电势为0.5伏

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

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