Tipping the Balance between Concerted versus Sequential Proton-Coupled Electron Transfer.
Tipping the Balance between Concerted versus Sequential Proton-Coupled Electron Transfer.
复制标题
打破协同与顺序质子耦合电子转移之间的平衡。
作者：
Joshua S. Kretchmer;Thomas F. Miller
我们利用量子化分子动力学模拟研究了无机催化剂中协同和顺序质子耦合电子转移（PCET）反应机制之间的竞争。通过分析反应非绝热PCET轨迹和计算协调和顺序的速率常数，我们表征了各种分子特征，管理无机PCET反应，包括溶剂极性，配体介导的电子-质子相互作用，和固有的质子转移（PT）的能量障碍。通过对1200多个原子的原子论模拟，我们发现对称的铁双咪唑啉体系由于配体介导的强电子-质子相互作用和较短的PT距离而非常偏向于协同机制.然而，通过调查系统浴模型，其中电子-质子相互作用被屏蔽，这是钌terpyridylbenzoates和铁（四苯基卟啉）苯甲酸盐的代表，我们预测，协调和顺序的PCET机制之间的交叉可能是通过增加溶剂的极性或通过增加固有的PT能垒。此外，我们预测的可能性交叉的PCET机制直接改变的配体介导的电子-质子相互作用的强度。这里提出的结果揭示了新的策略，改变竞争PCET机制和设计原则之间的竞争，控制PCET在催化体系中。
We use quantized molecular dynamics simulations to investigate the competition between concerted and sequential proton-coupled electron-transfer (PCET) reaction mechanisms in inorganic catalysts. By analyzing reactive nonadiabatic PCET trajectories and computing both concerted and sequential rate constants, we characterize various molecular features that govern inorganic PCET reactions, including the solvent polarity, ligand-mediated electron-proton interactions, and intrinsic proton-transfer (PT) energy barrier. Using atomistic simulations with over 1200 atoms, we find that the symmetric iron biimidazoline system is extremely biased toward the concerted mechanism because of the strong ligand-mediated electron-proton interaction and the short PT distance. However, by investigating system-bath models in which electron-proton interactions are shielded, which are representative of ruthenium terpyridylbenzoates and iron (tetraphenylporphyrin)benzoates, we predict that a crossover between the concerted and sequential PCET mechanisms may be possible either by increasing the polarity of the solvent or by increasing the intrinsic PT energy barrier. In addition, we predict the possibility of a crossover in the PCET mechanism by directly varying the strength of the ligand-mediated electron-proton interactions. The results presented here reveal new strategies for altering the competition between the competing PCET mechanisms and design principles for controlling PCET in catalytic systems.
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DOI：
10.1126/science.3603005
发表时间：
1987
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Kuki,A;Wolynes,PG
通讯作者：
Wolynes,PG
影响因子：
16.6
作者：
Reece SY;Nocera DG
通讯作者：
Nocera DG
影响因子：
15
作者：
Usharani D;Lacy DC;Borovik AS;Shaik S
通讯作者：
Shaik S
双(咪唑)铁四苯基卟啉与苯甲酸盐的长程质子耦合电子转移反应。
DOI：
10.1021/jz400029w
发表时间：
2013
期刊：
The journal of physical chemistry letters
影响因子：
--
作者：
Warren,JeffreyJ;Menzeleev,ArturR;Kretchmer,JoshuaS;Miller3rd,ThomasF;Gray,HarryB;Mayer,JamesM
通讯作者：
Mayer,JamesM
影响因子：
15
作者：
Markle, Todd F.;Rhile, Ian J.;Mayer, James M.
通讯作者：
Mayer, James M.