Mayberry Darrell D, Linehan John C, Appel Aaron M
Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.
Inorg Chem. 2021 Nov 15;60(22):17132-17140. doi: 10.1021/acs.inorgchem.1c02397. Epub 2021 Nov 1.
The free energy for hydride transfer reactions of transition metal hydrides is known to be influenced by solvent effects. The first-row transition metal hydride [HNi(dmpe)][BF] (dmpe = 1,2-bis(dimethylphosphino)ethane) has starkly different hydride transfer reactivities with CO in different solvents. A binary mixture of water and acetonitrile was used to tune the hydride transfer reactivity of HNi(dmpe) with CO so that the free energy for this reaction approached zero. Various mole fractions of water were tested and a linear relationship between the hydride transfer free energy and solvent composition was established for 0-0.24 mole fraction of water. A deviation from linearity was found upon moving toward higher mole fractions of water. The tuning of the free energy for hydride transfer allowed HNi(dmpe) to be used as a catalyst for the hydrogenation of CO. The optimized catalyst conditions produced 58 turnovers at room temperature in 0.082 mole fraction of water using 60 atm of a 1:1 mixture of H to CO gas.
已知过渡金属氢化物的氢化物转移反应的自由能受溶剂效应影响。第一排过渡金属氢化物[HNi(dmpe)][BF]（dmpe = 1,2 - 双（二甲基膦基）乙烷）在不同溶剂中与CO的氢化物转移反应活性截然不同。水和乙腈的二元混合物用于调节HNi(dmpe)与CO的氢化物转移反应活性，以使该反应的自由能接近零。测试了不同摩尔分数的水，并针对水的摩尔分数为0 - 0.24建立了氢化物转移自由能与溶剂组成之间的线性关系。当水的摩尔分数增加时，发现偏离了线性关系。氢化物转移自由能的调节使得HNi(dmpe)可作为CO氢化反应的催化剂。优化后的催化剂条件在室温下，使用60个大气压的H与CO气体1:1混合物，在水的摩尔分数为0.082时产生了58次周转。
