Han Jia, Liu Pengcheng, Qiu Binglin, Wang Guanjun, Liu Shilin, Zhou Xiaoguo
Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China.
Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.
Dalton Trans. 2023 Dec 19;53(1):171-179. doi: 10.1039/d3dt03593j.
Reductive activation of carbon dioxide (CO) has drawn increasing attention as an effective and convenient method to unlock this stable molecule, especially transition metal-catalyzed reactions. Taking the [TaCO] ion-molecule complex formed in the laser ablation source as a representative, the reactivity of the tantalum metal cation towards CO molecules is explored using infrared photodissociation spectroscopy combined with quantum chemical calculations. The strong absorption in the carbonyl stretching region provides solid evidence for the insertion reactions into CO bonds by the tantalum cation. Two inserted oxocarbonyl products are identified based on the great agreement between the experimental results and simulated infrared spectra of energetically low-lying structures in the singlet and triplet states. The pivotal role of two-state reactivity in driving CO activation among three different spin states is rationalized by potential energy surface analysis. Our conclusion provides valuable insight into the intrinsic mechanisms of CO activation by the tantalum metal cation, highlighting the affinity of tantalum for CO bond insertion in addition to typical "end-on" binding configurations.
作为一种解锁这种稳定分子的有效且便捷的方法，二氧化碳（CO₂）的还原活化受到了越来越多的关注，尤其是过渡金属催化的反应。以激光烧蚀源中形成的[TaCO]离子 - 分子复合物为代表，结合量子化学计算，利用红外光解离光谱研究了钽金属阳离子与CO₂分子的反应活性。羰基伸缩区域的强吸收为钽阳离子插入C=O键的反应提供了确凿证据。基于实验结果与单重态和三重态能量较低结构的模拟红外光谱之间的高度吻合，鉴定出了两种插入的氧代羰基产物。通过势能面分析，阐明了三态反应性在驱动三种不同自旋态之间的CO₂活化中的关键作用。我们的结论为钽金属阳离子活化CO₂的内在机制提供了有价值的见解，突出了钽除典型的“端对端”结合构型外对C=O键插入的亲和力。
