Barwa Erik, Pascher Tobias F, Ončák Milan, van der Linde Christian, Beyer Martin K
Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
Angew Chem Int Ed Engl. 2020 May 4;59(19):7467-7471. doi: 10.1002/anie.202001292. Epub 2020 Mar 12.
We investigate activation of carbon dioxide by singly charged hydrated magnesium cations Mg (H O) , through infrared multiple photon dissociation (IRMPD) spectroscopy combined with quantum chemical calculations. The spectra of [MgCO (H O) ] in the 1250-4000 cm region show a sharp transition from n=2 to n=3 for the position of the CO antisymmetric stretching mode. This is evidence for the activation of CO via charge transfer from Mg to CO for n≥3, while smaller clusters feature linear CO coordinated end-on to the metal center. Starting with n=5, we see a further conformational change, with CO coordination to Mg gradually shifting from bidentate to monodentate, consistent with preferential hexa-coordination of Mg . Our results reveal in detail how hydration promotes CO activation by charge transfer at metal centers.
我们通过红外多光子解离（IRMPD）光谱结合量子化学计算，研究了单电荷水合镁阳离子Mg (H₂O)₆对二氧化碳的活化作用。[MgCO₂(H₂O)₄]在1250 - 4000 cm⁻¹区域的光谱显示，对于CO₂反对称伸缩模式的位置，从n = 2到n = 3有一个尖锐的转变。这证明了对于n≥3时，通过从Mg 向CO₂的电荷转移来活化CO₂，而较小的团簇具有CO₂以端对端方式线性配位到金属中心的特征。从n = 5开始，我们观察到进一步的构象变化，CO₂与Mg的配位逐渐从双齿向单齿转变，这与Mg的优先六配位一致。我们的结果详细揭示了水合作用如何通过金属中心的电荷转移促进CO₂的活化。
