Zimmermann Nina, Bernhardt Thorsten M, Bakker Joost M, Barnett Robert N, Landman Uzi, Lang Sandra M
Institute of Surface Chemistry and Catalysis , University of Ulm , 89069 Ulm , Germany.
Radboud University , Institute of Molecules and Materials, FELIX Laboratory , Toernooiveld 7 , 6525 ED Nijmegen , The Netherlands.
J Phys Chem A. 2020 Feb 27;124(8):1561-1566. doi: 10.1021/acs.jpca.9b11258. Epub 2020 Feb 12.
The interaction of manganese oxide clusters MnO ( = 2-5, ≥ ) with CO is studied via infrared multiple-photon dissociation spectroscopy (IR-MPD) in the spectral region of 630-1860 cm. Along with vibrational modes of the manganese oxide cluster core, two bands are observed around 1200-1450 cm and they are assigned to the characteristic Fermi resonance of CO arising from anharmonic coupling between the symmetric stretch vibration and the overtone of the bending mode. The spectral position of the lower frequency band depends on the cluster size and the number of adsorbed CO molecules, whereas the higher frequency band is largely unaffected. Despite these effects, the observation of the Fermi dyad indicates only a small perturbation of the CO molecule. This finding is confirmed by the theoretical investigation of MnO(CO) revealing only small orbital mixing between the dimanganese oxide cluster and CO, indicative of mainly electrostatic interaction.
通过红外多光子解离光谱（IR-MPD）在630 - 1860 cm的光谱区域研究了氧化锰簇MnO（ = 2 - 5，≥ ）与CO的相互作用。除了氧化锰簇核心的振动模式外，在1200 - 1450 cm附近观察到两个谱带，它们被归因于CO的特征费米共振，这是由对称伸缩振动与弯曲模式泛音之间的非谐耦合引起的。低频带的光谱位置取决于簇尺寸和吸附的CO分子数量，而高频带基本不受影响。尽管有这些影响，但费米二元组的观察表明CO分子仅受到很小的扰动。对MnO(CO)的理论研究证实了这一发现，该研究表明二聚氧化锰簇与CO之间只有很小的轨道混合，表明主要是静电相互作用。
