State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
J Chem Phys. 2018 Oct 14;149(14):144305. doi: 10.1063/1.5050836.
Mass-selected heteronuclear vanadium-nickel carbonyl anions VNi(CO) ( = 2-6) were investigated by photoelectron velocity-map imaging spectroscopy and quantum chemical calculations to obtain their chemical bonding and intrinsic electronic structure in the gas phase. The calculated energies (adiabatic detachment energies)/vertical detachment energies (VDEs) match well with experimental values: 1.30/1.49, 1.66/1.95, 2.22/2.48, 2.70/2.89, and 2.95/3.15 eV. The VDE value of VNi(CO) increases with an increase of cluster size, implying that the negative electron is stabilized upon the bonding of CO molecules. VNi(CO) consists of one bridging carbonyl and one terminal carbonyl, whose feature is different from Ni(CO) ( = Sc, Y, La, and Ce) with the involvement of one side-on-bonded carbonyl and one terminal CO carbonyl. The building block composed of three bridging carbonyls is favored for VNi(CO) , the structure of which persists up to = 6. The additional CO ligands are preferentially coordinated in the terminal mode to the Ni atom at = 4 and then to the V atom at = 5 and 6. The results obtained in this work would provide a molecular-level understanding about chemisorbed CO molecules on alloy surfaces/interfaces, which is important to understand CO molecule activation processes.
通过光电离速度成像谱和量子化学计算研究了质量选择的异核钒-镍羰基阴离子 VNi(CO) ( = 2-6)，以获得其气相中的化学成键和本征电子结构。计算出的能量（绝热离解能）/垂直离解能（VDE）与实验值吻合较好：1.30/1.49、1.66/1.95、2.22/2.48、2.70/2.89 和 2.95/3.15 eV。VNi(CO) 的 VDE 值随团簇尺寸的增加而增加，这表明负电子在 CO 分子的成键过程中得到稳定。VNi(CO) 由一个桥联羰基和一个端基羰基组成，其特征不同于 Ni(CO) ( = Sc、Y、La 和 Ce)，其中涉及一个侧接羰基和一个端 CO 羰基。由三个桥联羰基组成的构建块有利于 VNi(CO) ，其结构一直持续到 = 6。额外的 CO 配体优先以端基模式配位到 Ni 原子上（ = 4），然后配位到 V 原子上（ = 5 和 6）。本工作的结果将提供对合金表面/界面上化学吸附 CO 分子的分子水平理解，这对于理解 CO 分子的活化过程很重要。
