Xie Hua, Zou Jinghan, Yuan Qinqin, Fan Hongjun, Tang Zichao, Jiang Ling
State Key Laboratory of Molecular Reaction Dynamics, Collaborative Innovation Center of Chemistry for Energy and Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.
J Chem Phys. 2016 Mar 28;144(12):124303. doi: 10.1063/1.4944529.
The heteronuclear metal carbonyl anions MNi(CO)3(-) (M = Mg, Ca, Al) have been investigated using photoelectron velocity-map imaging spectroscopy. Electron affinities of neutral MNi(CO)3 (M = Mg, Ca, Al) are measured from the photoelectron spectra to be 1.064 ± 0.063, 1.050 ± 0.064, and 1.541 ± 0.040 eV, respectively. The C-O stretching mode in these three clusters is observed and the vibrational frequency is determined to be 2049, 2000, and 2041 cm(-1) for MgNi(CO)3, CaNi(CO)3, and AlNi(CO)3, respectively. Density functional theory calculations are carried out to elucidate the geometric and electronic structures and to aid the experimental assignments. It has been found that three terminal carbonyls are preferentially bonded to the nickel atom in these heterobinuclear nickel carbonyls MNi(CO)3 (-1/0), resulting in the formation of the Ni(CO)3 motif. Ni remains the 18-electron configuration for MgNi(CO)3 and CaNi(CO)3 neutrals, but not for AlNi(CO)3. This is different from the homobinuclear nickel carbonyl Ni-Ni(CO)3 with the involvement of three bridging ligands. Present findings would be helpful for understanding CO adsorption on alloy surfaces.
已使用光电子速度成像光谱法对异核金属羰基阴离子MNi(CO)₃⁻（M = Mg、Ca、Al）进行了研究。通过光电子能谱测量得出中性MNi(CO)₃（M = Mg、Ca、Al）的电子亲和能分别为1.064±0.063、1.050±0.064和1.541±0.040 eV。观察到这三个簇中的C - O伸缩模式，确定MgNi(CO)₃、CaNi(CO)₃和AlNi(CO)₃的振动频率分别为2049、2000和2041 cm⁻¹。进行了密度泛函理论计算以阐明几何和电子结构并辅助实验归属。已发现三个端基羰基优先与这些异双核镍羰基MNi(CO)₃⁻¹/⁰中的镍原子键合，从而形成Ni(CO)₃基序。对于MgNi(CO)₃和CaNi(CO)₃中性体，Ni保持18电子构型，但对于AlNi(CO)₃则不然。这与涉及三个桥连配体的同双核镍羰基Ni - Ni(CO)₃不同。目前的研究结果将有助于理解CO在合金表面的吸附。
