title: Photoelectron velocity-map imaging and theoretical studies of heteronuclear metal carbonyls MNi(CO)3(-) (M = Mg, Ca, Al).
abstract: 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.
authors.affiliation: 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.
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
authors.affiliation: 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.
authors.forename: Jinghan
authors.initials: J
authors.lastname: Zou
authors.affiliation: 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.
authors.forename: Qinqin
authors.initials: Q
authors.lastname: Yuan
authors.affiliation: 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.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Fan
authors.affiliation: 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.
authors.forename: Zichao
authors.initials: Z
authors.lastname: Tang
authors.affiliation: 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.
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang