A study of the structure and bonding of small aluminum oxide clusters by photoelectron spectroscopy: AlxOy- (x=1-2, y=1-5)
A study of the structure and bonding of small aluminum oxide clusters by photoelectron spectroscopy: AlxOy- (x=1-2, y=1-5)
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DOI：
10.1063/1.474085
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发表时间：
1997-01-22
影响因子：
4.4
通讯作者：
Wang, LS
中科院分区：
文献类型：
--
作者：
Desai, SR;Wu, HB;Wang, LS
用阴离子光电子能谱（PES）研究了氧化铝团簇AlxOy （x=1-2, y=1-5）的结构和成键，并与初步计算结果进行了比较。分别在2.33、3.49、4.66和6.42 eV的剥离光子能量下获得了光谱。在6.42 eV光谱中，AlO-具有X (2) Sigma（+）基态和两个激发态。AlO2-的6.42 eV谱也显示了AlO2的三种状态：X (2) Pi(g)基态和A (2) Pi(u)和B (2) Sigma(g)（+）激发态。Al2Oy-团簇的光谱显示出由sp型轨道产生的振动分辨基态和以氧2p特征为主的高结合能激发态。Al2O2具有D-2h菱形结构，电子亲和能（EA）为1.88 eV，单重态-三重态激发能为0.49 eV。对于较大的Al2Oy簇，测量到的ea要高得多。Al2O3-、Al2O4-和Al2O5-的PES光谱显示出非常相似的电子结构和振动结构。此外，这三种分子的基态振动频率也相似。这些观察结果使我们认为这些分子都具有类似Al2O2的菱形结构，氧原子顺序地附着在末端的铝原子上。光谱与离子键观点一致，振动频率与理论结果吻合较好。获得并讨论了这些小氧化铝团簇的结构和键合的重要信息。(C) 1997年美国物理研究所。
The structure and bonding of aluminum oxide clusters, AlxOy (x=1-2, y=1-5), are studied with anion photoelectron spectroscopy (PES) and are compared with preliminary ab initio calculations. The spectra were obtained at four detachment photon energies: 2.33, 3.49, 4.66, and 6.42 eV. The 6.42 eV spectrum for AlO- reveals the X (2) Sigma(+) ground state and two excited states of AlO. The 6.42 eV spectrum for AlO2- also shows three states for AlO2: X (2) Pi(g) ground state and the A (2) Pi(u) and B (2) Sigma(g)(+) excited states. The spectra for Al2Oy- clusters show vibrationally resolved ground states which come from Al sp-type orbitals and also high binding energy excited states, which are mainly of oxygen 2p character. Al2O2, which has a D-2h rhombus structure, has an electron affinity (EA) of 1.88 eV and its singlet-triplet excitation energy is measured to be 0.49 eV. Much higher EAs are measured for the larger Al2Oy clusters. The PES spectra of Al2O3-, Al2O4-, and Al2O5- show very similar electronic and vibrational structure. Furthermore, the ground state vibrational frequencies of these three molecules are also similar. These observations lead us to suggest that these molecules all have a rhombuslike structure, similar to Al2O2, with the oxygen atoms sequentially attaching to the terminal aluminum atoms. The spectra are consistent with an ionic bonding view of these clusters and the vibrational frequencies are in good agreement with the theoretical results. Significant information about the structure and bonding of these small aluminum oxide clusters is obtained and discussed. (C) 1997 American Institute of Physics.