Structures and Dynamics of Negatively-Charged Molecular Clusters

带负电分子团的结构和动力学

• 批准号: 06453015
• 负责人: NAGATA Takashi
• 金额: $ 4.03万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06453015/
• 关键词: Molecular cluster anions; Photoelectron spectroscopy; Isomers; Cluster ion-molecule reaction; Charge resonance complex; 気相分子クラスター; 電子束縛状態; クラスター負イオン; Molecular cluster anions; Photoelectron spectroscopy; Isomers; Cluster ion-molecule reaction; Charge resonance complex; 気相分子クラスター; 電子束縛状態; クラスター負イオン

In the present study, we have concentrated our attention to (1) the geometrical and electronic structures and (2) reactivities of negatively-charged molecular clusters :(1) The electronic structures of [(CO_2)_nROH]^-(R=H,CH_3, and C_2H_5) were investigated by photoelectron spectroscopy. The analysis of the spectra revealed that two forms of isomers coexist in [(CO_2)_nROH]^-(2*n*3) ; one has an electronic structure described as [C_2O_4^-・ROH(CO_2)_<n-2>]where the excess electron is delocalized over two CO_2 molecules, and the other involves a monomer anionic core as [CO_2^-・ROH(CO_2)_<n-1>]. This is one of the few experimental rasults which demonstrates the coexistence of isomers of negatively-charged molecular clusters having defferent electronic structures. The present findings are also supported byab initio calculations at the unrestricted Hatree-Fock levels.(2) New type of gas-phase reactions involving nagatively-charged molecular clusters were investigated by mass spectrometric technique combined with photoelectron spectroscopy. For example, we have reported reactions of (CO_2)_n^-with CH_3I leading to the formation of a novel molecular anion [CO_2CH_3I]^-, which has not been observed in the corresponding condensed-phase reaction. It turned out that [CO_2CH_3I]^-has a large vertical detachment energy, implyintg that the excess electron is delocalized over [CO_2CH_3I]^-to form an acetate-iodine complex [CH_3CO_2-I]^-. This suggests that (CO_2)_n^-reacts with CH_3I via anucleophilic process. Ab initio calculations are under way to get information on the geometrical and electronic structures of [CO_2CH_3I]^-.

在介绍研究中，我们将注意力集中在（1）（1）（2）呈负电荷分子簇的反应性：（1）[（co_2）_nroh]^ - （r = h，ch_3和c_2H_5）的电子结构通过光学谱调查。对光谱的分析表明，[（co_2）_nroh]^ - （2*n*3）中的两种形式的异构体共存；一种具有描述为[C_2O_4^ - roH（CO_2）_ <n-2>]的电子结构，其中多余的电子在两个CO_2分子上被定位，另一个涉及单体阴离子核为[CO_2^-ROH ROH（CO_2）_ <n-1>]。这是为数不多的实验性rasults之一，它证明了具有较不伸缩电子结构的负荷分子簇的异构体的共存。目前的发现也受支持在不受限制的Hatree-fock水平上BYAB启动计算。（2）通过质谱技术结合光电部光谱法研究了涉及的新型气相反应，涉及自然荷叶的分子簇。例如，我们报道了（co_2）_n^ - 与CH_3I的反应，导致形成新型分子阴离子[CO_2CH_3I]^ - ，该反应在相应的冷凝相反应中尚未观察到。事实证明，[CO_2CH_3I]^ - 具有较大的垂直分离能，这意味着在[CO_2CH_3I]^ - 形成乙酸酯 - 碘复合物[CH_3CO_2-I]^ - 。这表明（co_2）_n^ - 通过CH_3I通过核核过程进行了反应。从头开始计算，以获取有关[CO_2CH_3I]^ - 的几何和电子结构的信息。