SolvationStructure and Stability of [(CH3)2NH]m[NH3]n-H Hypervalent Clusters: Ionization potentials and Switching of Hydrogen-Atom Localized Site
SolvationStructure and Stability of [(CH3)2NH]m[NH3]n-H Hypervalent Clusters: Ionization potentials and Switching of Hydrogen-Atom Localized Site
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[(CH3)2NH]m[NH3]n-H 高价团簇的溶剂化结构和稳定性：电离势和氢原子定域位点的转换
DOI：
10.1021/jp204331q
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
K. Fuke
中科院分区：
文献类型：
--
作者：
Y. Yamada;H. Ishikawa;K. Fuke
用ArF准分子激光光解二甲胺（DMA）-氨混合团簇产生的[（CH 3）2NH]m（NH3）n-H超价自由基团簇的电离势（IPs）由光电离阈值测量得到. DMA 1（NH3）n-H超价自由基的IPs随氨数ton= 4迅速下降，当n ≥ 5时下降速度变慢。这一趋势与NH_4（NH_3）n团簇非常相似。对DMA 1（NH3）n-H的稳定结构和IP的计算结果以及观测到的IP表明，当n = 1时，氢原子定位的位置是NH3部分，而当n = 2-4时，双配位的DMA-H是有利的，当n ≥ 5时，四配位的NH 4又是更稳定的.这些变化与DMAn-H团簇的飞秒泵浦-探测实验结果一致。切换的氢原子本地化网站归因于DMA-H对氢原子解离的不稳定性。
Ionization potentials (IPs) of [(CH3)2NH]m(NH3)n–H hypervalent radical clusters produced by an ArF excimer laser photolysis of dimethylamine (DMA)–ammonia mixed clusters are determined by the photoionization threshold measurements. The IPs of the DMA1(NH3)n–H hypervalent radicals decrease rapidly with the number of ammonia up ton= 4, and then its decrease rate becomes much slower forn≥ 5. This trend is very similar to that found for NH4(NH3)nclusters. The calculated results on the stable structures and IP as well as the observed IP for DMA1(NH3)n–H indicate that the hydrogen atom-localized site is the NH3moiety forn= 1, while the doubly coordinated DMA–H is favorable forn= 2–4, and then 4-fold-coordinated NH4is again more stable forn≥ 5. These changes are consistent with the results on the femtosecond pump–probe experiments of DMAn–H clusters. Switching of the hydrogen atom-localized site is ascribed to the instability of DMA–H against a hydrogen-atom dissociation.