Room-temperature isolation of V(benzene)2 sandwich clusters via soft-landing into n-alkanethiol self-assembled monolayers.
Room-temperature isolation of V(benzene)2 sandwich clusters via soft-landing into n-alkanethiol self-assembled monolayers.
复制标题
通过软着陆成正烷硫醇自组装单层来室温分离 V(苯)2 夹层簇。
DOI：
10.1021/jp061806
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
A. Nakajima
中科院分区：
文献类型：
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作者：
Shuhei Nagaoka;Takeshi Matsumoto;E. Okada;M. Mitsui;A. Nakajima
采用红外反射吸收光谱（IRAS）和程序升温脱附（TPD）研究了软着陆到不同链长n-烷硫醇自组装单分子层（Cn-SAM，n = 8、12、16、18和22）上的V（苯）2夹心团簇的吸附状态和热稳定性。 IRAS 测量证实 V(苯)2 簇被分子吸附并在所有 SAM 基底上保持三明治结构。此外，支撑在 SAM 基底上的簇的分子轴与表面法线倾斜 70-80 度。 TPD 光谱的阿伦尼乌斯分析表明，支撑团簇解吸的活化能随着 SAM 的链长线性增加。对于最长链的C22-SAM，活化能达到约150 kJ/mol，并且在室温附近可以显着抑制负载团簇的热解吸。此处观察到的受支撑簇的明显链长依赖性热稳定性可以通过簇渗透到 SAM 矩阵中得到很好的解释。
The adsorption state and thermal stability of V(benzene)2 sandwich clusters soft-landed onto a self-assembled monolayer of different chain-length n-alkanethiols (Cn-SAM, n = 8, 12, 16, 18, and 22) were studied by means of infrared reflection absorption spectroscopy (IRAS) and temperature-programmed desorption (TPD). The IRAS measurement confirmed that V(benzene)2 clusters are molecularly adsorbed and maintain a sandwich structure on all of the SAM substrates. In addition, the clusters supported on the SAM substrates are oriented with their molecular axes tilted 70-80 degrees off the surface normal. An Arrhenius analysis of the TPD spectra reveals that the activation energy for the desorption of the supported clusters increases linearly with the chain length of the SAMs. For the longest chain C22-SAM, the activation energy reaches approximately 150 kJ/mol, and the thermal desorption of the supported clusters can be considerably suppressed near room temperature. The clear chain-length-dependent thermal stability of the supported clusters observed here can be explained well in terms of the cluster penetration into the SAM matrixes.