Stability and fragmentation of organic silicon functionalizations studied by laser desorption mass spectrometry
Stability and fragmentation of organic silicon functionalizations studied by laser desorption mass spectrometry
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DOI：
10.1016/j.apsusc.2007.01.101
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发表时间：
2007-05-30
影响因子：
6.7
通讯作者：
Hess, Peter
中科院分区：
文献类型：
--
作者：
Lingenfelser, Dominic;Hess, Peter
介绍了一种通过激光诱导热脱附（LITD）研究硅上有机功能化的方法，其中良好有序的Si（111）-（1x 1）：H（D）表面用于确定脱附温度作为激光能量密度的函数。为了证明这种技术的潜力，用有机端基官能化具有氧化物层的硅表面。用聚焦XeCl激光脉冲解吸的物种进行了监测，在一个倾斜的角度和他们的飞行时间（TOF）分布测量后，电子碰撞电离与四极质量分析仪。通过假设氧化物层和有机层对加热效应的贡献可忽略不计，可以使用针对Si（111）-（1 × 1）：H（D）测量的TOF温度来确定解吸物质的质量。详细的结果是二甲基甲硅烷基（DMS），溴甲基二甲基甲硅烷基（BMDMS），和氯甲基二甲基甲硅烷基（CMDMS）终止的表面，这是通过硅烷化与合适的氯和二硅氮烷化合物制备。而对于DMS终止二甲基硅烷醇（76 u）作为一个单一的物种解吸，清楚地识别的终止基团，在BMDMS和CMDMS的情况下，端基的进一步碎片发生在表面。(C)2007 Elsevier B. V.保留所有权利。
A method is introduced to investigate organic functionalizations on silicon by laser-induced thermal desorption (LITD), where well-ordered Si(1 1 1)-(1 x 1):H(D) surfaces are used to determine the desorption temperature as a function of laser fluence. To demonstrate the potential of this technique silicon surfaces with ultrathin oxide layers were functionalized with organic end groups. The species desorbed with focused XeCl laser pulses were monitored at an oblique angle and their time-of-flight (TOF) distributions were measured with a quadrupole mass analyzer after electron impact ionization. By assuming a negligible contribution of the oxide and organic layers to the heating effect, the TOF temperatures measured for Si(1 1 1)-(1 x 1):H(D) could be used to determine the mass of the desorbed species. Detailed results are presented for dimethylsilyl (DMS), bromomethyldimethylsilyl (BMDMS), and chloromethyldimethylsilyl (CMDMS) terminated surfaces which were prepared by silanization with suitable chloro and disilazane compounds. While for the DMS termination dimethylsilanol (76 u) is desorbed as a single species, clearly identifying the terminating group, in the case of BMDMS and CMDMS further fragmentation of the end group occurs at the surface. (C) 2007 Elsevier B.V. All rights reserved.