Low-Density Self-Assembled Monolayers on Gold Derived from Chelating 2-Monoalkylpropane-1,3-dithiols
Low-Density Self-Assembled Monolayers on Gold Derived from Chelating 2-Monoalkylpropane-1,3-dithiols
复制标题
螯合 2-单烷基丙烷-1,3-二硫醇在金上形成的低密度自组装单分子层
作者：
Y. Shon;R. Colorado;C. Williams;C. Bain;T. Lee
通过一系列特殊设计的2-单烷基丙烷-1，3-二硫醇衍生物CH3（CH2）nCH [CH2SH] 2（n = 11，13，14）的吸附，在金表面制备了低密度自组装单分子膜（SAMs）.采用光学椭圆偏振仪、X射线光电子能谱、接触角测角仪、偏振调制红外反射吸收光谱和和频发生等方法对膜进行了表征。将这些数据与从具有相似链长的正链烷硫醇CH3（CH2）n +2SH和2，2-二烷基丙烷-1，3-二硫醇衍生物[CH3（CH2）n] 2C [CH2SH] 2产生的SAM上收集的数据进行比较，表明新的"单链烷二硫醇" SAM是最不结晶的，由于烷基链的低密度，在界面处暴露甲基和亚甲基。进一步比较这些低密度自组装膜上得到的支化和线性聚乙烯薄膜表明，接触的界面亚甲基基团是更大的聚合物薄膜。
Low-density self-assembled monolayers (SAMs) on gold were generated by the adsorption of a series of specifically designed 2-monoalkylpropane-1,3-dithiol derivatives, CH3(CH2)nCH[CH2SH]2, where n = 11, 13, 14. The monolayers were characterized by optical ellipsometry, X-ray photoelectron spectroscopy, contact angle goniometry, polarization modulation infrared reflection absorption spectroscopy, and sum-frequency generation. Comparison of these data to those collected on SAMs generated from normal alkanethiols, CH3(CH2)n+2SH, and 2,2-dialkylpropane-1,3-dithiol derivatives, [CH3(CH2)n]2C[CH2SH]2, of similar chain length suggests that the new “monoalkanedithiol” SAMs are the least crystalline, exposing both methyl and methylene groups at the interface due to the low density of alkyl chains. Further comparison of these low-density SAMs to those obtained on branched and linear polyethylene films suggests that the exposure of interfacial methylene groups is greater for the polymer films.