Langmuir-Blodgett films of metal complexes of 4-(10,12-pentacosadiynamidomethyl)pyridine: A structural investigation
Langmuir-Blodgett films of metal complexes of 4-(10,12-pentacosadiynamidomethyl)pyridine: A structural investigation
复制标题
4-(10,12-二十五碳二酰氨基甲基)吡啶金属配合物的 Langmuir-Blodgett 薄膜：结构研究
作者：
P. Werkman;R. H. Wieringa;E. Vorenkamp;A. Schouten
4-（10，12-pentacosadipidomethyl）pyridine与亚相中的金属离子形成络合物，在表面压力高达35 mN m（-1）时，形成稳定的Langmuir单分子膜.电子显微镜照片显示聚合前的单体单层平坦，聚合后的聚合物单层呈现出更多的条纹结构。两亲物的多层膜只有在与金属离子络合后才能形成。X射线光电子能谱（XPS）的测量肯定地证实了金属离子的存在下，在多层膜，和金属和两亲物之间的摩尔比是来自光谱。这些多层膜的进一步特征在于通过小角度X射线反射测量和傅里叶变换红外（FT-IR）光谱，这表明两亲物具有相对于表面法线的大倾斜角（α）。多层膜的聚合是通过紫外光照射，紫外-可见光谱是用来研究聚合过程。聚合过程中的结构变化推导出从小角X射线反射测量和FT-IR光谱。在所有情况下，双层间距在聚合过程中减小，而在某些情况下，烷基链的全反式构象的规则平面被转化为含有笨拙构象的不规则平面。对于从含CuCl 2的亚相建立的多层膜，在聚合过程中整个独特的层结构被破坏。
Complex formation between 4-(10,12-pentacosadiynamidomethyl)pyridine and metal ions in the subphase results in stable Langmuir monolayers up to surface pressures of 35 mN m(-1). Electron microscopy pictures show a flat monomer monolayer before polymerization and a polymer monolayer exhibiting a more striated structure after polymerization. Multilayers of the amphiphile can only be built up after complexation with metal ions. X-ray photoelectron spectroscopy (XPS) measurements definitely confirm the presence of metal ions in the multilayers, and the molar ratio between metal and amphiphile is derived from the spectra. These multilayers are further characterized by means of small-angle X-ray reflection measurements and Fourier transform infrared (FT-IR) spectroscopy, which show that the amphiphile has a large tilt angle (a) with respect to the surface normal. The multilayers are polymerized by means of UV irradiation, and UV-vis spectroscopy is used to study the polymerization process. The structural changes during polymerization are deduced from small-angle X-ray reflection measurements and FT-IR spectroscopy. In all cases, the bilayer spacing decreases during the polymerization process, whereas in some cases the regular plane of the all-trans conformation of the alkyl chains is converted to an irregular one containing gauche conformations. For multilayers built up from a CuCl2-containing subphase, the whole distinct layer structure is destroyed during the polymerization process.