Hostnik Gregor, Podlipnik Črtomir, Mériguet Guillaume, Cerar Janez
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna Pot 113, SI-1000 Ljubljana, Slovenia.
Faculty of Chemistry and Chemical Technology, University of Maribor, SI-2000 Maribor, Slovenia.
Macromolecules. 2020 Feb 25;53(4):1119-1128. doi: 10.1021/acs.macromol.9b02161. Epub 2020 Feb 10.
Poly(thiophen-3-ylacetic acid) (PTAA) is a representative of conjugated polyelectrolytes which are used in many optoelectronics devices. The performance of these devices is affected by the polymer conformation, which, among others, depends on the nature of the counterion. In this study, the binding of tetrabutylammonium counterions (TBA) on PTAA was determined using a combination of nuclear Overhauser effect spectroscopy (NOESY) and molecular dynamics (MD) simulation. It was found that TBA ions specifically bind on the hydrophobic main chain of PTAA, while, according to MD simulations, alkali counterions predominantly bind in the vicinity of negatively charged carboxylic groups located on side chains. The MD trajectories were used to compute the relaxation matrices and the NOESY spectra. With the help of these latter calculations, the changes of intensities in experimental NOESY spectra upon binding of TBA ions to PTAA were interpreted.
聚（噻吩-3-基乙酸）（PTAA）是共轭聚电解质的一种代表物，这类物质被应用于许多光电器件中。这些器件的性能受聚合物构象影响，而聚合物构象尤其取决于抗衡离子的性质。在本研究中，结合使用核Overhauser效应光谱法（NOESY）和分子动力学（MD）模拟来测定四丁基铵抗衡离子（TBA）与PTAA的结合情况。研究发现，TBA离子特异性地结合在PTAA的疏水主链上，而根据MD模拟，碱金属抗衡离子主要结合在位于侧链上带负电荷的羧基附近。MD轨迹用于计算弛豫矩阵和NOESY光谱。借助这些后续计算，解释了TBA离子与PTAA结合后实验性NOESY光谱中强度的变化。
