Blunt Matthew O, Russell James C, Giménez-López María Del Carmen, Garrahan Juan P, Lin Xiang, Schröder Martin, Champness Neil R, Beton Peter H
School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Science. 2008 Nov 14;322(5904):1077-81. doi: 10.1126/science.1163338.
A molecular network that exhibits critical correlations in the spatial order that is characteristic of a random, entropically stabilized, rhombus tiling is described. Specifically, we report a random tiling formed in a two-dimensional molecular network of p-terphenyl-3,5,3',5'-tetracarboxylic acid adsorbed on graphite. The network is stabilized by hexagonal junctions of three, four, five, or six molecules and may be mapped onto a rhombus tiling in which an ordered array of vertices is embedded within a nonperiodic framework with spatial fluctuations in a local order characteristic of an entropically stabilized phase. We identified a topological defect that can propagate through the network, giving rise to a local reordering of molecular tiles and thus to transitions between quasi-degenerate local minima of a complex energy landscape. We draw parallels between the molecular tiling and dynamically arrested systems, such as glasses.
描述了一种分子网络，该网络在空间顺序上呈现出关键相关性，这种空间顺序具有随机、熵稳定的菱形平铺的特征。具体而言，我们报道了在吸附于石墨上的对三联苯 - 3,5,3',5'- 四羧酸二维分子网络中形成的随机平铺。该网络通过三个、四个、五个或六个分子的六边形连接得以稳定，并且可以映射到一个菱形平铺，其中有序的顶点阵列嵌入在非周期性框架内，局部顺序存在空间波动，这是熵稳定相的特征。我们识别出一种能够在网络中传播的拓扑缺陷，它会引起分子平铺的局部重新排序，进而导致复杂能量景观的准简并局部极小值之间的转变。我们将分子平铺与诸如玻璃等动态停滞系统进行了类比。
