Zhao Ke, Dron Paul I, Kaleta Jiří, Rogers Charles T, Michl Josef
Department of Physics, University of Colorado, Boulder, CO, 80309, USA.
Top Curr Chem. 2014;354:163-211. doi: 10.1007/128_2013_513.
Regular two-dimensional or three-dimensional arrays of mutually interacting dipolar molecular rotors represent a worthy synthetic objective. Their dielectric properties, including possible collective behavior, will be a sensitive function of the location of the rotors, the orientation of their axes, and the size of their dipoles. Host-guest chemistry is one possible approach to gaining fine control over these factors. We describe the progress that has been achieved in recent years using tris (o-phenylenedioxy)cyclotriphosphazene as a host and a series of rod-shaped dipolar molecular rotors as guests. Structures of both surface and bulk inclusion compounds have been established primarily by solid-state nuclear magnetic resonance (NMR) and powder X-ray diffraction (XRD) techniques. Low-temperature dielectric spectroscopy revealed rotational barriers as low as 1.5 kcal/mol, but no definitive evidence for collective behavior has been obtained so far.
相互作用的偶极分子转子的规则二维或三维阵列是一个有价值的合成目标。它们的介电性质，包括可能的集体行为，将是转子位置、轴的取向及其偶极大小的敏感函数。主客体化学是对这些因素进行精细控制的一种可能方法。我们描述了近年来以三（邻苯二氧基）环三磷腈作为主体和一系列棒状偶极分子转子作为客体所取得的进展。表面和本体包合物的结构主要通过固态核磁共振（NMR）和粉末X射线衍射（XRD）技术确定。低温介电光谱显示旋转势垒低至1.5千卡/摩尔，但迄今为止尚未获得集体行为的确切证据。
