Chiroptical sensing of asymmetric hydrocarbons using a homochiral supramolecular Box from a bismetalloporphyrin rotamer
Chiroptical sensing of asymmetric hydrocarbons using a homochiral supramolecular Box from a bismetalloporphyrin rotamer
复制标题
DOI：
10.1002/anie.200604330
复制
发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Aida, Takuzo
中科院分区：
文献类型：
--
作者：
Aimi, Junko;Oya, Kazumasa;Aida, Takuzo
碳氢化合物的分子识别是超分子化学领域的难点之一。[1,2]本文描述了一种非手性有机染料分子对不对称碳氢化合物的手性感应，该分子可以自组装形成一个盒状的手性环四聚体。[3,4]不对称分子的手性感应是一种允许发色宿主与手性客体相互作用的方法。[5-11]当手性客体通过多点相互作用与宿主分子适当结合时，宿主[12]在可见吸收区表现出圆二色性（CD）响应，无需其他共存分子的干扰即可诊断。在这里，CD响应的符号和强度分别反映了手性客体的绝对构型和对映体纯度对于不对称碳氢化合物的热力传感，迄今为止只报道了有限的例子，因为这些化合物不具有定向多点相互作用的适当功能我们的手性传感策略利用了双金属卟啉旋转体1的箱形手性超分子组装。[3,14,15]在不对称碳氢化合物（如柠檬烯）存在的情况下，手性盒子的两种对映体形式中的任何一种都会发生富集，从而增强了可见吸收区的CD响应。这是基于我们最近的发现，二乙烯连接的双卟啉2与中位吡啶基的锌配合物自组装形成盒形环四聚体（BOX），其中2作为构建块采用平面(k)或垂直（?）构象（方案1）由2 （2k）的平面构象组成的BOX是非手性的，BOX？由它的垂直构象（2?）组成的是手性（同手性）。由于只有后一种组合才有资格用于热感测，因此我们合成了1，一种新的2的四炔基乙烯版本，并期望其
Molecular recognition of hydrocarbons is one of the challenging subjects in supramolecular chemistry.[1, 2] Here we describe the chiroptical sensing of asymmetric hydrocarbons with an achiral organic dye molecule that self-assembles to form a box-shaped chiral cyclic tetramer.[3, 4] Chiroptical sensing of asymmetric molecules is a method in which a chromophoric host is allowed to interact with a chiral guest.[5–11] When the chiral guest is appropriately associated with the host molecule through multipoint interactions,[12] the host displays a circular dichroism (CD) response in the visible absorption region, which can be diagnosed without interference from other coexisting molecules. Here, the sign and intensity of the CD response reflects the absolute configuration and enantiomeric purity, respectively, of the chiral guest.[13] For chiroptical sensing of asymmetric hydrocarbons, only limited examples have so far been reported,[2] since these compounds do not possess appropriate functionalities for directional multipoint interactions.[1] Our strategy for chiroptical sensing makes use of a boxshaped chiral supramolecular assembly of the bismetalloporphyrin rotamer 1.[3, 14, 15] In the presence of an asymmetric hydrocarbon, such as limonene, enrichment of either of the two enantiomeric forms of the chiral box takes place, thereby allowing an enhanced CD response in the visible absorption region. This is based on our recent finding that the zinc complex of dialkynylene-linked bisporphyrin 2 with meso pyridyl groups self-assembles to form a box-shaped cyclic tetramer (BOX), where 2 as the building block adopts either a planar (k) or a perpendicular (?) conformation (Scheme 1).[3] While BOXk consisting of the planar conformer of 2 (2k) is achiral, BOX? composed of its perpendicular conformer (2?) is chiral (homochiral). Since only the latter assembly is eligible for chiroptical sensing, we synthesized 1, a new tetraalkynylene version of 2, with an expectation that the