De Santis Alessandra, Forni Alessandra, Liantonio Rosalba, Metrangolo Pierangelo, Pilati Tullio, Resnati Giuseppe
The G Natta Department of Chemistry, Materials, and Chemical Engineering, Polytechnic of Milan 7, via Mancinelli, 20131 Milan, Italy.
Chemistry. 2003 Aug 18;9(16):3974-83. doi: 10.1002/chem.200204655.
The N.Br halogen bonding drives the self-assembly of 1,4-dibromotetrafluorobenzene (1 a) and its 1,3 or 1,2 analogues (1 b,c, respectively) with dipyridyl derivatives 2 a,b. The isomeric supramolecular architectures 3 a-f are obtained as cocrystals that are stable in the air at room temperature. The solid-state features of these 1D infinite chains 3 have been fully characterized by single-crystal X-ray, Raman, and IR analyses. The occurrence of N.Br halogen bonding in solution has been detected with (19)F NMR spectroscopy. The N.Br halogen bonding is highly selective and directional and the geometry of the single strands of noncovalent copolymers 3 is programmed by the geometry of halogen-bonding donor and acceptor sites on the starting modules. The composition and topology of the instructed networks can be predicted with great accuracy. Experiments of competitive cocrystal formation established the strength of the N.Br interaction relative to other halogen bondings and the ability of different modules 1 to be involved in site-selective supramolecular syntheses.
N.Br卤键驱动1,4 - 二溴四氟苯（1a）及其1,3或1,2类似物（分别为1b、c）与联吡啶衍生物2a、b的自组装。得到了异构的超分子结构3a - f作为共晶体，它们在室温下的空气中是稳定的。这些一维无限链3的固态特征已通过单晶X射线、拉曼和红外分析进行了全面表征。溶液中N.Br卤键的存在已通过（19）F核磁共振光谱检测到。N.Br卤键具有高度选择性和方向性，非共价共聚物3单链的几何结构由起始模块上卤键供体和受体位点的几何结构决定。所构建网络的组成和拓扑结构可以非常准确地预测。竞争性共晶形成实验确定了N.Br相互作用相对于其他卤键的强度以及不同模块1参与位点选择性超分子合成的能力。
