Abstract A new cobalt phosphonate coordination polymer {[Co2(BrBzPO3)2(bpy)]∙2H2O}n (1) has been synthesized from the reactions of Co(NO3)2, 2-bromobenzyl phosphonic acid (BrBzP(O)(OH)2), and 4,4′-bipyridine (bpy) via reactants slow diffusion in H2O/ethanol solvent media at 60°C. Single-crystal X-ray diffraction analysis reveals that the Co(II) center has a {CoO3N} tetrahedral geometry. The coordinative network of 1 shows a layer structure constructed from Co–BrBzPO3 chains, which contain four-membered rings assembled from vertex-sharing {CoO3N} and {CPO3} tetrahedral units, connected by bpy linkers. It is worthy to note that net-to-net Br–Br halogen bonding interactions play the key supramolecular interactions to significantly dominate network expansion from a two-dimensional (3,4)-connected coordinative layer with a point symbol of (426)(42638) to a three-dimensional (4,4)-connected supramolecular network having a point symbol of (42638)(42638). Further, there are multiple noncovalent supramolecular interactions involving strong O–H∙∙∙O and weak C–H∙∙∙Br and C–H∙∙∙π interactions that provide powerful supports for stabilizing the whole crystal structure. Thermogravimetric (TG) analysis indicates that the coordinative network of 1 is high thermally stable upon heating to 340°C.

中文翻译：

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含4,4'-联吡啶配体的四面体膦酸钴配位聚合物的卤素键相互作用辅助网络扩展

摘要 由 Co(NO3)2, 2-溴苄基膦酸 (BrBzP(O)(OH) 的反应合成了一种新的膦酸钴配位聚合物 {[Co2(BrBzPO3)2(bpy)]∙2H2O}n (1) )2) 和 4,4'-联吡啶 (bpy) 通过反应物在 60°C 下在 H2O/乙醇溶剂介质中缓慢扩散。单晶 X 射线衍射分析表明 Co(II) 中心具有 {CoO3N} 四面体几何形状。1 的配位网络显示了由 Co-BrBzPO3 链构成的层结构，其中包含由顶点共享的 {CoO3N} 和 {CPO3} 四面体单元组装而成的四元环，通过 bpy 接头连接。值得注意的是，网对网 Br-Br 卤素键相互作用起着关键的超分子相互作用，从二维（3，4)-连接协调层，点符号为(426)(42638) 到三维(4,4)-连接的超分子网络，点符号为(42638)(42638)。此外，存在多种非共价超分子相互作用，包括强 O-H∙∙∙O 和弱 C-H∙∙∙Br 和 C-H∙∙∙π 相互作用，为稳定整个晶体结构提供了强有力的支持。热重 (TG) 分析表明，1 的配位网络在加热至 340°C 时具有高热稳定性。