A new cobalt(II) compound with the formula [Co(5-Br-pyc)(2,2′-bipy)(H2O)(Cl)]·2H2O (1·H2O) (5-Br-Hpyc = 5-bromo-pyridine-2-carboxylic acid, 2,2′-bipy = 2,2′-bipyridine) has been hydrothermally synthesized and well characterized. The X-ray single-crystal diffraction analysis showed that 1⋅2H2O has crystallizes in the monoclinic system, space group P21/c (no. 14). The Co(II) center was octahedrally bonded by one bidentate chelate 5-Br-pyc anion and one 2,2′-bipy, one water molecule as well as one chloride anion to form the mononuclear structure of 1⋅2H2O. Complex1⋅2H2O forms a 3D network through abundant O–H⋅⋅⋅O hydrogen bonds and π⋅⋅⋅π stacking interactions. Notably, the 5-Br-Hpyc ligand was in situ generated by decarboxylation of the 3-bromo-pyridine-2,6-dicarboxylic acid (3-Br-H2pydc) precursor selectively on 2-position under hydrothermal conditions. The magnetic properties, the Hirshfeld surface structure and the synthetic process for 1⋅2H2O have been carefully described and discussed.

中文翻译：

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一种由 3-溴-吡啶-2,6-二羧酸衍生的不对称单核钴 (II) 化合物，涉及原位水热脱羧：结构、磁性和 Hirshfeld 表面分析

一种新型钴 (II) 化合物，分子式为 [Co(5-Br-pyc)(2,2'-bipy)(H2个O)(Cl)]·2H2个O（1·H2个O) (5-Br-Hpyc = 5-bromo-pyridine-2-carboxylic acid, 2,2'-bipy = 2,2'-bipyridine) 已被水热合成并得到很好的表征。X射线单晶衍射分析表明，1⋅2H2个O在单斜晶系中有结晶，空间群P2个1个/C（第 14 号）。Co(II) 中心由一个双齿螯合 5-Br-pyc 阴离子和一个 2,2'-bipy、一个水分子以及一个氯阴离子八面体键合形成 1⋅2H 的单核结构2个O.复杂1⋅2H2个O 通过丰富的 O–H⋅⋅⋅O 氢键和 π⋅⋅⋅π 堆叠相互作用形成 3D 网络。值得注意的是，5-Br-Hpyc 配体是就地由 3-溴-吡啶-2,6-二羧酸 (3-Br-H2个pydc) 前体在水热条件下选择性地位于 2 位。1⋅2H的磁性、Hirshfeld表面结构和合成工艺2个O 已被仔细描述和讨论。