Suckert Stefan, Wöhlert Susanne, Jess Inke, Näther Christian
Institut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany.
Acta Crystallogr E Crystallogr Commun. 2015 Dec 6;71(Pt 12):m242-3. doi: 10.1107/S2056989015021829. eCollection 2015 Dec 1.
In the crystal structure of the title compound, [Co(NCS)2(C6H8N2)2(H2O)2]·C6H8N2, the Co(II) cation is coordinated by the N atoms of two terminal thio-cyanate anions, the O atoms of two water mol-ecules and two N atoms of two 2,6-di-methyl-pyrazine ligands. The coordination sphere of the resulting discrete complex is that of a slightly distorted octa-hedron. The asymmetric unit comprises a Co(II) cation and half of a 2,5-di-methyl-pyrazine ligand, both of which are located on centres of inversion, and a water ligand, a 2,6-di--methyl-pyrazine ligand and one thio-cyanate anion in general positions. In the crystal, the discrete complexes are arranged in such a way that cavities are formed in which the 2,5-di-methyl-pyrazine solvent mol-ecules are located. The coordination of the 2,5-di-methyl-pyrazine mol-ecules to the metal is apparently hindered due to the bulky methyl groups in vicinal positions to the N atoms, leading to a preferential coordination of the 2,6-di-methyl-pyrazine ligands. The discrete complexes are linked by O-H⋯N hydrogen bonds between one water H atom and the non-coordinating N atom of the 2,6-di-methyl-pyrazine ligands. The remaining water H atom is hydrogen bonded to one N atom of the 2,5-di-methyl-pyrazine solvent mol-ecule. This arrangement leads to the formation of a two-dimensional network extending parallel to (010).
在标题化合物[Co(NCS)₂(C₆H₈N₂)₂(H₂O)₂]·C₆H₈N₂的晶体结构中，Co(II)阳离子由两个末端硫氰酸根阴离子的N原子、两个水分子的O原子以及两个2,6 - 二甲基吡嗪配体的两个N原子配位。所得离散配合物的配位球为略微扭曲的八面体。不对称单元包括一个Co(II)阳离子和半个2,5 - 二甲基吡嗪配体（二者均位于对称中心），以及一个处于一般位置的水配体、一个2,6 - 二甲基吡嗪配体和一个硫氰酸根阴离子。在晶体中，离散配合物以这样一种方式排列，即形成了一些空腔，2,5 - 二甲基吡嗪溶剂分子位于其中。由于N原子邻位的甲基体积较大，2,5 - 二甲基吡嗪分子与金属的配位显然受到阻碍，导致2,6 - 二甲基吡嗪配体优先配位。离散配合物通过一个水分子的H原子与2,6 - 二甲基吡嗪配体的非配位N原子之间的O - H⋯N氢键相连。剩余的水分子H原子与2,5 - 二甲基吡嗪溶剂分子的一个N原子形成氢键。这种排列导致形成了一个平行于(010)延伸的二维网络。
