The crystal structures of the azomethine nickel complexes Pigment Orange 68 (P.O.68, C 29 H 18 N 4 O 3 Ni), Pigment Red 257 (P.R.257, C 16 H 4 Cl 8 N 6 O 2 Ni), and Solvent Brown 53 (S.Br.53, C 18 H 10 N 4 O 2 Ni) were determined from powder diffraction data. The compounds are industrially used for the colouration of plastics and coatings. P.O.68 exists in two polymorphic forms, the commercial one is the α-phase. The crystal structures were solved from laboratory data using real-space methods and refined by the Rietveld method. For the Rietveld refinement of α-P.O.68, synchrotron data were employed. In all structures, the Ni 2+ ion is coordinated by two N atoms and two O atoms in a square-planar geometry. Both phases of P.O.68 crystallise in P 2 1 / c , Z = 4. In both structures, the molecules form dimers via an inversion centre, with Ni-to-Ni distances of 3.606 Å (α-phase) and 3.286 Å (β-phase). The dimers are stacked into columns. Neighbouring columns are connected by hydrogen bonds: one classical N–H⋅⋅⋅O bond, and one N–H⋅⋅⋅π bond to the naphthalene moiety of a molecule in the neighbouring stack. P.R.257 crystallises in P 2 1 / c , Z = 2, with molecules on inversion centres. The molecules show a typical van der Waals packing without close Ni-Ni contacts. S.Br.53 exhibits Pbcn symmetry with Z = 8. The molecules form columns with Ni-to-Ni distances of 3.508 Å.

中文翻译：

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工业偶氮甲碱镍络合物颜料。X射线粉末衍射数据得出的四种晶体结构

偶氮甲碱镍络合物的晶体结构为颜料橙68（PO68，C 29 H 18 N 4 O 3 Ni），颜料红257（PR257，C 16 H 4 Cl 8 N 6 O 2 Ni）和溶剂棕53（S从粉末衍射数据确定了.Br.53，C 18 H 10 N 4 O 2 Ni）。这些化合物在工业上用于塑料和涂料的着色。PO68以两种多晶型形式存在，商业一种是α相。使用实空间方法从实验室数据中解析晶体结构，并通过Rietveld方法进行精制。为了对α-PO68进行Rietveld精修，采用了同步加速器数据。在所有结构中，Ni 2+离子由两个N原子和两个O原子以正方形平面的几何形状进行配位。PO68的两个相均在P 2 1 / c中结晶，Z =4。在这两个结构中，分子都通过一个反转中心形成二聚体，Ni-Ni距离为3.606Å（α相）和3.286Å（β相）。二聚体堆叠成列。相邻的列通过氢键连接：一个经典的N–H⋅·⋅O键和一个N–H⋅·⋅π键与相邻堆栈中分子的萘部分相连。PR257结晶于P 2 1 / c，Z = 2，分子位于反演中心。分子显示出典型的范德华堆积，没有紧密的Ni-Ni接触。S.Br.53在Z = 8时表现出Pbcn对称性。分子形成Ni-Ni距离为3.508Å的柱。在反演中心的分子。分子显示出典型的范德华堆积，没有紧密的Ni-Ni接触。S.Br.53在Z = 8时表现出Pbcn对称性。分子形成Ni-Ni距离为3.508Å的柱。在反演中心的分子。分子显示出典型的范德华堆积，没有紧密的Ni-Ni接触。S.Br.53在Z = 8时表现出Pbcn对称性。分子形成Ni-Ni距离为3.508Å的柱。