A novel pyrazolylpyrimidine ligand (L) and its complex CuLCl2 were prepared and structurally characterized. The simultaneous crystallization of three polymorphs of CuLCl2, green (G), emerald green (EG) and orange (O), was discovered. The molecular structures vary only slightly between the three forms. The Cu atom forms four coordinate bonds with the two N and two Cl atoms, and a shortened Cu...H contact with an H atom of the phenyl ring in L. The structural difference between polymorphs was analyzed with the boundary surfaces of molecular Voronoi–Dirichlet polyhedra. The difference in colour of the polymorphs is likely to be due to the different π–π stackings. There is no stacking in the G modification, but EG and O polymorphs demonstrate face-to-face and slipped stacking, resulting in dimers and infinite chains, respectively. The EG and O polymorphs are packed according to the hexagonal close-packing motif, while in G no special topology is found.
制备了一种新型吡唑嘧啶配体(L)及其复合物 CuLCl2,并对其进行了结构表征。发现了 CuLCl2 的三种多晶型:绿色(G)、翠绿色(EG)和橙色(O)。三种形态的分子结构仅略有不同。Cu 原子与两个 N 原子和两个 Cl 原子形成四个坐标键,并与 L 中苯环的一个 H 原子形成缩短的 Cu...H 接触。多晶体的颜色差异可能是由于不同的 π-π 堆叠造成的。G 型多晶体没有堆叠,但 EG 和 O 型多晶体出现了面对面堆叠和滑动堆叠,分别形成了二聚体和无限链。EG 和 O 多晶体按照六边形紧密堆积模式堆积,而 G 多晶体则没有发现特殊的拓扑结构。