Metallosupramolecular Architectures of Pseudoterpyridine-Type Ligands and Zn^II Metal Ions

This paper reports the solid state structures of two new metallosupramolecular complexes resulting from pseudoterpyridine bis-hydrazone-type 3 and bis-acylhydrazone-type 4 ligands and ZnII metal ions. The complex 32ZnII are quantitatively trapped by crystallization via constitutionally driven selection from binary solutions of 1:1 and 2:1 3:ZnII (mol:mol). The constitutional internal overlap between the phenyl moieties and the central pyridine moiety clearly plays an important role for internal holding and stabilizing the duplex formation by π−π stacking. The crystal 4ZnII*4 heterostructure and its packing reported in this paper present uncommon features with many other similar architectures reported by now. This structure shows a relatively new structural concept: the 4ZnII complex in which the ZnII ions are coordinated by one ligand rolling the axial position of the metal ion, further interacting by H-bonding with the free ligand 4 in the crystal, allowing one to obtain 2D-layered architectures.本论文报道了由假三联吡啶(pseudoterpyridine)双腙型(bis-hydrazone-type)配体3、双酰腙型(bis-acylhydrazone-type)配体4与二价锌离子(ZnII)构筑的两种新型金属超分子配合物的固态结构。配合物3₂ZnII可通过从配体3与二价锌离子物质的量比为1:1和2:1的二元溶液中经组成驱动的选择性结晶过程被定量得到。苯基片段与中心吡啶片段之间的组成内重叠作用，可通过π-π堆积(π−π stacking)对配合物的内部约束及双链结构的稳定发挥关键作用。本论文报道的4ZnII*4异质结构晶体及其堆积模式，与当前已报道的多数同类结构相比展现出独特的结构特征。该结构体现了一种较为新颖的结构设计理念：在4ZnII配合物中，一个配体配位占据了二价锌离子的轴向位点，该配合物还可通过氢键(H-bonding)与晶体中的游离配体4发生相互作用，进而构筑得到二维层状结构(2D-layered architectures)。