Publikationsdatum:
2017-10-19
Beschreibung:
A series of five new Zn(II) and Cd(II) mixed-ligand coordination polymers, namely, {[Zn(L1)(4,4'-bpy)]*(ClO4)*2H2O} (1), {[Zn(L2)(4,4'-bpy)0.5]*(ClO4)} (2), {[Zn(L3)(4,4'-bpy)]*(NO3)*2H2O} (3), {[Cd(L4)(4,4'-bpy)0.5(NO3)]*5H2O} (4) and {[Zn(L4)(4,4'-bpy)]*Cl*H2O} (5), have been obtained by the reactions of the 4,4'-bipyridine with four dicarboxylate zwitterionic pyridine ligands. Single-crystal X-ray structural analyses reveal that the five complexes demonstrate different molecular frameworks coming from various coordination modes and flexibilities of different dicarboxylate zwitterionic pyridine ligands and metal centers. Mononuclear 2-fold dinuclear 2D 2-fold interpenetrating net for 2, four-coordinate mononuclear 2-fold interpenetrating 2D layer for 3, mononuclear 2D layer arranged in parallel and with large grids for 4 and 2-fold trans interpenetrating 2D network for compound 5. The structural diversities in 1-5 indicate that the nature of the ligands and the presence of different metal atoms have a great influence on metal center coordination modes and the structural topologies of the metal-organic molecular architectures. In addition, π***π stacking interactions also play important roles in the final crystal packing and supramolecular frameworks. The powder X-ray diffraction, elemental analysis and the photoluminescence properties of 1-5 were studied, which show that architectures play an important role in emission bands and intensities.
Print ISSN:
0044-2313
Digitale ISSN:
1521-3749
Thema:
Chemie und Pharmazie
Permalink