.1,3,4 - Thiadiazole Supramolecular Complexes Building, Structure, And Performance

In this paper, we synthesize two ligands: L1 is 2,6-di(N,N'-5-ethyl-1,3,4-thia-diazole-2-formamide)-pyridine and the other is 3-methyl-6-phenyl-[1,2,4]-triazole [3,4-b][1,3,4] thiadiazole. Firstly, nine novel supramolecular complexes (Ⅰ 2-Ⅰ 10) have been synthesized by treatments of the L1 with different metal ions. And in these compounds the coordinated patterns of L1 as a multi-dentate ligand are not always same. Ⅰ 1 exhibits two-dimensional structure formed by hydrogen bonds and π-π interactions. Both Ⅰ 2 and Ⅰ 3 are mono-nuclear complexes which are linked through hydrogen bonds and n-n interactions into two dimension and three dimension, respectively, in which the L1 as tri-dentate ligand coordinated metal center. Ⅰ 5 contains 2D layers that are formed through hydrogen bonding and π-π stacking effects, and in Ⅰ 6 the structure was extended into three-dimensional network through hydrogen bonding and π-π stacking effects, In Ⅰ 5 or Ⅰ 6 there is di-nuclear structure and LI as tetra-dentate ligand coordinated two mental centers. All of Ⅰ 4,Ⅰ 7 , Ⅰ 8 contain triangle frames constituted by three metal ions bridged by μ3-O or μ3-OH, I 4 contains 1D infinite polymeric chains that formed through hydrogen bonding, whereas, in Ⅰ 5 the structure is extended two-dimension structure by the similar force, the structure of Ⅰ 8 is linked into three-dimension network by the hydrogen bonding between water molecular and carbonyl of the ligand. Ⅰ 9 contains five-metal skeleton, and L1 either as penta-dental ligand coordinated three different metals or as a hexa-dentate ligand coordinated four different mental ions forming a novel pentanuclear configuration. Different from above mentioned complexes in this paper, Ⅰ 10 is a two-dimensional network polymer linked by coordinating bond, and L1 as bi-dentate ligand bridging two different metals. Secondly, the reaction of copper( Ⅱ) ions , L2 and other monodentate ligands afford two complexes, and through hydrogen bonding and n-n stacking effects the structure of two complexes are extended into three-dimension network, respectively. Finally, we have investigated the thermo-stabilities and thermalanalysis kinetics of Ⅰ 2, Ⅰ 4, Ⅰ 10 . We also have explored the photo-luminescent properties of Ⅰ 8,Ⅰ 10 , and the result indicate that the luminescent property of I 8 is induced by intramolecular charge transfer, and the luminescent property of Ⅰ 10 is assigned to ligand-to-metal charge transfer(LMCT).