Construction Of Coordination Complexes Based On Tripyridyltriazole Ligand And Dipyridyl Ligand

Crystal-engineering techniques are widely used for design and synthesis ofmultifarious functional crystalline materials. The construction of coordinationpolymers have attracted great interest not only because of their architectural beautytheir potential applications in luminescence, magnetism, gas storage, ion exchange,etc.In this paper, we have employed three novel multidentate N-donor linker, namely3,4-bis(2-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (pptp),4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole (3-bpt), and4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole (4-bpt), to designnew coordination polymers. In conjunction with different the IIB group metal ions,and dca (NH4SCN) as the coligands, twelve novel metallosupramolecular complexeshave been achieved, namely{[Cu(pptp)(dca)(OAc)]·1.5H2O}n(1)，[Cu(pptp)(dca)Br]2(2)，[Cu(pptp)(OAc)2]2(3)，[Cu(pptp)Cl2]2(4)，[Cu(pptp)2(ClO4)2](5)，{[Zn (pptp)(dca)(H2O)]·(dca)·(H2O)}n(6)，[Cd0.5(H2O)(pptp)]·(ClO4)(7)，[Co0.5(H2O)(pptp)]·(ClO4)(8)，[Mn0.5(pptp)(SCN)(H2O)2](9)，{[Cd(3-bpt)Br2]}n(10)，{[Cd (3-bpt)(H2O)(SO4)](H2O)2}n(11)，{[Cd(4-bpt)(SO4)(H2O)3]·H2O}n(12), dca=N(CN)2-. Allcomplexes been characterized by IR spectra, single crystal and elemental analysistechniques. Solid-state properties of thermal stability for these crystalline materialsare also presented.Single-crystal X-ray diffraction analyses indicate that anion effect and metal ionsmay play a crucial role in forming the supramolecular frameworks of these complexes.In the cases of1–2,3–5, or10–11, all factors are kept constant and the only changedfactor is inorganic anions, which lead to a variety of coordination complexes.Moreover, for complexes1and3, which both present acetate as counter anions, theintroduction of auxiliary dca ligand can also result in the different crystal structures.In addition, the research result demonstrates that the different structures of thecomplexes1and6may depend on the radii of metal centers, and dca display differentunidentate and μ1,5-binding mode, respectively.In all complexes1–12, the pptp ligands adopts cisoid conformations, and canshow various coordination modes in different conditions behaving as good bridgingligand. The3-bpt and4-bpt ligands display trans-μ3-bridging and μ3-bridgingcoordination fashions, respectively. Further, higher-dimensional supramolecularnetworks are constructed via secondary interactions such as hydrogen-bonding and aromatic stacking in complexes2,3,4,6,7,8,9and10.