Temperature Tuned Synthesis of Zinc N,N-bis-(1(2)H-tetrazol-5-yl)-amine Complexes: From Zn3O Cluster-Based 3-Connected 63-hcband (3,6)-Connected (43)2(46)-kgdLayers to Zn5(OH)4Chain-Based 3D Open Framework.

Hydrothermal in situ [2 + 3] cycloaddition reaction of dicyanamide and azide in the presence of Zn(II) ions at 120, 150, and 180 °C generated [Zn 4O(Hbta) 3(H 2O) 6] 1, [Zn 7(OH) 2(Hbta) 6(H 2O) 6] 2, and [Zn 5(OH) 4(bta) 2]·2H 2O 3(H 3bta = N,N-bis-(1(2)H-tetrazol-5-yl)-amine), respectively. 1crystallizes in hexagonal space group P6̅2 cand shows a layered structure with 3-connected 6 3- hcbtopology in which Zn 3O clusters and unsaturated three-coordinate Zn(II) ions function as 3-connected nodes; 2crystallizes in trigonal space group P3̅ c1 and also shows a layered structure with (3,6)-connected (4 3) 2(4 6)- kgdtopology in which Zn 3O clusters and six-coordinated Zn(II) sites function as 3-connected nodes as 6-connected nodes, respectively; 3is a 3D organic−inorganic hybrid open framework constructed by Zn 5(OH) 4chains. The triply deprotonated bta 3−anion is first observed in 3, and rare three-coordinate Zn(II) ions are revealed in 1. Analysis of relationship between structure and synthesis condition reveals that 1is a metastable kinetic phase whose structure is closely related to that of 2. Both 1and 2are constructed by Zn 3O(Hbta) 3units and discrete Zn ions. The coordination mode of doubly deprotonated Hbta in 1and 2are also same. This study reveals that a higher reaction temperature is helpful to remove amine-hydrogen of H 3bta to form triply deprotonated bta anion. The emergence of triply deprotonated bta species may explain why structure of 3is significantly different from those of 1and 2. Compounds 1−3show strong blue-green emission, assigned as ligand-centered π→π* excitation. [ABSTRACT FROM AUTHOR]