Temperature Tuned Synthesis of Zinc N,N-bis-(1(2)H-tetrazol-5-yl)-amine Complexes: From Zn3O Cluster-Based 3-Connected 63-hcb and (3,6)-Connected (43)2(46)-kgd Layers to Zn5(OH)4 Chain-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 4 O(Hbta) 3 (H 2 O) 6 ] 1, [Zn 7 (OH) 2 (Hbta) 6 (H 2 O) 6 ] 2, and [Zn 5 (OH) 4 (bta) 2 ]·2H 2 O 3 (H 3 bta = N,N-bis-(1(2)H-tetrazol-5-yl)-amine), respectively. 1 crystallizes in hexagonal space group P 6̅2 c and shows a layered structure with 3-connected 6 3 - hcb topology in which Zn 3 O clusters and unsaturated three-coordinate Zn(II) ions function as 3-connected nodes; 2 crystallizes in trigonal space group P 3̅ c 1 and also shows a layered structure with (3,6)-connected (4 3 ) 2 (4 6 )- kgd topology in which Zn 3 O clusters and six-coordinated Zn(II) sites function as 3-connected nodes as 6-connected nodes, respectively; 3 is a 3D organic−inorganic hybrid open framework constructed by Zn 5 (OH) 4 chains. 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 1 is a metastable kinetic phase whose structure is closely related to that of 2 . Both 1 and 2 are constructed by Zn 3 O(Hbta) 3 units and discrete Zn ions. The coordination mode of doubly deprotonated Hbta in 1 and 2 are also same. This study reveals that a higher reaction temperature is helpful to remove amine-hydrogen of H 3 bta to form triply deprotonated bta anion. The emergence of triply deprotonated bta species may explain why structure of 3 is significantly different from those of 1 and 2 . Compounds 1 −3 show strong blue-green emission, assigned as ligand-centered π→π* excitation.