Synthesis, crystal structures and properties of three new mixed-ligand d10 metal complexes constructed from pyridinecarboxylate and in situ generated amino-tetrazole ligand

Three new metal–organic frameworks, [Zn(atz)(nic)]n(1), [Zn(atz)(isonic)]n·nHisonic(2) and [Cd(atz)(isonic)]n(3) (Hnic=nicotinic acid, Hisonic=isonicotinic acid), have been firstly synthesized by employing mixed-ligand of pyridinecarboxylate with the in situ generated ligand of 5-amino-tetrazolate(atz−), and characterized by elemental analysis, IR spectroscopy, TGA and single crystal X-ray diffraction. The results revealed that 1 presents a two-dimensional (2D) “sql” topological network constructed from the linear chain subunit of Zn(nic)2 and atz− ligand. A remarkable feature of 2 is a 2-fold interpenetrated diamondoid network with free Hisonic molecules locating in the channels formed by the zigzag chain subunits of Zn(isonic)2. Complex 3 is a 3D non-interpenetrated pillared framework constructed from the double chain subunits of Cd–COO−–Cd. It possesses a rarely observed (4,6)-connected “fsc” topology. The thermal stabilities and fluorescent properties of the complexes were investigated. All of these complexes exhibited intense fluorescent emissions in the solid state at room temperature.

Graphical abstractThree new mixed-ligand d10 metal complexes have been synthesized by employing mixed-ligand synthetic approach. Complex 1 presents a 2D “sql” topological network. Complex 2 is a 2-fold interpenetrated diamondoid network with microporous channels. Rarely observed (4,6)-connected “fsc” topological network was found in complex 3.Figure optionsDownload full-size imageDownload as PowerPoint slide