Synthesis, Structures, Magnetic and Luminescent Properties of a Series of Iron(II) and Zinc(II) Coordination Frameworks with Versatile 4‐Substitued 1, 2,4‐Triazole Ligands

Three multi‐dentate 1, 2,4‐triazole derivative ligands containing different 4‐substituted groups, namely N‐1, 2,4‐triazol‐4‐yl(pyridin‐3‐yl)methylenimine (L 1 ), N‐1, 2,4‐triazol‐ 4‐yl(pyridin‐4‐yl)methylenimine (L 2 ), and 4‐(2‐pyridine)‐1, 2,4‐triazole (L 3 ) were used to isolate five iron(II) and zinc(II) coordination frameworks, [Zn(μ 2 ‐L 1 )Cl 2 ] ( 1 ), [Zn(μ 2 ‐L 2 )Br 2 ] ( 2 ), [Fe(L 1 ) 2 (NCS) 2 (H 2 O) 2 ] ( 3 ), [Fe(L 3 ) 2 (dca) 2 (H 2 O) 2 ] ( 4 ), and [Fe(L 3 ) 2 (μ 2 ‐dca)] ( 5 ) (dca = dicyanamide anion). When different zinc(II) salts were used to react with L 1 and L 2 under solvothermal conditions, two one‐dimensional (1D) zinc(II) coordination frameworks 1 and 2 containing four‐coordinate central zinc(II) atoms were isolated. 1 is a 3D achiral supra‐molecular framework, whereas 2 is a 3D chiral supra‐molecular framework containing helical chains on a 2 1 axis. 3 is a mono‐nuclear iron(II) coordination framework containing six‐coordinate central Fe II atoms. When L 3 was employed, mono‐nuclear iron(II) framework 4 and 1D iron(II) chain 5 could be isolated when different amounts of Nadca were introduced into the reaction system. Variable‐temperature magnetic susceptibility data of 3 – 5 were recorded in the 2–300 K temperature range indicating weak anti‐ferromagnetic interactions. The solid‐state luminescent properties of coordination polymers 1 and 2 were also investigated at room temperature.