Reactions of 2,2′-Pyridyl with the cadmium(II) compounds: Synthesis, crystal structure, and luminescence properties of [Cd(Pic)2(H2O)2] · H2O

Abstract

The reactions of 2,2'-pyridyl, (2-Py)C(O)C(O)(2-Py), with the Cd(II) compounds under various conditions are studied. The medium and nature of the anions exert a decisive effect on the compositions and structures of the formed cadmium complexes. The reaction of cadmium diacetate with 2,2'-pyridyl in an aqueous-alcohol medium in air affords coordination compound [Cd(Рic)₂(H₂O)₂] · H₂O (I) (Pic⁻ is picolinate ion, CO₂C₅H₄N), and its crystal structure is determined. The crystals are monoclinic: space group P2₁/c, a = 7.499(1), b = 15.676(1), с = 12.719(1) Å, β = 94.79(1)°, V = 1490.0(2) Å3, Z = 4, ρ_calcd = 1.502 g/cm³. The molecular packing of compound I is a supramolecular 3D framework consisting of discrete complexes [Cd(Pic)₂(H₂O)₂] linked by hydrogen bonds O–H…O. The coordination sphere of Cd²⁺ contains two O atoms and two N atoms of the ligand and two water molecules. The coordination polyhedron of Cd²⁺ is a distorted octahedron.