Syntheses, crystal structure, spectroscopic and photoluminescence studies of mononuclear copper(II), manganese(II), cadmium(II), and a 1D polymeric Cu(II) complexes with a pyrimidine derived Schiff base ligand

The complexation behaviour of Schiff base ligand 2-((2-(4,6- dimethylpyrimidin-2-yl)hydrazono)methyl)phenol [HL] towards different metal centres is reported by the syntheses and characterization of three mononuclear Cu(II), Mn(II) and Cd(II) complexes, [Cu(L)(H₂O)₂](NO ₃)(H₂O) (1), [Mn(L)₂](CH₃OH) (2), [Cd(L)₂](CH₃OH) (3) and a 1D polymeric Cu(II) complex, [Cu(L)(ClO₄)(C₂N₂O₂H)] _n(CH₃OH) (4) respectively. In the complexes 1-4 the deprotonated uninegative tridentate ligand serves as NNO donor where one pyrimidine ring N, the azomethine N and the salicyl hydroxyl oxygen atoms are coordinatively active. The complex 1 has almost square pyramidal geometry [τ = 0.2081] whereas the metal centres maintain distorted octahedral geometry in the remaining three complexes 2-4. All the complexes are characterized by X-ray crystallography. The Cd(II) complex has considerable fluorescence while the rest of the complexes and the ligand molecule are fluorescent silent.