Syntheses and crystal structures of copper(II) complexes derived from 2,4,6-tris(2-pyridyl)-1,3,5-triazine

Treatment of freshly precipitated Cu(OH)(2)center dot xH(2)O and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) with oxalic and malonic acids in methanol-water at room temperature gave [ Cu( tptz)(C2O4)(H2O)]center dot 4H(2)O (1) and [Cu(pma)(C3H2O4)(H2O)] center dot H2O ( 2) ( pma 2-aminocarbonylpyridine), respectively. Reaction in the absence of any acid resulted in [Cu(bpca)(tca)] center dot 2H(2)O (3) (bpca bis(2-pyridylcarbonyl) amide anion; tca = 2-pyridine-carboxylate anion). Complex 1 consists of [ Cu( tptz)( C2O4)( H2O)] and lattice H2O molecules; the tridentate tptz ligand, bidentate oxalate dianion and an aqua ligand are bound to Cu with distorted octahedral geometry. Complex 2 is composed of [ Cu( pma)(C3H2O4)( H2O)] and lattice H2O molecules; the bidentate 2-aminocarbonylpyridine ligand, a bidentate malonate dianion and an aqua ligand are coordinated to Cu with a slightly distorted square pyramidal geometry. Complex 3 consists of [ Cu( bpca)( tca)] and lattice H2O molecules. Square pyramidally coordinated Cu atoms are surrounded by tridentate bpca with nitrogen donor atoms and a bidentate 2-pyridinecarboxylate anion.