The crystal structures and electronic properties of bis(di-2-pyridylamine)copper(II), bis(tetrafluoroborate) and bis[bis-aquabis(di-2-pyridylamine)copper(II)] sulfate heptahydrate

Abstract

In the [Cu(C10H9N3)2][BF4]2 (1) complex, the Cu(II) ion is in a compressed tetrahedral environment of four N atoms from two di-2-pyridylamine ligands, with an average Cu–N distance of 1.962(7) Å; the dihedral angle between the N–Cu–N planes of the two ligands is 55.0(2)°. The asymmetric unit of [Cu(C10H9N3)2(H2O)2][SO4]·7H2O (2) contains two units of one-half [Cu(C10H9N3)2] moieties (the other half is inversion related), one sulfate and nine water molecules. Each Cu(II) ion involves the elongated rhombic octahedral CuN4O2 chromophore, and is surrounded by four N atoms from the two inversion related dpyam ligands, with an average Cu–N distance of 2.019(2) Å. The axial positions of Cu(1) are occupied by the centrosymmetrically related O atoms of the two water molecules at 2.496(3) Å, giving it a tetragonally distorted Cu(1)N4O2 octahedron. Similarly, the inversion related water oxygens at 2.465(3) Å give a Cu(2)N4O2 chromophore. The electronic and ESR spectra of 1 and 2 are consistent with the compressed tetrahedral and the elongated rhombic octahedral stereochemistries, respectively, as reported for other related complexes.