Syntheses and characterization of four heterometallic Ln–Co or Ln–Ni heptanuclear clusters with glycine as ligand

Syntheses, structures, and properties of a series of novel high-nuclear 3d–4f clusters with mixed amino acids as ligands: {Ln6Cu24}(Ln = Gd, Tb, Pr and Sm)

The first examples of high-nuclear 3d–4f heterometallic clusters {Ln₆Cu₂₄}(Ln = Gd, Tb, Pr and Sm) with mixed amino acid ligands are reported.

Poly[di-μ-glycinato-copper(II)]: a two-dimensional coordination polymer

The title coordination polymer, [Cu(C(2)H(4)NO(2))(2)](n), is two-dimensional and consists of a distorted octa-hedral copper coordination polyhedron with two bidentate glycine ligands chelating the metal through the O and N atoms in a trans-square-planar configuration. The two axial coordination sites are occupied by carbonyl O atoms of neighbouring glycine mol-ecules. The Cu-O distances for the axial O atoms [2.648 (2) and 2.837 (2) Å] are considerably longer than both the Cu-O [1.9475 (17) and 1.9483 (18) Å] and Cu-N [1.988 (2) and 1.948 (2) Å] distances in the equatorial plane, which indicates a strong Jahn-Teller effect. In the crystal, the two-dimensional networks are arranged parallel to (001) and are linked via N-H⋯O hydrogen bonds, forming a three-dimensional arrangement.