N-phthaloylglycinato complexes of cobalt, nickel, copper and zinc

The cobalt(II), nickel(II), copper(II) and zinc(II) complexes of N-phthaloylglycinato (Nphgly) ligands have been synthesised and characterised. The cobalt and zinc complexes have the composition [M(Nphgly)2(H2O)4]2H2O with an octahedral geometry around the metal ion. In these two complexes, the phthaloylglycinato groups are monodentate and have four coordinated water molecules and two molecules of lattice water. The lattice water molecules are held through hydrogen bonding with one carbonyl group of the phthalimide part and the carbonyl group of glycinato part. Such water molecules are further held by hydrogen bonding to two coordinated water molecules. There are also two other coordinated water molecules having a different hydrogen-bonding environment. These two water molecules attached to the metal are stabilised by hydrogen bonding through two carbonyl groups from the glycinato part and the phthalimide part. Distinctions of these two sets of water environment are reflected in thermogravimetry and DSC of the complexes. In the thermogram of these two complexes there is loss of four water molecules at a relatively lower temperature than the other two water molecules. The copper complex containing N-phthaloylglycinato and pyridine ligands, having the composition [Cu(Nphgly)2(py)3], is prepared. This complex has a square pyramidal structure with one pyridine molecule at the axial position. The complex on thermal degradation leads to the formation of CuO at 380 °C. The similar nickel complex has the composition [Ni(Nphgly)2(py)31.3H2O], having a trimeric H-bonded structure with a distorted octahedral environment around nickel(II).

Cobalt(II), zinc(II), copper(II) and nickel(II) complexes of N-phthaloylglycinato (Nphgly) ligands are synthesised and characterised. The cobalt and zinc complexes have composition [M(Nphgly)2(H2O)4]2H2O and are iso-structural with octahedral geometry around the metal. A copper complex with composition [Cu(Nphgly)2(py)3] where (py = pyridine) has a square pyramidal structure. Similar nickel complex has composition of [Ni(Nphgly)2(py)31.3H2O] has a trimeric H-bonded network.Figure optionsDownload as PowerPoint slide