Synthesis and structural characterisation of four saccharinate – Metal complexes with 2,2′:6,2″-terpyridine (terpy) as a co-ligand

Four saccharinate complexes of divalent transition metals with 2,2′:6,2″-terpyridine (terpy) as a co-ligand have been synthesised, and characterised by elemental analysis and single crystal X-ray diffraction at low temperature. The complexes [M(terpy)(sac)(H2O)2] sac · H2O (1, M = Mn; 2, M = Co; 3, M = Ni) are isostructural, crystallising in space group Pbca. The metal ions have approximately octahedral coordination, with the two coordinated water molecules occupying cis-positions. These water molecules are hydrogen-bonded to the oxygen atom in the free water molecule. The copper(II) ion in the anhydrous complex [Cu(terpy)(sac)2] 4 is five-coordinate; the compound crystallises in the space group P2(1)/c.