THE CHARACTERIZATION OF BOTH THE COORDINATED AND NONCOORDINATED SACCHARINATE ION - THE SYNTHESES AND CRYSTAL-STRUCTURES OF AQUA(2-FORMYLPYRIDINE THIOSEMICARBAZONATO)(SACCHARINATO-N)COPPER(II) HEMIHYDRATE AND 2,2'-BIPYRIDYL-(2-FORMYLPYRIDINE THIOSEMICARBAZONATO)COPPER(II) SACCHARINATE DIHYDRATE

The preparation of the complex [CuL(sacc)- (H2O)]·0.5H2O (HL=2-formylpyridine thiosemicarbazone, Hsacc = saccharin) from the reaction of Na(sacc) with [{CuL(CH3COO)}2] is described. The complex [CuL(bpy)](sacc)·2H2O (bpy = 2,2′- bipyridyl) is obtained if the reaction is carried out in the presence of 2,2′-bipyridyl. The complexes have been characterized by a variety of physicochemical techniques and their crystal and molecular structures determined. Crystals of [CuL(sacc)(H2O)]·0.5H2O are monoclinic, space group P21/n, with a = 7.465(7), b = 9.245(7), c = 26.209(33) Å, β = 97.18(9)° and Z = 4. Crystals of [CuL(bpy)](sacc)·2H2O are triclinic, space group P1, a = 9.243(1), b = 12.393(1), c = 13.323(1) Å, α = 75.511(5), β = 67.751(5), λ = 73.294(7)° and Z = 2. Both complexes contain five coordinate copper with three donor atoms (NNS) contributed by L, which forms a tricyclic ligating system. For [CuL(sacc)(H2O)]·0.5H2O the coordination sphere is completed by a monodentate N-bound saccharinate ion and a more weakly bound water molecule giving a distorted square-pyramidal geometry. For the complex [CuL(bpy)](sacc)-2H2O the remaining coordination sites are occupied by two N atoms from 2,2′-bipyridyl, resulting in a geometry intermediate between square-pyramidal and trigonal- bipyramidal. The saccharinate ion is a non- coordinated anion. © 1990.