Use of Cu(II)-di-Schiff bases as metalloligands in the formation of complexes with Cu(II), Ni(II) and Zn(II) perchlorate

One linear homo-metallic trinuclear [{CuL1(CH3OH)}(2)Cu(ClO4)(2)] (1); five trinuclear hetero-metallic; bent [(CuL1)(2)Ni(H2O)(2)](ClO4)(2)center dot H2O (2), linear [(CuL1)(2)Zn(ClO4)(2)] (3), bent [{CuL2(ClO4)}{CuL2(CH3OH)} Ni(CH3OH)(2)](ClO4)center dot(CH3OH)center dot 0.25(H2O) (4), triangular [(CuL2){CuL2(CH3CN)}Ni(CH3CN)(2)](ClO4)2 (5), triangular [(CuL2)(2)Ni(H2O)(2)](ClO4)(2)center dot 3H(2)O (6) and one rare tetranuclear star-shaped [{CuL2(H2O)}(2)(CuL2)ZnI(ClO4)(2)center dot H2O (7) complexes have been synthesized by reacting the "metalloligand", [CuL1] or [CuL2] with corresponding metal perchlorate where the di-Schiff base ligands H2L1 = N,N'-bis(salicylidene)-1,3-propanediamine and H2L2 = (N,N'-bis(alpha-methylsalicylidene)-1,3-propanediamine. The structures of all the seven complexes have been determined by X-ray crystallography. Structural analysis shows that complexes 1-6 are discrete trinuclear species where phenoxido groups of two terminal "metalloligands" coordinate to a central Cu(II) in 1 or Ni(II) in 2,4-6 or Zn(II) in 3. In 1 and 3 two trans axial positions of the central Cu(II) are weakly coordinated by the oxygen atoms of perchlorate anions and the molecules are linear. However, in 2, 4-6 two solvent molecules coordinate to the cis positions of the central Ni(II) to complete its distorted octahedral geometry that makes the molecules bent or triangular. On the other hand, complex 7 is a star-shaped tetranuclear species. In which three metalloligands bind a central Zn(II) ion through double phenoxido bridge. (C) 2013 Elsevier Ltd. All rights reserved.