A novel zinc(II) complex with the ligand 2,20,200-(1,4,7-triazanonane-1,4,7-triyl)- triacetate (NOTA)

Abstract

The zinc(II) complex with NOTA [2,20 ,200-(1,4,7-triazanonane1,4,7-triyl)triacetate] has previously been synthesized and studied in solution, but was not isolated. The corresponding title ZnII complex pentasodium(I) bis{[2,20 ,200-(1,4,7-triazanonane-1,4,7-triyl)triacetato]zinc(II)} tris(perchlorate) methanol solvate, Na5[Zn(C12H18N3O6)]2(ClO4)3 CH3OH, was crystallized as a sodium perchlorate double salt in methanol solution. The asymmetric unit contains two independent [Zn(NOTA)] complex anion entities, five sodium cations, three perchlorate anions and a methanol solvent molecule. The two ZnII cations exhibit a distorted trigonal-prismatic N3O3 coordination with a bifacial arrangement of the donor atoms. Neither the methanol solvent molecule nor the perchlorate anions appear to be coordinated to the Zn centres. The crystal structure shows a layer arrangement parallel to (001) generated by interactions between the [Zn(NOTA)] units, the Na+ cations, two ClO4 units and the methanole molecule, leading to an overall layer composition of [Na5[Zn(C12H18N3O6)]2(ClO4)2 .- CH3OH]+ . The third ClO4 anion is isolated and situated between the layers without any significant interactions