Syntheses, structures and properties of pentacoordinated zinc(II) halide complexes containing a tridentate Schiff base as end capping ligand

34-40Three neutral pentacoordinated complexes of the type [Zn(L)X2].nH2O [L = (<span style="mso-bidi-font-style: italic">N,N-diethyl,N'-(pyridin-2-yl)benzylidene)-ethane-1,2-diamine; X = Cl-, n = 0.5, X = Br-, n = 0 and<b style="mso-bidi-font-weight: normal"> X = I-, n = 0]<span style="mso-bidi-font-style: italic"> have been isolated using 1:1 molar ratio of the corresponding zinc(II) halide and the tridentate Schiff base. The compounds are characterized by elemental analyses, spectroscopic and other physicochemical data. Single crystal X-ray structural analyses reveals that the zinc(II) center in these complexes adopts a distorted square pyramidal geometry with a ZnN3X2 chromophore. Intermolecular C-H···O, C-H···Br and C-H···I hydrogen bonds along with ··· and C-H··· interactions indicate different crystalline aggregates. The complexes display intraligand 1(-*) fluorescence in DMF solutions at room temperature.