Extended structures based on hydrogen bonding and π-π interactions:: synthesis and characterization of two zinc complexes:: [Zn(dap)Cl2] and [Zn(dap)2Cl2]

Two new Zn(II) complexes, [Zn(dap)Cl-2] (1) and [Zn(dap)(2)Cl-2] (2) (dap stands for 2,3-diaminopyridine), were prepared and spectroscopically and crystallographically characterized. In both compounds, the zinc(II) atom has a pseudo-tetrahedral ZnN2Cl2 coordination environment. Compound I adopts a three-dimensional structure built up from [Zn(dap)Cl-2](n) zig-zag chains, which are linked by N-(HCl)-Cl-... hydrogen bonds. In compound 2 the dap is monodentate coordinating via the pyridine nitrogen the mononuclear tetrahedral [Zn(dap),Cl,] units are linked into two-dimensional sheets through extensive N-(HCl)-Cl-... hydrogen bonding. Inter-sheet pi-pi interactions connect them into a three-dimensional network. (C) 2003 Elsevier B.V. All rights reserved.