Three one-dimensional mercury(II) complexes, [Hg2(μN,N-((Me2N-Ba)2Bn)(μ-X)2X2]n, where X = Cl (I), Br (II), and I (III), (Me2N-Ba)2Bn = N,N′-bis(dimethylaminobenzylidene)butane-1,4-diamine, involving a bidentate Schiff base with a flexible spacer (=N-C-C-C-C-N=) were prepared under mild condition and characterized by elemental analyses (CHN), FT-IR, 1H & 13C-NMR spectroscopy. The crystal structure of II has been determined by X-ray single-crystal diffraction. Each Hg(II) center adopts a distorted [HgNBr3] tetrahedron environment arising from two crystallographically equivalent (Me2N-Ba)2Bn Schiff base ligands. Each of ligands acts as N2-bis-chelating ligand with the nitrogen atoms of two imine functions in anti-form leading to the dinuclear [Hg2(μN,N-(Me2N-Ba)2Bn)Br2] groups. Such dinuclear [Hg2(μN,N-((Me2Nvg-Ba)2Bn)Br2] groups are bridged two iodine anions (μ-Br)2 to form a neutral 1D-chain mercury (II) coordination polymer.