An Aqua-Bridged Helical-Chain Copper(II)-Saccharinato Polymer Linked into a Two-Dimensional Supramolecular Framework

Abstract

A new assembly [Cu<inf>2</inf>(sac)<inf>2</inf>(μ-dmea) <inf>2</inf>(μ-H<inf>2</inf>O)]<inf>n</inf> (sac = saccharinate and Hdmea = 2-dimethylaminoethanol) has been synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group C2/c and consists of dinuclear modules of [Cu<inf>2</inf>(sac)<inf>2</inf>(dmea) <inf>2</inf>]. The sac ligand is N-coordinated, while the dmea ligand is in the deprotanated form by losing the ethanol hydrogen atom and acts as a bidentate donor through the alkoxo group and N atom. The alkoxo group also serves as a bridge between two copper(II) ions, leading to an intra-dimer Cu⋯Cu separation of 3.0229(7) Å. The dimeric units are bridged by aqua ligands to generate a one-dimensional water-bridged helical chain, in which the copper(II) ions exhibit a distorted square-pyramidal CuN<inf>2</inf>O <inf>3</inf> coordination. The Cu-Cu distance in the chain separated by the bridging aqua ligands is 5.297 Å. The polymeric chains are further linked by π(sac)⋯π(sac) and C-H⋯π(sac) interactions into a two-dimensional supramolecular network. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.