Two novel saccharinate complexes, [Cu(mu-OH)(sac-N)(deten)](2)center dot 2H(2)O (1) and [Cu(mu-OH)(sac-O)(tmen)](2) (2) (deten = N,N-diethylethylenediamine, tmen = N,N,N ',N '-tetramethylethylenediamine and sac = saccharinate) have been synthesized and characterized by elemental analyses, IR and UV-Vis spectroscopy, thermal analysis and single crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic P2(1)/c space group, while 2 crystallizes in the triclinic P (1) over bar space group. The geometry in the centrosymmetric dinuclear complexes around each Cu(11) ion is a distorted square pyramidal coordination, in which the equatorial plane is formed by two oxygen atoms from bridged hydroxo ligands and two nitrogen atoms of a bidentate deten or tmen ligand. The axial position in the square pyramid is occupied by a nitrogen atom for I and an oxygen atom for 2 of a sac ligand. In complex 1, the lattice contains two water molecules held together in a hydrogen-bonded network. Thermal behaviors of the complexes were studied using TA, DTA and DTG in a static air atmosphere. The antimicrobial activity of sodium saccharinate and the complexes was studied against selected microorganisms. While all the new compounds were found to be weakly active against the bacteria tested, there was not any activity on Aspergilhis niger. Also, [Cu(mu-OH)(sac-N)(deten)](2)center dot 2H(2)O displayed weak activity against Candida albicans. (c) 2007 Elsevier Ltd. All rights reserved.