Variation in the coordination mode of arenedisulfonates to copper(II): synthesis and structural characterization of six copper(II) arenedisulfonate complexes

Six copper(II) arenedisulfonate complexes with the general formula Cu(N-4)(nds/bpds). nH(2)O (nds=naphthalenedisulfonate, bpds=biphenyldisulfonate) have been synthesized in aqueous solution and structurally characterized by X-ray single crystal diffraction, IR and UV spectroscopies, TGA and DSC. In Cu(en)(2)(1,5nds). 2H(2)O 1, Cu(N-meen)(2)(2,6nds). 2H(2)O 2 (N-meen=N-methylethylenediamine), Cu(dpn)(2)(bpds) 3 (dpn=2,3-diaminopropane), and Cu(cylam)(1,5nds) 4 the SO3- group coordinates monodentately to the axial position of Cu2+ which is equatorially coordinated by four amino nitrogens. In 1 and 4 intramolecular hydrogen bonds are formed between the SO3- oxygens and amino hydrogens which reinforce interaction between the SO3- group and Cu2+ complex cation. In Cu(dpn)(2)(1,5nds). 2H(2)O 5 and Cu(N,N'-meen)(2)(1,5nds). 3H(2)O 6 (N,N'-meen=N,N'-dimethylethylenediamine), due to the steric hindrance caused by the methyl substitution of the amino ligands and the rigidity of the naphthalene ring, water molecules, instead of the bulky SO3- group, coordinate to the axial position of Cu2+. Structures 1-4 represent the first synthesis and structural characterization of polymeric 1-dimensional structures constructed by arenedisulfonates and divalent transition metals. Also, 1 crystallizes in the enantiomorphic space group P4(1)2(1)2 and displays interesting chiral grids constructed by ionic hydrogen bonds. The coordination geometries of Cu2+, as well as the coordination modes of arenedisulfonates, are discussed in detail.