Polynuclear complexes of macrocyclic oxamide with 5-sulfosalicylate: syntheses, crystal structures and magnetic properties.

Hydrothermal reactions of mixed ligands 5-sulfosalicylic acid (H(3)SSAL) and macrocyclic oxamide complex (CuL) with M(ClO(4))(2)·6H(2)O (M = Mn, Gd and Cu) afford three new complexes, including [Mn(II)(2)Mn(III)(SSAL)(2)(CuL)(2)(OH)(H(2)O)(3)]n (1), {[Gd(2)(HSSAL)(2)(CuL)(4)(C(2)O(4))(H(2)O)(2)]·2H(2)O}(n) (2) and [Cu(2)(HSSAL)(2)(CuL)(4)]·2H(2)O (3) (CuL, H(2)L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-diene). Complex 1 has very interesting mixed-valence manganese-copper Cu(II)Mn(II)Mn(III)Mn(II)Cu(II) units and consists of a 1D ladderlike chain formed by the linkage of copper(ii) and Mn(3) clusters via the oxamide and SSAL(3-) bridges. The structure of 2 consists of hexanuclear Cu(II)(4)Gd(III)(2) molecules and is arranged in a 1D ladderlike chain formed by the linkage of copper(ii) and gadolinium(iii) via the oxamide, oxalate and HSSAL(2-) bridges. Complex 3 is a hexanuclear Cu(II)(6) molecule including both oxamide and HSSAL(2-) bridges. The results of magnetic determination show pronounced antiferromagnetic interactions in 1 and 3, and ferromagnetic interactions in 2.