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

摘要

Hydrothermal reactions of mixed ligands 5-sulfosalicylic acid (H 3SSAL) and macrocyclic oxamide complex (CuL) with M(ClO _4)_2·6H_2O (M = Mn, Gd and Cu) afford three new complexes, including [Mn~(II)_2Mn ~(III)(SSAL)_2(CuL)_2(OH)(H_2O) _3]n (1), {[Gd_2(HSSAL)_2(CuL)_4(C _2O_4)(H_2O)_2]·2H _2O}_n (2) and [Cu_2(HSSAL)_2(CuL) _4]·2H2O (3) (CuL, H2L = 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 Mn3 clusters via the oxamide and SSAL3- bridges. The structure of 2 consists of hexanuclear Cu~(II)_4Gd ~(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.