A Series of Cu^II-Azide Polymers of Cu₆ Building Units and the Role of Chelating Diamine in Controlling their Dimensionality: Synthesis, Structures, and Magnetic Behavior

Abstract

Four new neutral copper-azido polymers [Cu6(N3)12(aem)2]n(1), [Cu6(N3)12(dmeen)2(H2O)2]n (2), [Cu6(N3)12(N,N′-dmen)2]n (3), and [Cu6(N3)12(hmpz)2]n (4) [aem = 4-(2-aminoethyl)morpholine; dmeen = N,N-dimethyl-N′-ethylethylenediamine; N,N′-dmen = N,N′-dimethylethylenediamine and hmpz = homopiperazine] have been synthesized by using 0.33 mol equiv of the chelating diamine ligands with Cu(NO3)2·3H2O/CuCl2·2H2O and an excess of NaN3. Single crystal X-ray structures show that the basic unit of these complexes, especially 1−3, contains very similar CuII6 building blocks. But the overall structures of these complexes vary widely in dimensionality. While 1 is three-dimensional (3D) in nature, 2 and 3 have a two-dimensional (2D) arrangement (with different connectivity) and 4 has a one-dimensional (1D) structure. Cryomagnetic susceptibility measurements over a wide range of temperature exhibit dominant ferromagnetic behavior in all the four complexes. The experimental susceptibility data have been analyzed by some theoretical model equations