A new one-dimensional ferromagnet based on copper(ii) and hexacyanochromate(iii), with a rope-ladder chain structure

Abstract

A novel 1-D ferromagnetic compound based on copper(II) and hexacyanochromate(III) with formula {[Cu(cyclam)]₃[Cr(CN)₆]₂·4H₂O}_n (1; cyclam = 1,4,8,11-tetraazacyclotetradecane) was synthesized and structurally and magnetically characterized. The compound crystallizes in the monoclinic system of the space group P2₁/n, The structure of 1 can be described as formed by Cu₃Cr₂ fragments that are S shaped and connected amongst them to give a rope-ladder chain structure running along the c axis. Each Cu(II) atom is coordinated to four N atoms of the macrocycle and two CN groups of the hexacyanometalate in trans positions. Magnetic measurements have been performed for the compound, showing a moderate ferromagnetic coupling. The best least-squares fit gives J = 4.33 cm⁻¹, g_average = 2.03 and R = 2.80 × 10⁻⁴.