Synthesis, structural characterization, and magnetic property study of {Cr 3 Ln 3 }, Ln = Gd and Dy complexes

Abstract

We have successfully prepared and structurally characterized triangle-in-triangle {Cr3Ln3} complexes with Ln = Gd and Dy employing alcohol-amine, N-methyldiethanolamine (H2mdea) and pivalate ligands. These complexes and the Yttrium analogue proved to be isostructural and crystallized in a P1 triclinic cell. DC and AC magnetic measurements were carried out and supported by quantum computations at DFT and CASSCF levels. DC magnetic data are dominated by the Cr(iii)-Ln(iii) antiferromagnetic interaction and by single-ion anisotropy in the case of the Dy(iii) complex. Ln(iii)-Ln(iii) magnetic interactions are negligible, as well as Cr(iii)-Cr(iii) ones. From AC data, slow relaxation of the magnetization is observed at 0 DC applied magnetic field in the case of the Dy(iii) complex below 4 K. From temperature and field dependence data, possible Raman and Orbach relaxation mechanisms are established in the absence of quantum tunnelling pathways, suggesting a successful suppression of the latter due to the Cr(iii)-Dy(iii) exchange interaction.