Structure and magnetism of two chair-shaped hexanuclear dysprosium(III) complexes exhibiting slow magnetic relaxation

摘要

Two novel hexanuclear Dy-III complexes with polyhydroxy Schiff-base ligands, [Dy-6(L-1)(4)(mu(3)-OH)(4)(MeOH)(4)] Cl-2 center dot 2MeOH center dot 2MeCN (1) and [Dy-6(HL2)(2)(mu(3)-OH)(2)(mu(3)-OCH3)(2)(piv)(10)(MeOH)(2)] (2) (H3L1 = N,N'-bis(3-methoxysalicylidene)(propylene-2-ol)-1,3-diamine, H3L2 = 2,3-dihydroxypropylimino)methyl)-6methoxyphenol, piv = pivalate), have been prepared under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction, elemental analyses, thermal analyses, and IR spectroscopy. Each of the hexanuclear complexes is constructed with Dy-3 triangular motifs as building blocks, and the six Dy-III ions are arranged in a chair-shaped conformation. Variable-temperature magnetic susceptibility measurements in the temperature range of 2-300 K indicate dominant ferromagnetic exchange interactions between the Dy-III ions in the complexes. Both complexes exhibit slow magnetic relaxation behavior.