Regulating the solution structural integrity and slow magnetic relaxation behavior of two Dy6 clusters with a pyridine–triazole ligand

Abstract

Using the pyridine–triazole based ligand of bis(3-(pyridin-2-yl)-1,2,4-triazol-5-yl)methane (H₂L), two hexanuclear dysprosium(III) complexes, [Dy₆(μ₄-NO₃)₂ (OAc)₆(L)₄(DMF)₂]·2NO₃ (1) and [Dy₆(μ₃-OH)₄(μ₂-OH)₂(OAc)₄(L)₄(EtOH)₄]·2H₂O (2), have been successfully obtained by hydrothermal reaction in different solvents. The crystal structure analysis reveals that the {Dy₆} core in 1 is connected by two μ₄-NO₃⁻ ions, whereas by four μ₃-OH⁻ and two μ₂-OH⁻ ions in 2. The HRESI-MS (high-resolution electrospray ionization mass spectrum) measurement of 1–2 was recorded. The presence of prominent peaks for the {Dy₆} fragment in 1 (m/z, 1354–1380) at different ion-source voltages showed the higher solution stability and structural integrity of the {Dy₆} cluster in 1, compared with that in 2. Temperature- and frequency-dependent alternating current (AC) susceptibility measurements of 1–2 in a zero direct current field display only a characteristic feature of single-molecule magnet (SMM) behavior for 2, indicating different magnetic behavior.