An oxide-bridged Dy–ReV–Dy single-molecule magnet

Abstract The reaction of diamagnetic trans -[Re V (O) 2 (py) 4 ]NO 3 with [Ln(hfac) 3 (H 2 O) 2 ] (Ln = Dy, Y, Tb; hfac −  = 1,1,1,5,5,5-hexafluoroacetylacetonate(1–)) in chloroform yields oxide-bridged, trinuclear [Ln(hfac) 3 (H 2 O)–Re(O) 2 (py) 4 –Ln(hfac) 3 (NO 3 )] ( DyReDy , YReY , TbReTb ). The series is isostructural to a fluoride-bridged {Dy–Cr–Dy} complex previously reported (Dreiser et al. , Chem. Sci. 3 (2012) 1024) but, notably, DyReDy exhibits frequency-dependent out-of-phase ac susceptibility ( χ″ ) signals at higher temperatures than the chromium analogue. Magnetic investigations of a solid solution of Dy 3+ in YReY reveal the presence of a small Dy–Dy exchange interaction in DyReDy .