Squaring the cube: a family of octametallic lanthanide complexes including a Dy8 single-molecule magnet

A series of isostructural octanuclear lanthanide complexes of general formula [Ln8(sao)4(μ3-OH)4(NO3)12(DMF)12] (Ln = Nd (), Sm (), Eu (), Gd (), Tb (), Dy (), Ho (), Er (); DMF = dimethylformamide) have been prepared via reactions of salicylaldoxime (saoH2), tetramethylammonium hydroxide (Me4NOH) with the appropriate lanthanide nitrate salt (Ln(NO3)3·6H2O). The metallic skeletons of the complexes describe [Ln4] tetrahedra encapsulated inside a [Ln4] square with the inner core stabilised through μ3-OH(-) ions and the periphery by μ4-sao(2-) ligands. The magnetic properties of compounds were investigated by dc and ac magnetometry. Temperature dependent ac magnetic susceptibility data reveal that the dysprosium analogue () displays an out-of-phase signal in the absence of an applied magnetic field indicative of slow relaxation of the magnetization typical of a Single-Molecule Magnet (SMM). Micro-SQUID measurements reveal temperature and sweep rate dependent hysteresis below 1.0 K.