A series of isostructural octanuclear lanthanide complexes of general formula [Ln 8 (sao) 4 (μ 3 -OH) 4

(NO 3 ) 12 (DMF) 12 ] (Ln = Nd ( 1 ), Sm ( 2 ), Eu ( 3 ), Gd ( 4 ), Tb ( 5 ), Dy ( 6 ), Ho ( 7 ), Er ( 8 ); DMF = dimethylform- amide) have been prepared via reactions of salicylaldoxime (saoH 2 ), tetramethylammonium hydroxide (Me 4 NOH) with the appropriate lanthanide nitrate salt (Ln(NO 3 ) 3 ·6H 2 O). The metallic skeletons of the complexes describe [Ln 4 ] tetrahedra encapsulated inside a [Ln 4 ] square with the inner core stabilised through μ 3 -OH − ions and the periphery by μ 4 -sao 2 − ligands. The magnetic properties of compounds 2 – 8 were investigated by dc and ac magnetometry. Temperature dependent ac magnetic sus- ceptibility data reveal that the dysprosium analogue ( 6 ) displays an out-of-phase signal in the absence of an applied magnetic fi eld 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.