Assisted Self-Assembly to Target Heterometallic Mn-Nd and Mn-Sm SMMs: Synthesis and Magnetic Characterisation of [Mn${}_7$Ln${}_3$(O)${}_4$(OH)${}_4$(mdea)${}_3$(piv)${}_9$(NO${}_3$)${}_3$] (Ln=Nd, Sm, Eu, Gd)**

Assisted self-assembly by using a preformed [Mn${}_6$O${}_2$(piv)${}_{10}$(4-Me-py)${}_2$(pivH)${}_2$] (1) (pivH=pivalic acid) cluster leads to 3 different outcomes of the reaction with Ln(NO${}_3$)${}_3$ ⋅ xH${}_2$O (Ln=Pr−Ho and Y): Mn${}_7$Ln${}_3$ and in some cases the inverse butterfly Mn${}_2$Ln${}_2$ for Ln=Pr−Eu, Mn${}_5$Ln${}_4$ for Ln=Tb-Ho and in the special case of Gd all three possibilities can form. Whilst the magnetic properties for the Mn${}_5$Ln${}_4$ systems show the expected known SMM properties, for Mn${}_7$Ln${}_3$ two new examples of Nd- and Sm-containing SMMs have been discovered.
in an assisted self-assembly approach starting from the [Mn${}_6$O${}_2$(piv)${}_{10}$(4-Me-py)${}_2$(pivH)${}_2$] cluster a family of Mn−Ln compounds (Ln=Pr−Yb) was synthesised. The reaction of [Mn${}_6$O${}_2$(piv)${}_{10}$(4-Me-py)${}_2$(pivH)${}_2$] (1) with N-methyldiethanolamine (mdeaH${}_2$) and Ln(NO${}_3$)${}_3$ ⋅ 6H${}_2$O in MeCN generally yields two main structure types: for Ln=Tb−Yb a previously reported Mn${}_5$Ln${}_4$ motif is obtained, whereas for Ln=Pr−Eu a series of Mn${}_7$Ln${}_3$ clusters is obtained. Within this series the Gd${}^{III}$ analogue represents a special case because it shows both structural types as well as a third Mn${}_2$Ln${}_2$ inverse butterfly motif. ... mehrVariation in reaction conditions allows access to different structure types across the whole series. This prompts further studies into the reaction mechanism of this cluster assisted self-assembly approach. For the Mn${}_7$Ln${}_3$ analogues reported here variable-temperature magnetic susceptibility measurements suggest that antiferromagnetic interactions between the spin carriers are dominant. Compounds incorporating Ln=Nd${}^{III}$(2), Sm${}^{III}$(3) and Gd${}^{III}$ (5) display SMM behaviour. The slow relaxation of the magnetisation for these compounds was confirmed by ac measurements above 1.8 K.