Inorganic Approach to Stabilizing Nanoscale Toroidicity in a Tetraicosanuclear Fe18Dy6 Single Molecule Magnet

Kaemmerer H, Baniodeh A, Peng Y, et al. Inorganic Approach to Stabilizing Nanoscale Toroidicity in a Tetraicosanuclear Fe18Dy6 Single Molecule Magnet. Journal of the American Chemical Society. 2020;142(35):4838–14842.Cyclic coordination clusters (CCCs) are proving to provide an extra dimension in terms of exotic magnetic behavior as a result of their finite but cyclized chain structures. The Fe18Dy6 CCC is a Single Molecule Magnet with the highest nuclearity among Ln containing clusters. The three isostructural compounds [Fe18Ln6(mu-OH)6(ampd)12(Hampd)12(PhCO2)24](NO3)6·38MeCN for Ln = DyIII (1), LuIII (2), or YIII (3), where H2ampd = 2-amino-2-methyl-1,3-propanediol, are reported. These can be described in terms of the cyclization of six {Fe3Ln(muOH)(ampd)2(Hampd)2(PhCO2)4}+ units with six nitrate counterions to give the neutral cluster. The overall structure consists of two giant Dy3 triangles sandwiching a strongly antiferromagnetically coupled Fe18 ring, leading to a toroidal arrangement of the anisotropy axis of the Dy ions, making this the biggest toroidal arrangement on a molecular level known so far