One-dimensional supramolecular assembly of an Mn12 single molecule magnet by ligand interactions

A new Mn12 complex was synthesized using ligand substitution reaction of Mn12–OAc with 4-(thiophen-3-yl)benzoic acid and complex’s structural and magnetic properties were analysed. [Mn12O12(O2CC6H4C4H3S)16(H2O)3]·14CH2Cl2 (1) crystallized in the P21/c space group. Intermolecular π–π interactions between phenyl and thiophene rings of two adjacent Mn12 molecules result in one-dimensional supramolecular assembly of 1 in the crystal. On the other hand, steric repulsion between the neighbouring molecules causes unusual ligand arrangement and coordination geometry of Mn(III) ion with five coordination. The ac magnetic study of 1 gives Ueff = 69.98 K and 1/τ0 = 1.456 × 108 s−1 and dc reduced magnetization measurement gives S = 10, g = 1.95 and D = −0.425 cm−1 showing that outer ligand distortion has little effect on the magnetic properties.