Mn4 Single-Molecule-Magnet-Based Polymers of a One-Dimensional Helical Chain and a Three-Dimensional Network: Syntheses, Crystal Structures, and Magnetic Properties

Two Mn4 single-molecule-magnet (SMM)-based coordination polymers, {[Mn4O­(salox)3(N3)3(DMF)2(H2O)­(dpp)]·0.5MeOH}n (1·0.5MeOH; H2salox = salicylaldoxime; dpp = 1,3-di-4-pyridylpropane; DMF = N,N-dimethylformamide) and {[Mn4O­(Me-salox)3(N3)3(dpp)1.5]·1.5Et2O}n (2·1.5Et2O; Me-H2salox = hydroxyphenylethanone oxime), are self-assembled from Mn­(ClO4)2·6H2O/H2salox and Mn­(ClO4)2·6H2O/Me-H2salox systems with dpp and NaN3 in DMF/MeOH, respectively. Both compounds comprise a mixed-valence tetranuclear manganese core, [MnIIMnIII3O]9+, which serves as a building unit for subsequent assembly via oximate and azido ligands. The flexible dpp ligand links with a Mn4 unit, leading to the formation of a one-dimensional helical structure in 1·0.5MeOH and a three-dimensional pcu network in 2·1.5Et2O. The magnetic data analysis shows that antiferromagnetic interactions within the Mn4 units resulted in S = 3/2 and 7/2 ground states for 1·0.5MeOH and 2·1.5Et2O, respectively. Both compounds show SMM behavior, as evidenced by frequency-dependent out-of-phase signals in alternating-current magnetic susceptibility and magnetic hysteresis loop studies with an energy barrier of Ueff = 37 K for 2·1.5Et2O.