An oximate-based hexanuclear mixed-valence MnIII4MnII2 edge-sharing bitetrahedral core with an St = 5 spin ground state

摘要: The synthesis, structures and magnetic properties of two hexanuclear Mn6 clusters are reported: Mn6(μ4-O)2(dapdo)2(dapdoH)4(μ2-OH)2](ClO4)2·6MeCN (1·6MeCN) [Mn6(μ4-O)2(dapdo)2(dapdoH)4(μ2-OCH3)2](ClO4)2·2Et2O (2·2Et2O) [dapdo2− is the dianion 2,6-diacetylpyridine dioxime dapdoH− monoanion aforesaid ligand]. Both complexes mixed-valent with MnII four MnIII atoms disposed in an edge-sharing bitetrahedral core. 1 2 display same [MnIII4MnII2(μ4-O)2(μ2-OR)2]10+ core which R = H for Me 2. [MnIII4MnII2] rather uncommon compared to reported [MnIII2MnII4] literature. DC susceptibility measurements on reveal presence competing exchange interactions resulting St 5 ground spin state. behavior compounds indicates antiferromagnetic coupling between manganese(III) centers, whereas manganese(II) weakly or ferromagnetic depending bridging environments. Finally interaction centers from fused tetrahedra nature stabilizing state