Structures and magnetism of two manganese crowns assembled with 2,4-dihydroxyacetophenone oxime
摘要:
Reactions of 2,4-dihydroxyacetophenone oxime with manganese salts yielded two manganese crowns, [Mn3( 3-O)(4-OH-Me-sao)3(HCOO)(MeOH)5]center dot MeOH (1) and [Mn3( 3-O)(4-OH-Me-sao)3(CH3COO)(MeOH)5]center dot MeOH (2) (4-OH-Me-saoH2=2,4-dihydroxyacetophenone oxime). Both compounds possess [MnIII 3( 3-O)]7+ cores which contain 9-MC-3 metallacrown (MC) rings with the repeating pattern [MnNO]. However, the difference in the structures of both compounds is coordinated carboxylates. In 1 and 2, the MC molecules are connected with each other through intermolecular hydrogen bonds, generating similar 3-D supramolecular networks. Magnetic properties reveal that in 1 and 2 the metal ions exhibit ferromagnetic exchange coupling.