Structures and magnetism of two manganese crowns assembled with 2,4-dihydroxyacetophenone oxime

Abstract

Reactions of 2,4-dihydroxyacetophenone oxime with manganese salts yielded two manganese crowns, [Mn₃(μ ₃-O)(4-OH-Me-sao)₃(HCOO)(MeOH)₅]·MeOH (1) and [Mn₃(μ ₃-O)(4-OH-Me-sao)₃(CH₃COO)(MeOH)₅]·MeOH (2) (4-OH-Me-saoH₂=2,4-dihydroxyacetophenone oxime). Both compounds possess [Mn^III ₃(μ ₃-O)]⁷⁺ cores which contain 9-MC-3 metallacrown (MC) rings with the repeating pattern [–Mn–N–O–]. 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.

Keywords:

• [Mn^III ₃(μ ₃-O)]⁷⁺ core
• 9-MC-3 metallacrown
• Magnetic properties
• 2,4-Dihydroxyacetophenone oxime

Acknowledgements

This work was supported by the National Natural Science Foundation of P.R. China (Nos. 20671048, 21041002) and Shandong Province Higher School Science and Technology Plan Projects (No. J10LB61).