A helical salicyladoxime-based manganese triangle chain with single-molecule magnet behavior

• A one-dimensional helical chain was constructed from a Mn3 unit.
• The magnetic properties of complex 1 were investigated.
• Both ferro- and antiferromagnetic interactions exist in complex 1 in the resulting of S = 2 ground state.
• A new helical single-chain magnet exhibits a magnetic anisotropy of Ueff = 28 K.

The reaction of 2-hydroxyphenylpropanone oxime (Et-H2salox) with Mn(NO3)2·4H2O, NEt3 and 1,3-bis(4-pyridyl)propane-N,N′-dioxide (bppo) in EtOH/H2O mixture afforded a one-dimensional coordination polymer with the formula [Mn3O(Et-salox)3(bppo)(MeOH)(H2O)3](NO3)0.5(Et-Hsalox)0.5·MeOH·H2O (1·MeOH·H2O). 1·MeOH·H2O had a manganese triangle structure, [MnIII3O]7 +, which was used as a building unit for a subsequent assembly of an oximate and central oxide. The flexible bppo ligand linked the units, resulting in the formation of a 1D helical structure. Variable temperature direct current magnetic susceptibility measurements of complex 1·MeOH·H2O were carried out. Exchange interactions of the metal centers of complex 1·MeOH·H2O were examined, and the results indicate that both ferro- and antiferromagnetic interactions simultaneously coexist in 1·MeOH·H2O, resulting in an S = 2 ground state. Moreover, complex 1·MeOH·H2O shows the frequency dependence of the out-of-phase component in alternating current magnetic susceptibility measurements, indicating single-molecule magnet behavior with Ueff = 28 K and τ0 = 1.8 × 10− 9 s.

A one-dimensional complex 1·MeOH·H2O showed the slow magnetic relaxation of a single-molecule magnet behavior with the Ueff = 28 K and τ0 = 1.8 × 10− 9 s.Figure optionsDownload as PowerPoint slide