Anion-dependent dysprosium(iii) cluster single-molecule magnets

A new Schiff base ligand, which is formed by the condensation reaction of 5-fluorosalicylaldehyde and pyrimidine-4-carbonyl hydrazide {H2LSchiff = (E)-N '-(5-fluoro-2-hydroxybenzylidene)pyrimidine-4-carbohydrazide}, was made to react with different dysprosium(III) salts in an alkaline solution to assemble Dy-4 and Dy-6 cluster complexes, [Dy-4(OH)(2)(L-Schiff)(4)(H2O)(2)(NO3)(2)]4MeCNMeOH (1) and [Dy-6(CO3)(2)(L-Schiff)(6)(H2O)(3)(MeOH)Cl-2]5MeOH (2), depending on whether the anion used is nitrate or chloride. Complex 1 corresponding to the nitrate anion is a butterfly-like Dy-4 cluster complex with four different Dy(III) coordination configurations of [O6N2], [O8N], [O7N2] and [O6N3]; when the anion is replaced by the chloride anion, carbon dioxide can be automatically captured from the air and converted into a carbonate bridging ligand, and the final product obtained is complex 2, which is a triangular prism-type Dy-6 cluster complex with double mu(3)-carbonate bridging ligands. Both 1 and 2 show good zero-field SMM properties, with U-eff/k values of 116.5 K for 1 and 150.9 K for 2.

Automated summary

A new Schiff base ligand was synthesized and used to react with different dysprosium(III) salts, resulting in the formation of two dysprosium cluster complexes with distinct structures. Both complexes exhibit promising magnetic properties.