Assembly of Homochiral Magneto-Optical Dy Triangular Clusters by Fixing Carbon Dioxide in the Air.

A new hydrazone Schiff base bridging ligand (HL ()-'-((1-hydroxynaphthalen-2-yl)methylene)pyrazine-2-carbohydrazide) and /-proline were used to construct a pair of homochiral Dy cluster complexes, [Dy(CO)(-Pro)(L)(HL)]·5DMA·2HO (-, -HPro = -proline; DMA = ,-dimethylacetamide) and [Dy(CO)(-Pro)(L)(HL)]·5DMA·2HO (-, -HPro = -proline), which show a novel triangular Dy topology. Notably, the fixation of CO in the air formed a carbonato central bridge, playing a key role in assembling -/-. Magnetic measurements revealed that -/- displays intramolecular ferromagnetic coupling and magnetic relaxation behaviours. Furthermore, -/- shows a distinct magneto-optical Faraday effect and has a second harmonic generation (SHG) response (1.0 × KDP) at room temperature. The results show that the immobilization of CO provides a novel pathway for homochiral multifunctional 4f cluster complexes.