Enhancement of Optical Faraday Effect of Nonanuclear Tb(III) Complexes

The effective magneto–optical properties of novel nonanuclear Tb­(III) complexes with Tb–O lattice (specifically, [Tb9(sal-R)16(μ-OH)10]+NO3–, where sal-R = alkyl salicylate (R = −CH3 (Me), −C2H5 (Et), −C3H7 (Pr), or −C4H9 (Bu)) are reported. The geometrical structures of these nonanuclear Tb­(III) complexes were characterized using X-ray single-crystal analysis and shape-measure calculation. Optical Faraday rotation was observed in nonanuclear Tb­(III) complexes in the visible region. The Verdet constant per Tb­(III) ion of the Tb9(sal-Me) complex is 150 times larger than that of general Tb­(III) oxide glass. To understand their large Faraday rotation, electron paramagnetic resonance measurements of Gd­(III) complexes were carried out. In this Report, the magneto–optical relation to the coordination geometry of Tb ions is discussed.