Chiroptical and magneto-optical properties of chiral nona-nuclear Tb(III) clusters

摘要

The Faraday effect causes a rotation of polarization by a material as the result of the application of an external magnetic field.1 We recently described nona-nuclear Tb(III) clusters coordinated with salicylate ligands that were a new type of lanthanide (Ln(III)) material exhibiting a large Faraday effect." We also found that the Faraday rotation angles were different depending on the organic ligands of these clusters. To maximize the unique characteristics of the inorganic-organic hybrid clusters, we focused on introducing chiral ligands to the Tb(III) cluster. Ln(III) complexes containing chiral ligands show circular dichroism (CD) and circularly polarized luminescence (CPL), which are derived from the chirality. The origin is different from that of the Faraday effect.1,3 The dissymmetry factors (g__(CD) or g_(CPL),) of chiral Ln(III) complexes are known to be large, which is attributed to the large transition magnetic dipole moment of the Ln(III) ion.4 In this work, the effect of large transition magnetic dipole moments on the Faraday rotation was investigated for the chiral Tb(III) clusters.