Mirror-image magnetic circularly polarized luminescence (MCPL) from optically inactive Eu III and Tb III tris(β-diketonate).

Five optically inactive EuIII(hfa)3, TbIII(hfa)3, EuIII(acac)3·Phen, TbIII(acac)3·Phen and EuIII(hfa)3·BDPB (hfa: hexafluoroacetylacetonate, acac: acetylacetonate, BDPB: 2,2'-bis(diphenylphosphino)biphenyl and Phen: phenanthroline) complexes showed clear mirror-image magnetic circularly polarised luminescence (MCPL) spectra in CHCl3, acetone, and DMF solutions, in a poly(methyl methacrylate) film, a KBr pellet and bulk powder at room temperature under 1.6 T as an external magnetic field with Faraday geometry. The signs of the MCPL signals were determined via N-up and S-up geometries. The gMCPL values of EuIII(hfa)3 and TbIII(hfa)3 were ±(0.046-2.0) × 10-2 T-1 at the 5D0 → 5FJ transitions (J = 1-4) in the range of 590 nm and 703 nm and ±(0.0081-1.0) × 10-2 T-1 at the 5D4 → 7FJ transitions (J = 3-6) in the range of 480 nm and 630 nm, respectively. Interestingly, the photoluminescence spectra of EuIII(hfa)3 and TbIII(hfa)3 in CHCl3 and acetone under 1.6 T considerably redshifted by 10-114 cm-1, while those of EuIII(acac)3·Phen and TbIII(acac)3·Phen did not reveal detectable redshifts.