Chirogenesis and Pfeiffer Effect in Optically Inactive Eu(III) and Tb(III) Tris(β-diketonate) Upon Intermolecular Chirality Transfer From Poly- and Monosaccharide Alkyl Esters and α-Pinene: Emerging Circularly Polarized Luminescence (CPL) and Circular Dichroism (CD)

We report emerging circularly polarized luminescence (CPL) at 4f-4f transitions when lanthanide (Eu(III) and Tb(III)) tris(β-diketonate) embedded to cellulose triacetate (CTA), cellulose acetate butyrate (CABu), D-/L-glucose pentamethyl esters (D-/L-Glu), and D-/L-arabinose tetramethyl esters (D-/L-Ara) are in film states. Herein, 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate (fod) and 2,2,6,6-tetramethyl-3,5-heptanedione (dpm) were chosen as the β-diketonates. The g(lum) value of Eu(fod)(3) in CABu are +0.0671 at 593 nm ((5) [Formula: see text] F(1)) and −0.0059 at 613 nm ((5) [Formula: see text] F(2)), respectively, while those in CTA are +0.0463 and −0.0040 at these transitions, respectively. The g(lum) value of Tb(fod)(3) in CABu are −0.0029 at 490 nm ((5) [Formula: see text] F(6)), +0.0078 at 540 nm ((5) [Formula: see text] F(5)), and −0.0018 at 552 nm ((5) [Formula: see text] F(5)), respectively, while those in CTA are −0.0053, +0.0037, and −0.0059 at these transitions, respectively. D-/L-Glu and D-/L-Ara induced weaker g(lum) values at 4f-4f transitions of Eu(fod)(3), Tb(fod)(3), and Tb(dpm)(3). For comparison, Tb(dpm)(3) in α-pinene showed clear CPL characteristics, though Eu(dpm)(3) did not. A surplus charge neutralization hypothesis was applied to the origin of attractive intermolecular interactions between the ligands and saccharides. This idea was supported from the concomitant opposite tendency in upfield (19)F-NMR and downfield (1)H-NMR chemical shifts of Eu(fod)(3) and the opposite Mulliken charges between F-C bonds (fod) and H-C bonds (CTA and D-/L-Glu). An analysis of CPL excitation (CPLE) and CPL spectra suggests that (+)- and (–)-sign CPL signals of Eu(III) and Tb(III) at different 4f-4f transitions in the visible region are the same with the (+)-and (–)-sign exhibited by CPLE bands at high energy levels of Eu(III) and Tb(III) in the near-UV region.