Near Infrared Circularly Polarized Luminescence From Water Stable Organic Nanoparticles Containing a Chiral Yb(III) Complex

Abstract

We report the first example of very efficient NIR Circularly Polarized Luminescence (CPL) (around 970 nm) in water, obtained thanks to the combined use of a chiral Yb complex and of poly lactic-co-glycolic acid (PLGA) nanoparticles. [YbL(tta) 2 ]CH 3 COO (L = N, N'-bis(2-pyridylmethylidene)-1,2-(R,R + S,S) cyclohexanediamine and tta = 2-thenoyltrifluoroacetonate) shows good CPL in organic solvents, because the tta ligands efficiently sensitize Yb NIR lumines-cence and the readily prepared chiral ligand L endows the complex with the necessary dissymmetry. PLGA nanoparticles incorporate the complex and protect the metal ion from the intrusion of solvent molecules, while ensuring biocompatibility, water solubility and stability to the complex. Hydrophilic NIR-CPL optical probes can find applications in the field of NIR-CPL bio-assays.

Circularly polarized luminescence from Tb(iii) interacting with chiral polyether macrocycles

“…The study of chiral lanthanide complexes is a strong and developing field of research. 1–26 These complexes often display interesting circularly polarized luminescence (CPL) properties and, 27 for this reason, applications can be found in key research areas such as in bioanalytical assays and imaging 28–39 or circularly polarized OLEDs. 40–44 To promote efficient chiroptical properties, polydentate monoligands, such as triazacyclononane or tetraazacyclododecane, are usually employed.…”

Two Chiral YbIII Enantiomeric Pairs with Distinct Enantiomerically Pure N-Donor Ligands Presenting Significant Differences in Photoluminescence, Circularly Polarized Luminescence, and Second-Harmonic Generation

“…As shown in Figure 5a, Yb-R-1 and Yb-S-1 display mirror-symmetry CPL profiles with trisignate peaks centered at 980, 1001, and 1040 nm, respectively, which correspond to the total luminescence spectra with three split peaks at the same wavelengths (Figure 5b). The luminescence dissymmetry factor (g lum ) is 0.077 at 980 nm for Yb-R-1 (Figure S10), which is larger than 0.031 for the R,R-isomer of a mononuclear eight-coordinated [YbL- 82 It is much larger than 0.013 for the (+)Yb-isomer of a dinuclear eightcoordinated [Yb((+)/(−)-facam) 3 (L)] 2 enantiomer [(+)/(−)-facam = 3-trifluoro-acetyl-(+)/(−)-camphorato and L = bis(1,10-phenantro [5,6b])tetrathiafulvalene triad]. 34 Different from Yb-R-1/Yb-S-1, CPL spectra of Yb-R-2/Yb-S-2 only show mirror-image bisignate peaks centered at 980 and 1020 nm (Figure 5c), being also related well to the total luminescence spectra with two split peaks at the same wavelengths (Figure 5d).…”

“…As shown in Figure a, Yb- R -1 and Yb- S -1 display mirror-symmetry CPL profiles with trisignate peaks centered at 980, 1001, and 1040 nm, respectively, which correspond to the total luminescence spectra with three split peaks at the same wavelengths (Figure b). The luminescence dissymmetry factor ( g lum ) is 0.077 at 980 nm for Yb- R -1 (Figure S10), which is larger than 0.031 for the R , R- isomer of a mononuclear eight-coordinated [YbL(tta) 2 ]CH 3 COO enantiomer (L = N , N ′-bis(2-pyridylmethylidene)-1,2-( R , R + S , S ) -cyclohexane-diamine) . It is much larger than 0.013 for the (+)Yb-isomer of a dinuclear eight-coordinated [Yb((+)/(−)-facam) 3 (L)] 2 enantiomer [(+)/(−)-facam = 3-trifluoro-acetyl-(+)/(−)-camphorato and L = bis(1,10-phenantro[5,6b])tetrathiafulvalene triad] .…”

“…The observed lifetime values (τ obs ) are 20 [28] and 8 [15] μs for Yb- R -1 and Yb- R -2 at room temperature (Figure S8) and [77 K] (Figure S9), respectively. The τ obs values of Yb- R -1 are much larger than those of Yb- R -2 and are also much larger than those of most Yb III emitting complexes. − Moreover, the solid-state overall quantum yields (Φ tot ) were measured to be 1.26% for Yb- R -1 and 0.48% for Yb- R -2 at room temperature. The Φ tot of Yb- R -1 is more than two times higher than that of Yb- R -2 and is also rather high for NIR-emission Yb III complexes (usually <1%) .…”

“…The luminescence dissymmetry factor (g lum ) is 0.077 at 980 nm for Yb-R-1 (Figure S10), which is larger than 0.031 for the R,R-isomer of a mononuclear eight-coordinated [YbL-(tta) 2 ]CH 3 COO enantiomer (L = N,N′-bis(2-pyridylmethylidene)-1,2-(R,R + S,S) -cyclohexane-diamine). 82 It is much larger than 0.013 for the (+)Yb-isomer of a dinuclear eightcoordinated [Yb((+)/(−)-facam) 3 (L)] 2 enantiomer [(+)/(−)-facam = 3-trifluoro-acetyl-(+)/(−)-camphorato and L = bis(1,10-phenantro [5,6b])tetrathiafulvalene triad]. 34 Different from Yb-R-1/Yb-S-1, CPL spectra of Yb-R-2/Yb-S-2 only show mirror-image bisignate peaks centered at 980 and 1020 nm (Figure 5c), being also related well to the total luminescence spectra with two split peaks at the same wavelengths (Figure 5d).…”