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We describe the synthesis of C 2 -symmetrical enantiopure lanthanide complexes (Tb, Eu, Sm, Dy) supported by the decadentate ligand N , N , N ′, N ′-tetrakis[(6-carboxypyridin-2-yl)methyl]-1,2-diaminocyclohexane (tpadac). The chiral tpadac ligand was designed to protect the lanthanide center from coordination of inner-sphere water molecules resulting in air- and water-stable, and highly luminescent complexes in water. The complexes exhibit strong chiroptical properties, with high dissymmetry factors g lum (0.11 to 0.25) and CPL brightness B CPL (up to 245 M −1 cm −1 for Tb, λ exc 295 nm, λ em 544 nm) in water. These are the first example of aqueous Sm CPL and second example of aqueous Dy CPL reported to date. The lanthanide complexes obtained gave a reversible CPL response to pH ranging from 6.0 to 8.0. In addition, distinctive CPL responses (including a change in CPL sign) towards toxic cations (Pb 2+ , Cd 2+ , and Mn 2+ ) were also observed, demonstrating the potential of our complexes to be used as aqueous probes.
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Vanol‐Supported Lanthanide Complexes for Strong Circularly Polarized Luminescence at 1550 nm
Abstract Strong circularly polarized luminescence (CPL) at 1550 nm is reported for lanthanide complexes supported by Vanol; these are the first examples of coordination of Vanol to lanthanides. A change in the ligand design from a 1,1’‐bi‐2‐naphthol (in Binol) to a 2,2’‐bi‐1‐naphthol (in Vanol) results in significantly improved dissymmetry factors for (Vanol)3ErNa3(|glum|=0.64) at 1550 nm. This is among the highest reported dissymmetry factors to date in the telecom C‐band region, and among the highest for any lanthanide complexes. Comparative solid‐state structural analysis of (Vanol)3ErNa3and (Binol)3ErNa3suggests that a less distorted geometry around the metal center is in part responsible for the high chiroptical metrics of (Vanol)3ErNa3. This phenomenon was further evidenced in the analogous ytterbium complex (Vanol)3YbNa3that also exhibit a significantly improved dissymmetry factor (|glum|=0.21). This confirms and generalizes the same observation that was made in other visibly emitting, six‐coordinate lanthanide complexes. Due to their strong CPL at 1550 nm, the reported complexes are potential candidates for applications in quantum communication technologies. More importantly, our structure‐CPL activity relationship study provides guidance towards the generation of even better near‐infrared CPL emitters.
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- Award ID(s):
- 2041084
- PAR ID:
- 10419153
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 29
- Issue:
- 36
- ISSN:
- 0947-6539
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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