Quantification of C−H Quenching in Near-IR Luminescent Ytterbium and Neodymium Cryptates

Bischof, Caroline; Wahsner, Jessica; Scholten, Julia; Trosien, Simon; Seitz, Michael

doi:10.1021/ja105768w

Cited by 93 publications

(66 citation statements)

References 20 publications

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“…Due to the presence of transitions with small energetic differences Δ E between the electronic states, samarium complexes are especially sensitive towards non‐radiative deactivation processes and some additional efforts are necessary to prepare luminescent samarium complexes. Generally, deuteration of the ligand scaffold can suppress multiphonon quenching processes efficiently, most efficiently in the case of the benzylic positions ,. Furthermore the deuteration of only the benzylic positions of the non‐oxidised bipyridine units offers an acceptable trade‐off between efficient ligand synthesis and the improvement of the luminescence properties.…”

Section: Resultssupporting

confidence: 73%

Circularly Polarised Luminescence in Enantiopure Samarium and Europium Cryptates

Kreidt

Arrico

Zinna

et al. 2018

Chemistry A European J

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Circularly polarised luminescence (CPL) is a chiroptical phenomenon gaining more and more attention, as the availability of the necessary spectrometers is getting better and first applications in bioimaging or for the preparation of OLEDs (organic light emitting diodes) are coming within range. Until now most examples of distinctly CPL-active compounds were europium and terbium complexes though theoretically the electronic structure of samarium should be as suitable as the one of terbium. This discrepancy can be accounted for by the high susceptibility of samarium to non-radiative deactivation processes. The aim of this study was to strategically circumvent this difficulty by the use of a ligand scaffold which has already proven to efficiently suppress these processes, namely the cryptates. The prepared partly deuterated samarium and europium complexes exhibit distinct circularly polarised luminescence with dissymmetry factors up to g =+0.13 (Sm ) or g =-0.19 (Eu ).

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Section: Resultssupporting

confidence: 73%

Circularly Polarised Luminescence in Enantiopure Samarium and Europium Cryptates

Kreidt

Arrico

Zinna

et al. 2018

Chemistry A European J

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“…21000 cm –1 ) . The lower quantum yields obtained with near infrared emitters are likely due to luminescence quenching by CH oscillators of the ligand , …”

Section: Resultsmentioning

confidence: 98%

Solid State Structures, Solution Behavior, and Luminescence of Simple Tetrakis(2‐pyridylmethyl)ethylenediamine Lanthanide Complexes

2019

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We report the synthesis, characterization, solid‐state structure and solution behavior of simple lanthanide trifluoromethanesulfonate complexes supported by a hexadentate tetrakis(2‐pyridylmethyl)ethylenediamine ligand. The complexes' solid‐state structures exhibit different trifluoromethanesulfonate coordination, correlating with the size difference of the lanthanide ions. The ligand is capable of sensitizing Nd, Sm, Eu, Tb, Dy, and Yb yielding metal‐centered emission with moderate quantum yields.

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“…In solid‐state materials, inorganic matrices produce low‐energy phonons, typically less than

\overset{ν}{true}

=1200 cm −1 , and the overtones do not lead to efficient nonradiative luminescence‐quenching mechanisms. In contrast, O−H, N−H, and C−H oscillators are observed in the energy domain of

\overset{ν}{true}

=1000–3500 cm −1 at the molecular level, and the overtones afford efficient quenching mechanisms, especially for near‐infrared (NIR)‐emitting Ln cations . Such processes result in shortening of the excited‐states lifetimes with a concomitant decrease of the possible UC efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, OÀH, NÀH, and CÀHo scillators are observed in the energy domain of ñ = 1000-3500 cm À1 at the molecular level, and the overtones afford efficientq uenching mechanisms, [16] especially for near-infrared (NIR)-emitting Ln cations. [17] Such processes result in shorteningofthe excited-states lifetimes with aconcomitant decreaseo ft he possible UC efficiency.Afirst step toward the protection of the Ln cations is encapsulationo ft he ions into organic ligands, thus fulfilling the first coordinations phere, and displacement of the solvent molecules, in particular water, from the inner sphere. In as econd step, the introductiono f heavya toms into the organicb ackboneo ft he ligands is an attractive alternative.…”

Section: Introductionmentioning

confidence: 99%

Energy Transfer in Supramolecular Heteronuclear Lanthanide Dimers and Application to Fluoride Sensing in Water

Nonat

Liu

Jeannin

et al. 2018

Chemistry A European J

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In the presence of fluoride anions, [LnL(H O)] complexes, based on the coordination of a lanthanide (Ln) cation into the cavity of a C symmetrical cyclen-based ligand (L), self-assemble in water to form [(LnL) F] dimers. The crystal structures of the Yb hydrated monomer and of the fluorinated dimer are reported and analyzed to unravel the impact of the cumulative effect of weak hydrogen bonding and aromatic stacking interactions in the supramolecular assembly. The assembly is stable over a broad range of pH 3-8. A combination of equimolar amounts of Eu and Tb complexes led to a quasistatistical mixture of homo- and heterodimers, as observed by using electrospray mass spectrometry. In the heterodimers, selective excitation into the F → D absorption band of the Tb center at λ=488 nm allowed the observation of a Tb-to-Eu downshifting energy transfer, not observed in the absence of fluoride ions. Analysis of the excited-state lifetimes of the dimers within the frame of the Förster theory of energy transfer showed the transfer to have an efficiency of 34 %, with a corresponding Förster radius of 4.1 Å; thereby, unraveling the short Ln-Ln distance as a crucial parameter of the energy-transfer process. By using equimolar mixtures of the Tb and Eu complexes, the energy-transfer phenomenon was used for a ratiometric sensing of fluoride anions in water with a detection limit of 17.7 nm.

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Quantification of C−H Quenching in Near-IR Luminescent Ytterbium and Neodymium Cryptates

Cited by 93 publications

References 20 publications

Circularly Polarised Luminescence in Enantiopure Samarium and Europium Cryptates

Circularly Polarised Luminescence in Enantiopure Samarium and Europium Cryptates

Solid State Structures, Solution Behavior, and Luminescence of Simple Tetrakis(2‐pyridylmethyl)ethylenediamine Lanthanide Complexes

Energy Transfer in Supramolecular Heteronuclear Lanthanide Dimers and Application to Fluoride Sensing in Water

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