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1. [Ga 3+ 8 Sm 3+ 2 , Ga 3+ 8 Tb 3+ 2 ] Metallacrowns are Highly Promising Ratiometric Luminescent Molecular Nanothermometers Operating at Physiologically Relevant Temperatures

   https://doi.org/10.1002/chem.202003239  

   Salerno, Elvin V. ; Zeler, Justyna ; Eliseeva, Svetlana V. ; Hernández‐Rodríguez, Miguel A. ; Carneiro Neto, Albano N. ; Petoud, Stéphane ; Pecoraro, Vincent L. ; Carlos, Luís D. ( September 2020 , Chemistry – A European Journal)

   Nanothermometry is the study of temperature at the submicron scale with a broad range of potential applications, such as cellular studies or electronics. Molecular luminescent‐based nanothermometers offer a non‐contact means to record these temperatures with high spatial resolution and thermal sensitivity. A luminescent‐based molecular thermometer comprised of visible‐emitting Ga³⁺/Tb³⁺and Ga³⁺/Sm³⁺metallacrowns (MCs) achieved remarkable relative thermal sensitivity associated with very low temperature uncertainty ofS_r=1.9 % K⁻¹andδT<0.045 K, respectively, at 328 K, as an aqueous suspension of polystyrene nanobeads loaded with the corresponding MCs. To date, they are the ratiometric molecular nanothermometers offering the highest level of sensitivity in the physiologically relevant temperature range.

    

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2. Lifetimes of Be 3 2– and Mg 3 2– Cluster Dianions

   https://doi.org/10.1021/acs.jpca.1c00770  

   Davis, Jeremy U. ; Phung, Quan Manh ; Yanai, Takeshi ; Ehara, Masahiro ; Sommerfeld, Thomas ( May 2021 , The Journal of Physical Chemistry A)
3. Comparing Pr 3+ and Nd 3+ for deactivating the Er 3+ :  4 I 13/2 level in lanthanum titanate glass

   https://doi.org/10.1364/OME.517790  

   Topper, Brian ; Neumann, Alexander ; Wilke, Stephen_K ; Youngman, Randall_E ; Alrubkhi, Abdulrahman ; Weber, Richard ( April 2024 , Optical Materials Express)

   Erbium lanthanum titanate glasses were prepared by levitation melting for the spectroscopic study of ways to promote the mid-infrared fluorescence. Two series of heavily erbium doped glasses (15 wt%) were prepared with the addition of either Pr³⁺or Nd³⁺in amounts relative to Er³⁺of 0.05, 0.1, and 0.2. Both ions quench the lower Er³⁺laser level with the Pr³⁺doing so more rapidly. Although high co-dopant concentrations result in higher energy transfer, as clearly evidenced in upconversion and downconversion fluorescence measurements, the mid-infrared lifetime also suffers a reduction and, therefore, a balance must be struck in the co-dopant concentration. Lifetime and spectral measurements indicate that, at a fixed relative co-dopant amount, Pr³⁺is more effective than Nd³⁺at removing the bottleneck of the Er^3+ 4I_13/2level. Moreover, consideration of the lifetimes alongside the absorption data of the individual ions indicates that despite the large absorption cross-section of Nd³⁺at 808 nm, the concentration needed to yield more absorbed power than utilizing direct 976 nm excitation of Er³⁺results in unfavorable lifetimes of the mid-infrared transition. In the end, Pr³⁺prevails as the superior co-dopant in terms of the effects on fluorescence lifetimes as well as potential laser system design considerations. In a unique self-doping approach, a reducing melt atmosphere of Ar instead of O₂creates a small fraction of Ti³⁺. In 5Er₂O₃-12La₂O₃-83TiO₂glass, the presence of Ti³⁺quenches the⁴I_13/2emission about 2.6 times more than the⁴I_11/2when lifetimes are compared to an O₂melt environment. As an additional means of increasing the mid-infrared emission, the effect of temperature on the mid- and near- infrared lifetimes of a lightly doped lanthanum titanate composition is investigated between 77-300 K. The mid-infrared lifetime increases by ∼30% while the near-infrared lifetime increases by ∼10%, which suggests in addition to co-doping, active cooling of the gain media will further enhance performance.

    

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4. Al(OR F ) 3 (R F = C(CF 3 ) 3 ) activated silica: a well-defined weakly coordinating surface anion

   https://doi.org/10.1039/C9SC05904K  

   Culver, Damien B. ; Venkatesh, Amrit ; Huynh, Winn ; Rossini, Aaron J. ; Conley, Matthew P. ( February 2020 , Chemical Science)

   Weakly Coordinating Anions (WCAs) containing electron deficient delocalized anionic fragments that are reasonably inert allow for the isolation of strong electrophiles. Perfluorinated borates, perfluorinated aluminum alkoxides, and halogenated carborane anions are a few families of WCAs that are commonly used in synthesis. Application of similar design strategies to oxide surfaces is challenging. This paper describes the reaction of Al(OR F ) 3 *PhF (R F = C(CF 3 ) 3 ) with silica partially dehydroxylated at 700 °C (SiO 2-700 ) to form the bridging silanol Si–OH⋯Al(OR F ) 3 ( 1 ). DFT calculations using small clusters to model 1 show that the gas phase acidity (GPA) of the bridging silanol is 43.2 kcal mol −1 lower than the GPA of H 2 SO 4 , but higher than the strongest carborane acids, suggesting that deprotonated 1 would be a WCA. Reactions of 1 with NOct 3 show that 1 forms weaker ion-pairs than classical WCAs, but stronger ion-pairs than carborane or borate anions. Though 1 forms stronger ion-pairs than these state-of-the-art WCAs, 1 reacts with alkylsilanes to form silylium type surface species. To the best of our knowledge, this is the first example of a silylium supported on derivatized silica. 

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5. Variability of Jupiter's IR H 3 + aurorae during Juno approach: JUPITER'S H 3 + AURORAE

   https://doi.org/10.1002/2017GL073156  

   Moore, L. ; O'Donoghue, J. ; Melin, H. ; Stallard, T. ; Tao, C. ; Zieger, B. ; Clarke, J. ; Vogt, M. F. ; Bhakyapaibul, T. ; Opher, M. ; et al ( May 2017 , Geophysical Research Letters)