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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)

   Abstract 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. Branching Ratio for O + H ₃ ⁺ Forming OH ⁺ + H ₂ and H ₂ O ⁺ + H

   https://doi.org/10.3847/1538-4357/ac41ce  

   Hillenbrand, Pierre-Michel; Ruette, Nathalie de; Urbain, Xavier; Savin, Daniel W. (March 2022, The Astrophysical Journal)

   Abstract The gas-phase reaction of O + H 3 + has two exothermic product channels: OH + + H 2 and H 2 O + + H. In the present study, we analyze experimental data from a merged-beams measurement to derive thermal rate coefficients resolved by product channel for the temperature range from 10 to 1000 K. Published astrochemical models either ignore the second product channel or apply a temperature-independent branching ratio of 70% versus 30% for the formation of OH + + H 2 versus H 2 O + + H, respectively, which originates from a single experimental data point measured at 295 K. Our results are consistent with this data point, but show a branching ratio that varies with temperature reaching 58% versus 42% at 10 K. We provide recommended rate coefficients for the two product channels for two cases, one where the initial fine-structure population of the O( 3 P J ) reactant is in its J = 2 ground state and the other one where it is in thermal equilibrium. 

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3. Modulating optical properties through cation substitution: composition-property relationships in MI3M ^III P ₃ O ₉ N:Eu ²⁺ (M ^I = Na, K; M ^III = Al, Ga, In)

   https://doi.org/10.1039/d5qi00410a  

   Lee, Nakyung; Zeler, Justyna; Sójka, Małgorzata; Zych, Eugeniusz; Brgoch, Jakoah (April 2025, Inorganic Chemistry Frontiers)

   Developing phosphors with narrow photoluminescence emission peaks and high chromatic stability is significant for light-emitting diode (LED) technologies. This work studies the connection between composition, structure, and peak shape. 

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4. Experimental study of the proton-transfer reaction C + H ₂ ⁺ → CH ⁺ + H and its isotopic variant (D ₂ ⁺ )

   https://doi.org/10.1039/D0CP04810K  

   Hillenbrand, Pierre-Michel; Bowen, Kyle P.; Dayou, Fabrice; Miller, Kenneth A.; de Ruette, Nathalie; Urbain, Xavier; Savin, Daniel W. (December 2020, Physical Chemistry Chemical Physics)

   We report absolute integral cross section (ICS) measurements using a dual-source merged-fast-beams apparatus to study the titular reactions over the relative translational energy range of E r ∼ 0.01–10 eV. We used photodetachment of C − to produce a pure beam of atomic C in the ground electronic 3 P term, with statistically populated fine-structure levels. The H 2 + and D 2 + were formed in an electron impact ionization source, with well known vibrational and rotational distributions. The experimental work is complemented by a theoretical study of the CH 2 + electronic system in the reactant and product channels, which helps to clarify the possible reaction mechanisms underlying the ICS measurements. Our measurements provide evidence that the reactions are barrierless and exoergic. They also indicate the apparent absence of an intermolecular isotope effect, to within the total experimental uncertainties. Capture models, taking into account either the charge-induced dipole interaction potential or the combined charge-quadrupole and charge-induced dipole interaction potentials, produce reaction cross sections that lie a factor of ∼4 above the experimental results. Based on our theoretical study, we hypothesize that the reaction is most likely to proceed adiabatically through the 1 4 A′ and 1 4 A′′ states of CH 2 + via the reaction C( 3 P) + H 2 + ( 2 Σ+g) → CH + ( 3 Π) + H( 2 S). We also hypothesize that at low collision energies only H 2 + ( v ≤ 2) and D 2 + ( v ≤ 3) contribute to the titular reactions, due to the onset of dissociative charge transfer for higher vibrational v levels. Incorporating these assumptions into the capture models brings them into better agreement with the experimental results. Still, for energies ≲0.1 eV where capture models are most relevant, the modified charge-induced dipole model yields reaction cross sections with an incorrect energy dependence and lying ∼10% below the experimental results. The capture cross section obtained from the combined charge-quadrupole and charge-induced dipole model better matches the measured energy dependence but lies ∼30–50% above the experimental results. These findings provide important guidance for future quasiclassical trajectory and quantum mechanical treatments of this reaction. 

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5. Observation of Transition‐Metal–Boron Triple Bonds in IrB ₂ O ⁻ and ReB ₂ O ⁻

   https://doi.org/10.1002/anie.202006652  

   Chen, Teng‐Teng; Cheung, Ling Fung; Chen, Wei‐Jia; Cavanagh, Joseph; Wang, Lai‐Sheng (June 2020, Angewandte Chemie International Edition)

   Abstract Multiple bonds between boron and transition metals are known in many borylene (:BR) complexes via metal d_π→BR back‐donation, despite the electron deficiency of boron. An electron‐precise metal–boron triple bond was first observed in BiB₂O⁻[Bi≡B−B≡O]⁻in which both boron atoms can be viewed as sp‐hybridized and the [B−BO]⁻fragment is isoelectronic to a carbyne (CR). To search for the first electron‐precise transition‐metal‐boron triple‐bond species, we have produced IrB₂O⁻and ReB₂O⁻and investigated them by photoelectron spectroscopy and quantum‐chemical calculations. The results allow to elucidate the structures and bonding in the two clusters. We find IrB₂O⁻has a closed‐shell bent structure (C_s,¹A′) with BO⁻coordinated to an Ir≡B unit, (⁻OB)Ir≡B, whereas ReB₂O⁻is linear (C_∞v,³Σ⁻) with an electron‐precise Re≡B triple bond, [Re≡B−B≡O]⁻. The results suggest the intriguing possibility of synthesizing compounds with electron‐precise M≡B triple bonds analogous to classical carbyne systems. 

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