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1. Characterizing Infrared Spectra of OH ^– ·(H ₂ O) ₂ and OH ^– ·(H ₂ O) ₃ with Constrained Nuclear-Electronic Orbital Molecular Dynamics

   https://doi.org/10.1021/acs.jpca.5c04334  

   Liu, Zhe; Wang, Yiwen; Zhang, Yuzhe; Yang, Nan; Yang, Yang (October 2025, The Journal of Physical Chemistry A)
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. A Synthetically Generated LFe ^IV OH _n Complex

   https://doi.org/10.1021/acs.inorgchem.8b03200  

   Weitz, Andrew C.; Mills, Matthew R.; Ryabov, Alexander D.; Collins, Terrence J.; Guo, Yisong; Bominaar, Emile L.; Hendrich, Michael P. (January 2019, Inorganic Chemistry)
4. HCOO ⁻ _aq degradation in droplets by OH _aq in an atmospheric pressure glow discharge

   https://doi.org/10.1088/1361-6463/acc958  

   Meyer, Mackenzie; Nayak, Gaurav; Bruggeman, Peter J.; Kushner, Mark J. (April 2023, Journal of Physics D: Applied Physics)

   Abstract Plasmas in contact with liquids can degrade organic molecules in a solution, as reactive oxygen and nitrogen species produced in the plasma solvate into the liquid. Immersing small droplets (tens of microns in diameter) in the plasma can more rapidly activate the liquid compared to treating a large volume of liquid with a smaller surface-to-volume ratio. The interactions between a radio frequency glow discharge sustained in He/H₂O and a water droplet containing formate (HCOO⁻_aq) immersed in and flowing through the plasma were modeled using a zero-dimensional global plasma chemistry model to investigate these activation processes. HCOO⁻_aqinteracts with OH_aq, which is produced from the solvation of OH from the gas phase. The resulting HCOO⁻_aqconcentrations were benchmarked with previously reported experimental measurements. The diameter of the droplet, initial HCOO⁻_aqconcentration, and gas flow rate affect only the HCOO⁻_aqconcentration and OH_aqdensity, leaving the OH density in the gas phase unaffected. Power deposition and gas mixture (e.g. percentage of H₂O) change both the gas and liquid phase chemistry. A general trend was observed: during the first portion of droplet exposure to the plasma, OH_aqprimarily consumes HCOO⁻_aq. However, O₂⁻_aq, a byproduct of HCOO⁻_aqconsumption, consumes OH_aqonce O₂⁻_aqreaches a critically large density. Using HCOO⁻_aqas a surrogate for OH_aq-sensitive contaminants, combinations of residence time, droplet diameter, water vapor density, and power will determine the optimum remediation strategy. 

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5. Plasma-droplet interaction study to assess transport limitations and the role of ^⋅ OH, O ^⋅ ,H ^⋅ ,O ₂ (a ¹ Δ _g ),O ₃ , He(2 ³ S) and Ar(1s ₅ ) in formate decomposition

   https://doi.org/10.1088/1361-6595/ac2676  

   Nayak, Gaurav; Oinuma, Gaku; Yue, Yuanfu; Santos Sousa, João; Bruggeman, Peter J (November 2021, Plasma Sources Science and Technology)

   Abstract Plasmas interacting with liquid microdroplets are gaining momentum due to their ability to significantly enhance the reactivity transfer from the gas phase plasma to the liquid. This is, for example, critically important for efficiently decomposing organic pollutants in water. In this contribution, the role of ⋅ OH as well as non- ⋅ OH-driven chemistry initiated by the activation of small water microdroplets in a controlled environment by diffuse RF glow discharge in He with different gas admixtures (Ar, O 2 and humidified He) at atmospheric pressure is quantified. The effect of short-lived radicals such as O ⋅ and H ⋅ atoms, singlet delta oxygen (O 2 ( a 1 Δ g )), O 3 and metastable atoms of He and Ar, besides ⋅ OH radicals, on the decomposition of formate dissolved in droplets was analyzed using detailed plasma diagnostics, droplet characterization and ex situ chemical analysis of the treated droplets. The formate decomposition increased with increasing droplet residence time in the plasma, with ∼70% decomposition occurring within ∼15 ms of the plasma treatment time. The formate oxidation in the droplets is shown to be limited by the gas phase ⋅ OH flux at lower H 2 O concentrations with a significant enhancement in the formate decomposition at the lowest water concentration, attributed to e − /ion-induced reactions. However, the oxidation is diffusion limited in the liquid phase at higher gaseous ⋅ OH concentrations. The formate decomposition in He/O 2 plasma was similar, although with an order of magnitude higher O ⋅ radical density than the ⋅ OH density in the corresponding He/H 2 O plasma. Using a one-dimensional reaction–diffusion model, we showed that O 2 ( a 1 Δ g ) and O 3 did not play a significant role and the decomposition was due to O ⋅ , and possibly ⋅ OH generated in the vapor containing droplet-plasma boundary layer. 

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