Cross-Reactions of Glyoxal and Glycolaldehyde in Aqueous Aerosol Mimics: Implications for Brown Carbon Product Formation

ACS ES&T Air, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

Language: Английский

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Atmospheric Photochemical Oxidation of 4-Nitroimidazole

Atmosphere, Journal Year: 2025, Volume and Issue: 16(5), P. 624 - 624

Published: May 20, 2025

Nitro-functionalized heterocycles, such as nitroimidazoles, are significant environmental contaminants and have been identified components of secondary organic aerosols (SOA) biomass-burning (BBOA). Their strong absorption in the near-UV (300–400 nm) makes photochemistry a critical aspect their atmospheric processing. This study investigates both direct hydroxyl radical (OH) oxidation 4-nitroimidazole (4-NI). The photolysis rate 4-NI was found to be J4-NI = 4.3 × 10−5 (±0.8) s−1, corresponding an lifetime 391 (±77) min under bulk aqueous conditions simulating cloud water. Electrospray ionization mass spectrometry (ESI-MS) analysis following irradiation indicated loss nitro group, while NO elimination observed more minor channel photolysis. In addition, constant for reaction with OH radicals, kNI+OH, determined 2.9 109 (±0.6) M−1s−1. Following oxidation, ESI-MS results show emergence dominant peak at m/z 130 amu, consistent hydroxylation 4-NI. Computational indicate that addition occurs lowest barrier C2 C5 positions combined from experiments suggest OH-mediated degradation is likely dominate aerosol-phase conditions, where concentrations elevated, expected primary mechanism high-humidity environments

Language: Английский

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Theoretical Study on the Synthesis Efficiency and Yield of Imidazole Derivatives Based on the Glyoxal and Diamine

International Journal of Quantum Chemistry, Journal Year: 2024, Volume and Issue: 124(19)

Published: Sept. 26, 2024

ABSTRACT Imidazole structures are significant molecular frameworks in pharmaceutical and energetic material research. The synthesis efficiency yield of their derivatives often vary greatly, making it challenging to establish reaction regularity. In this study, we investigated two types imidazole with notably different efficiencies yields. Our findings reveal that the catalysis H 2 O molecules is crucial for ensuring efficiency, while side reactions influenced by acidity solution during process, thereby affecting yield. We observed energy barrier O‐catalyzed ipsilateral transfer process was reduced 12.0 from 40.1 kcal/mol, significantly enhancing efficiency. 34‐dihydroxyimidazolidine‐2‐ketone found have a low 19.2% due competitive system, which higher barriers compared desired pathway. These provide theoretical foundation future research optimize derivatives. Enhancing conditions could benefit applications development advanced materials.

Language: Английский

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Theoretical investigation on the oxidation mechanism of methylglyoxal in the aqueous phase

Chemosphere, Journal Year: 2024, Volume and Issue: unknown, P. 143425 - 143425

Published: Sept. 1, 2024

Language: Английский

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