Spontaneous Catalytic Paal–Knorr Reactions for N-Substituted Pyrrole Synthesis by Microdroplet Chemistry DOI
Jiayao Li, Jiannan Sun, Yizhou Wang

и другие.

ACS Sustainable Chemistry & Engineering, Год журнала: 2024, Номер 13(1), С. 571 - 582

Опубликована: Дек. 31, 2024

It is well recognized in recent studies that water molecules at the gas–liquid interface of microdroplets spontaneously dissociate into hydronium and hydroxide form superacids/superbases reactive species (hydrated electrons, radicals, hydrogen peroxide, radical cations/anions, etc.) due to 109 V m–1 electric field. In contrast extensive interest spontaneous redox reactions by microdroplet studies, limited attention has been attracted gram-scale organic synthesis catalyzed formed superacids/superbases. This study demonstrates catalysis superacids for Paal–Knorr reactions, one most classic pathways construct N-substituted pyrroles with biologically pharmaceutically important roles. can proceed no external catalysts isopropanol within 10 min room temperature. Sixteen were synthesized using method 83–99% yields, several orders magnitude reaction acceleration (a typical rate factor 1.18 × 103 based on ratio constants), a scale-up 5.50 g h–1. By avoiding catalysts, thermal irradiation, long times, problematic solvents required conventional methods, was green, efficient, attractive alternative construction their derivatives.

Язык: Английский

Microdroplet Surface Drives and Accelerates Proton-Controlled, Size-Dependent Nitrate Photolysis DOI
Xiaowu Zhang, Qishen Huang, Yuxin Liu

и другие.

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Июнь 1, 2025

Particulate nitrate photolysis regenerates reactive oxidized nitrogen species (HONO and NOx) in the atmosphere, influencing tropospheric ozone, atmospheric oxidation capacity, particulate matter formation. However, reported rates vary by orders of magnitude, roles protons air-water interface accelerating deliquesced aerosols (i.e., microdroplets) remain unclear. Using confocal Raman spectroscopy aerosol optical tweezer, we measured rate coefficients (j) microdroplets, ranging from 5.28 × 10-8 to 9.07 10-6 s-1, depending on pH (3.2-7.4) radius (3.7 μm 6.0 mm). j remained pH-independent under proton-sufficient conditions (pH < 6.5) but decreased with increasing proton-deficient > 6.5), resolving discrepancies previous studies. Moreover, identified a tipping-point (r* = 706 μm), below which scales inversely droplet above plateaus at aqueous bulk value (6.73 ± 2.12 s-1). These findings demonstrate that occurs predominantly microdroplets. With radii typically these tipping points (pH* 6.5, r* surface-driven size-dependent likely explains variations rates.

Язык: Английский

Процитировано

0
Evidence on Interfacial Reaction Governing NO2 Hydrolysis in Deliquesced Aerosol Particles DOI Creative Commons
Ruifeng Zhang, Rikuto Minamikawa, Masao Gen

и другие.

Environmental Science & Technology, Год журнала: 2025, Номер unknown

Опубликована: Июнь 3, 2025

Heterogeneous NO2 hydrolysis forms nitrate and nitrous acid but is believed to proceed slowly in the atmosphere. Accelerated reactions microdroplets have gained significant attention, whether or not accelerated deliquesced particles remains unclear. We address gap by measuring size-dependent rates sulfate- halide-containing droplets. Results show that reaction Na2SO4 droplets increased 25-fold as particle radius decreased from ∼40 ∼4 μm. An even higher enhancement of ∼100 times was observed NaCl NaI particles, likely due NO2-halide interactions. The NaBr however, comparable particles. Kinetic modeling results illustrate are ∼6 orders magnitude factor (EF) surface over bulk-phase rates. Compared increase factors 2.3, 1.5, 4.4 NaCl, NaBr, respectively. Under ambient conditions, EFs can up 108, corresponding production >1 μg m-3 h-1. those N2O5 OH + pathways, making a crucial source reactive nitrogen species.

Язык: Английский

Процитировано

0
Biomass-burning organic aerosols as a pool of atmospheric reactive triplets to drive multiphase sulfate formation DOI Creative Commons
Zhancong Liang, Liyuan Zhou,

Yuqing Chang

и другие.

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(51)

Опубликована: Дек. 13, 2024

Biomass-burning organic aerosol(s) (BBOA) are rich in brown carbon, which significantly absorbs solar irradiation and potentially accelerates global warming. Despite its importance, the multiphase photochemistry of BBOA after light absorption remains poorly understood due to challenges determining oxidant concentrations reaction kinetics within aerosol particles. In this study, we explored photochemical reactivity particles S(IV) oxidation sulfate. We found that sulfate formation under is predominantly driven by photosensitization involving triplet excited states ( 3 * ) instead iron, nitrate, photochemistry. Rates three orders magnitude higher than those observed bulk solution, primarily fast interfacial reactions. Our results highlight chemistry can greatly contribute sulfate, as an example secondary pollutants. Photosensitization will likely become increasingly crucial intensified wildfires.

Язык: Английский

Процитировано

1
Spontaneous Catalytic Paal–Knorr Reactions for N-Substituted Pyrrole Synthesis by Microdroplet Chemistry DOI
Jiayao Li, Jiannan Sun, Yizhou Wang

и другие.

ACS Sustainable Chemistry & Engineering, Год журнала: 2024, Номер 13(1), С. 571 - 582

Опубликована: Дек. 31, 2024

It is well recognized in recent studies that water molecules at the gas–liquid interface of microdroplets spontaneously dissociate into hydronium and hydroxide form superacids/superbases reactive species (hydrated electrons, radicals, hydrogen peroxide, radical cations/anions, etc.) due to 109 V m–1 electric field. In contrast extensive interest spontaneous redox reactions by microdroplet studies, limited attention has been attracted gram-scale organic synthesis catalyzed formed superacids/superbases. This study demonstrates catalysis superacids for Paal–Knorr reactions, one most classic pathways construct N-substituted pyrroles with biologically pharmaceutically important roles. can proceed no external catalysts isopropanol within 10 min room temperature. Sixteen were synthesized using method 83–99% yields, several orders magnitude reaction acceleration (a typical rate factor 1.18 × 103 based on ratio constants), a scale-up 5.50 g h–1. By avoiding catalysts, thermal irradiation, long times, problematic solvents required conventional methods, was green, efficient, attractive alternative construction their derivatives.

Язык: Английский

Процитировано

0