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The intramolecular O−H ... π hydrogen bond has garnered significant research interest in recent decades. In this work, we utilized the infrared (IR)-vacuum-ultraviolet (VUV) nonresonant ionization detected IR spectroscopy (NRID-IR) method to study the molecular structure of neutral and cationic 2-methylallyl alcohol (MAA, CH2=C(CH3)−CH2−OH). Density functional theory calculations revealed five stable neutral and three stable cationic MAA conformers, respectively. Two neutral MAA conformers are expected to have an O−H ... π intramolecular hydrogen bond interaction, based on the structural characterization that the OH group is directed toward the C=C double bond. The IR spectra of both neutral (2700−3700 cm−1) and cationic MAA (2500−7200 cm−1) were measured, and the anharmonic IR spectra were calculated at the B3LYP-D3(BJ)/def2-TZVPP level. The OH stretching vibration frequency of neutral MAA was observed at 3656 cm−1, slightly lower than those of methanol and ethanol. In contrast, the OH stretching vibration of cationic MAA was red-shifted by about 140 cm−1 compared to neutral MAA. The interaction region indicator and natural bond orbital analysis suggest that the O−H ... π interaction in neutral MAA is weak, and may not play a major role in stabilizing the neutral MAA. [ABSTRACT FROM AUTHOR]

We have used the OH laser-induced fluorescence (LIF) method to measure the kinetics of the simplest Criegee intermediate (CH2OO) reacting with two abundant amines in the atmosphere: dimethylamine ((CH3)2NH) and trimethylamine ((CH3)3N). Our experiments were conducted under pseudo-first-order approximation conditions. The rate coefficients we report are (2.15 ± 0.28) × 10−11 cm3 molecule−1 s−1 for (CH3)2NH at 298 K and 10 Torr, and (1.56 ± 0.23) × 10−12 cm3 molecule−1 s−1 for (CH3)3N at 298 K and 25 Torr with Ar as the bath gas. Both reactions exhibit a negative temperature dependence. The activation energy and pre-exponential factors derived from the Arrhenius equation were (−2.03 ± 0.26) kcal mol−1 and (6.89 ± 0.90) × 10−13 cm3 molecule−1 s−1 for (CH3)2NH, and (−1.60 ± 0.24) kcal mol−1 and (1.06 ± 0.16) × 10−13 cm3 molecule−1 s−1 for (CH3)3N. We propose that the electronegativity of the atom in the co-reactant attached to the C atom of CH2OO, in addition to the dissociation energy of the fragile covalent bonds with H atoms (H–X bond), plays an important role in the 1,2-insertion reactions. Under certain circumstances, the title reactions can contribute to the sink of amines and Criegee intermediates and to the formation of secondary organic aerosol (SOA). [ABSTRACT FROM AUTHOR]

We have used the OH laser-induced fluorescence (LIF) method to measure the kinetics of the simplest Criegee intermediate (CH 2 OO) reacting with two abundant amines in the atmosphere: dimethylamine ((CH 3 ) 2 NH) and trimethylamine ((CH 3 ) 3 N). Our experiments were conducted under pseudo-first-order approximation conditions. The rate coefficients we report are (2.15 ± 0.28) × 10 -11 cm 3 molecule -1 s -1 for (CH 3 ) 2 NH at 298 K and 10 Torr, and (1.56 ± 0.23) × 10 -12 cm 3 molecule -1 s -1 for (CH 3 ) 3 N at 298 K and 25 Torr with Ar as the bath gas. Both reactions exhibit a negative temperature dependence. The activation energy and pre-exponential factors derived from the Arrhenius equation were (-2.03 ± 0.26) kcal mol -1 and (6.89 ± 0.90) × 10 -13 cm 3 molecule -1 s -1 for (CH 3 ) 2 NH, and (-1.60 ± 0.24) kcal mol -1 and (1.06 ± 0.16) × 10 -13 cm 3 molecule -1 s -1 for (CH 3 ) 3 N. We propose that the electronegativity of the atom in the co-reactant attached to the C atom of CH 2 OO, in addition to the dissociation energy of the fragile covalent bonds with H atoms (H-X bond), plays an important role in the 1,2-insertion reactions. Under certain circumstances, the title reactions can contribute to the sink of amines and Criegee intermediates and to the formation of secondary organic aerosol (SOA).