Role of Hydrogen-Bonded Intermediates in the Bimolecular Reactions of the Hydroxyl Radical

Smith, Ian W. M.; Ravishankara, A. R.

doi:10.1021/jp014234w

Cited by 207 publications

(249 citation statements)

References 67 publications

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“…Accordingly, the binary OH-H 2 O complex has been extensively studied by theoretical and experimental methods. 31,40,88,93,94,96 This complex was observed and investigated by gas phase microwave spectroscopy. 93,96 Infrared spectra were obtained in rare gas matrices leading to agreement as to the global minimum geometry which features a hydrogen bond between the hydrogen of OH and the oxygen in H 2 O.…”

Section: Bimolecular Reactions In Water Complexesmentioning

confidence: 99%

Perspective: Water cluster mediated atmospheric chemistry

Vaida

2011

The Journal of Chemical Physics

279

249

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The importance of water in atmospheric and environmental chemistry initiated recent studies with results documenting catalysis, suppression and anti-catalysis of thermal and photochemical reactions due to hydrogen bonding of reagents with water. Water, even one water molecule in binary complexes, has been shown by quantum chemistry to stabilize the transition state and lower its energy. However, new results underscore the need to evaluate the relative competing rates between reaction and dissipation to elucidate the role of water in chemistry. Water clusters have been used successfully as models for reactions in gas-phase, in aqueous condensed phases and at aqueous surfaces. Opportunities for experimental and theoretical chemical physics to make fundamental new discoveries abound. Work in this field is timely given the importance of water in atmospheric and environmental chemistry.

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Section: Bimolecular Reactions In Water Complexesmentioning

confidence: 99%

Perspective: Water cluster mediated atmospheric chemistry

Vaida

2011

The Journal of Chemical Physics

279

249

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“…Weakly bound complexes have also been invoked to explain rate coefficients that increase as the temperature is lowered [7]. Electronic structure calculations by Xu and Lin [8] for the reaction between OH and methanol have shown the presence of a weakly-bound (~ 20 kJ mol -1 ) hydrogen-bonded complex prior to the barrier to reaction, as shown in Figure 1.…”

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confidence: 99%

Accelerated chemistry in the reaction between the hydroxyl radical and methanol at interstellar temperatures facilitated by tunnelling

et al. 2013

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Understanding the abundances of molecules observed in dense interstellar clouds requires knowledge of the rates of gas phase reactions between two neutral species. However, reactions possessing an activation barrier were considered too slow to play any important role at the low temperatures in these clouds. Here we show that despite the presence of a barrier the rate coefficient for the reaction between the hydroxyl radical (OH) and methanol, one of the most abundant organic molecules in space, is almost two orders of magnitude larger at 63K than previously measured at ~200K. We also observe formation of the methoxy radical product that was recently detected in space. These results are interpreted through the formation of a hydrogen-bonded complex that is sufficiently long-lived to undergo quantum mechanical tunnelling to form products. We postulate that this tunnelling

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“…Kinetic studies have shown that the OH ϩ HONO 2 reaction is unusual in several respects (3,(5)(6)(7)(8)(9)(10)(11), particularly under the temperature and pressure conditions found in the lower atmosphere. Under these conditions, this reaction exhibits a negative temperature dependence, a pressure dependence, and a strong kinetic isotope effect.…”

mentioning

confidence: 99%

Spectroscopic identification and stability of the intermediate in the OH + HONO ₂ reaction

O’Donnell

Lester

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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The reaction of nitric acid with the hydroxyl radical influences the residence time of HONO2 in the lower atmosphere. Prior studies [Brown SS, Burkholder JB, Talukdar RK, Ravishankara AR (2001) J Phys Chem A 105:1605-1614] have revealed unusual kinetic behavior for this reaction, including a negative temperature dependence, a complex pressure dependence, and an overall reaction rate strongly affected by isotopic substitution. This behavior suggested that the reaction occurs through an intermediate, theoretically predicted to be a hydrogen-bonded OH-HONO2 complex in a six-membered ring-like configuration. In this study, the intermediate is generated directly by the association of photolytically generated OH radicals with HONO2 and stabilized in a pulsed supersonic expansion. Infrared action spectroscopy is used to identify the intermediate by the OH radical stretch ( 1) and OH stretch of nitric acid ( 2) in the OH-HONO2 complex. Two vibrational features are attributed to OH-HONO2: a rotationally structured 1 band at 3516.8 cm ؊1 and an extensively broadened 2 feature at 3260 cm ؊1 , both shifted from their respective monomers. These same transitions are identified for OD-DONO 2. Assignments of the features are based on their vibrational frequencies, analysis of rotational band structure, and comparison with complementary high level ab initio calculations. In addition, the OH (v ‫؍‬ 0) product state distributions resulting from 1 and 2 excitation are used to determine the binding energy of OH-HONO2, D0 < 5.3 kcal⅐mol ؊1 , which is in good accord with ab initio predictions.atmospheric chemistry ͉ hydroxyl radical ͉ nitric acid ͉ reaction intermediate N itric acid is a chemically inactive and photochemically stable reservoir for reactive HO x and NO x species in the atmosphere. In the troposphere, HONO 2 is usually removed by dry deposition or rainout faster than it is photochemically converted back to NO x , making it a permanent sink for NO x (1, 2). In the upper troposphere and stratosphere, where there is no rain, HONO 2 can be removed by solar photolysis and reaction with OH (3, 4),This reaction results in the conversion of HONO 2 into reactive NO x species, because the unstable nitrate radical rapidly decomposes into NO or NO 2 .Kinetic studies have shown that the OH ϩ HONO 2 reaction is unusual in several respects (3, 5-11), particularly under the temperature and pressure conditions found in the lower atmosphere. Under these conditions, this reaction exhibits a negative temperature dependence, a pressure dependence, and a strong kinetic isotope effect. The indirect mechanism inferred from these studies consists of initial OH radical addition forming an energized OH-HONO 2 * intermediate, followed by redissociation or reaction to form products. The energized intermediate can also be temporarily stabilized by collisions with bath gas M, and then redissociate to reactants or decompose to products as shown in the following scheme:The unusual kinetic behavior arises because of enhanced formation and collisional st...

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Role of Hydrogen-Bonded Intermediates in the Bimolecular Reactions of the Hydroxyl Radical

Cited by 207 publications

References 67 publications

Perspective: Water cluster mediated atmospheric chemistry

Perspective: Water cluster mediated atmospheric chemistry

Accelerated chemistry in the reaction between the hydroxyl radical and methanol at interstellar temperatures facilitated by tunnelling

Spectroscopic identification and stability of the intermediate in the OH + HONO ₂ reaction

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Role of Hydrogen-Bonded Intermediates in the Bimolecular Reactions of the Hydroxyl Radical

Cited by 207 publications

References 67 publications

Perspective: Water cluster mediated atmospheric chemistry

Perspective: Water cluster mediated atmospheric chemistry

Accelerated chemistry in the reaction between the hydroxyl radical and methanol at interstellar temperatures facilitated by tunnelling

Spectroscopic identification and stability of the intermediate in the OH + HONO 2 reaction

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Spectroscopic identification and stability of the intermediate in the OH + HONO ₂ reaction