819. Infra-red spectrum of nitric and of deuteronitric acid vapour. Completion of identification of the fundamental frequencies. Entropy of nitric acid. Barrier resisting rotation of the hydroxyl group

Cohn, Henry; Ingold, C. K.; Poole, H. G.

doi:10.1039/jr9520004272

Cited by 45 publications

(33 citation statements)

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“…The SFG spectra of liquid HNO 3 and aqueous HNO 3 solutions reveal no nitric acid O−H resonances. The free-OH vibration of HNO 3 is predicted to be near the gas-phase molecular absorption at 3560 cm -1 . There is no resonance observed in that region, hence there are negligible HNO 3 free-OH vibrations.…”

Section: Discussionmentioning

confidence: 97%

Sum Frequency Generation of O−H Vibrations on the Surface of H₂O/HNO₃Solutions and Liquid HNO₃

et al. 1999

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The surfaces of aqueous HNO3 solutions and liquid HNO3 are examined using sum frequency generation (SFG). A molecular-level picture of these atmospherically relevant systems is developed. Consistent with previous interpretations, an electric double layer comprised of subsurface anions and cations develops in 0.005x and 0.01x HNO3 solutions, where x = mole fraction. Compared to pure water, these solutions generate more SFG signal in the hydrogen-bonded region as water molecules respond to the subsurface electric field by aligning with the surface normal. At higher concentrations, 0.05x and 0.4x HNO3, ionic complexes or molecules sufficiently approach the surface to disrupt the hydrogen-bonding network and perturb the first water layer. Neither liquid nitric acid nor its solutions show a clear O−H.

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Section: Discussionmentioning

confidence: 97%

Sum Frequency Generation of O−H Vibrations on the Surface of H₂O/HNO₃Solutions and Liquid HNO₃

et al. 1999

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“…Three distinct peaks appear. Those at 1673 cm À1 and 1303 cm À1 are assigned to well known n 2 (NO 2 antisymmetric stretch) and n 4 (NO 2 symmetric stretch) vibrational modes of HNO 3 , which have been reported for HNO 3 in aqueous solutions, 26,74,75 in the gas phase 76,77 and on ice. 23,24,78,79 The peak at 1265 cm À1 is assigned to the nitrite ion, 80 and indicates that the uptake of HNO 3 onto the crystal is accompanied by a surface reaction that forms NO 2…”

mentioning

confidence: 99%

Experimental and theoretical studies of the interaction of gas phase nitric acid and water with a self-assembled monolayer

Moussa

Stern

Raff

et al. 2013

Phys. Chem. Chem. Phys.

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Experimental and theoretical studies of the interaction of gas phase nitric acid and water with a self-assembled monolayer surface of a germanium infrared-transmitting attenuated total reflectance (ATR) crystal that was coated with a thin layer of silicon oxide (SiO x ). The SAM was exposed at 298 AE 2 K to dry HNO 3 in a flow of N 2 , followed by HNO 3 in humid N 2 at a controlled relative humidity (RH) between 20-90%. For comparison, similar studies were carried out using a similar crystal without the SAM coating. Changes in the surface were followed using Fourier transform infared spectroscopy (FTIR). In the case of the SAMcoated crystal, molecular HNO 3 and smaller amounts of NO 3 À ions were observed on the surface upon exposure to dry HNO 3 . Addition of water vapor led to less molecular HNO 3 and more H 3 O + and NO 3 À complexed to water, but surprisingly, molecular HNO 3 was still evident in the spectra up to 70% RH.This suggests that part of the HNO 3 observed was initially trapped in pockets within the SAM and shielded from water vapor. After increasing the RH to 90% and then exposing the film to a flow of dry N 2 , molecular nitric acid was regenerated, as expected from recombination of protons and nitrate ions as water evaporated. The nitric acid ultimately evaporated from the film. On the other hand, exposure of the SAM to HNO 3 and H 2 O simultaneously gave only hydronium and nitrate ions. Molecular dynamics simulations of defective SAMs in the presence of HNO 3 and water predict that nitric acid intercalates in defects as a complex with a single water molecule that is protected by alkyl chains from interacting with additional water molecules. These studies are consistent with the recently proposed hydrophobic nature of HNO 3 . Under atmospheric conditions, if HNO 3 is formed in organic layers on surfaces in the boundary layer, e.g. through NO 3 or N 2 O 5 reactions, it may exist to a significant extent in its molecular form rather than fully dissociated to nitrate ions. IntroductionNitric acid is considered to be the end-product of oxidation of oxides of nitrogen in the atmosphere. 1 This acid reacts with ammonia and amines to form solid or aqueous phase nitrate particles, and can also be taken up into other types of atmospheric particles. Removal of gaseous HNO 3 and particulate nitrates takes place primarily through wet and dry deposition, in what were once considered to be terminal removal processes. However, there are now a number of laboratory and field studies that suggest that nitric acid can be converted back into gaseous oxides of nitrogen such as NO, NO 2 and HONO. 2-8Nitric acid is a strong acid, but it requires a cluster of at least four water molecules to dissociate in the gas phase. [9][10][11] In bulk aqueous solutions and on ice, nitric acid can form hydrates with 1, 2 or 3 water molecules, depending on the concentration. 12-24 Such hydrates, as well as the HNO 3 dimer, have also been seen on solid surfaces during the hydrolysis of NO 2 at

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“…The persistence of the former in other nitramines and the fact that it is scarcely affected by deuteration suggests it is a skeleton mode. Kohlrausch and Wittek assigned the Raman feature 598(+) to the in-plane deformation mode of the (N-NO2) grouping; this cannot be regarded as certain, but it is supported by comparison with the similar modes in nitric acid 14 and in nitromethane 15 where the values are 610 cm-1 and 481 cm-1 respectively. The " out-of-plane " (NOz) rocking mode is at 767 cm-1 in nitric acid and at 608cm-1 in nitromethane.…”

Section: R E S U L T S and Discussionmentioning

confidence: 98%

The vibrational spectra and structures of nitramide and its methyl derivatives

Davies¹,

Jonathan²

1958

Trans. Faraday Soc.

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The infra-red spectra of nitramide and its mono-and dimethyl-derivatives have been studied between 2 and 25 p : deuteration of the nitramide was also effected. The results show the amino structure NH2 . NO2 as the only one observable for the molecule. Hydrogen bonding is very weak in crystalline nitramide. Some evidence that the molecule approximates to, if it does not attain, an all-planar configuration and clear evidence of bonding above that of a mingle bond in the (N-N) link is adduced. Some assessments of the bonding within the (NH2) and (NOz) groups are presented.As originally suggested by Thiele and Lachmann 1 nitramide is usually written H2N . NO2 although Hantzsch 2 over a number of years advanced alternatives, most significantly the aci-form HN : NO . OH. Some kinetic and optical evidence was adduced in favour of this 3 although later kinetic study4 was interpreted as supporting the amino-structure. The dipole moment 5 was taken to indicate a further alternative, N = N(OH)2, but the Raman spectrum described by Kohlrausch and Wittek 6 suggested the usually accepted structure. Whilst the present studies were in progress Beevers and Trotman-Dickinson 7 reported an X-ray crystallographic investigation which, although not locating the hydrogen atoms precisely, is consistent with the amino form.

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819. Infra-red spectrum of nitric and of deuteronitric acid vapour. Completion of identification of the fundamental frequencies. Entropy of nitric acid. Barrier resisting rotation of the hydroxyl group

Cited by 45 publications

References 0 publications

Sum Frequency Generation of O−H Vibrations on the Surface of H₂O/HNO₃Solutions and Liquid HNO₃

Sum Frequency Generation of O−H Vibrations on the Surface of H₂O/HNO₃Solutions and Liquid HNO₃

Experimental and theoretical studies of the interaction of gas phase nitric acid and water with a self-assembled monolayer

The vibrational spectra and structures of nitramide and its methyl derivatives

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819. Infra-red spectrum of nitric and of deuteronitric acid vapour. Completion of identification of the fundamental frequencies. Entropy of nitric acid. Barrier resisting rotation of the hydroxyl group

Cited by 45 publications

References 0 publications

Sum Frequency Generation of O−H Vibrations on the Surface of H2O/HNO3Solutions and Liquid HNO3

Sum Frequency Generation of O−H Vibrations on the Surface of H2O/HNO3Solutions and Liquid HNO3

Experimental and theoretical studies of the interaction of gas phase nitric acid and water with a self-assembled monolayer

The vibrational spectra and structures of nitramide and its methyl derivatives

Contact Info

Product

Resources

About

Sum Frequency Generation of O−H Vibrations on the Surface of H₂O/HNO₃Solutions and Liquid HNO₃

Sum Frequency Generation of O−H Vibrations on the Surface of H₂O/HNO₃Solutions and Liquid HNO₃