Elsevier

Chemical Physics

Volume 280, Issue 3, 1 July 2002, Pages 211-227
Chemical Physics

Infrared matrix isolation and quantum chemical studies of the nitrous acid complexes with water

https://doi.org/10.1016/S0301-0104(02)00588-8Get rights and content

Abstract

The 1:1 and 2:1 complexes between water and trans- and cis-isomers of nitrous acid have been isolated in argon matrices and studied using FTIR spectroscopy and DFT(B3LYP) calculations with a 6-311++G(2d,2p) basis set. The analysis of the experimental spectra indicate that 1:1 complexes trapped in solid argon involve very strong hydrogen bond in which acid acts as the proton donor and water as the proton acceptor. The perturbed OH stretches are −248, −228 cm−1 red shifted from their free-molecules values in complexes formed by trans- and cis-HONO isomers, respectively. The calculated spectral parameters for the two complexes are in good agreement with experimental data. The calculations also predict stability of two more 1:1 weakly bound complexes formed by each isomer. In these the water acts as the proton donor and one of the two oxygen atoms of the acid as the acceptor. The experimental spectra demonstrate also formation of 2:1 complex between water and trans-HONO isomer in an argon matrix. The performed calculations indicate that the complex involves a seven-membered ring in which OH group of HONO forms very strong hydrogen bond with the oxygen atom of one water molecule and nitrogen atom acts as a weak proton acceptor for the hydrogen atom of the second water molecule of the water dimer. The observed perturbations of the OH stretch of trans-HONO (750 cm−1 red shift) is much larger than that predicted by calculations (556 cm−1 red shift); this difference is attributed to strong solvation effect of argon matrix on very strong hydrogen bond.

Introduction

The experimental and theoretical investigation of structural and dynamical properties of small molecular clusters has attracted a great deal of interest in last years [1]. They serve as simple model systems to study intermolecular forces, solvation effects or reaction catalysis on a molecular scale. Of special interest are the hydrogen bonded clusters containing water molecules [2], [3], [4]. This is due to the role the water plays as ubiquitous solvent and in atmospheric and extraterrestrial chemistry.

The constitution and structure of clusters in the gas phase has been investigated by the combination of various laser and mass spectroscopies and molecular beam techniques [1]. Matrix isolation technique combined with FTIR spectroscopy has been shown to provide complementary information on bonding and structure of small aggregates. The technique has been used very successfully to study numerous binary molecular complexes. A number of higher order complexes have also been studied by help of matrix isolation spectroscopy. Among them are water [5], [6], methanol [7], ammonia [8], hydrogen halides aggregates [9], [10], ternary complexes containing water and nitrogen [11], water and ethylene [12] and water and hydrogen chloride [13] of stoichiometry 1:2 or 2:1 and ternary complexes containing water, hydrogen chloride and ethylene molecules [12].

We have investigated recently a number of binary complexes of nitrous acid with bases of atmospheric significance [14], [15], [16], [17], [18]. In this paper we present the results of infrared matrix isolation and ab initio studies on the nitrous acid complexes with water and water dimers. The complexes of nitrous acid with water are interesting in atmospheric chemistry due to the presence of nitrous acid and water in the atmosphere, and due to the fact that water is one of the products of decomposition of (HONO)2 dimer.

Section snippets

Matrix isolation studies

The HONO/H2O/Ar matrices were prepared by simultaneous deposition of HONO/Ar and H2O/Ar mixtures from two separate spray-on lines. Ammonium nitrate was used as a source of nitrous acid and HONO/Ar gas mixtures were prepared in the same way as previously described [14], [15], [16]. The concentration of the HONO/Ar and H2O/Ar mixtures varied in the range 1/300–1/800 and 1/100–1/1000, respectively.

Gas mixtures were prepared by standard manometric techniques and sprayed onto a gold-plated copper

Experimental spectra

The spectra of HONO/Ar [14] and H2O/Ar [5], [23] matrices are in good agreement with those previously reported. In the spectra of matrices with higher HONO concentration bands due to NH4NO2 decomposition products, namely to NH3, NO and NO2, were also present.

Spectra of HONO/H2O/Ar matrices show a number of new absorptions as compared to the spectra of H2O/Ar and HONO/Ar. Most of the product absorptions appeared in the vicinity of trans- and cis-HONO monomer bands. Additional product bands were

Observed spectra

The set of bands observed in the spectra of HONO/H2O/Ar matrices at 3323.0, 1653.5, 1368.1, 873.7 and 672.1 cm−1 close to the trans-HONO absorptions and at 3721.9, 3635.7 cm−1 in the region of water stretching vibrations is assigned to the 1:1 H2O⋯HONO-trans complexes. Irradiation of the matrix with Xe lamp considerably decreased the 3323.0, 1653.5, 1368.1, 873.7, 672.1 and 3721.9, 3635.7 cm−1 bands and increased the 3184.5, 1614.0, 912.9 and 3720.8 cm−1 absorptions. This fact allowed us to

Conclusions

MP2 and DFT calculations indicate that both trans- and cis-HONO isomers form with water molecule three stable 1:1 complexes. In the most stable 1IT and 1IC complexes the OH group of HONO acts as a proton donor toward an oxygen atom of water molecule. In the other four complexes water molecule serves as a proton donor and an oxygen atom of OH group (1IIT) or an oxygen atom of NO group (1IIIT,1IIIC) act as proton acceptors. In 1IIC complex cyclic hydrogen bond is formed in which two hydrogen

Acknowledgements

The authors would like to gratefully acknowledge Z. Latajka for helpful discussion, comment and critical reading of the manuscript. A.O-M. acknowledges the Wrocław Supercomputer Centre for providing computer time and facilities.

References (35)

  • R.M. Helm et al.

    Chem. Phys.

    (1998)
    H.-D. Barth et al.

    Chem. Phys.

    (1998)
    F.C. Hagemeister et al.

    Chem. Phys.

    (1998)
  • R.M. Bentwood et al.

    J. Mol. Spectrosc.

    (1980)
  • A. Engdahl et al.

    J. Chem. Phys.

    (1987)
  • S. Coussan et al.

    J. Chem. Phys.

    (1997)
  • B. Nelander

    J. Phys. Chem.

    (1988)
  • Z. Mielke et al.

    J. Phys. Chem.

    (1996)
  • Z. Mielke et al.

    J. Phys. Chem. A

    (2000)
  • M.J. Frish

    Gaussian 98, Revision A.9

    (1998)
  • C.M. Deeley et al.

    Mol. Phys.

    (1985)
  • Z. Latajka et al.

    Phys. Chem. Chem. Phys.

    (1999)
  • L. AndrewsR.K. Thomas, Unpublished gas-phase...G.L. Johnson et al.

    J. Am. Chem. Soc.

    (1982)
  • R.E. Miller et al.

    Chem. Phys.

    (1998)
  • U. Buck et al.

    Chem. Rev.

    (2000)
  • R.E. Miller

    Science

    (2000)
  • S. Suzer et al.

    J. Chem. Phys.

    (1987)
  • L. Andrews et al.

    J. Phys. Chem.

    (1984)
  • A.J. Barnes et al.

    Trans. Faraday Soc.

    (1969)
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