Ammonium chlorite, NH4ClO2, at 150 K

inorganic papers

i38

Smolentsev and Naumov _NH

4ClO2 doi:10.1107/S1600536805005088 Acta Cryst.(2005). E61, i38–i40

Acta Crystallographica Section E Structure Reports Online

ISSN 1600-5368

Ammonium chlorite, NH

4

ClO

2

, at 150 K

Anton I. Smolentsev* and Dmitry Yu. Naumov

Nikolaev Institute of Inorganic Chemistry, SB Russian Academy of Sciences, Academition Lavrentiev Avenue 3, Novosibirsk 90, 630090 Russia

Correspondence e-mail: smolentsev@ngs.ru

Key indicators

Single-crystal X-ray study T= 150 K

Mean(Cl–O) = 0.001 A˚ Rfactor = 0.016 wRfactor = 0.040

Data-to-parameter ratio = 11.9

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2005 International Union of Crystallography Printed in Great Britain – all rights reserved

The structure of tetragonal (P421m) ammonium chlorite, NH4ClO2, has been redetermined by single-crystal X-ray analysis with higher precision. The NH4

+

cation is at a site of 4 symmetry, while the unique Cl and O atoms are at sites with symmetriesmmandm, respectively. The structure consists of corrugated layers of NH4+cations coordinated by ClO2anions. The H atoms of the ammonium cation hydrogen bond to four chlorite O atoms. The resultant coordination is almost ideal tetrahedral.

Comment

The salts of chlorous acid were first investigated crystal-lographically by Levi & Scherillo (1931). However, they attempted a structure determination only for one of the salts studied,viz. ammonium chlorite, and because this substance decomposes to ammonium chloride and chlorate in a few hours at ordinary temperatures, they had considerable diffi-culty in the estimation of intensities. The structure which they proposed could only be regarded as tentative. Later, this incorrect structure was corrected by Gillespie et al. (1959). Their experiment was carried out at lower temperature (238 K), but the structural data were of poor quality (R = 0.149; no H atoms located).

The purpose of the present investigation was to obtain precise structural data for ammonium chlorite, (I). In other words, we tried to produce precise bond lengths and angles (the main goal in the structural study of a simple inorganic compound such as this). Moreover, the number of chlorite structures so far studied is small and, because this compound forms suitable crystals more readily than many other chlorites, it seemed worthwhile searching for a better crystal and redetermining the structure.

The previously determined structure of ammonium chlorite (Gillespieet al., 1959) has been confirmed. It contains separate layers within which the NH4+ cation is hydrogen bonded to four chlorite O atoms forming a tetrahedron compressed along a twofold axis (Fig. 1). These layers are parallel to theab

plane and are linked by van der Waals interactions (Fig. 2). The ClO2

anions serve as tetradentate bridging ligands between the NH4

+

cations. The structure of the layer is very similar to that found in the LiClO2structure (Smolentsev & Naumov, 2005). However, the layer packings are different; in

LiClO2, the layers are stacked in such a way that adjacent layers are rotated by 90_{. There are also some similarities to}

the layers in NH4H2PO2(Naumovaet al., 2004) and LiH2PO2 (Naumovet al., 2004) which contain chains of cation-centered tetrahedra linked by H2PO2

anions.

The O—Cl—O angle is wider than in the previous deter-mination (Fig. 3): 111.88 (12) versus 110.5_{. Comparison can}

be made with other O—Cl—O angles in the literature: 110.0 (3)_{in LiClO}

2and 108.18 (18)in KClO2(Smolentsev & Naumov, 2005), 107.0 (1) _{in AgClO}

2 (Okuda et al., 1990), 111.4 (1) _{in Zn(ClO}

2)22H2O (Pakkanen, 1979) and 112.5 (5)_{in Pb(ClO}

2)2(Okudaet al., 1990). The present Cl— O bond distance [1.5759 (14) A˚ ] is close to the earlier value [1.57 (3) A˚ ] and compares well with the following literature values, in the same order as above: 1.578 (4), 1.565 (2), 1.575 (2), 1.580 (3) and 1.577 (9) A˚ .

Experimental

Ammonium chlorite was synthesized by mixing aqueous solutions of barium chlorite, Ba(ClO2)2and ammonium sulfate in an equimolar

ratio. The reaction mixture was filtered and the crystals were grown by evaporation at room temperature. This compound decomposes at room temperature, even after a few hours, and it was necessary to grow crystals quickly from a concentrated solution. Also, it was found that the crystals are stable at low temperatures for a very long time. The crystals were mostly thin colorless needles with a maximum size of 0.5 mm, suitable for X-ray diffraction. Crystals yellowed over time as a result of decomposition. The X-ray powder pattern at room temperature shows good agreement between the bulk product and the single crystal. However, additional peaks indicate the presence of NH4Cl and NH4ClO3phases. The precursor used for the preparation

of ammonium chlorite, Ba(ClO2)2, was obtained according to the

method described by Smolentsev & Naumov (2005).

Crystal data

NH4ClO2

Mr= 85.49

Tetragonal,P42₁m a= 6.3397 (3) A˚ c= 3.7560 (2) A˚ V= 150.960 (13) A˚3

Z= 2

Dx= 1.881 Mg m 3

MoKradiation Cell parameters from 939

reflections

= 4.6–32.6 = 1.01 mm1

T= 150 (2) K Needle, colorless 0.420.120.07 mm

Data collection

Bruker–Nonius X8 APEX CCD area-detector diffractometer

’scans

Absorption correction: multi-scan (SADABS; Bruker, 2004) Tmin= 0.676,Tmax= 0.932

1087 measured reflections

203 independent reflections 200 reflections withI> 2(I) Rint= 0.014

max= 28.2

h=8!8 k=8!8 l=4!2

inorganic papers

Acta Cryst.(2005). E61, i38–i40 Smolentsev and Naumov _NH

[image:2.610.51.285.70.341.2] [image:2.610.51.288.71.629.2]

4ClO2

i39

Figure 3

Displacement ellipsoid plot, drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radius. The dashed line indicates a hydrogen bond.

Figure 1

[image:2.610.315.565.72.202.2]

The (001) projection of the layer in NH4ClO2.

Figure 2

[image:2.610.55.286.363.627.2]

Refinement

Refinement onF2 R[F2_{> 2(F}2_{)] = 0.016}

wR(F2) = 0.040 S= 1.26 203 reflections 17 parameters

All H-atom parameters refined

w= 1/[2

(Fo2) + (0.0174P)2

+ 0.0433P]

whereP= (Fo2+ 2Fc2)/3

(/)max< 0.001

max= 0.20 e A˚

3

min=0.25 e A˚

3

Absolute structure: Flack (1983), 74 Friedel pairs

Flack parameter =0.02 (1)

Table 1

Selected geometric parameters (A˚ ,_).

Cl—O 1.5759 (14)

O—Cl—Oi 111.88 (12)

O—N—Oii

105.69 (3)

Oii—N—Oiii 117.33 (5) Symmetry codes: (i) 1x;y;z; (ii)y;x;z; (iii)y;x;z.

Table 2

Hydrogen-bonding geometry (A˚ ,_).

D—H A D—H H A D A D—H A

N—H O 0.866 (15) 1.985 (15) 2.8438 (9) 171.2 (18)

Data collection:APEX2(Bruker, 2004); cell refinement:SAINT (Bruker, 2004); data reduction:SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2004); program(s) used to refine structure: SHELXTL; molecular graphics: BS (Ozawa & Kang, 2004); software used to prepare material for publication:SHELXTL.

The authors are grateful to N. V. Kuratieva for helpful comments.

References

Bruker (2004). APEX2 (Version 1.08), SAINT (Version 7.03), SADABS (Version 2.11) andSHELXTL(Version 6.12). Bruker AXS Inc., Madison, Wisconsin, USA.

Flack, H. D. (1983).Acta Cryst.A39, 876–881.

Gillespie, R. B., Sparks, R. A. & Trueblood, K. N. (1959).Acta Cryst.12, 867– 872.

Levi, G. R. & Scherillo, A. (1931).Z. Kristallogr.76, 431–452.

Naumov, D. Yu., Naumova, M. I., Podberezskaya, N. V. & Kuratieva N. V. (2004).Acta Cryst.C60, i73-i75.

Naumova, M. I., Kuratieva, N. V., Naumov, D. Yu. & Podberezskaya, N. V. (2004).Zh. Struct. Khim.(Russ.),45, 493–499.

Okuda, M., Ishihara, M., Yamanaka, M., Ohba, S. & Saito, Y. (1990).Acta Cryst.C46, 1755–1759.

Ozawa, T. C. & Kang, S. J. (2004).Balls and Sticks(BS). Version 1.51. URL: http://www.softbug.com/toycrate/bs.

Pakkanen, T. (1979).Acta Cryst.B35, 2670–2672.

Smolentsev, A. I. & Naumov, D. Y. (2005).Acta Cryst.C61, i17–i19.

inorganic papers

i40

Smolentsev and Naumov _NH

supporting information

sup-1

Acta Cryst. (2005). E61, i38–i40

supporting information

Acta Cryst. (2005). E61, i38–i40 [https://doi.org/10.1107/S1600536805005088]

Ammonium chlorite, NH

4

ClO

2

, at 150

K

Anton I. Smolentsev and Dmitry Yu. Naumov

ammonium chlorate(III)

Crystal data

NH4ClO2

Mr = 85.49 Tetragonal, P421m

Hall symbol: P -4 2ab

a = 6.3397 (3) Å

c = 3.7560 (2) Å

V = 150.96 (1) Å3

Z = 2

F(000) = 88

Dx = 1.881 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 939 reflections

θ = 4.6–32.6°

µ = 1.01 mm−1

T = 150 K Needle, colourless 0.42 × 0.12 × 0.07 mm

Data collection

Bruker–Nonius X8 APEX CCD area-detector diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

Detector resolution: 25 pixels mm-1

φ scans

Absorption correction: multi-scan (SADABS; Bruker, 2004)

Tmin = 0.676, Tmax = 0.932

1087 measured reflections 203 independent reflections 200 reflections with I > 2σ(I)

Rint = 0.014

θmax = 28.2°, θmin = 4.6°

h = −8→8

k = −8→8

l = −4→2

Refinement

Refinement on F2

Least-squares matrix: full

R[F2 _{> 2σ(F}2_{)] = 0.016}

wR(F2_{) = 0.040}

S = 1.26 203 reflections 17 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: difference Fourier map All H-atom parameters refined

w = 1/[σ2_(F

o2) + (0.0174P)2 + 0.0433P]

where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001

Δρmax = 0.20 e Å−3

Δρmin = −0.25 e Å−3

Absolute structure: Flack (1983), 74 Friedel pairs

Absolute structure parameter: −0.02 (1)

Special details

supporting information

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Acta Cryst. (2005). E61, i38–i40

Refinement. Refinement of F2 _{against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F}2_,

conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) is used}

only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2

are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2₎

x y z Uiso*/Ueq

Cl 0.5000 0.0000 0.62877 (14) 0.01303 (17)

N 0.0000 0.0000 0.0000 0.0147 (4)

O 0.35438 (14) 0.14562 (14) 0.3938 (4) 0.0174 (3) H 0.111 (2) 0.030 (3) 0.125 (5) 0.024 (4)*

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

Cl 0.01297 (19) 0.01297 (19) 0.0132 (3) 0.0001 (2) 0.000 0.000 N 0.0140 (5) 0.0140 (5) 0.0162 (9) 0.000 0.000 0.000 O 0.0152 (4) 0.0152 (4) 0.0220 (7) 0.0020 (5) −0.0036 (4) 0.0036 (4)

Geometric parameters (Å, º)

Cl—Oi _{1.5759 (14) N—O}ii _{2.8438 (9)}

Cl—O 1.5759 (14) N—Oiii _{2.8438 (9)}

N—O 2.8438 (9) N—H 0.866 (15)

O—Cl—Oi _{111.88 (12) O—N—O}iii _{105.69 (2)}

O—N—Oii _{105.69 (3) O}ii_—N—Oiii _{117.33 (5)}

Symmetry codes: (i) −x+1, −y, z; (ii) y, −x, −z; (iii) −y, x, −z.

Hydrogen-bond geometry (Å, º)

D—H···A D—H H···A D···A D—H···A