metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

tert-Butyl­ammonium di­hydrogenarsenate

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aDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland
*Correspondence e-mail: w.harrison@abdn.ac.uk

(Received 28 July 2004; accepted 25 August 2004; online 4 September 2004)

The title compound, (C4H12N)[H2AsO4], contains a network of tert-butyl­ammonium cations and di­hydrogenarsenate anions [dav(As—O) = 1.682 (2) Å]. The crystal packing involves N—H⋯O [dav(H⋯O) = 1.96 Å, θav(N—H⋯O) = 169° and dav(N⋯O) = 2.837 (3) Å] and O—H⋯O [dav(H⋯O) = 1.68 Å, θav(O—H⋯O) = 169° and dav(O⋯O) = 2.626 (2) Å] hydrogen bonds, resulting in a layered structure.

Comment

The title compound, (I[link]) (Fig. 1[link]), was prepared as part of our ongoing structural studies of hydrogen-bonding interactions in protonated amine (di)­hydrogen arsenates (Lee & Harrison, 2003a[Lee, C. & Harrison, W. T. A. (2003a). Acta Cryst. E59, m739-m741.],b[Lee, C. & Harrison, W. T. A. (2003b). Acta Cryst. E59, m959-m960.],c[Lee, C. & Harrison, W. T. A. (2003c). Acta Cryst. E59, m1151-m1153.]).[link]

[Scheme 1]

The [H2AsO4] di­hydrogenarsenate group in (I[link]) shows its normal tetrahedral geometry [dav(As—O) = 1.682 (2) Å], with the protonated As1—O3 and As1—O4 vertices showing their expected lengthening relative to the unprotonated As—O bonds, which have formal partial double-bond character (Table 1[link]). The tert-butyl­ammonium cation shows no unusual geometrical features.

As well as electrostatic attractions, the component species in (I[link]) interact by means of a network of cation-to-anion N—H⋯O and anion-to-anion O—H⋯O hydrogen bonds (Table 2[link]). The [H2AsO4] units are linked into polymeric chains propagating along [010] by way of inversion-generated pairs of O—H⋯O bonds, alternately involving O3—H1⋯O1 and O4—H2⋯O1 links (Fig. 2[link]). This results in every [H2AsO4] tetrahedron in the chain making one hydrogen bond to each of its neighbours and accepting one hydrogen bond from each neighbour. The As⋯Asi (via O3—H1⋯O1i) and As⋯Asii (via O4—H2⋯O1ii) separations are 4.3002 (4) and 4.2662 (3) Å, respectively (see Table 2[link] for symmetry codes). Similar hydrogen-bonded chains of [H2AsO4] anions have been seen in piperidinum di­hydrogenarsenate, (C5H12N)[H2AsO4] (Lee & Harrison, 2003b[Lee, C. & Harrison, W. T. A. (2003b). Acta Cryst. E59, m959-m960.]), although in this case they are generated by a 21 screw axis.

As shown in Table 2[link], the organic species interacts with the di­hydrogenarsenate chains by way of three N—H⋯O hydrogen bonds [dav(H⋯O) = 1.96 Å, θav(N—H⋯O) = 169° and dav(N⋯O) = 2.837 (3) Å], such that each tert-butyl­ammonium cation cross-links a di­hydrogenarsenate chain to its neighbour by forming two hydrogen bonds to one chain, and one to the other. This results in neutral (101) layers (Fig. 3[link]) of stoichiometry (C4H12N)[H2AsO4], which interact with each other by van der Waals forces.

[Figure 1]
Figure 1
The asymmetric unit of (I[link]) (50% displacement ellipsoids). H atoms are drawn as small spheres of arbitrary radius and the hydrogen bond is indicated by a dashed line. C—H H atoms have been omitted for clarity.
[Figure 2]
Figure 2
Detail of a hydrogen-bonded di­hydrogenarsenate/tert-butyl­ammonium sheet in (I[link]). Colour key: [H2AsO4] tetrahedra green, O atoms red, H atoms grey, C atoms blue, N atoms green (all radii arbitrary). The H⋯O portions of the O—H⋯O and N—H⋯O hydrogen bonds are highlighted in yellow and orange, respectively. Symmetry codes as in Table 2[link]; additionally, (v) x,y − 1,z; (vi) x, 1 + y, z.
[Figure 3]
Figure 3
Projection of (I[link]) onto (010). The colour key is as in Fig. 2[link].

Experimental

An aqueous tert-butyl­amine solution (10 ml of 0.5 M) was added to a H3AsO4 solution (10 ml of 0.5 M), resulting in a clear solution. A mass of plate-shaped and rod-like crystals of (I[link]) grew as the water evaporated over the course of a few days.

Crystal data
  • (C4H12N)[H2AsO4]

  • Mr = 215.08

  • Monoclinic, P21/n

  • a = 9.7364 (5) Å

  • b = 6.3254 (3) Å

  • c = 14.2606 (8) Å

  • β = 94.864 (1)°

  • V = 875.10 (8) Å3

  • Z = 4

  • Dx = 1.633 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 3025 reflections

  • θ = 2.4–32.4°

  • μ = 3.85 mm−1

  • T = 293 (2) K

  • Bar, colourless

  • 0.55 × 0.15 × 0.05 mm

Data collection
  • Bruker SMART1000 CCD diffractometer

  • ω scans

  • Absorption correction: multi-scan (SADABS; Bruker, 1999[Shape Software (1999). ATOMS. Shape Software, 525 Hidden Valley Road, Kingsport, Tennessee, USA.]) Tmin = 0.226, Tmax = 0.831

  • 8742 measured reflections

  • 3165 independent reflections

  • 1807 reflections with I > 2σ(I)

  • Rint = 0.023

  • θmax = 32.5°

  • h = −10 → 14

  • k = −7 → 9

  • l = −21 → 21

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.024

  • wR(F2) = 0.064

  • S = 0.88

  • 3165 reflections

  • 95 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.0332P)2] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max = 0.001

  • Δρmax = 0.47 e Å−3

  • Δρmin = −0.51 e Å−3

Table 1
Selected bond distances (Å)

As1—O2 1.6412 (13)
As1—O1 1.6687 (13)
As1—O3 1.7061 (13)
As1—O4 1.7101 (14)

Table 2
Hydrogen-bonding geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O3—H1⋯O1i 0.97 1.62 2.5752 (19) 166
O4—H2⋯O1ii 0.94 1.74 2.6763 (19) 172
N1—H3⋯O2 0.89 1.92 2.801 (2) 168
N1—H4⋯O2iii 0.89 1.88 2.765 (2) 173
N1—H5⋯O3iv 0.89 2.07 2.944 (2) 166
Symmetry codes: (i) -x,-y,1-z; (ii) -x,1-y,1-z; (iii) [{\script{1\over 2}}-x,y-{\script{1\over 2}},{\script{1\over 2}}-z]; (iv) [{\script{1\over 2}}-x,{\script{1\over 2}}+y,{\script{1\over 2}}-z].

The O—H H atoms were found in difference maps and refined by riding on their carrier O atoms in their as-found relative positions. H atoms bonded to C and N atoms were placed in calculated positions [d(C—H) = 0.96 Å and d(N—H) = 0.89 Å] and refined as riding, with the rigid NH3 or CH3 groups allowed to freely rotate about the bond joining the atoms in question to atom C1. The constraint Uiso(H) = 1.2Ueq(O or N parent atom) or 1.5Ueq(methyl C parent atom) was applied as appropriate.

Data collection: SMART (Bruker, 1999[Bruker (1999). SMART (Version 5.624), SAINT-Plus (Version 6.02A) and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT-Plus (Bruker, 1999[Bruker (1999). SMART (Version 5.624), SAINT-Plus (Version 6.02A) and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97; molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and ATOMS (Shape Software, 1999[Shape Software (1999). ATOMS. Shape Software, 525 Hidden Valley Road, Kingsport, Tennessee, USA.]); software used to prepare material for publication: SHELXL97.

Supporting information


Computing details top

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97; molecular graphics: ORTEP-3 (Farrugia, 1997) and ATOMS (Shape Software, 1999); software used to prepare material for publication: SHELXL97.

tert-Butylammonium dihydrogenarsenate top
Crystal data top
(C4H12N)[H2AsO4]F(000) = 440
Mr = 215.08Dx = 1.633 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3025 reflections
a = 9.7364 (5) Åθ = 2.4–32.4°
b = 6.3254 (3) ŵ = 3.85 mm1
c = 14.2606 (8) ÅT = 293 K
β = 94.864 (1)°Bar, colourless
V = 875.10 (8) Å30.55 × 0.15 × 0.05 mm
Z = 4
Data collection top
Bruker SMART1000 CCD
diffractometer
3165 independent reflections
Radiation source: fine-focus sealed tube1807 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.023
ω scansθmax = 32.5°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
h = 1014
Tmin = 0.226, Tmax = 0.831k = 79
8742 measured reflectionsl = 2121
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.024Hydrogen site location: difmap (O-H) and geom (C-H and N-H)
wR(F2) = 0.064H-atom parameters constrained
S = 0.88 w = 1/[σ2(Fo2) + (0.0332P)2]
where P = (Fo2 + 2Fc2)/3
3165 reflections(Δ/σ)max = 0.001
95 parametersΔρmax = 0.47 e Å3
0 restraintsΔρmin = 0.51 e Å3
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only

used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and

goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) 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) top
xyzUiso*/Ueq
As10.096480 (18)0.25182 (3)0.428460 (11)0.02877 (6)
O10.07070 (14)0.2606 (2)0.44605 (10)0.0360 (3)
O20.13620 (15)0.3528 (2)0.32825 (9)0.0424 (4)
O30.15368 (15)0.0032 (2)0.43072 (9)0.0402 (3)
H10.11020.08630.47730.048*
O40.18923 (15)0.3676 (3)0.52194 (10)0.0482 (4)
H20.15450.50060.53780.058*
N10.38027 (16)0.2563 (2)0.24651 (10)0.0334 (3)
H30.30620.27250.27830.040*
H40.38240.12490.22430.040*
H50.37660.34740.19880.040*
C10.5091 (2)0.2971 (3)0.31140 (15)0.0380 (5)
C20.4956 (3)0.5164 (4)0.35241 (18)0.0608 (7)
H60.41470.52240.38650.091*
H70.48800.61850.30240.091*
H80.57550.54710.39430.091*
C30.5148 (3)0.1313 (4)0.38747 (18)0.0643 (7)
H90.52110.00620.35970.097*
H100.43280.13920.42030.097*
H110.59400.15530.43090.097*
C40.6306 (3)0.2805 (4)0.2525 (2)0.0677 (8)
H120.63290.14180.22540.102*
H130.71430.30510.29160.102*
H140.62170.38420.20320.102*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
As10.03246 (9)0.02705 (9)0.02761 (8)0.00106 (11)0.00722 (6)0.00055 (9)
O10.0324 (6)0.0318 (7)0.0448 (7)0.0000 (7)0.0090 (5)0.0018 (7)
O20.0539 (10)0.0385 (9)0.0368 (8)0.0031 (7)0.0162 (7)0.0104 (6)
O30.0507 (9)0.0294 (7)0.0433 (8)0.0085 (7)0.0196 (6)0.0027 (6)
O40.0452 (9)0.0500 (10)0.0474 (9)0.0071 (8)0.0072 (7)0.0177 (7)
N10.0389 (8)0.0304 (7)0.0312 (7)0.0000 (9)0.0053 (6)0.0001 (8)
C10.0392 (11)0.0367 (12)0.0371 (10)0.0018 (8)0.0017 (8)0.0006 (7)
C20.0685 (18)0.0454 (14)0.0640 (16)0.0033 (13)0.0198 (13)0.0125 (12)
C30.0716 (19)0.0592 (17)0.0592 (16)0.0032 (15)0.0123 (13)0.0228 (14)
C40.0391 (12)0.099 (2)0.0653 (16)0.0058 (14)0.0064 (11)0.0033 (15)
Geometric parameters (Å, º) top
As1—O21.6412 (13)C1—C41.511 (3)
As1—O11.6687 (13)C1—C21.515 (3)
As1—O31.7061 (13)C2—H60.9600
As1—O41.7101 (14)C2—H70.9600
O3—H10.9710C2—H80.9600
O4—H20.9415C3—H90.9600
N1—C11.516 (3)C3—H100.9600
N1—H30.8900C3—H110.9600
N1—H40.8900C4—H120.9600
N1—H50.8900C4—H130.9600
C1—C31.506 (3)C4—H140.9600
O2—As1—O1115.01 (7)C2—C1—N1107.28 (18)
O2—As1—O3106.49 (7)C1—C2—H6109.5
O1—As1—O3110.46 (7)C1—C2—H7109.5
O2—As1—O4111.36 (8)H6—C2—H7109.5
O1—As1—O4109.03 (7)C1—C2—H8109.5
O3—As1—O4103.90 (7)H6—C2—H8109.5
As1—O3—H1111.3H7—C2—H8109.5
As1—O4—H2113.1C1—C3—H9109.5
C1—N1—H3109.5C1—C3—H10109.5
C1—N1—H4109.5H9—C3—H10109.5
H3—N1—H4109.5C1—C3—H11109.5
C1—N1—H5109.5H9—C3—H11109.5
H3—N1—H5109.5H10—C3—H11109.5
H4—N1—H5109.5C1—C4—H12109.5
C3—C1—C4111.7 (2)C1—C4—H13109.5
C3—C1—C2111.0 (2)H12—C4—H13109.5
C4—C1—C2112.1 (2)C1—C4—H14109.5
C3—C1—N1107.39 (18)H12—C4—H14109.5
C4—C1—N1107.17 (18)H13—C4—H14109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H1···O1i0.971.622.5752 (19)166
O4—H2···O1ii0.941.742.6763 (19)172
N1—H3···O20.891.922.801 (2)168
N1—H4···O2iii0.891.882.765 (2)173
N1—H5···O3iv0.892.072.944 (2)166
Symmetry codes: (i) x, y, z+1; (ii) x, y+1, z+1; (iii) x+1/2, y1/2, z+1/2; (iv) x+1/2, y+1/2, z+1/2.
 

Acknowledgements

HSW thanks the Carnegie Trust for the Universities of Scotland for an undergraduate vacation studentship.

References

First citationBruker (1999). SMART (Version 5.624), SAINT-Plus (Version 6.02A) and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationLee, C. & Harrison, W. T. A. (2003a). Acta Cryst. E59, m739–m741.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationLee, C. & Harrison, W. T. A. (2003b). Acta Cryst. E59, m959–m960.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationLee, C. & Harrison, W. T. A. (2003c). Acta Cryst. E59, m1151–m1153.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationShape Software (1999). ATOMS. Shape Software, 525 Hidden Valley Road, Kingsport, Tennessee, USA.  Google Scholar
First citationSheldrick, G. M. (1997). SHELXL97. University of Göttingen, Germany.  Google Scholar

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