Ammonium hydrogenselenate(IV)

The title compound, NH₄(HSeO₃), is isostructural with KHSeO₃ and contains tetra­hedral NH₄⁺ cations and trigonal–pyramidal HSeO₃⁻ anions, the latter containing two short Se–O bonds and one long Se–OH bond. The crystal packing is consolidated by a network of weak hydrogen bonds, with donor–acceptor distances (N...O and O...O) lying between 2.80 and 3.07 Å.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](e-O) = 0.002 Å
• R factor = 0.024
• wR factor = 0.058
• Data-to-parameter ratio = 17.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K
PLAT731_ALERT_1_C Bond    Calc     0.84(4), Rep   0.844(19) ......       2.11 su-Rat
              O2   -H5      1.555   1.555
PLAT731_ALERT_1_C Bond    Calc     0.90(4), Rep   0.895(19) ......       2.11 su-Rat
              N    -H1      1.555   1.555
PLAT731_ALERT_1_C Bond    Calc     0.90(4), Rep   0.896(19) ......       2.11 su-Rat
              N    -H2      1.555   1.555
PLAT731_ALERT_1_C Bond    Calc     0.90(4), Rep   0.900(19) ......       2.11 su-Rat
              N    -H3      1.555   1.555
PLAT731_ALERT_1_C Bond    Calc     0.91(4), Rep   0.907(19) ......       2.11 su-Rat
              N    -H4      1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.90(4), Rep   0.895(19) ......       2.11 su-Rat
              N    -H1      1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.90(4), Rep   0.896(19) ......       2.11 su-Rat
              N    -H2      1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.90(4), Rep   0.896(19) ......       2.11 su-Rat
              N    -H2      1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.90(4), Rep   0.900(19) ......       2.11 su-Rat
              N    -H3      1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.91(4), Rep   0.907(19) ......       2.11 su-Rat
              N    -H4      1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.84(4), Rep   0.844(19) ......       2.11 su-Rat
              O2   -H5      1.555   1.555

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
  14 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

  14 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 2004); software used to prepare material for publication: SHELXL97.

Ammonium hydrogenselenate(IV)

Crystal data

NH4(HSeO3)	Z = 2
Mr = 146.01	F(000) = 140
Triclinic, P1	Dx = 2.599 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.0660 (11) Å	Cell parameters from 1344 reflections
b = 5.9587 (12) Å	θ = 3.3–30.0°
c = 6.9337 (14) Å	µ = 9.89 mm^−1
α = 70.473 (4)°	T = 293 K
β = 72.124 (4)°	Lath, colourless
γ = 89.791 (4)°	0.08 × 0.05 × 0.02 mm
V = 186.60 (7) Å^3

Data collection

Bruker SMART APEX CCD diffractometer	1066 independent reflections
Radiation source: fine-focus sealed tube	1004 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
ω scans	θmax = 30.0°, θmin = 3.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −7→6
Tmin = 0.490, Tmax = 0.827	k = −8→8
2107 measured reflections	l = −9→9

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.024	Hydrogen site location: difference Fourier map
wR(F^2) = 0.058	All H-atom parameters refined
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0368P)^2] where P = (Fo^2 + 2Fc^2)/3
1066 reflections	(Δ/σ)max = 0.001
62 parameters	Δρmax = 0.68 e Å^−3
5 restraints	Δρmin = −0.57 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Se	0.05503 (5)	0.33293 (4)	0.82170 (4)	0.02377 (10)
O1	0.1509 (4)	0.1129 (3)	0.7254 (3)	0.0274 (4)
O2	0.2364 (5)	0.5941 (4)	0.6073 (4)	0.0351 (4)
O3	−0.2711 (4)	0.3613 (4)	0.8143 (3)	0.0335 (4)
N	0.3492 (5)	0.1243 (4)	0.2839 (4)	0.0294 (5)
H1	0.209 (7)	0.053 (8)	0.264 (8)	0.072 (7)*
H2	0.377 (10)	0.270 (5)	0.182 (6)	0.072 (7)*
H3	0.309 (9)	0.149 (9)	0.411 (5)	0.072 (7)*
H4	0.503 (7)	0.045 (8)	0.274 (8)	0.072 (7)*
H5	0.226 (10)	0.596 (9)	0.488 (5)	0.072 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Se	0.02916 (15)	0.02147 (14)	0.02534 (14)	0.00555 (9)	−0.01205 (10)	−0.01114 (10)
O1	0.0283 (9)	0.0253 (9)	0.0337 (9)	0.0081 (7)	−0.0099 (8)	−0.0169 (8)
O2	0.0421 (11)	0.0249 (9)	0.0342 (10)	−0.0080 (8)	−0.0116 (9)	−0.0058 (8)
O3	0.0226 (9)	0.0330 (10)	0.0440 (12)	0.0080 (8)	−0.0104 (8)	−0.0129 (9)
N	0.0299 (12)	0.0250 (11)	0.0336 (12)	0.0026 (9)	−0.0140 (10)	−0.0073 (9)

Geometric parameters (Å, º)

Se—O1	1.6678 (17)	N—H1	0.895 (19)
Se—O3	1.6747 (19)	N—H2	0.896 (19)
Se—O2	1.761 (2)	N—H3	0.900 (19)
O2—H5	0.844 (19)	N—H4	0.907 (19)
O1—Se—O3	103.79 (10)	H1—N—H3	116 (5)
O1—Se—O2	103.97 (10)	H2—N—H3	106 (4)
O3—Se—O2	100.93 (10)	H1—N—H4	114 (4)
Se—O2—H5	112 (4)	H2—N—H4	114 (4)
H1—N—H2	102 (4)	H3—N—H4	105 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N—H1···O1^i	0.90 (2)	2.05 (2)	2.934 (3)	170 (5)
N—H2···O3^ii	0.90 (2)	2.26 (4)	2.963 (3)	135 (4)
N—H2···O3^iii	0.90 (2)	2.51 (4)	3.065 (3)	121 (4)
N—H3···O1	0.90 (2)	2.02 (2)	2.891 (3)	164 (5)
N—H4···O1^iv	0.91 (2)	1.99 (2)	2.889 (3)	174 (5)
O2—H5···O3^ii	0.84 (2)	1.96 (2)	2.795 (3)	169 (5)

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