Piperidinium di­hydrogenarsenate

A combination of O—H...O [d_av(H...O) = 1.73 Å; θ_av(O—H...O) = 156°; d_av(O...O) = 2.609 (3) Å] and N—H...O [d_av(H...O) = 1.85 Å; θ_av(N—H...O) = 169°; d_av(N...O) = 2.740 (2) Å] hydrogen bonds defines a layered structure for the title compound, (C₅H₁₂N)[H₂AsO₄].

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.018
• wR factor = 0.042
• Data-to-parameter ratio = 31.6

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR) is > 1.10
            Tmin and Tmax reported:      0.171     0.259
            Tmin and Tmax expected:      0.141     0.259
            RR =      1.217
            Please check that your absorption correction is appropriate.
PLAT060_ALERT_3_C Ratio Tmax/Tmin (Exp-to-Rep) (too) Large .......       1.22

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           32.51
           From the CIF: _reflns_number_total               3187
           Count of symmetry unique reflns         1760
           Completeness (_total/calc)            181.08%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1427
           Fraction of Friedel pairs measured     0.811
           Are heavy atom types Z>Si present          yes

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

   0 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
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

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.

(I)

Crystal data

(C5H12N)[H2AsO4]	F(000) = 232
Mr = 227.09	Dx = 1.676 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 4144 reflections
a = 8.6593 (4) Å	θ = 2.5–32.5°
b = 6.3233 (3) Å	µ = 3.75 mm^−1
c = 8.9090 (4) Å	T = 293 K
β = 112.676 (1)°	Chunk, colourless
V = 450.11 (4) Å^3	0.56 × 0.53 × 0.36 mm
Z = 2

Data collection

Bruker SMART1000 CCD diffractometer	3187 independent reflections
Radiation source: fine-focus sealed tube	2936 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.014
ω scans	θmax = 32.5°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Bruker, 1999)	h = −12→13
Tmin = 0.171, Tmax = 0.259	k = −9→9
5328 measured reflections	l = −11→13

Refinement

Refinement on F^2	H-atom parameters constrained
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0246P)^2] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.018	(Δ/σ)max = 0.002
wR(F^2) = 0.042	Δρmax = 0.27 e Å^−3
S = 1.00	Δρmin = −0.29 e Å^−3
3187 reflections	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
101 parameters	Extinction coefficient: 0.0311 (18)
1 restraint	Absolute structure: Flack (1983), 1504 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.063 (8)
Hydrogen site location: inferred from neighbouring sites

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
As1	0.813891 (12)	0.47057 (2)	0.937213 (14)	0.02762 (4)
O1	0.64813 (15)	0.3917 (2)	0.96880 (16)	0.0449 (3)
O2	0.99181 (11)	0.4763 (4)	1.10049 (11)	0.03654 (19)
O3	0.76336 (14)	0.71511 (19)	0.85000 (16)	0.0398 (3)
H1	0.8520	0.7874	0.8671	0.048*
O4	0.84122 (17)	0.3272 (2)	0.78576 (14)	0.0450 (3)
H2	0.8704	0.1848	0.8375	0.054*
N1	0.35695 (16)	0.6115 (2)	0.80147 (17)	0.0345 (3)
H3	0.3520	0.7244	0.8609	0.041*
H4	0.4549	0.5453	0.8548	0.041*
C1	0.3511 (2)	0.6845 (3)	0.6411 (2)	0.0433 (4)
H5	0.4443	0.7788	0.6565	0.052*
H6	0.2481	0.7619	0.5849	0.052*
C2	0.3600 (2)	0.4968 (5)	0.5401 (2)	0.0497 (6)
H7	0.4681	0.4288	0.5914	0.060*
H8	0.3497	0.5452	0.4334	0.060*
C3	0.2232 (3)	0.3378 (4)	0.5215 (3)	0.0573 (5)
H9	0.2389	0.2138	0.4649	0.069*
H10	0.1153	0.3991	0.4567	0.069*
C4	0.2256 (3)	0.2733 (4)	0.6869 (3)	0.0566 (5)
H11	0.1311	0.1815	0.6720	0.068*
H12	0.3273	0.1947	0.7458	0.068*
C5	0.2173 (2)	0.4653 (6)	0.7853 (2)	0.0473 (3)
H13	0.1112	0.5372	0.7316	0.057*
H14	0.2251	0.4213	0.8923	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
As1	0.02546 (5)	0.02915 (6)	0.02792 (6)	0.00088 (10)	0.00993 (4)	0.00347 (10)
O1	0.0347 (5)	0.0522 (7)	0.0521 (7)	0.0012 (5)	0.0215 (5)	0.0214 (6)
O2	0.0335 (4)	0.0355 (4)	0.0321 (4)	0.0063 (8)	0.0033 (3)	−0.0007 (8)
O3	0.0297 (5)	0.0330 (5)	0.0492 (7)	−0.0015 (4)	0.0068 (5)	0.0137 (5)
O4	0.0518 (7)	0.0494 (7)	0.0288 (6)	0.0095 (6)	0.0103 (5)	−0.0031 (5)
N1	0.0345 (6)	0.0377 (7)	0.0338 (7)	0.0035 (5)	0.0159 (5)	−0.0040 (5)
C1	0.0469 (9)	0.0412 (9)	0.0436 (9)	0.0043 (7)	0.0193 (8)	0.0103 (7)
C2	0.0622 (9)	0.0603 (17)	0.0317 (7)	0.0107 (11)	0.0238 (6)	0.0086 (10)
C3	0.0698 (13)	0.0603 (13)	0.0365 (9)	−0.0028 (11)	0.0146 (9)	−0.0110 (9)
C4	0.0741 (14)	0.0454 (11)	0.0514 (12)	−0.0161 (10)	0.0254 (10)	−0.0065 (9)
C5	0.0468 (7)	0.0585 (9)	0.0437 (7)	−0.0108 (16)	0.0252 (6)	−0.0019 (16)

Geometric parameters (Å, º)

As1—O1	1.6431 (11)	C1—H6	0.9700
As1—O2	1.6622 (8)	C2—C3	1.513 (4)
As1—O3	1.7100 (11)	C2—H7	0.9700
As1—O4	1.7161 (13)	C2—H8	0.9700
O3—H1	0.8546	C3—C4	1.522 (3)
O4—H2	0.9988	C3—H9	0.9700
N1—C1	1.484 (2)	C3—H10	0.9700
N1—C5	1.484 (3)	C4—C5	1.516 (4)
N1—H3	0.9000	C4—H11	0.9700
N1—H4	0.9000	C4—H12	0.9700
C1—C2	1.509 (3)	C5—H13	0.9700
C1—H5	0.9700	C5—H14	0.9700
O1—As1—O2	115.65 (6)	C3—C2—H7	109.3
O1—As1—O3	105.37 (6)	C1—C2—H8	109.3
O2—As1—O3	111.49 (9)	C3—C2—H8	109.3
O1—As1—O4	111.63 (8)	H7—C2—H8	107.9
O2—As1—O4	109.72 (7)	C2—C3—C4	110.73 (16)
O3—As1—O4	102.08 (7)	C2—C3—H9	109.5
As1—O3—H1	110.3	C4—C3—H9	109.5
As1—O4—H2	101.6	C2—C3—H10	109.5
C1—N1—C5	112.09 (14)	C4—C3—H10	109.5
C1—N1—H3	109.2	H9—C3—H10	108.1
C5—N1—H3	109.2	C5—C4—C3	111.06 (18)
C1—N1—H4	109.2	C5—C4—H11	109.4
C5—N1—H4	109.2	C3—C4—H11	109.4
H3—N1—H4	107.9	C5—C4—H12	109.4
N1—C1—C2	109.80 (16)	C3—C4—H12	109.4
N1—C1—H5	109.7	H11—C4—H12	108.0
C2—C1—H5	109.7	N1—C5—C4	109.65 (14)
N1—C1—H6	109.7	N1—C5—H13	109.7
C2—C1—H6	109.7	C4—C5—H13	109.7
H5—C1—H6	108.2	N1—C5—H14	109.7
C1—C2—C3	111.75 (16)	C4—C5—H14	109.7
C1—C2—H7	109.3	H13—C5—H14	108.2

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H1···O2^i	0.85	1.74	2.588 (2)	169
O4—H2···O2^ii	1.00	1.72	2.629 (3)	149
N1—H3···O1^iii	0.90	1.85	2.720 (2)	162
N1—H4···O1	0.90	1.86	2.759 (2)	176

Symmetry codes: (i) −x+2, y+1/2, −z+2; (ii) −x+2, y−1/2, −z+2; (iii) −x+1, y+1/2, −z+2.