Cyclo­hexyl­ammonium hydrogensquarate hemihydrate

The components of the title compound, C₆H₁₄N⁺·C₄HO₄⁻·0.5H₂O, are connected by moderate inter­molecular N—H...O hydrogen bonds between the anions and cations into infinite three-dimensional networks. The cyclo­hexyl­ammonium cation inter­acts with the solvent mol­ecule by means of an N—H...O hydrogen bond. The hydrogensquarate anions form α chains through strong O—H...O inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.051
• wR factor = 0.141
• Data-to-parameter ratio = 13.8

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PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.50 Ratio
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.54

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S1. Comment

In the course of our spectroscopic and structural studies on hydrogensquarates (Kolev et al., 1998, 2006; Koleva et al., 2007), the crystal structure of cyclohexyammonium hydrogensquarate semihydrate (I) is reported. The molecular structure of (I) is depicted in Fig. 1. The crystal structure consists of three-dimensional networks of cations and anions connected by moderate intermolecular N—H···O [N···O = 2.811 (3), and 2.864 (2) Å] hydrogen bonds. The cations interact with solvent molecule by means of N—H···O [N···O = 2.859 (2) Å] hydrogen bonds and the hydrogensquarate anions form alpha chains through strong O—H···O [O···O = 2.485 (2) Å] interactions (Fig. 2).

Related literature

For related literature, see: Kolev et al. (1998, 2006); Koleva et al. (2007).

S2. Experimental

Cyclohexylammonium hydrogensquarate hemihydrate was prepared by mixing an equimolar ratio of cyclohexylamine (Merck) and squaric acid (Sigma-Aldrich) in 10 ml water. Suitable crystals for X-ray analysis, were grown by allowing the solution to slowly evaporate for a week, and were filtered off, washed with methanol and dried under air.

S3. Refinement

H atoms were constrained to idealized positions and refined using a riding model, with C—H distances of 0.98 Å (CH) and 0.97 Å (CH₂); [U_iso(H) = 1.2 U_iso(C)], N—H distances of 0.86 Å; [U_iso(H) = 1.5 U_iso(N)] and an O—H distance of 0.82 Å, [U_iso(H) = 1.5 U_iso(O)].

Computing details

Data collection: R3m/V (Siemens, 1989); cell refinement: R3m/V (Siemens, 1989); data reduction: XDISK (Siemens, 1989); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Sheldrick, 1995); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures

Fig. 1. The molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.

Cyclohexylammonium hydrogensquarate hemihydrate

Crystal data

C6H14N^+·C4HO4^−·0.5(H2O)	Dx = 1.283 Mg m^−3
Mr = 222.24	Melting point: not measured K
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 50 reflections
a = 9.3553 (8) Å	θ = 4.8–12.4°
b = 11.087 (4) Å	µ = 0.10 mm^−1
c = 22.1880 (19) Å	T = 294 K
V = 2301.4 (9) Å^3	Prism, colourless
Z = 8	0.53 × 0.51 × 0.48 mm
F(000) = 952

Data collection

Siemens P4 4-circle diffractometer	1272 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.037
Graphite monochromator	θmax = 25.0°, θmin = 2.9°
ω–scans	h = −1→11
Absorption correction: ψ scan (ABSPsiScan; Spek, 2003)	k = −1→13
Tmin = 0.948, Tmax = 0.953	l = −1→26
2655 measured reflections	3 standard reflections every 97 reflections
2015 independent reflections	intensity decay: 1%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.051	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.142	w = 1/[σ^2(Fo^2) + (0.0675P)^2 + 0.3613P] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max < 0.001
2015 reflections	Δρmax = 0.20 e Å^−3
146 parameters	Δρmin = −0.14 e Å^−3
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.021 (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
N1	0.86327 (19)	0.35921 (16)	0.16649 (8)	0.0419 (5)
H11	0.8933	0.4346	0.1719	0.063*
H12	0.8987	0.3124	0.1954	0.063*
H13	0.7682	0.3573	0.1679	0.063*
C1	0.9127 (2)	0.3146 (2)	0.10672 (10)	0.0426 (6)
H1	1.0160	0.3282	0.1039	0.051*
C2	0.8854 (3)	0.1809 (2)	0.10055 (12)	0.0555 (7)
H21	0.7838	0.1649	0.1041	0.067*
H22	0.9342	0.1378	0.1325	0.067*
C3	0.9391 (3)	0.1371 (3)	0.03954 (13)	0.0698 (9)
H31	1.0422	0.1461	0.0378	0.084*
H32	0.9169	0.0522	0.0350	0.084*
C4	0.8725 (4)	0.2066 (3)	−0.01147 (14)	0.0895 (11)
H41	0.9145	0.1805	−0.0492	0.107*
H42	0.7709	0.1890	−0.0130	0.107*
C5	0.8934 (4)	0.3396 (3)	−0.00458 (14)	0.0875 (11)
H51	0.8415	0.3813	−0.0362	0.105*
H52	0.9941	0.3586	−0.0091	0.105*
C6	0.8415 (3)	0.3845 (2)	0.05702 (12)	0.0638 (8)
H61	0.8635	0.4696	0.0613	0.077*
H62	0.7386	0.3749	0.0598	0.077*
O7	0.56071 (16)	0.39632 (13)	0.17312 (8)	0.0507 (5)
O8	0.21107 (16)	0.38561 (12)	0.18896 (8)	0.0538 (5)
H8	0.2417	0.4547	0.1860	0.081*
O9	0.21940 (16)	0.10179 (12)	0.18503 (8)	0.0537 (5)
O10	0.56638 (18)	0.10553 (14)	0.17129 (9)	0.0619 (6)
C7	0.4700 (2)	0.31678 (19)	0.17684 (10)	0.0352 (5)
C8	0.3163 (2)	0.30963 (18)	0.18360 (10)	0.0349 (5)
C9	0.3157 (2)	0.18191 (19)	0.18237 (10)	0.0368 (6)
C10	0.4724 (2)	0.18142 (19)	0.17581 (10)	0.0379 (6)
O20	0.0000	0.2003 (2)	0.2500	0.0474 (6)
H20	0.060 (3)	0.150 (2)	0.2342 (13)	0.071*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0394 (11)	0.0340 (10)	0.0524 (12)	−0.0024 (9)	−0.0006 (9)	−0.0033 (9)
C1	0.0386 (13)	0.0418 (13)	0.0475 (14)	−0.0004 (11)	0.0045 (11)	−0.0008 (11)
C2	0.0688 (18)	0.0414 (14)	0.0564 (16)	−0.0031 (13)	0.0067 (14)	−0.0052 (12)
C3	0.083 (2)	0.0600 (18)	0.066 (2)	−0.0056 (17)	0.0209 (16)	−0.0195 (15)
C4	0.108 (3)	0.108 (3)	0.0526 (19)	−0.002 (2)	0.0044 (19)	−0.0177 (19)
C5	0.119 (3)	0.090 (3)	0.0529 (18)	0.007 (2)	0.0053 (19)	0.0152 (18)
C6	0.079 (2)	0.0553 (17)	0.0574 (17)	0.0053 (15)	0.0030 (15)	0.0104 (13)
O7	0.0368 (9)	0.0352 (9)	0.0801 (13)	−0.0081 (7)	0.0038 (9)	0.0050 (9)
O8	0.0329 (9)	0.0232 (8)	0.1054 (15)	0.0006 (7)	0.0017 (9)	−0.0016 (8)
O9	0.0350 (9)	0.0232 (8)	0.1029 (15)	−0.0022 (7)	0.0070 (9)	−0.0036 (9)
O10	0.0422 (10)	0.0394 (10)	0.1042 (16)	0.0125 (8)	0.0161 (10)	−0.0014 (10)
C7	0.0334 (12)	0.0311 (11)	0.0411 (13)	−0.0017 (10)	0.0013 (10)	0.0020 (10)
C8	0.0327 (12)	0.0236 (11)	0.0485 (13)	0.0019 (10)	−0.0007 (10)	−0.0003 (10)
C9	0.0354 (12)	0.0237 (11)	0.0513 (14)	0.0004 (10)	0.0023 (11)	−0.0018 (10)
C10	0.0367 (13)	0.0311 (11)	0.0461 (14)	0.0026 (10)	0.0053 (11)	0.0014 (10)
O20	0.0435 (14)	0.0400 (13)	0.0585 (16)	0.000	0.0070 (12)	0.000

Geometric parameters (Å, º)

N1—C1	1.489 (3)	C5—C6	1.534 (4)
N1—H11	0.8900	C5—H51	0.9700
N1—H12	0.8900	C5—H52	0.9700
N1—H13	0.8900	C6—H61	0.9700
C1—C6	1.503 (3)	C6—H62	0.9700
C1—C2	1.511 (3)	O7—C7	1.226 (2)
C1—H1	0.9800	O8—C8	1.301 (2)
C2—C3	1.523 (3)	O8—H8	0.8200
C2—H21	0.9700	O9—C9	1.267 (2)
C2—H22	0.9700	O10—C10	1.221 (2)
C3—C4	1.504 (4)	C7—C8	1.449 (3)
C3—H31	0.9700	C7—C10	1.501 (3)
C3—H32	0.9700	C8—C9	1.416 (3)
C4—C5	1.496 (5)	C9—C10	1.473 (3)
C4—H41	0.9700	O20—H20	0.86 (2)
C4—H42	0.9700
C1—N1—H11	109.5	C3—C4—H42	109.2
C1—N1—H12	109.5	H41—C4—H42	107.9
H11—N1—H12	109.5	C4—C5—C6	111.7 (3)
C1—N1—H13	109.5	C4—C5—H51	109.3
H11—N1—H13	109.5	C6—C5—H51	109.3
H12—N1—H13	109.5	C4—C5—H52	109.3
N1—C1—C6	110.16 (19)	C6—C5—H52	109.3
N1—C1—C2	110.74 (19)	H51—C5—H52	107.9
C6—C1—C2	111.4 (2)	C1—C6—C5	110.2 (2)
N1—C1—H1	108.1	C1—C6—H61	109.6
C6—C1—H1	108.1	C5—C6—H61	109.6
C2—C1—H1	108.1	C1—C6—H62	109.6
C1—C2—C3	109.7 (2)	C5—C6—H62	109.6
C1—C2—H21	109.7	H61—C6—H62	108.1
C3—C2—H21	109.7	C8—O8—H8	109.5
C1—C2—H22	109.7	O7—C7—C8	137.1 (2)
C3—C2—H22	109.7	O7—C7—C10	135.1 (2)
H21—C2—H22	108.2	C8—C7—C10	87.78 (17)
C4—C3—C2	111.6 (3)	O8—C8—C9	130.3 (2)
C4—C3—H31	109.3	O8—C8—C7	136.50 (19)
C2—C3—H31	109.3	C9—C8—C7	93.22 (18)
C4—C3—H32	109.3	O9—C9—C8	134.6 (2)
C2—C3—H32	109.3	O9—C9—C10	135.23 (19)
H31—C3—H32	108.0	C8—C9—C10	90.12 (18)
C5—C4—C3	111.9 (3)	O10—C10—C9	136.7 (2)
C5—C4—H41	109.2	O10—C10—C7	134.5 (2)
C3—C4—H41	109.2	C9—C10—C7	88.88 (17)
C5—C4—H42	109.2

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O8—H8···O9^i	0.82	1.67	2.485 (2)	171
N1—H11···O10^ii	0.89	1.93	2.811 (3)	169
N1—H12···O20^iii	0.89	1.98	2.859 (2)	171
N1—H13···O7	0.89	1.99	2.864 (2)	166
O20—H20···O9	0.86 (2)	1.93 (2)	2.7358 (18)	156 (2)

Symmetry codes: (i) −x+1/2, y+1/2, z; (ii) −x+3/2, y+1/2, z; (iii) x+1, y, z.