4-Hy­droxy­anilinium perchlorate dihydrate

In the crystal structure of the title compound, C₆H₈NO⁺·ClO₄⁻·2H₂O, inter­molecular N—H...O and O—H...O hydrogen bonds occur. The protonated amine cations and the perchlorate anions are linked through the water mol­ecules, and the hy­droxy groups of the cations and the anions are linked through the water mol­ecules. The cations are connected to the perchlorate anions via inter­molecular N—H...O hydrogen bonds. In addition, the crystal structure exhibits weak inter­molecular C—H...π inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.048
• wR factor = 0.097
• Data-to-parameter ratio = 13.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1

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           27.48
           From the CIF: _reflns_number_total               2275
           Count of symmetry unique reflns         1226
           Completeness (_total/calc)            185.56%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1049
           Fraction of Friedel pairs measured     0.856
           Are heavy atom types Z>Si present        yes
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          8
PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels ..........          4
PLAT850_ALERT_4_G Check Flack Parameter Exact Value 0.00 and su ..       0.07

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   4 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
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

As a continuation of our study of phase transition materials, including organic ligands (Li et al., 2008), metal-organic coordination compounds (Zhang et al., 2009), organic–inorganic hybrids, we studied the dielectric properties of the title compound, unfortunately, there was no distinct anomaly observed from 93 K to 350 K, suggesting that this compound should be not a real ferroelectrics or there may be no distinct phase transition occurred within the measured temperature range. Here, we report the crystal structure of the title compound (Fig. 1).

The asymmetric unit of the title compound is made up of a 4–hydroxyanilinium cation cation wherein the non-hydrogen atoms are practically co-planar with a mean deviation of 0.015 (2) Å, a perchlorate anion and two solvent molecules of water (Fig. 1). The crystal packing (Fig. 2) is stabilized by intermolecular N—H···O , O—H···O hydrogen bonds and weak intermolecular C—H···π interactions. (Table 1). Both the protonated amine cations and the perchlorate anions are linked through the water molecules, and the hydroxy groups of the cations and the anions are linked through the water molecules. Additionally, the cations are connected to the perchlorate anions via intermolecular N—H···O hydrogen bonds.

Related literature

For background to phase transition materials, see: Li et al. (2008); Zhang et al. (2009)

S2. Experimental

1.09g (10 mmol) 4–aminophenol was firstly dissolved in 10ml ethanol, to which perchloric acid aqueous solution (70% w/w) was then added under stirring until the PH of the solution was ca. 6. Ethanol was added until the precipitated substrates disappeared. Colorless prism single crystal for X–ray was obtained by the acid solution slow evaporated at room temperature after two days.

S3. Refinement

Aryl H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93 Å. U_iso(H) = 1.2U_eq(C). The other H atoms attached to N and O atoms were found difference maps using restraints for O—H bond distances (O—H = 0.85 (5) Å) and H—O—H angles (H···H =1.35 (10) Å). Their displacement parameters were freely refined.

Computing details

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as a small cycles of arbitrary radius.
	Fig. 2. N—H···O, O—H···O and C—H···π interactions (dotted lines) in the crystal structure of the title compound. Cg denotes the ring centroid. [Symmetry codes: (i) - x + 1, - y + 2, z + 1/2; (ii) x, y + 1, z; (iii) x, y, z + 1; (iv) - x + 1, - y + 1, z - 1/2.]

4-Hydroxyanilinium perchlorate dihydrate

Crystal data

C6H8NO^+·ClO4^−·2H2O	F(000) = 512
Mr = 245.62	Dx = 1.631 Mg m^−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 4523 reflections
a = 24.341 (5) Å	θ = 3.1–55.2°
b = 5.253 (1) Å	µ = 0.40 mm^−1
c = 7.824 (2) Å	T = 298 K
V = 1000.4 (4) Å^3	Prism, colourless
Z = 4	0.40 × 0.30 × 0.20 mm

Data collection

Rigaku SCXmini diffractometer	2275 independent reflections
Radiation source: fine-focus sealed tube	1986 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.052
Detector resolution: 13.6612 pixels mm^-1	θmax = 27.5°, θmin = 3.1°
ω scans	h = −31→31
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −6→6
Tmin = 0.866, Tmax = 0.923	l = −10→10
9517 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.048	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.097	w = 1/[σ^2(Fo^2) + (0.0423P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.11	(Δ/σ)max = 0.001
2275 reflections	Δρmax = 0.21 e Å^−3
168 parameters	Δρmin = −0.53 e Å^−3
8 restraints	Absolute structure: Flack (1983), 1049 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.00 (7)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
Cl1	0.70519 (2)	0.26502 (10)	0.38081 (9)	0.03119 (16)
O1	0.41921 (9)	0.7270 (4)	0.6125 (3)	0.0418 (5)
H1O	0.4080 (14)	0.855 (5)	0.638 (4)	0.041 (10)*
O2	0.65704 (9)	0.1268 (4)	0.4283 (3)	0.0543 (6)
O3	0.72121 (12)	0.1930 (5)	0.2130 (3)	0.0615 (7)
O4	0.69370 (9)	0.5318 (3)	0.3859 (3)	0.0490 (5)
O5	0.74825 (10)	0.2072 (4)	0.4975 (4)	0.0633 (7)
N1	0.64637 (12)	0.7547 (5)	0.7092 (4)	0.0383 (6)
H1N	0.6637 (19)	0.763 (7)	0.624 (7)	0.067 (14)*
H2N	0.6575 (16)	0.911 (8)	0.768 (6)	0.082 (13)*
H3N	0.6580 (18)	0.587 (9)	0.759 (6)	0.102 (16)*
C1	0.47480 (12)	0.7447 (5)	0.6368 (3)	0.0303 (6)
C2	0.50729 (12)	0.5551 (5)	0.5650 (4)	0.0323 (6)
H2	0.4911	0.4256	0.5014	0.039*
C3	0.56328 (12)	0.5591 (5)	0.5878 (4)	0.0347 (6)
H3	0.5852	0.4326	0.5404	0.042*
C4	0.58649 (11)	0.7533 (4)	0.6821 (3)	0.0308 (6)
C5	0.55500 (11)	0.9431 (5)	0.7512 (4)	0.0320 (6)
H5	0.5714	1.0744	0.8124	0.038*
C6	0.49832 (11)	0.9382 (5)	0.7292 (4)	0.0324 (6)
H6	0.4765	1.0651	0.7768	0.039*
O1W	0.68473 (10)	0.2523 (4)	0.8370 (3)	0.0461 (6)
H1AW	0.680 (3)	0.245 (11)	0.937 (6)	0.19 (4)*
H1BW	0.7155 (18)	0.270 (10)	0.793 (8)	0.13 (2)*
O2W	0.62796 (12)	0.7872 (5)	0.0985 (4)	0.0514 (6)
H2AW	0.6577 (16)	0.773 (8)	0.172 (5)	0.079 (15)*
H2BW	0.6131 (18)	0.658 (6)	0.103 (6)	0.070 (14)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0311 (3)	0.0332 (3)	0.0292 (3)	0.0050 (2)	0.0005 (3)	−0.0030 (3)
O1	0.0300 (11)	0.0394 (11)	0.0560 (14)	0.0019 (10)	−0.0011 (10)	−0.0022 (11)
O2	0.0455 (12)	0.0505 (11)	0.0667 (15)	−0.0075 (10)	0.0107 (11)	0.0084 (11)
O3	0.0783 (17)	0.0697 (15)	0.0365 (14)	0.0053 (14)	0.0176 (13)	−0.0112 (11)
O4	0.0573 (13)	0.0358 (9)	0.0541 (12)	0.0082 (9)	−0.0003 (13)	0.0001 (11)
O5	0.0484 (15)	0.0774 (16)	0.0640 (17)	0.0242 (13)	−0.0244 (13)	−0.0038 (13)
N1	0.0317 (14)	0.0414 (15)	0.0419 (17)	0.0010 (12)	0.0015 (12)	0.0017 (13)
C1	0.0319 (14)	0.0327 (13)	0.0262 (14)	−0.0010 (12)	−0.0009 (12)	0.0064 (11)
C2	0.0337 (15)	0.0293 (13)	0.0341 (14)	−0.0031 (12)	−0.0005 (12)	−0.0067 (11)
C3	0.0357 (16)	0.0277 (12)	0.0405 (16)	0.0041 (11)	0.0070 (13)	−0.0073 (11)
C4	0.0292 (13)	0.0301 (13)	0.0331 (14)	0.0011 (12)	0.0000 (11)	0.0044 (11)
C5	0.0383 (15)	0.0287 (11)	0.0290 (13)	−0.0009 (11)	−0.0045 (12)	−0.0015 (11)
C6	0.0358 (14)	0.0295 (13)	0.0320 (15)	0.0087 (11)	−0.0014 (11)	−0.0040 (12)
O1W	0.0394 (12)	0.0513 (12)	0.0477 (18)	−0.0040 (12)	−0.0053 (10)	0.0005 (11)
O2W	0.0401 (15)	0.0486 (14)	0.0654 (17)	0.0015 (12)	−0.0133 (12)	0.0038 (13)

Geometric parameters (Å, º)

Cl1—O3	1.421 (2)	C2—C3	1.375 (4)
Cl1—O5	1.423 (2)	C2—H2	0.9300
Cl1—O2	1.428 (2)	C3—C4	1.379 (4)
Cl1—O4	1.4297 (18)	C3—H3	0.9300
O1—C1	1.370 (3)	C4—C5	1.369 (4)
O1—H1O	0.75 (3)	C5—C6	1.391 (4)
N1—C4	1.473 (4)	C5—H5	0.9300
N1—H1N	0.79 (5)	C6—H6	0.9300
N1—H2N	0.98 (4)	O1W—H1AW	0.79 (5)
N1—H3N	1.00 (5)	O1W—H1BW	0.83 (4)
C1—C6	1.372 (4)	O2W—H2AW	0.93 (4)
C1—C2	1.391 (4)	O2W—H2BW	0.77 (3)
O3—Cl1—O5	109.51 (18)	C3—C2—H2	120.0
O3—Cl1—O2	109.27 (17)	C1—C2—H2	120.0
O5—Cl1—O2	109.22 (16)	C2—C3—C4	119.1 (2)
O3—Cl1—O4	109.90 (17)	C2—C3—H3	120.4
O5—Cl1—O4	109.61 (14)	C4—C3—H3	120.4
O2—Cl1—O4	109.31 (13)	C5—C4—C3	121.4 (2)
C1—O1—H1O	105 (3)	C5—C4—N1	119.6 (2)
C4—N1—H1N	114 (3)	C3—C4—N1	119.1 (2)
C4—N1—H2N	110 (2)	C4—C5—C6	119.6 (2)
H1N—N1—H2N	102 (4)	C4—C5—H5	120.2
C4—N1—H3N	109 (3)	C6—C5—H5	120.2
H1N—N1—H3N	103 (4)	C1—C6—C5	119.5 (2)
H2N—N1—H3N	119 (4)	C1—C6—H6	120.2
O1—C1—C6	122.4 (3)	C5—C6—H6	120.2
O1—C1—C2	117.2 (2)	H1AW—O1W—H1BW	124 (7)
C6—C1—C2	120.4 (3)	H2AW—O2W—H2BW	106 (4)
C3—C2—C1	120.0 (3)
O1—C1—C2—C3	−178.6 (2)	C3—C4—C5—C6	1.3 (4)
C6—C1—C2—C3	0.7 (4)	N1—C4—C5—C6	−178.4 (3)
C1—C2—C3—C4	−0.2 (4)	O1—C1—C6—C5	179.1 (2)
C2—C3—C4—C5	−0.8 (4)	C2—C1—C6—C5	−0.2 (4)
C2—C3—C4—N1	178.9 (3)	C4—C5—C6—C1	−0.8 (4)

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the C1–C6 benzene ring.

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O···O2W^i	0.75 (3)	2.10 (3)	2.801 (3)	156 (4)
N1—H1N···O4	0.79 (5)	2.34 (5)	3.016 (4)	144 (4)
N1—H2N···O1W^ii	0.98 (4)	1.98 (5)	2.951 (4)	168 (4)
N1—H3N···O1W	1.00 (5)	1.97 (5)	2.972 (4)	175 (4)
O1W—H1AW···O3^iii	0.79 (5)	2.40 (7)	3.089 (3)	146 (8)
O1W—H1BW···O5	0.83 (4)	2.47 (6)	3.083 (4)	132 (5)
O2W—H2AW···O4	0.93 (4)	2.28 (4)	3.068 (4)	143 (4)
O2W—H2BW···O1^iv	0.77 (3)	2.17 (3)	2.937 (3)	173 (5)
C2—H2···Cg1^iv	0.93	2.88	3.677 (3)	144

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