(S)-2-(1-Hydroxy­ethyl)benzimid­azolium dihydrogen phosphate

Xia, R.

doi:10.1107/S1600536809028451

organic compounds

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Volume 65| Part 8| August 2009| Page o2032

doi:10.1107/S1600536809028451

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(S)-2-(1-Hydroxyethyl)benzimidazolium dihydrogen phosphate

Rong Xia ^a ^*

^aOrdered Matter Science Research Center, College of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, People's Republic of China
^*Correspondence e-mail: xiarong_103@yahoo.cn

(Received 22 June 2009; accepted 18 July 2009; online 29 July 2009)

The asymmetric unit of the title compound, C₉H₁₁N₂O⁺·H₂PO₄⁻, is built up from a 2-(1-hydroxyethyl)benzimidazolium cation and a dihydrogen phosphate anion which are connected by an N—H⋯O hydrogen bond. The cation is roughly planar, the dihedral angle between the rings being only 1.4 (2)°. The S configuration is deduced from the synthetic pathway and supported by the refinement of the Flack parameter. Intermolecular O—H⋯O and N—H⋯O hydrogen bonds build up a three-dimensionnal network.

Related literature

For the biological and pharmaceutical activity of imidazole and benzimidazole derivatives, see: Rodembusch et al. (2004 ); Gong et al. (2005 ); Chen (2005 ); Belmar et al. (1999 ). For the synthesis and crystal structure of (±)-1-(1H-benzimidazol-2-yl)ethanol, see: Xia & Xu (2008 ).

Experimental

Crystal data

C₉H₁₁N₂O⁺·H₂PO₄⁻
M_r = 260.18
Orthorhombic, P 2₁ 2₁ 2₁
a = 4.5869 (13) Å
b = 15.749 (5) Å
c = 15.876 (5) Å
V = 1146.8 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 293 K
0.20 × 0.20 × 0.20 mm

Data collection

Rigaku SCXmini diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ) T_min = 0.951, T_max = 0.953
11500 measured reflections
2565 independent reflections
1749 reflections with I > 2σ(I)
R_int = 0.125

Refinement

R[F² > 2σ(F²)] = 0.052
wR(F²) = 0.118
S = 0.82
2565 reflections
159 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.37 e Å⁻³
Absolute structure: Flack (1983 ), 1030 Friedel pairs
Flack parameter: 0.16 (17)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O4ⁱ	0.82	1.76	2.532 (4)	156
O2—H2⋯O5ⁱⁱ	0.82	1.76	2.539 (3)	157
N2—H2A⋯O4	0.86	1.88	2.729 (4)	167
N1—H1⋯O5ⁱⁱⁱ	0.86	1.81	2.659 (4)	167
O1—H1A⋯O2^iv	0.82	2.23	2.971 (4)	150
Symmetry codes: (i) x-1, y, z; (ii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]$ ; (iii) $[-x+{\script{3\over 2}}, -y+1, z-{\script{1\over 2}}]$ ; (iv) $[-x+2, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809028451/dn2468sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809028451/dn2468Isup2.hkl

checkCIF report

Comment top

The benzimidazoles, benzothiazoles, and benzoxazoles can be utilized as not only a wide variety of biologically active and medicinally significant compounds but also as advanced materials including non-linear optics (NLO), organic light-emitting diodes (OLED), and liquid crystals (Rodembusch et al., 2004; Gong et al., 2005; Chen, 2005; Belmar et al., 1999).

The title compound is built up from a dihydrogen phosphate anion and a (1H-benzimidazol-2-yl)ethanolium cation which are connected by a N-H···O hydrogen bond (Fig. 1).The S absolute configuration is deduced from the synthetic pathway and supported by the refinement of the Flack parameter (Flack, 1983). The phenyl ring and imidazole ring are roughly planar, making a dihedral angle of only1.4°. All bond lengths and angels are normal.

The molecules are connected via O—H···O and N—H···O hydrogen bonds making a three dimensionnal network (Table 1, Fig. 2).

Related literature top

For the biological and pharmaceutical activity of imidazole and benzimidazole derivatives, see: Rodembusch et al. (2004); Gong et al. (2005); Chen (2005); Belmar et al. (1999). For the synthesis and crystal structure of (±)-1-(1H-benzimidazol-2-yl)ethanol, see: Xia & Xu (2008).

Experimental top

A solution of phosphoric acid (1 mmol) in water was added to a methanol solution of L-(-)-1-(1H-Benzimidazol-2-yl)ethanol (1 mmol), and then the mixture was stirred for half an hour at room temperature. The mixture was then filtered and the filtrate was evaporated at room temperature for a period of one month.Crystals suitable for X-ray diffraction analysis were obtained then. L-(-)-1-(1H-Benzimidazol-2-yl)ethanol was synthesized by the reaction of Benzene-1, 2-diamine and Ethyl L-(-)-lactate(R. Xia, et al., 2008).

Computing details top

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 top

	Fig. 1. Molecular structure of the title compound with the atom labeling scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are represented as small spheres of arbitrary radii. H bond is shown as dashed line.
	Fig. 2. Packing diagram of the title compound viewed along the a axis. Intermolecular O—H···O hydrogen bonds and N—H···O hydrogen bonds are shown as dashed lines. H atoms not involved in hydrogen bondings have been omitted for clarity.

(S)-2-(1-Hydroxyethyl)benzimidazolium dihydrogen phosphate top

Crystal data top

C₉H₁₁N₂O⁺·H₂PO₄⁻	F(000) = 544
M_r = 260.18	D_x = 1.507 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 3144 reflections
a = 4.5869 (13) Å	θ = 2.6–27.4°
b = 15.749 (5) Å	µ = 0.25 mm⁻¹
c = 15.876 (5) Å	T = 293 K
V = 1146.8 (6) Å³	Block, pale yellow
Z = 4	0.20 × 0.20 × 0.20 mm

Data collection top

Rigaku SCXmini diffractometer	2565 independent reflections
Radiation source: fine-focus sealed tube	1749 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.125
Detector resolution: 13.6612 pixels mm^-1	θ_max = 27.3°, θ_min = 2.6°
ω scans	h = −5→5
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −20→20
T_min = 0.951, T_max = 0.953	l = −20→20
11500 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.052	H-atom parameters constrained
wR(F²) = 0.118	w = 1/[σ²(F_o²) + (0.0314P)²] where P = (F_o² + 2F_c²)/3
S = 0.82	(Δ/σ)_max < 0.001
2565 reflections	Δρ_max = 0.39 e Å⁻³
159 parameters	Δρ_min = −0.37 e Å⁻³
0 restraints	Absolute structure: Flack (1983), 1030 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.16 (17)

Crystal data top

C₉H₁₁N₂O⁺·H₂PO₄⁻	V = 1146.8 (6) Å³
M_r = 260.18	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 4.5869 (13) Å	µ = 0.25 mm⁻¹
b = 15.749 (5) Å	T = 293 K
c = 15.876 (5) Å	0.20 × 0.20 × 0.20 mm

Data collection top

Rigaku SCXmini diffractometer	2565 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	1749 reflections with I > 2σ(I)
T_min = 0.951, T_max = 0.953	R_int = 0.125
11500 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.052	H-atom parameters constrained
wR(F²) = 0.118	Δρ_max = 0.39 e Å⁻³
S = 0.82	Δρ_min = −0.37 e Å⁻³
2565 reflections	Absolute structure: Flack (1983), 1030 Friedel pairs
159 parameters	Absolute structure parameter: 0.16 (17)
0 restraints

Special details top

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 > 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

	x	y	z	U_iso*/U_eq
P1	0.8027 (2)	0.34270 (6)	0.42082 (6)	0.0274 (2)
O5	0.8944 (6)	0.34283 (14)	0.51179 (14)	0.0379 (7)
O4	1.0419 (5)	0.36640 (16)	0.35969 (15)	0.0389 (7)
O3	0.5477 (6)	0.40686 (15)	0.4094 (2)	0.0470 (8)
H3	0.3968	0.3809	0.3992	0.070*
O2	0.6959 (7)	0.25204 (15)	0.39269 (13)	0.0415 (7)
H2	0.5776	0.2339	0.4270	0.062*
N2	0.8351 (7)	0.44478 (17)	0.21853 (17)	0.0336 (7)
H2A	0.9180	0.4266	0.2636	0.040*
N1	0.7140 (7)	0.52823 (18)	0.11523 (16)	0.0369 (8)
H1	0.7060	0.5722	0.0832	0.044*
C8	1.0565 (9)	0.5932 (2)	0.2193 (2)	0.0385 (9)
H8	1.2233	0.6030	0.1820	0.046*
O1	0.8750 (6)	0.66679 (16)	0.21909 (17)	0.0514 (8)
H1A	0.9367	0.7010	0.1844	0.077*
C1	0.5597 (9)	0.4529 (2)	0.1022 (2)	0.0336 (9)
C5	0.5154 (9)	0.3179 (2)	0.1774 (2)	0.0421 (10)
H5	0.5643	0.2822	0.2219	0.051*
C2	0.3599 (10)	0.4283 (3)	0.0413 (2)	0.0449 (11)
H2B	0.3066	0.4640	−0.0027	0.054*
C6	0.6383 (9)	0.3991 (2)	0.1692 (2)	0.0322 (9)
C7	0.8737 (8)	0.5219 (2)	0.1839 (2)	0.0329 (9)
C4	0.3198 (10)	0.2939 (2)	0.1167 (2)	0.0478 (11)
H4	0.2345	0.2404	0.1200	0.057*
C9	1.1665 (13)	0.5756 (2)	0.3069 (3)	0.0635 (14)
H9A	1.2756	0.6237	0.3267	0.095*
H9B	1.2900	0.5264	0.3060	0.095*
H9C	1.0043	0.5656	0.3437	0.095*
C3	0.2448 (10)	0.3478 (3)	0.0497 (2)	0.0523 (12)
H3A	0.1127	0.3285	0.0096	0.063*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
P1	0.0291 (5)	0.0195 (4)	0.0336 (4)	−0.0002 (4)	−0.0001 (4)	0.0016 (4)
O5	0.0578 (18)	0.0220 (12)	0.0341 (13)	0.0091 (14)	0.0013 (13)	−0.0032 (10)
O4	0.0261 (14)	0.0505 (17)	0.0400 (15)	−0.0040 (13)	−0.0005 (12)	0.0139 (12)
O3	0.0274 (15)	0.0281 (14)	0.085 (2)	0.0010 (13)	−0.0108 (17)	−0.0035 (14)
O2	0.065 (2)	0.0229 (13)	0.0362 (14)	−0.0107 (15)	0.0061 (14)	−0.0083 (10)
N2	0.043 (2)	0.0280 (16)	0.0300 (15)	0.0026 (15)	−0.0003 (16)	0.0105 (12)
N1	0.053 (2)	0.0261 (16)	0.0315 (15)	0.0063 (17)	0.0011 (16)	0.0088 (12)
C8	0.038 (2)	0.0279 (19)	0.050 (2)	−0.0014 (19)	0.004 (2)	0.0047 (17)
O1	0.067 (2)	0.0256 (15)	0.0619 (19)	0.0066 (16)	0.0083 (17)	0.0083 (12)
C1	0.040 (2)	0.030 (2)	0.030 (2)	0.0079 (19)	0.0019 (18)	0.0006 (14)
C5	0.054 (3)	0.027 (2)	0.045 (2)	0.003 (2)	0.003 (2)	0.0048 (16)
C2	0.057 (3)	0.048 (2)	0.030 (2)	0.012 (2)	−0.003 (2)	0.0021 (17)
C6	0.036 (2)	0.0259 (18)	0.035 (2)	0.0062 (17)	0.0018 (17)	0.0025 (14)
C7	0.039 (2)	0.0258 (18)	0.0341 (19)	0.0044 (17)	0.0068 (17)	0.0041 (14)
C4	0.059 (3)	0.032 (2)	0.053 (3)	−0.008 (2)	0.001 (2)	−0.0043 (17)
C9	0.082 (4)	0.037 (2)	0.071 (3)	−0.010 (3)	−0.033 (3)	0.007 (2)
C3	0.057 (3)	0.050 (3)	0.050 (2)	−0.004 (3)	−0.012 (2)	−0.012 (2)

Geometric parameters (Å, º) top

P1—O5	1.504 (2)	C8—H8	0.9800
P1—O4	1.512 (3)	O1—H1A	0.8200
P1—O3	1.556 (3)	C1—C2	1.388 (5)
P1—O2	1.574 (2)	C1—C6	1.406 (4)
O3—H3	0.8200	C5—C4	1.370 (5)
O2—H2	0.8200	C5—C6	1.404 (5)
N2—C7	1.345 (4)	C5—H5	0.9300
N2—C6	1.395 (4)	C2—C3	1.380 (5)
N2—H2A	0.8600	C2—H2B	0.9300
N1—C7	1.317 (4)	C4—C3	1.403 (5)
N1—C1	1.397 (4)	C4—H4	0.9300
N1—H1	0.8600	C9—H9A	0.9600
C8—O1	1.427 (4)	C9—H9B	0.9600
C8—C9	1.505 (5)	C9—H9C	0.9600
C8—C7	1.510 (5)	C3—H3A	0.9300

O5—P1—O4	114.40 (15)	C4—C5—C6	116.7 (4)
O5—P1—O3	108.76 (16)	C4—C5—H5	121.7
O4—P1—O3	108.07 (15)	C6—C5—H5	121.7
O5—P1—O2	111.14 (13)	C3—C2—C1	116.2 (3)
O4—P1—O2	105.53 (15)	C3—C2—H2B	121.9
O3—P1—O2	108.77 (16)	C1—C2—H2B	121.9
P1—O3—H3	109.5	N2—C6—C5	132.6 (3)
P1—O2—H2	109.5	N2—C6—C1	106.3 (3)
C7—N2—C6	108.7 (3)	C5—C6—C1	121.1 (4)
C7—N2—H2A	125.6	N1—C7—N2	109.5 (3)
C6—N2—H2A	125.6	N1—C7—C8	124.1 (3)
C7—N1—C1	109.9 (3)	N2—C7—C8	126.3 (3)
C7—N1—H1	125.1	C5—C4—C3	121.8 (4)
C1—N1—H1	125.1	C5—C4—H4	119.1
O1—C8—C9	110.3 (3)	C3—C4—H4	119.1
O1—C8—C7	106.2 (3)	C8—C9—H9A	109.5
C9—C8—C7	113.2 (3)	C8—C9—H9B	109.5
O1—C8—H8	109.0	H9A—C9—H9B	109.5
C9—C8—H8	109.0	C8—C9—H9C	109.5
C7—C8—H8	109.0	H9A—C9—H9C	109.5
C8—O1—H1A	109.5	H9B—C9—H9C	109.5
C2—C1—N1	132.5 (3)	C2—C3—C4	122.3 (4)
C2—C1—C6	121.8 (4)	C2—C3—H3A	118.8
N1—C1—C6	105.7 (3)	C4—C3—H3A	118.8

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O4ⁱ	0.82	1.76	2.532 (4)	156
O2—H2···O5ⁱⁱ	0.82	1.76	2.539 (3)	157
N2—H2A···O4	0.86	1.88	2.729 (4)	167
N1—H1···O5ⁱⁱⁱ	0.86	1.81	2.659 (4)	167
O1—H1A···O2^iv	0.82	2.23	2.971 (4)	150

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

Experimental details

Crystal data
Chemical formula	C₉H₁₁N₂O⁺·H₂PO₄⁻
M_r	260.18
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	293
a, b, c (Å)	4.5869 (13), 15.749 (5), 15.876 (5)
V (Å³)	1146.8 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.25
Crystal size (mm)	0.20 × 0.20 × 0.20

Data collection
Diffractometer	Rigaku SCXmini diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku, 2005)
T_min, T_max	0.951, 0.953
No. of measured, independent and observed [I > 2σ(I)] reflections	11500, 2565, 1749
R_int	0.125
(sin θ/λ)_max (Å⁻¹)	0.646

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.052, 0.118, 0.82
No. of reflections	2565
No. of parameters	159
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.37
Absolute structure	Flack (1983), 1030 Friedel pairs
Absolute structure parameter	0.16 (17)

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O4ⁱ	0.82	1.76	2.532 (4)	156.3
O2—H2···O5ⁱⁱ	0.82	1.76	2.539 (3)	156.9
N2—H2A···O4	0.86	1.88	2.729 (4)	167.2
N1—H1···O5ⁱⁱⁱ	0.86	1.81	2.659 (4)	167.1
O1—H1A···O2^iv	0.82	2.23	2.971 (4)	149.9

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

Acknowledgements

The author gratefully acknowledges financial support by the start-up fund of Southeast University.

References

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