A new polymorph of 2-(2H-benzotriazol-2-yl)acetic acid

Abstract

A new polymorph of 2-(benzotriazol-2-yl)acetic acid, C₈H₇N₃O₂, crystallizes in the space group C2/c (Z = 8). The non-planar mol­ecule has a synplanar conformation of the carb­oxy group. The crystal structure features helices parallel to the b axis sustained by O—H⋯N hydrogen bonding which are similar to those in the known polymorph [Giordano & Zagari (1978 ▶). J. Chem. Soc. Perkin Trans. 2, pp. 312–315]. However, in the title structure, columns are formed by π–π stacking inter­actions between benzotriazole fragments of centrosymmetrically related adjacent mol­ecules [centroid-centroid distances = 3.593 (10) and 3.381 (10) Å] whereas π–π stacking inter­actions are not observed in the other polymorph. In the crystal of the title compound, C—H⋯O inter­actions are also observed.

Related literature  

For general background to the biological activity of benzotriazole derivatives, see: Hirokawa et al. (1998 ▶); Yu et al. (2003 ▶); Kopanska et al. (2004 ▶). For the previously reported polymorph, see: Giordano & Zagari (1978 ▶).

Experimental  

Crystal data  

• C₈H₇N₃O₂

• M _r = 177.17

• Monoclinic,

• a = 11.719 (9) Å

• b = 8.308 (3) Å

• c = 17.246 (5) Å

• β = 96.703 (5)°

• V = 1667.6 (15) ų

• Z = 8

• Cu Kα radiation

• μ = 0.89 mm⁻¹

• T = 293 K

• 0.40 × 0.32 × 0.28 mm

Data collection  

• Oxford Diffraction Xcalibur, Ruby diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.181, T _max = 1.000

• 4907 measured reflections

• 1488 independent reflections

• 1235 reflections with I > 2σ(I)

• R _int = 0.022

Refinement  

• R[F ² > 2σ(F ²)] = 0.036

• wR(F ²) = 0.100

• S = 1.04

• 1488 reflections

• 120 parameters

• H-atom parameters constrained

• Δρ_max = 0.15 e Å⁻³

• Δρ_min = −0.12 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536812036768/ds2205Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1A⋯N3i	0.82	1.91	2.7273 (17)	171
C2—H2⋯O2ii	0.93	2.54	3.365 (3)	148
C7—H7A⋯O1iii	0.97	2.49	3.387 (3)	154
C7—H7B⋯O2iv	0.97	2.39	3.268 (3)	150

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .

supplementary crystallographic information

Comment

Benzotriazol derivatives exhibit a good degree of analgesic, diuretic, anti-inflammatory, antiviral and antihypertensive activities (Kopanska et al., 2004; Yu et al., 2003; Hirokawa et al., 1998).

In the known polymorphic form (polymorph I) of the title compound reported by Giordano et al.(1978) [J. Chem. Soc., Perkin Trans. 2, 312–315] the molecules are linked in helices parallel to b axis by a strong O—H···N hydrogen bond [D···A =2.6995 Å; angle D—H···A =168.08°]. We have now obtained a new polymorph of benzotriazol-2-yl-acetic acid (II), which crystallizes in the space group C2/c and its crystal structure is reported here. The asymmetric unit comprises a non-planar independent molecule with a synplanar conformation of the carboxyl group (Fig. 1). Carboxyl group is twisted away from the plane of the 1,2,3-benzotriazol fragment (C1/C2/C3/C4/C5/C6/N1/N2/N3) by 88.41 (15)°. There are helices parallel to b axis forming by intermolecular O—H···N hydrogen bonds [D···A =2.7273 (17) Å; D—H···A =171°] as in polymorph I (Table 1). Columns form by π-π stacking interactions between benzotriazol fragments of centrosymmetrically related adjacent molecules [centroid-centroid (1.5 - x, 0.5 - y,-z) distance = 3.593 (10) Å, C6···C6 (1.5 - x, 0.5 - y, -z) distance is 3.381 (10) Å] and [C6···C2 (1 - x, 1 - y, -z) distance is 3.361 (10) Å]. In the known polymorph I stacking interactions are not observed. The crystal structure of the title compound is further stabilized via C—H···O interactions [C2···O2 = 3.365 (3) Å; angle C2—H2···O2 = 148°, C7···O1 = 3.387 (3) Å; angle C7—H7A···O1 = 154°, C7···O2 = 3.268 (3) Å; angle C7—H7B···O2 = 150°] (Fig. 2).

Experimental

Solid benzotriazol-2-yl-acetic acid was dissolved in dimethylformamide, filtered and left for crystallization by slow evaporation of the solvent at 30°C temperature. Colourless block crystals were obtained after two weeks.

Refinement

H atoms were positioned geometrically, with O—H = 0.82 Å (for OH) and C—H = 0.93 and 0.97 Å for aromatic and methylene H, with U_iso(H) = 1.2Ueq(C) and U_iso(H) = 1.5Ueq(O).

Figures

Fig. 1.

The molecular structure of (II), showing the atom-labelling scheme. Displacements ellipsoids are at the 50% probability level.

Fig. 2.

A packing diagram of (II). Hydrogen bonds are shown as dashed lines.

Crystal data

C8H7N3O2	F(000) = 736
Mr = 177.17	Dx = 1.411 Mg m−3
Monoclinic, C2/c	Cu Kα radiation, λ = 1.54184 Å
Hall symbol: -C 2yc	Cell parameters from 408 reflections
a = 11.719 (9) Å	θ = 5.2–43.7°
b = 8.308 (3) Å	µ = 0.89 mm−1
c = 17.246 (5) Å	T = 293 K
β = 96.703 (5)°	Block, colourless
V = 1667.6 (15) Å3	0.40 × 0.32 × 0.28 mm
Z = 8

Data collection

Oxford Diffraction Xcalibur, Ruby diffractometer	1488 independent reflections
Radiation source: fine-focus sealed tube	1235 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
Detector resolution: 10.2576 pixels mm-1	θmax = 67.1°, θmin = 5.2°
ω scans	h = −12→13
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	k = −9→9
Tmin = 0.181, Tmax = 1.000	l = −20→19
4907 measured reflections

Refinement

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)] = 0.036	H-atom parameters constrained
wR(F2) = 0.100	w = 1/[σ2(Fo2) + (0.0576P)2 + 0.4124P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
1488 reflections	Δρmax = 0.15 e Å−3
120 parameters	Δρmin = −0.12 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0012 (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
C1	0.55191 (14)	0.2934 (2)	−0.01273 (10)	0.0573 (4)
H1	0.5107	0.2146	0.0103	0.069*
C2	0.52406 (16)	0.3401 (2)	−0.08830 (10)	0.0713 (6)
H2	0.4617	0.2915	−0.1175	0.086*
C3	0.58612 (18)	0.4597 (3)	−0.12416 (10)	0.0763 (6)
H3	0.5632	0.4868	−0.1760	0.092*
C4	0.67792 (18)	0.5361 (2)	−0.08543 (9)	0.0682 (5)
H4	0.7186	0.6142	−0.1094	0.082*
C5	0.70856 (14)	0.49131 (18)	−0.00695 (8)	0.0511 (4)
C6	0.64717 (12)	0.37216 (17)	0.02830 (8)	0.0454 (4)
C7	0.85382 (12)	0.48491 (19)	0.18123 (8)	0.0517 (4)
H7A	0.9296	0.5179	0.1701	0.062*
H7B	0.8618	0.3840	0.2096	0.062*
C8	0.80584 (12)	0.61084 (19)	0.23154 (8)	0.0480 (4)
N1	0.79426 (11)	0.54651 (15)	0.04583 (7)	0.0542 (4)
N2	0.78104 (10)	0.46083 (14)	0.10872 (7)	0.0468 (3)
N3	0.69527 (10)	0.35514 (14)	0.10293 (6)	0.0457 (3)
O1	0.87531 (9)	0.63393 (16)	0.29596 (6)	0.0666 (4)
H1A	0.8481	0.7025	0.3227	0.100*
O2	0.71669 (10)	0.67914 (16)	0.21507 (6)	0.0672 (4)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0544 (9)	0.0607 (10)	0.0547 (9)	0.0124 (7)	−0.0024 (7)	−0.0122 (7)
C2	0.0694 (11)	0.0844 (13)	0.0551 (10)	0.0264 (10)	−0.0136 (8)	−0.0231 (9)
C3	0.1008 (15)	0.0870 (13)	0.0384 (9)	0.0391 (12)	−0.0026 (9)	−0.0039 (9)
C4	0.0975 (13)	0.0652 (10)	0.0433 (9)	0.0255 (10)	0.0145 (9)	0.0059 (8)
C5	0.0650 (9)	0.0475 (8)	0.0414 (8)	0.0153 (7)	0.0087 (6)	−0.0012 (6)
C6	0.0507 (8)	0.0468 (8)	0.0383 (7)	0.0133 (6)	0.0031 (6)	−0.0038 (6)
C7	0.0471 (8)	0.0582 (9)	0.0482 (9)	0.0004 (7)	−0.0008 (6)	−0.0039 (7)
C8	0.0475 (8)	0.0574 (9)	0.0386 (7)	−0.0016 (7)	0.0026 (6)	0.0013 (6)
N1	0.0677 (8)	0.0487 (7)	0.0479 (7)	0.0021 (6)	0.0132 (6)	0.0007 (5)
N2	0.0512 (7)	0.0488 (7)	0.0403 (6)	0.0007 (5)	0.0046 (5)	−0.0023 (5)
N3	0.0477 (7)	0.0483 (7)	0.0403 (6)	0.0032 (5)	0.0027 (5)	−0.0008 (5)
O1	0.0524 (6)	0.0924 (9)	0.0518 (7)	0.0143 (6)	−0.0069 (5)	−0.0215 (6)
O2	0.0643 (7)	0.0858 (9)	0.0482 (6)	0.0216 (6)	−0.0072 (5)	−0.0114 (6)

Geometric parameters (Å, º)

C1—C2	1.362 (3)	C6—N3	1.3510 (17)
C1—C6	1.411 (2)	C7—N2	1.4431 (18)
C1—H1	0.9300	C7—C8	1.509 (2)
C2—C3	1.415 (3)	C7—H7A	0.9700
C2—H2	0.9300	C7—H7B	0.9700
C3—C4	1.356 (3)	C8—O2	1.1937 (19)
C3—H3	0.9300	C8—O1	1.3126 (17)
C4—C5	1.409 (2)	N1—N2	1.3214 (17)
C4—H4	0.9300	N2—N3	1.3296 (17)
C5—N1	1.354 (2)	O1—H1A	0.8200
C5—C6	1.403 (2)
C2—C1—C6	115.77 (18)	C5—C6—C1	121.70 (14)
C2—C1—H1	122.1	N2—C7—C8	111.85 (12)
C6—C1—H1	122.1	N2—C7—H7A	109.2
C1—C2—C3	122.69 (18)	C8—C7—H7A	109.2
C1—C2—H2	118.7	N2—C7—H7B	109.2
C3—C2—H2	118.7	C8—C7—H7B	109.2
C4—C3—C2	122.14 (17)	H7A—C7—H7B	107.9
C4—C3—H3	118.9	O2—C8—O1	124.82 (14)
C2—C3—H3	118.9	O2—C8—C7	124.56 (13)
C3—C4—C5	116.61 (18)	O1—C8—C7	110.62 (13)
C3—C4—H4	121.7	N2—N1—C5	102.73 (13)
C5—C4—H4	121.7	N1—N2—N3	117.02 (11)
N1—C5—C6	108.97 (13)	N1—N2—C7	121.50 (13)
N1—C5—C4	129.93 (17)	N3—N2—C7	121.45 (12)
C6—C5—C4	121.10 (16)	N2—N3—C6	103.30 (11)
N3—C6—C5	107.98 (13)	C8—O1—H1A	109.5
N3—C6—C1	130.32 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···N3i	0.82	1.91	2.7273 (17)	171
C2—H2···O2ii	0.93	2.54	3.365 (3)	148
C7—H7A···O1iii	0.97	2.49	3.387 (3)	154
C7—H7B···O2iv	0.97	2.39	3.268 (3)	150

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