3-(4-Chloro­phen­yl)-2-methyl­acrylic acid

In the crystal structure of the title compound, C₁₀H₉ClO₂, dimers form as a result of inter­molecular O—H...O bonding. These dimers are linked to each other via C—H...O bonds, where the CH group belongs to the benzene ring and the O atom is from the carbonyl group of an adjacent mol­ecule. There exist two inter­molecular C—H...O hydrogen bonds, which individually form five-membered rings. There also exists a π–π inter­action between the aromatic ring and its symmetry counterpart, with a centroid–centroid distance of 4.0202 (17) Å, and a C—H...π inter­action between a methyl CH group and the aromatic ring.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.060
• wR factor = 0.218
• Data-to-parameter ratio = 22.1

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.96

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   0 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
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

---

S1. Comment

Cinnamic acids compose a relatively large family of organic acid isomers (Bravo, 1998). In nature, cinnamic acid derivatives are important metabolic building blocks in the production of lignins for higher plants. Cinnamic acid possesses antibacterial, antifungal and parasite fighting abilities (Burt, 2004). A derivative of cinnamic acid is an important pharmaceutical for high blood pressure, stroke prevention and possess antitumour activity (Hertog et al., 1995). In continuation of our efforts to synthesize various derivatives of cinnamic acids (Niaz et al., 2008, Muhammad, Ali et al., 2008) and their tin complexes (Muhammad et al., 2008a, 2008b), we herein report the structure of the title compound (I).

The crystal structure of 3-(4-Bromophenyl)-2-methylacrylic acid (II) (Muhammad et al., 2007a) and 3-(4-Bromophenyl)-2-ethylacrylic acid (Muhammad et al., 2007b) has been previously reported. The title compound (I) have a replacement of Br-atom with Cl-atom. Thus the reported compound (II) is the best example for the comparison of bond geometry etc.

In the crystal structure of the title compound, the C—C bonds are in the range [1.467 (3)–1.503 (4) Å], and C==C have a value of 1.341 (3) Å. The resonant C—O bonds have values of 1.231 (3) and 1.310 (3) Å. In the asymmetric unit, there are two intermolecular H-bonds of C—H···O type (Table 2, Fig 1). Due to these H-bonds two five membered rings (O1/C1/C2/C4/H4···O1) and (O2/C1/C2/C3/H3A···O2) are formed. Centrosymmetric dimers, R₂²(8) (Bernstein et al. 1995) are formed due to the intermolecular O1—H1···O2ⁱ [symmetry code: i = -x - 1, -y + 1, -z] hydrogen bonding. These dimers are linked to each other by intermolecular H-bonding, C9—H9···O2ⁱⁱ [symmetry code: ii = x + 1, y, z + 1] as shown in Fig 2. There exist an interaction, C3—H3A···Cgⁱⁱⁱ [symmetry code: iii = -x, -y, -z] with a distance of 3.638 (3) Å between C3 and Cgⁱⁱⁱ [Cg is the center of the (C5-C10) benzene ring]. There also exist a π···π-interaction between the benzene rings of adjacent molecules. The distance between the centroids of Cg and Cg^iv [symmetry code: iv = -x + 1, -y + 1, -z + 1], is 4.0202 (17) Å.

Related literature

For related literature, see: Bernstein et al. (1995); Bravo (1998); Burt (2004); Hertog et al. (1995); Muhammad et al. (2007a,b, 2008a,b); Muhammad, Ali et al., 2008); Niaz et al. (2008).

S2. Experimental

Compound (I) was prepared according to the reported procedure (Muhammad et al., 2007a). A mixture of 4-chlorobenzaldehyde (1.40 g, 10 mmol), methylmalonic acid (2.36 g, 20 mmol) and piperidine (1.98 ml, 20 mmol) in a pyridine (12.5 ml) solution was heated on a steam-bath for 24 h. The reaction mixture was cooled and added to a mixture of 25 ml of concentrated HCl and 50 g of ice. The precipitate formed in the acidified mixture was filtered off and washed with ice-cold water. The product was recrystallized from ethanol. The yield was 89%.

S3. Refinement

The coordinates of H atom attached to O1 were refined freely. All other H atoms were positioned geometrically, C—H = 0.93, and 0.96 Å for aromatic and methyl H, and constrained to ride on their parent atoms and were treated as isotropic with U_iso(H) = xU_eq(C,O), where x = 1.5 for methyl H, and x = 1.2 for all other H atoms.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2 (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2003).

Figures

	Fig. 1. ORTEP drawing of (I) with the atom numbering scheme. The thermal ellipsoids are drawn at the 50% probability level. The intramolecular H-bonds are shown by doted lines.
	Fig. 2. The packing figure (PLATON: Spek, 2003) which shows the dimeric nature of the compound and the interlinkages of the dimers.

3-(4-Chlorophenyl)-2-methylacrylic acid

Crystal data

C10H9ClO2	Z = 2
Mr = 196.62	F(000) = 204
Triclinic, P1	Dx = 1.402 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.2164 (6) Å	Cell parameters from 2692 reflections
b = 8.2746 (7) Å	θ = 2.6–30.3°
c = 9.1762 (8) Å	µ = 0.37 mm^−1
α = 115.182 (4)°	T = 296 K
β = 108.022 (4)°	Prism, colourless
γ = 90.052 (5)°	0.28 × 0.20 × 0.18 mm
V = 465.91 (7) Å^3

Data collection

Bruker Kappa APEXII CCD diffractometer	2692 independent reflections
Radiation source: fine-focus sealed tube	1782 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
Detector resolution: 7.2 pixels mm^-1	θmax = 30.3°, θmin = 2.6°
ω scans	h = −10→8
Absorption correction: multi-scan (SADABS; Bruker, 2005)	k = −10→11
Tmin = 0.910, Tmax = 0.930	l = −12→12
7513 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.059	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.217	H atoms treated by a mixture of independent and constrained refinement
S = 1.10	w = 1/[σ^2(Fo^2) + (0.1083P)^2 + 0.1931P] where P = (Fo^2 + 2Fc^2)/3
2692 reflections	(Δ/σ)max < 0.001
122 parameters	Δρmax = 0.53 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
Cl1	0.80795 (12)	0.09608 (15)	0.42599 (12)	0.0771 (4)
O1	−0.2602 (3)	0.5461 (3)	0.1669 (2)	0.0510 (6)
O2	−0.3959 (3)	0.3388 (3)	−0.1034 (2)	0.0543 (6)
C1	−0.2554 (3)	0.4027 (3)	0.0322 (3)	0.0390 (7)
C2	−0.0735 (3)	0.3196 (3)	0.0525 (3)	0.0371 (7)
C3	−0.0680 (4)	0.1670 (4)	−0.1102 (3)	0.0484 (8)
C4	0.0606 (3)	0.3764 (3)	0.2098 (3)	0.0403 (7)
C5	0.2464 (3)	0.3096 (3)	0.2602 (3)	0.0364 (6)
C6	0.3638 (4)	0.2508 (4)	0.1573 (3)	0.0432 (8)
C7	0.5363 (4)	0.1864 (4)	0.2086 (3)	0.0461 (8)
C8	0.5923 (4)	0.1793 (4)	0.3641 (3)	0.0438 (7)
C9	0.4803 (4)	0.2379 (4)	0.4686 (3)	0.0493 (8)
C10	0.3099 (4)	0.3051 (4)	0.4171 (3)	0.0451 (7)
H1	−0.377 (5)	0.580 (5)	0.142 (5)	0.0612*
H3A	−0.19861	0.10124	−0.17914	0.0725*
H3B	0.01747	0.08750	−0.08293	0.0725*
H3C	−0.01950	0.21487	−0.17241	0.0725*
H4	0.03229	0.46997	0.29797	0.0484*
H6	0.32524	0.25512	0.05263	0.0518*
H7	0.61382	0.14812	0.13947	0.0554*
H9	0.51873	0.23233	0.57269	0.0592*
H10	0.23624	0.34816	0.48924	0.0541*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0555 (5)	0.1129 (8)	0.0698 (6)	0.0449 (5)	0.0181 (4)	0.0492 (5)
O1	0.0415 (10)	0.0576 (12)	0.0430 (10)	0.0207 (8)	0.0116 (8)	0.0147 (9)
O2	0.0436 (10)	0.0686 (13)	0.0391 (10)	0.0217 (9)	0.0075 (8)	0.0183 (9)
C1	0.0377 (11)	0.0459 (13)	0.0373 (12)	0.0117 (10)	0.0140 (9)	0.0213 (10)
C2	0.0357 (11)	0.0379 (12)	0.0411 (12)	0.0091 (9)	0.0141 (9)	0.0202 (10)
C3	0.0444 (13)	0.0477 (14)	0.0430 (13)	0.0116 (11)	0.0115 (11)	0.0138 (11)
C4	0.0365 (11)	0.0418 (12)	0.0395 (12)	0.0109 (9)	0.0122 (9)	0.0160 (10)
C5	0.0335 (10)	0.0351 (11)	0.0363 (11)	0.0060 (9)	0.0105 (9)	0.0131 (9)
C6	0.0397 (12)	0.0562 (15)	0.0408 (12)	0.0112 (10)	0.0143 (10)	0.0276 (12)
C7	0.0359 (11)	0.0604 (16)	0.0443 (13)	0.0130 (11)	0.0152 (10)	0.0245 (12)
C8	0.0349 (11)	0.0487 (14)	0.0413 (12)	0.0103 (10)	0.0060 (10)	0.0192 (11)
C9	0.0461 (13)	0.0627 (17)	0.0323 (12)	0.0133 (12)	0.0063 (10)	0.0200 (12)
C10	0.0412 (12)	0.0563 (15)	0.0310 (11)	0.0105 (11)	0.0116 (10)	0.0141 (11)

Geometric parameters (Å, º)

Cl1—C8	1.734 (3)	C7—C8	1.385 (4)
O1—C1	1.310 (3)	C8—C9	1.376 (4)
O2—C1	1.231 (3)	C9—C10	1.382 (4)
O1—H1	0.88 (4)	C3—H3A	0.9600
C1—C2	1.480 (3)	C3—H3B	0.9600
C2—C3	1.503 (4)	C3—H3C	0.9600
C2—C4	1.341 (3)	C4—H4	0.9300
C4—C5	1.467 (3)	C6—H6	0.9300
C5—C10	1.386 (4)	C7—H7	0.9300
C5—C6	1.397 (4)	C9—H9	0.9300
C6—C7	1.381 (4)	C10—H10	0.9300
C1—O1—H1	109 (3)	C5—C10—C9	121.4 (2)
O1—C1—O2	121.8 (2)	C2—C3—H3A	109.00
O1—C1—C2	116.5 (2)	C2—C3—H3B	109.00
O2—C1—C2	121.7 (2)	C2—C3—H3C	109.00
C1—C2—C4	118.9 (2)	H3A—C3—H3B	109.00
C3—C2—C4	126.8 (2)	H3A—C3—H3C	109.00
C1—C2—C3	114.2 (2)	H3B—C3—H3C	110.00
C2—C4—C5	128.1 (2)	C2—C4—H4	116.00
C4—C5—C10	118.9 (2)	C5—C4—H4	116.00
C6—C5—C10	118.1 (2)	C5—C6—H6	119.00
C4—C5—C6	122.9 (2)	C7—C6—H6	119.00
C5—C6—C7	121.0 (2)	C6—C7—H7	120.00
C6—C7—C8	119.2 (3)	C8—C7—H7	120.00
Cl1—C8—C7	118.7 (2)	C8—C9—H9	120.00
Cl1—C8—C9	120.3 (2)	C10—C9—H9	120.00
C7—C8—C9	120.9 (3)	C5—C10—H10	119.00
C8—C9—C10	119.2 (3)	C9—C10—H10	119.00
O1—C1—C2—C3	−174.4 (2)	C10—C5—C6—C7	1.3 (5)
O1—C1—C2—C4	9.9 (4)	C4—C5—C10—C9	177.8 (3)
O2—C1—C2—C3	6.7 (4)	C6—C5—C10—C9	−2.5 (5)
O2—C1—C2—C4	−169.1 (3)	C5—C6—C7—C8	0.4 (5)
C1—C2—C4—C5	177.8 (3)	C6—C7—C8—Cl1	179.4 (3)
C3—C2—C4—C5	2.6 (5)	C6—C7—C8—C9	−1.0 (5)
C2—C4—C5—C6	35.4 (4)	Cl1—C8—C9—C10	179.5 (3)
C2—C4—C5—C10	−145.0 (3)	C7—C8—C9—C10	−0.2 (5)
C4—C5—C6—C7	−179.0 (3)	C8—C9—C10—C5	2.0 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2^i	0.88 (4)	1.76 (4)	2.643 (3)	176.4 (14)
C3—H3A···O2	0.96	2.41	2.765 (4)	101
C4—H4···O1	0.93	2.32	2.720 (3)	106
C9—H9···O2^ii	0.93	2.57	3.458 (3)	159
C3—H3a···Cg^iii	0.96	2.84	3.638 (3)	141

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