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α-Oxo­benzene­acetic (phenyl­glyoxy­lic) acid, C8H6O3, adopts a transoid di­carbonyl conformation in the solid state, with the carboxyl group rotated 44.4 (1)° from the nearly planar benzoyl moiety. The heterochiral acid-to-ketone catemers [O...O = 2.686 (3) and H...O = 1.78 (4) Å] have a second, longer, intermolecular O—H...O contact to a carboxyl sp3 O atom [O...O = 3.274 (2) and H...O = 2.72 (4) Å], with each flat ribbon-like chain lying in the bc plane and extending in the c direction. In α-oxo-2,4,6-tri­methyl­benzene­acetic (mesityl­glyoxy­lic) acid, C11H12O3, the ketone is rotated 49.1 (7)° from planarity with the aryl ring and the carboxyl group is rotated a further 31.2 (7)° from the ketone plane. The solid consists of chiral conformers of a single handedness, aggregating in hydrogen-bonding chains whose units are related by a 31 screw axis, producing hydrogen-bonding helices that extend in the c direction. The hydrogen bonding is of the acid-to-acid type [O...O = 2.709 (6) and H...O = 1.87 (5) Å] and does not formally involve the ketone; however, the ketone O atom in the acceptor mol­ecule has a close polar contact with the same donor carboxyl group [O...O = 3.005 (6) and H...O = 2.50 (5) Å]. This secondary hydrogen bond is probably a major factor in stabilizing the observed cisoid di­carbonyl conformation. Several intermolecular C—H...O close contacts were found for the latter compound.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S010827010000812X/fg1604sup1.cif
Contains datablocks I, II, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S010827010000812X/fg1604Isup2.hkl
Contains datablock I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S010827010000812X/fg1604IIsup3.hkl
Contains datablock II

CCDC references: 150856; 150857

Computing details top

For both compounds, data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

(I) α-Oxobenzeneacetic acid top
Crystal data top
C8H6O3Dx = 1.381 Mg m3
Mr = 150.13Melting point: 342 K
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 7.462 (2) ÅCell parameters from 15 reflections
b = 16.513 (5) Åθ = 3.2–12.3°
c = 6.483 (3) ŵ = 0.11 mm1
β = 115.32 (2)°T = 293 K
V = 722.1 (4) Å3Parallelepiped, colorless
Z = 40.64 × 0.50 × 0.30 mm
F(000) = 312
Data collection top
Siemens P4
diffractometer
Rint = 0.022
Radiation source: normal-focus sealed tubeθmax = 25.0°, θmin = 2.5°
Graphite monochromatorh = 88
2θθ scansk = 119
1562 measured reflectionsl = 17
1271 independent reflections3 standard reflections every 97 reflections
740 reflections with I > 2σ(I) intensity decay: variation < 1.8%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.059Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.153H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.0743P)2]
where P = (Fo2 + 2Fc2)/3
1271 reflections(Δ/σ)max < 0.001
105 parametersΔρmax = 0.20 e Å3
0 restraintsΔρmin = 0.19 e Å3
Special details top

Experimental. Crystal mounted in glass capillary and coated with grease

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 (Å2) top
xyzUiso*/Ueq
O10.1528 (4)0.62379 (13)0.4709 (4)0.0711 (7)
O20.3784 (4)0.68636 (14)0.1497 (4)0.0777 (8)
O30.0991 (3)0.73600 (13)0.1469 (4)0.0667 (7)
H30.125 (6)0.780 (3)0.075 (7)0.123 (16)*
C10.2363 (4)0.52537 (16)0.2631 (5)0.0510 (8)
C20.2801 (5)0.50725 (19)0.0795 (6)0.0617 (9)
C30.3127 (5)0.4272 (2)0.0415 (7)0.0761 (11)
C40.3020 (5)0.3672 (2)0.1792 (8)0.0807 (12)
C50.2541 (5)0.3844 (2)0.3572 (7)0.0808 (12)
C60.2219 (5)0.46344 (18)0.3989 (6)0.0645 (9)
C70.2028 (4)0.60937 (17)0.3189 (5)0.0523 (8)
C80.2376 (5)0.68093 (17)0.1917 (5)0.0555 (8)
H20.28720.54810.01550.085 (5)*
H3A0.34240.41430.08010.085 (5)*
H40.32740.31400.15300.085 (5)*
H50.24360.34300.44850.085 (5)*
H60.19010.47540.51950.085 (5)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.1039 (18)0.0484 (13)0.0811 (16)0.0081 (11)0.0588 (15)0.0032 (12)
O20.0759 (16)0.0660 (15)0.108 (2)0.0024 (12)0.0554 (15)0.0166 (13)
O30.0732 (15)0.0471 (12)0.0856 (18)0.0051 (11)0.0396 (13)0.0091 (12)
C10.0442 (17)0.0442 (16)0.058 (2)0.0009 (13)0.0156 (15)0.0034 (15)
C20.058 (2)0.059 (2)0.069 (2)0.0046 (15)0.0283 (18)0.0027 (17)
C30.067 (2)0.069 (2)0.088 (3)0.0021 (19)0.029 (2)0.023 (2)
C40.064 (2)0.044 (2)0.119 (4)0.0031 (16)0.025 (2)0.010 (2)
C50.083 (3)0.0471 (19)0.103 (3)0.0015 (18)0.031 (2)0.014 (2)
C60.067 (2)0.0499 (18)0.074 (2)0.0034 (15)0.0280 (19)0.0026 (17)
C70.0517 (18)0.0452 (17)0.061 (2)0.0049 (13)0.0250 (16)0.0012 (16)
C80.0580 (19)0.0433 (16)0.065 (2)0.0037 (15)0.0262 (17)0.0020 (15)
Geometric parameters (Å, º) top
O1—C71.217 (3)C2—C31.386 (4)
O2—C81.196 (3)C3—C41.358 (5)
O3—C81.312 (4)C4—C51.376 (5)
C1—C61.383 (4)C5—C61.374 (5)
C1—C21.395 (4)C7—C81.525 (4)
C1—C71.481 (4)
C6—C1—C2119.7 (3)C5—C6—C1120.6 (3)
C6—C1—C7118.0 (3)O1—C7—C1121.5 (3)
C2—C1—C7122.3 (3)O1—C7—C8117.9 (3)
C3—C2—C1118.7 (3)C1—C7—C8120.6 (3)
C4—C3—C2121.0 (4)O2—C8—O3125.7 (3)
C3—C4—C5120.7 (3)O2—C8—C7123.4 (3)
C6—C5—C4119.4 (3)O3—C8—C7110.9 (3)
C6—C1—C2—C31.5 (5)C6—C1—C7—O14.2 (4)
C7—C1—C2—C3178.9 (3)C2—C1—C7—O1175.4 (3)
C1—C2—C3—C40.2 (5)C6—C1—C7—C8173.6 (3)
C2—C3—C4—C51.4 (5)C2—C1—C7—C86.8 (4)
C3—C4—C5—C61.7 (5)O1—C7—C8—O2134.3 (3)
C4—C5—C6—C10.3 (5)C1—C7—C8—O243.6 (4)
C2—C1—C6—C51.3 (5)O1—C7—C8—O342.5 (4)
C7—C1—C6—C5179.1 (3)C1—C7—C8—O3139.6 (3)
(II) α-oxo-2,4,6-trimethylbenzeneacetic acid top
Crystal data top
C11H12O3Dx = 1.257 Mg m3
Mr = 192.21Melting point: 392 K
Trigonal, P31Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 31Cell parameters from 17 reflections
a = 9.121 (1) Åθ = 5.6–12.0°
c = 10.576 (1) ŵ = 0.09 mm1
V = 761.97 (14) Å3T = 248 K
Z = 3Block, colorless
F(000) = 3060.30 × 0.28 × 0.26 mm
Data collection top
Siemens P4
diffractometer
574 reflections with I > 2σ(I)
Radiation source: normal-focus sealed tubeRint = 0.046
Graphite monochromatorθmax = 25.0°, θmin = 2.6°
2θθ scansh = 1010
Absorption correction: numerical
(SHELXTL; Sheldrick, 1997)
k = 010
Tmin = 0.967, Tmax = 0.977l = 012
2050 measured reflections3 standard reflections every 97 reflections
1772 independent reflections intensity decay: variation < 3.3%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.127H atoms treated by a mixture of independent and constrained refinement
S = 1.02 w = 1/[σ2(Fo2) + (0.0648P)2]
where P = (Fo2 + 2Fc2)/3
886 reflections(Δ/σ)max < 0.001
141 parametersΔρmax = 0.13 e Å3
1 restraintΔρmin = 0.18 e Å3
Special details top

Experimental. Crystal mounted on glass fiber using epoxy cement

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 with 886 Friedel pairs merged. 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
xyzUiso*/UeqOcc. (<1)
O10.6580 (6)0.8177 (6)0.2937 (4)0.0803 (14)
O20.3786 (5)0.7123 (5)0.1425 (4)0.0607 (10)
O30.5133 (5)0.6231 (5)0.0138 (3)0.0538 (10)
H30.434 (6)0.615 (5)0.039 (5)0.031 (13)*
C10.6922 (7)0.5872 (7)0.2251 (5)0.0493 (15)
C20.8699 (7)0.6594 (7)0.2300 (5)0.0529 (14)
C30.9367 (8)0.5533 (9)0.2347 (5)0.0647 (17)
C40.8351 (9)0.3801 (9)0.2392 (5)0.0595 (16)
C50.6630 (8)0.3119 (8)0.2361 (5)0.0591 (17)
C60.5883 (7)0.4115 (7)0.2286 (5)0.0502 (15)
C70.6204 (7)0.6998 (7)0.2226 (5)0.0527 (14)
C80.4881 (7)0.6756 (7)0.1218 (5)0.0504 (13)
C90.9885 (8)0.8482 (8)0.2232 (6)0.075 (2)
C100.9125 (11)0.2667 (11)0.2484 (7)0.089 (2)
C110.3965 (8)0.3292 (8)0.2295 (5)0.0669 (18)
H3A1.05490.60050.23470.065 (19)*
H50.59340.19360.23920.031 (13)*
H9A1.09950.87070.19610.091 (19)*0.77 (8)
H9B0.99720.89780.30590.091 (19)*0.77 (8)
H9C0.94510.89740.16300.091 (19)*0.77 (8)
H9D0.92830.90650.24720.091 (19)*0.23 (8)
H9E1.03070.87950.13750.091 (19)*0.23 (8)
H9F1.08280.87990.28040.091 (19)*0.23 (8)
H10A0.82290.14930.25230.092 (19)*0.75 (8)
H10B0.98150.29490.32400.092 (19)*0.75 (8)
H10C0.98240.28350.17460.092 (19)*0.75 (8)
H10D1.03490.33580.24830.092 (19)*0.25 (8)
H10E0.87640.19020.17660.092 (19)*0.25 (8)
H10F0.87550.20160.32600.092 (19)*0.25 (8)
H11A0.34740.21670.26580.063 (10)*
H11B0.35590.32110.14360.063 (10)*
H11C0.36380.39720.27970.063 (10)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.098 (3)0.087 (3)0.076 (3)0.061 (3)0.029 (2)0.038 (3)
O20.061 (2)0.084 (3)0.049 (2)0.045 (2)0.002 (2)0.007 (2)
O30.053 (2)0.072 (3)0.0382 (18)0.033 (2)0.0096 (18)0.0090 (18)
C10.052 (4)0.055 (4)0.036 (3)0.023 (3)0.002 (3)0.003 (2)
C20.052 (4)0.060 (4)0.044 (3)0.026 (3)0.009 (3)0.001 (3)
C30.055 (4)0.090 (5)0.053 (4)0.039 (4)0.002 (3)0.011 (3)
C40.076 (5)0.071 (5)0.044 (3)0.046 (4)0.004 (3)0.008 (3)
C50.077 (5)0.055 (4)0.034 (3)0.025 (4)0.001 (3)0.006 (3)
C60.048 (3)0.057 (4)0.032 (3)0.016 (3)0.001 (2)0.004 (3)
C70.064 (4)0.057 (4)0.040 (3)0.032 (3)0.001 (3)0.007 (3)
C80.047 (3)0.055 (3)0.045 (3)0.023 (3)0.001 (3)0.001 (3)
C90.059 (4)0.069 (5)0.085 (5)0.024 (4)0.014 (3)0.001 (3)
C100.119 (6)0.118 (6)0.067 (5)0.086 (6)0.019 (4)0.022 (4)
C110.062 (4)0.065 (4)0.049 (4)0.014 (3)0.005 (3)0.014 (3)
Geometric parameters (Å, º) top
O1—C71.213 (6)C2—C91.509 (9)
O2—C81.221 (6)C3—C41.375 (9)
O3—C81.303 (6)C4—C51.369 (9)
C1—C61.396 (7)C4—C101.519 (9)
C1—C21.412 (8)C5—C61.384 (9)
C1—C71.469 (8)C6—C111.520 (9)
C2—C31.380 (8)C7—C81.541 (8)
C6—C1—C2119.8 (5)C4—C5—C6122.1 (6)
C6—C1—C7121.2 (5)C5—C6—C1118.7 (5)
C2—C1—C7118.9 (5)C5—C6—C11119.9 (5)
C3—C2—C1118.7 (6)C1—C6—C11121.4 (6)
C3—C2—C9119.1 (6)O1—C7—C1125.5 (5)
C1—C2—C9122.1 (5)O1—C7—C8114.3 (5)
C4—C3—C2121.8 (6)C1—C7—C8120.2 (5)
C5—C4—C3118.8 (6)O2—C8—O3125.2 (5)
C5—C4—C10120.6 (7)O2—C8—C7121.7 (5)
C3—C4—C10120.5 (6)O3—C8—C7113.0 (5)
C6—C1—C2—C31.8 (6)C2—C1—C6—C50.4 (6)
C7—C1—C2—C3178.9 (5)C7—C1—C6—C5177.4 (5)
C6—C1—C2—C9178.4 (5)C2—C1—C6—C11177.2 (5)
C7—C1—C2—C94.6 (7)C7—C1—C6—C110.2 (7)
C1—C2—C3—C42.4 (7)C6—C1—C7—O1128.0 (6)
C9—C2—C3—C4179.1 (5)C2—C1—C7—O149.0 (8)
C2—C3—C4—C51.5 (8)C6—C1—C7—C853.4 (7)
C2—C3—C4—C10178.1 (5)C2—C1—C7—C8129.6 (5)
C3—C4—C5—C60.0 (8)O1—C7—C8—O231.4 (8)
C10—C4—C5—C6179.6 (5)C1—C7—C8—O2149.8 (5)
C4—C5—C6—C10.5 (7)O1—C7—C8—O3144.8 (5)
C4—C5—C6—C11178.2 (5)C1—C7—C8—O334.0 (7)
 

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