The title compound, C8H6O4, consists of a cyclic diether fused to benzoic acid and crystallizes as a hydrogen-bonded carboxylic acid dimer.
Supporting information
CCDC reference: 613708
Key indicators
- Single-crystal X-ray study
- T = 173 K
- Mean (C-C) = 0.004 Å
- R factor = 0.063
- wR factor = 0.176
- Data-to-parameter ratio = 10.0
checkCIF/PLATON results
No syntax errors found
Alert level B
RINTA01_ALERT_3_B The value of Rint is greater than 0.15
Rint given 0.154
PLAT020_ALERT_3_B The value of Rint is greater than 0.10 ......... 0.15
Alert level C
CELLV02_ALERT_1_C The supplied cell volume s.u. differs from that
calculated from the cell parameter s.u.'s by > 2
Calculated cell volume su = 18.91
Cell volume su given = 16.00
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent ..... ?
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor .... 3.15
0 ALERT level A = In general: serious problem
2 ALERT level B = Potentially serious problem
3 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 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
0 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: EXPOSE in IPDS Software (Stoe & Cie, 2000); cell refinement: CELL in IPDS Software; data reduction: INTEGRATE in IPDS Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.
2,3-Methylenedioxybenzoic acid
top
Crystal data top
C8H6O4 | F(000) = 344 |
Mr = 166.13 | Dx = 1.630 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 5689 reflections |
a = 9.7327 (13) Å | θ = 2.6–26.0° |
b = 7.2600 (7) Å | µ = 0.13 mm−1 |
c = 12.394 (2) Å | T = 173 K |
β = 129.395 (11)° | Prism, colourless |
V = 676.77 (16) Å3 | 0.50 × 0.40 × 0.20 mm |
Z = 4 | |
Data collection top
Stoe IPDS diffractometer | 957 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.154 |
Graphite monochromator | θmax = 25.9°, θmin = 2.7° |
Detector resolution: 0.81 pixels mm-1 | h = −11→11 |
φ scans | k = −8→8 |
4940 measured reflections | l = −15→15 |
1302 independent reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.063 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.176 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.03 | w = 1/[σ2(Fo2) + (0.1155P)2] where P = (Fo2 + 2Fc2)/3 |
1302 reflections | (Δ/σ)max < 0.001 |
130 parameters | Δρmax = 0.33 e Å−3 |
0 restraints | Δρmin = −0.54 e Å−3 |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.3597 (2) | 0.5043 (2) | 0.03568 (18) | 0.0279 (6) | |
O2 | 0.4902 (2) | 0.2614 (2) | 0.02229 (19) | 0.0283 (6) | |
O3 | 0.0839 (2) | 0.2475 (2) | 0.22587 (19) | 0.0298 (6) | |
O4 | 0.1959 (3) | 0.4490 (2) | 0.1528 (2) | 0.0291 (6) | |
C1 | 0.3920 (3) | 0.3348 (3) | 0.0469 (2) | 0.0215 (7) | |
C2 | 0.3175 (3) | 0.2086 (3) | 0.0916 (2) | 0.0204 (7) | |
C3 | 0.3351 (3) | 0.0164 (3) | 0.0898 (2) | 0.0234 (7) | |
C4 | 0.2642 (3) | −0.1031 (4) | 0.1308 (3) | 0.0256 (7) | |
C5 | 0.1765 (3) | −0.0377 (3) | 0.1783 (2) | 0.0248 (8) | |
C6 | 0.1621 (3) | 0.1500 (3) | 0.1819 (2) | 0.0217 (7) | |
C7 | 0.2295 (3) | 0.2715 (3) | 0.1388 (2) | 0.0209 (7) | |
C8 | 0.1013 (4) | 0.4384 (3) | 0.2058 (3) | 0.0278 (8) | |
H2 | 0.52920 | 0.34410 | 0.00070 | 0.0430* | |
H3 | 0.395 (3) | −0.039 (4) | 0.057 (2) | 0.021 (6)* | |
H4 | 0.270 (3) | −0.222 (4) | 0.125 (3) | 0.031 (7)* | |
H5 | 0.121 (4) | −0.115 (4) | 0.205 (3) | 0.046 (8)* | |
H8A | −0.020 (4) | 0.482 (4) | 0.134 (3) | 0.036 (7)* | |
H8B | 0.164 (4) | 0.501 (5) | 0.290 (4) | 0.054 (9)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0409 (10) | 0.0120 (9) | 0.0451 (10) | 0.0030 (7) | 0.0340 (9) | 0.0040 (7) |
O2 | 0.0418 (11) | 0.0181 (9) | 0.0474 (11) | −0.0005 (7) | 0.0388 (10) | 0.0003 (7) |
O3 | 0.0474 (11) | 0.0163 (10) | 0.0516 (11) | 0.0012 (7) | 0.0436 (10) | 0.0017 (7) |
O4 | 0.0485 (11) | 0.0090 (9) | 0.0560 (11) | 0.0018 (7) | 0.0455 (10) | 0.0006 (7) |
C1 | 0.0307 (13) | 0.0152 (12) | 0.0295 (12) | −0.0008 (9) | 0.0242 (11) | −0.0007 (9) |
C2 | 0.0282 (12) | 0.0103 (12) | 0.0289 (12) | −0.0009 (8) | 0.0210 (11) | −0.0006 (8) |
C3 | 0.0322 (12) | 0.0146 (12) | 0.0296 (12) | 0.0018 (9) | 0.0226 (11) | −0.0012 (9) |
C4 | 0.0367 (13) | 0.0102 (12) | 0.0348 (13) | 0.0005 (10) | 0.0250 (11) | 0.0003 (9) |
C5 | 0.0333 (13) | 0.0132 (13) | 0.0335 (13) | −0.0029 (9) | 0.0239 (11) | 0.0010 (9) |
C6 | 0.0290 (13) | 0.0147 (13) | 0.0268 (12) | −0.0003 (9) | 0.0203 (11) | 0.0006 (8) |
C7 | 0.0298 (13) | 0.0115 (12) | 0.0314 (13) | 0.0001 (8) | 0.0242 (11) | −0.0010 (8) |
C8 | 0.0453 (15) | 0.0132 (13) | 0.0454 (15) | 0.0037 (10) | 0.0385 (14) | 0.0037 (10) |
Geometric parameters (Å, º) top
O1—C1 | 1.256 (3) | C3—C4 | 1.390 (4) |
O2—C1 | 1.289 (4) | C4—C5 | 1.392 (5) |
O3—C6 | 1.380 (4) | C5—C6 | 1.374 (3) |
O3—C8 | 1.437 (3) | C6—C7 | 1.392 (4) |
O4—C7 | 1.367 (3) | C3—H3 | 0.98 (3) |
O4—C8 | 1.433 (5) | C4—H4 | 0.87 (3) |
O2—H2 | 0.8400 | C5—H5 | 0.97 (4) |
C1—C2 | 1.477 (4) | C8—H8A | 0.98 (4) |
C2—C7 | 1.386 (4) | C8—H8B | 0.93 (4) |
C2—C3 | 1.408 (3) | | |
| | | |
O1···O4 | 2.783 (4) | C5···C5xii | 3.516 (3) |
O1···O2i | 2.622 (3) | C5···O2x | 3.338 (3) |
O1···C1i | 3.375 (4) | C5···C1x | 3.455 (4) |
O2···O1i | 2.622 (3) | C5···C6xii | 3.575 (3) |
O2···C6ii | 3.363 (3) | C6···O2v | 3.363 (3) |
O2···C5iii | 3.338 (3) | C6···C5xii | 3.575 (3) |
O3···O4 | 2.324 (3) | C6···C4xii | 3.455 (4) |
O3···C8iv | 3.308 (4) | C6···C1v | 3.555 (3) |
O3···C1v | 3.168 (3) | C8···O3ix | 3.308 (4) |
O4···O3 | 2.324 (3) | C1···H2i | 2.6400 |
O4···C4vi | 3.365 (3) | C1···H8Avii | 3.10 (4) |
O4···O1 | 2.783 (4) | C3···H8Bii | 2.96 (4) |
O1···H4vi | 2.68 (3) | C8···H5ix | 3.02 (4) |
O1···H8Avii | 2.56 (4) | H2···O1i | 1.7900 |
O1···H2i | 1.7900 | H2···O2i | 2.8700 |
O2···H3viii | 2.49 (3) | H2···C1i | 2.6400 |
O2···H2i | 2.8700 | H2···H2i | 2.3300 |
O2···H3 | 2.51 (3) | H2···H3viii | 2.5800 |
O3···H8Aiv | 2.91 (4) | H3···O2 | 2.51 (3) |
O3···H8Biv | 2.91 (5) | H3···O2viii | 2.49 (3) |
O3···H5ix | 2.81 (4) | H3···H2viii | 2.5800 |
O4···H4vi | 2.58 (3) | H3···H8Bii | 2.58 (4) |
O4···H8Avii | 2.85 (3) | H4···O1xi | 2.68 (3) |
C1···C4iii | 3.223 (4) | H4···O4xi | 2.58 (3) |
C1···C5iii | 3.455 (4) | H5···O3iv | 2.81 (4) |
C1···O1i | 3.375 (4) | H5···C8iv | 3.02 (4) |
C1···C6ii | 3.555 (3) | H8A···O3ix | 2.91 (4) |
C1···O3ii | 3.168 (3) | H8A···O1vii | 2.56 (4) |
C2···C4iii | 3.536 (4) | H8A···O4vii | 2.85 (3) |
C4···C1x | 3.223 (4) | H8A···C1vii | 3.10 (4) |
C4···C2x | 3.536 (4) | H8B···O3ix | 2.91 (5) |
C4···O4xi | 3.365 (3) | H8B···C3v | 2.96 (4) |
C4···C6xii | 3.455 (4) | H8B···H3v | 2.58 (4) |
| | | |
C6—O3—C8 | 105.7 (2) | O4—C7—C2 | 128.7 (3) |
C7—O4—C8 | 106.4 (2) | C2—C7—C6 | 121.4 (2) |
C1—O2—H2 | 109.00 | O4—C7—C6 | 109.9 (3) |
O1—C1—O2 | 123.4 (3) | O3—C8—O4 | 108.2 (2) |
O2—C1—C2 | 116.5 (2) | C2—C3—H3 | 121.5 (17) |
O1—C1—C2 | 120.1 (3) | C4—C3—H3 | 117.2 (17) |
C1—C2—C7 | 122.4 (2) | C3—C4—H4 | 121 (2) |
C3—C2—C7 | 116.6 (3) | C5—C4—H4 | 118 (2) |
C1—C2—C3 | 121.0 (3) | C4—C5—H5 | 125 (2) |
C2—C3—C4 | 121.3 (3) | C6—C5—H5 | 118 (2) |
C3—C4—C5 | 121.4 (3) | O3—C8—H8A | 105.3 (19) |
C4—C5—C6 | 117.0 (3) | O3—C8—H8B | 110 (2) |
O3—C6—C7 | 109.8 (2) | O4—C8—H8A | 109 (2) |
C5—C6—C7 | 122.2 (3) | O4—C8—H8B | 110 (3) |
O3—C6—C5 | 128.0 (3) | H8A—C8—H8B | 115 (3) |
| | | |
C8—O3—C6—C5 | −178.8 (2) | C1—C2—C3—C4 | −179.5 (2) |
C8—O3—C6—C7 | 1.2 (3) | C3—C2—C7—O4 | 179.2 (2) |
C6—O3—C8—O4 | −1.6 (3) | C1—C2—C7—O4 | 0.0 (4) |
C8—O4—C7—C2 | −180.0 (2) | C1—C2—C7—C6 | −179.3 (2) |
C8—O4—C7—C6 | −0.6 (3) | C2—C3—C4—C5 | −1.5 (4) |
C7—O4—C8—O3 | 1.4 (3) | C3—C4—C5—C6 | 0.4 (4) |
O2—C1—C2—C3 | −7.8 (3) | C4—C5—C6—C7 | 0.8 (3) |
O1—C1—C2—C3 | 172.8 (2) | C4—C5—C6—O3 | −179.2 (2) |
O1—C1—C2—C7 | −8.1 (3) | C5—C6—C7—C2 | −1.0 (3) |
O2—C1—C2—C7 | 171.4 (2) | O3—C6—C7—O4 | −0.4 (3) |
C3—C2—C7—C6 | −0.1 (3) | O3—C6—C7—C2 | 179.0 (2) |
C7—C2—C3—C4 | 1.3 (3) | C5—C6—C7—O4 | 179.7 (2) |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) x, −y+1/2, z−1/2; (iii) −x+1, y+1/2, −z+1/2; (iv) −x, y−1/2, −z+1/2; (v) x, −y+1/2, z+1/2; (vi) x, y+1, z; (vii) −x, −y+1, −z; (viii) −x+1, −y, −z; (ix) −x, y+1/2, −z+1/2; (x) −x+1, y−1/2, −z+1/2; (xi) x, y−1, z; (xii) −x, −y, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O1i | 0.84 | 1.79 | 2.622 (3) | 171 |
C3—H3···O2viii | 0.98 (3) | 2.49 (3) | 3.448 (4) | 164 (2) |
C4—H4···O4xi | 0.87 (3) | 2.58 (3) | 3.365 (3) | 150 (3) |
C8—H8A···O1vii | 0.98 (4) | 2.56 (4) | 3.495 (4) | 161 (3) |
Symmetry codes: (i) −x+1, −y+1, −z; (vii) −x, −y+1, −z; (viii) −x+1, −y, −z; (xi) x, y−1, z. |