Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102015597/fr1394sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102015597/fr1394Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102015597/fr1394IIAsup3.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102015597/fr1394IIBsup4.hkl |
CCDC references: 199418; 199419; 199420
Both compounds were obtained from Aldrich Chemical Co. Inc. Recrystallization of the ortho compound, (I), from acetone, benzene, dichloromethane or chloroform all gave similar crystals; the crystal used here was obtained from chloroform. Two polymorphs were found for the meta compound, (II). Sublimation, or recrystallization from benzene, dichloromethane or diethylether, gave polymorph A; the crystal used here was obtained from benzene. Recrystallization from acetone or chloroform gave polymorph B; the crystal used here was obtained from chloroform. Both polymorphs had the same melting points to within experimental error.
In every case, the H atoms were included at idealized positions, with C—H = 0.95 Å and Uiso(H) = 1.2 times larger than the Uav for the attached C atom. This was done to improve the data-to-parameter ratio for the ortho crystal, (I), and for the sake of consistency with the meta crystals, (II). The ortho crystals, (I), are noncentrosymmetric, but with no atoms heavier than O, the correct polarity could not be determined. The Friedel pairs were averaged for the final refinement.
For all compounds, data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT; 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.
C8H6O2 | Dx = 1.377 Mg m−3 |
Mr = 134.13 | Melting point = 328–331 K |
Orthorhombic, Pna21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2c -2n | Cell parameters from 2907 reflections |
a = 7.282 (2) Å | θ = 3.1–26.8° |
b = 13.140 (3) Å | µ = 0.10 mm−1 |
c = 6.760 (2) Å | T = 174 K |
V = 646.8 (3) Å3 | Irregular prism, colorless |
Z = 4 | 0.5 × 0.2 × 0.1 mm |
F(000) = 280 |
Siemens SMART area-detector diffractometer | 802 independent reflections |
Radiation source: fine-focus sealed tube | 752 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.032 |
ω scans | θmax = 27.5°, θmin = 3.1° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) | h = −9→9 |
Tmin = 0.97, Tmax = 0.99 | k = −17→17 |
7182 measured reflections | l = −8→8 |
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)] = 0.027 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.078 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.051P)2 + 0.045P] where P = (Fo2 + 2Fc2)/3 |
802 reflections | (Δ/σ)max = 0.004 |
91 parameters | Δρmax = 0.19 e Å−3 |
1 restraint | Δρmin = −0.16 e Å−3 |
C8H6O2 | V = 646.8 (3) Å3 |
Mr = 134.13 | Z = 4 |
Orthorhombic, Pna21 | Mo Kα radiation |
a = 7.282 (2) Å | µ = 0.10 mm−1 |
b = 13.140 (3) Å | T = 174 K |
c = 6.760 (2) Å | 0.5 × 0.2 × 0.1 mm |
Siemens SMART area-detector diffractometer | 802 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) | 752 reflections with I > 2σ(I) |
Tmin = 0.97, Tmax = 0.99 | Rint = 0.032 |
7182 measured reflections |
R[F2 > 2σ(F2)] = 0.027 | 1 restraint |
wR(F2) = 0.078 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.19 e Å−3 |
802 reflections | Δρmin = −0.16 e Å−3 |
91 parameters |
Refinement. Since there are no atoms heavier than O, the Friedel pairs were averaged and no attempt was made to find the correct polarity. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.13957 (18) | 0.52733 (9) | 0.3704 (3) | 0.0512 (4) | |
O2 | 0.28771 (18) | 0.66817 (10) | −0.1058 (2) | 0.0481 (4) | |
C7 | 0.0869 (2) | 0.60272 (13) | 0.4565 (3) | 0.0384 (4) | |
H1 | 0.0266 | 0.5929 | 0.5796 | 0.046* | |
C8 | 0.1907 (2) | 0.65608 (12) | 0.0352 (3) | 0.0373 (4) | |
H2 | 0.1257 | 0.5937 | 0.0464 | 0.045* | |
C1 | 0.10846 (18) | 0.70859 (11) | 0.3865 (3) | 0.0294 (3) | |
C2 | 0.16637 (19) | 0.73320 (11) | 0.1939 (2) | 0.0287 (3) | |
C3 | 0.1924 (2) | 0.83533 (12) | 0.1442 (3) | 0.0345 (4) | |
H3 | 0.2302 | 0.8530 | 0.0142 | 0.041* | |
C4 | 0.1634 (2) | 0.91086 (13) | 0.2830 (3) | 0.0401 (4) | |
H4 | 0.1838 | 0.9800 | 0.2485 | 0.048* | |
C5 | 0.1047 (2) | 0.88642 (13) | 0.4721 (3) | 0.0423 (5) | |
H5 | 0.0839 | 0.9387 | 0.5666 | 0.051* | |
C6 | 0.0764 (2) | 0.78546 (13) | 0.5229 (3) | 0.0373 (4) | |
H6 | 0.0347 | 0.7688 | 0.6521 | 0.045* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0605 (7) | 0.0325 (6) | 0.0605 (9) | 0.0011 (5) | −0.0066 (8) | 0.0079 (7) |
O2 | 0.0584 (7) | 0.0524 (8) | 0.0336 (6) | −0.0010 (6) | 0.0068 (6) | −0.0028 (7) |
C7 | 0.0364 (8) | 0.0404 (8) | 0.0384 (9) | −0.0059 (7) | −0.0049 (7) | 0.0109 (7) |
C8 | 0.0458 (9) | 0.0319 (8) | 0.0343 (9) | −0.0042 (6) | −0.0018 (8) | −0.0005 (7) |
C1 | 0.0250 (6) | 0.0324 (7) | 0.0306 (7) | −0.0019 (5) | −0.0025 (6) | 0.0031 (7) |
C2 | 0.0252 (7) | 0.0286 (7) | 0.0323 (8) | −0.0019 (5) | −0.0035 (6) | 0.0016 (6) |
C3 | 0.0317 (7) | 0.0337 (8) | 0.0382 (9) | −0.0032 (6) | −0.0046 (7) | 0.0080 (7) |
C4 | 0.0377 (9) | 0.0260 (7) | 0.0567 (11) | 0.0010 (6) | −0.0080 (8) | 0.0015 (8) |
C5 | 0.0382 (9) | 0.0378 (9) | 0.0510 (11) | 0.0065 (7) | −0.0018 (8) | −0.0151 (9) |
C6 | 0.0321 (7) | 0.0460 (9) | 0.0337 (8) | 0.0013 (7) | −0.0001 (7) | −0.0020 (8) |
O1—C7 | 1.211 (2) | C2—C3 | 1.396 (2) |
O2—C8 | 1.197 (2) | C3—C4 | 1.382 (3) |
C7—C1 | 1.478 (2) | C3—H3 | 0.9500 |
C7—H1 | 0.9500 | C4—C5 | 1.386 (3) |
C8—C2 | 1.486 (2) | C4—H4 | 0.9500 |
C8—H2 | 0.9500 | C5—C6 | 1.386 (3) |
C1—C6 | 1.387 (2) | C5—H5 | 0.9500 |
C1—C2 | 1.407 (2) | C6—H6 | 0.9500 |
O1—C7—C1 | 125.64 (18) | C4—C3—C2 | 120.42 (18) |
O1—C7—H1 | 117.2 | C4—C3—H3 | 119.8 |
C1—C7—H1 | 117.2 | C2—C3—H3 | 119.8 |
O2—C8—C2 | 123.70 (14) | C3—C4—C5 | 120.46 (16) |
O2—C8—H2 | 118.2 | C3—C4—H4 | 119.8 |
C2—C8—H2 | 118.2 | C5—C4—H4 | 119.8 |
C6—C1—C2 | 119.88 (13) | C6—C5—C4 | 119.75 (18) |
C6—C1—C7 | 117.07 (16) | C6—C5—H5 | 120.1 |
C2—C1—C7 | 122.99 (15) | C4—C5—H5 | 120.1 |
C3—C2—C1 | 118.97 (15) | C5—C6—C1 | 120.49 (17) |
C3—C2—C8 | 117.76 (16) | C5—C6—H6 | 119.8 |
C1—C2—C8 | 123.17 (14) | C1—C6—H6 | 119.8 |
O1—C7—C1—C6 | −166.24 (17) | C1—C2—C3—C4 | 0.6 (2) |
O1—C7—C1—C2 | 11.0 (3) | C8—C2—C3—C4 | 176.99 (14) |
C6—C1—C2—C3 | 0.7 (2) | C2—C3—C4—C5 | −1.3 (2) |
C7—C1—C2—C3 | −176.57 (14) | C3—C4—C5—C6 | 0.5 (3) |
C6—C1—C2—C8 | −175.48 (14) | C4—C5—C6—C1 | 0.8 (3) |
C7—C1—C2—C8 | 7.3 (2) | C2—C1—C6—C5 | −1.4 (2) |
O2—C8—C2—C3 | 26.8 (2) | C7—C1—C6—C5 | 176.01 (15) |
O2—C8—C2—C1 | −157.06 (16) |
C8H6O2 | F(000) = 280 |
Mr = 134.13 | Dx = 1.392 Mg m−3 |
Monoclinic, P21/n | Melting point: 360-362 K K |
Hall symbol: -P 2yn | Mo Kα radiation, λ = 0.71073 Å |
a = 3.776 (1) Å | Cell parameters from 1982 reflections |
b = 11.171 (3) Å | θ = 2.7–25.3° |
c = 15.229 (4) Å | µ = 0.10 mm−1 |
β = 94.98 (1)° | T = 174 K |
V = 640.0 (3) Å3 | Needle, colorless |
Z = 4 | 0.50 × 0.15 × 0.10 mm |
Siemens SMART area-detector diffractometer | 1461 independent reflections |
Radiation source: fine-focus sealed tube | 1138 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.040 |
ω scans | θmax = 27.5°, θmin = 2.3° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) | h = −4→4 |
Tmin = 0.98, Tmax = 0.99 | k = −14→14 |
7258 measured reflections | l = −19→19 |
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)] = 0.039 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.099 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.038P)2 + 0.185P] where P = (Fo2 + 2Fc2)/3 |
1461 reflections | (Δ/σ)max = 0.001 |
91 parameters | Δρmax = 0.21 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
C8H6O2 | V = 640.0 (3) Å3 |
Mr = 134.13 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 3.776 (1) Å | µ = 0.10 mm−1 |
b = 11.171 (3) Å | T = 174 K |
c = 15.229 (4) Å | 0.50 × 0.15 × 0.10 mm |
β = 94.98 (1)° |
Siemens SMART area-detector diffractometer | 1461 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) | 1138 reflections with I > 2σ(I) |
Tmin = 0.98, Tmax = 0.99 | Rint = 0.040 |
7258 measured reflections |
R[F2 > 2σ(F2)] = 0.039 | 0 restraints |
wR(F2) = 0.099 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.21 e Å−3 |
1461 reflections | Δρmin = −0.19 e Å−3 |
91 parameters |
x | y | z | Uiso*/Ueq | ||
O1 | 0.5734 (3) | 0.90024 (10) | 0.80041 (7) | 0.0430 (3) | |
O3 | 0.8064 (3) | 0.89332 (9) | 0.38797 (6) | 0.0369 (3) | |
C1 | 0.5787 (3) | 0.82684 (12) | 0.65384 (8) | 0.0260 (3) | |
C2 | 0.6535 (3) | 0.85677 (12) | 0.56903 (9) | 0.0249 (3) | |
H2 | 0.7593 | 0.9318 | 0.5579 | 0.030* | |
C3 | 0.5726 (3) | 0.77623 (11) | 0.50021 (9) | 0.0254 (3) | |
C4 | 0.4192 (4) | 0.66585 (12) | 0.51721 (9) | 0.0291 (3) | |
H4 | 0.3606 | 0.6116 | 0.4701 | 0.035* | |
C5 | 0.3517 (4) | 0.63477 (12) | 0.60246 (10) | 0.0312 (3) | |
H5 | 0.2522 | 0.5589 | 0.6139 | 0.037* | |
C6 | 0.4300 (4) | 0.71482 (12) | 0.67039 (9) | 0.0295 (3) | |
H6 | 0.3830 | 0.6940 | 0.7287 | 0.035* | |
C7 | 0.6546 (4) | 0.91429 (13) | 0.72568 (9) | 0.0314 (3) | |
H1 | 0.7744 | 0.9861 | 0.7126 | 0.038* | |
C8 | 0.6506 (4) | 0.80486 (13) | 0.40942 (9) | 0.0303 (3) | |
H3 | 0.5727 | 0.7497 | 0.3644 | 0.036* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0589 (8) | 0.0430 (7) | 0.0280 (6) | 0.0027 (5) | 0.0100 (5) | −0.0015 (5) |
O3 | 0.0472 (7) | 0.0354 (6) | 0.0293 (6) | −0.0051 (5) | 0.0103 (5) | 0.0044 (4) |
C1 | 0.0243 (7) | 0.0276 (7) | 0.0263 (7) | 0.0060 (5) | 0.0034 (5) | 0.0027 (5) |
C2 | 0.0236 (6) | 0.0228 (7) | 0.0286 (7) | 0.0029 (5) | 0.0046 (5) | 0.0030 (5) |
C3 | 0.0234 (7) | 0.0264 (7) | 0.0268 (7) | 0.0042 (5) | 0.0037 (5) | 0.0024 (5) |
C4 | 0.0292 (7) | 0.0254 (7) | 0.0329 (7) | −0.0002 (6) | 0.0044 (6) | −0.0018 (6) |
C5 | 0.0313 (7) | 0.0237 (7) | 0.0394 (8) | −0.0003 (6) | 0.0081 (6) | 0.0059 (6) |
C6 | 0.0293 (7) | 0.0313 (7) | 0.0291 (7) | 0.0044 (6) | 0.0084 (6) | 0.0080 (6) |
C7 | 0.0330 (8) | 0.0328 (8) | 0.0284 (7) | 0.0040 (6) | 0.0026 (6) | 0.0016 (6) |
C8 | 0.0339 (8) | 0.0306 (7) | 0.0270 (7) | −0.0001 (6) | 0.0057 (6) | −0.0016 (6) |
O1—C7 | 1.2143 (17) | C3—C8 | 1.4736 (18) |
O3—C8 | 1.2094 (17) | C4—C5 | 1.389 (2) |
C1—C2 | 1.3867 (19) | C4—H4 | 0.9500 |
C1—C6 | 1.4033 (19) | C5—C6 | 1.380 (2) |
C1—C7 | 1.4761 (19) | C5—H5 | 0.9500 |
C2—C3 | 1.3948 (19) | C6—H6 | 0.9500 |
C2—H2 | 0.9500 | C7—H1 | 0.9500 |
C3—C4 | 1.3961 (19) | C8—H3 | 0.9500 |
C2—C1—C6 | 119.95 (13) | C6—C5—C4 | 119.61 (13) |
C2—C1—C7 | 119.26 (12) | C6—C5—H5 | 120.2 |
C6—C1—C7 | 120.80 (12) | C4—C5—H5 | 120.2 |
C1—C2—C3 | 119.69 (12) | C5—C6—C1 | 120.42 (13) |
C1—C2—H2 | 120.2 | C5—C6—H6 | 119.8 |
C3—C2—H2 | 120.2 | C1—C6—H6 | 119.8 |
C2—C3—C4 | 119.84 (12) | O1—C7—C1 | 124.10 (14) |
C2—C3—C8 | 121.10 (12) | O1—C7—H1 | 118.0 |
C4—C3—C8 | 119.05 (12) | C1—C7—H1 | 118.0 |
C5—C4—C3 | 120.46 (13) | O3—C8—C3 | 124.91 (13) |
C5—C4—H4 | 119.8 | O3—C8—H3 | 117.5 |
C3—C4—H4 | 119.8 | C3—C8—H3 | 117.5 |
C6—C1—C2—C3 | 1.48 (19) | C4—C5—C6—C1 | −0.3 (2) |
C7—C1—C2—C3 | −178.01 (12) | C2—C1—C6—C5 | −1.1 (2) |
C1—C2—C3—C4 | −0.41 (19) | C7—C1—C6—C5 | 178.36 (13) |
C1—C2—C3—C8 | −179.60 (12) | C2—C1—C7—O1 | 174.03 (14) |
C2—C3—C4—C5 | −1.0 (2) | C6—C1—C7—O1 | −5.5 (2) |
C8—C3—C4—C5 | 178.17 (13) | C2—C3—C8—O3 | 5.0 (2) |
C3—C4—C5—C6 | 1.4 (2) | C4—C3—C8—O3 | −174.23 (14) |
C8H6O2 | F(000) = 280 |
Mr = 134.13 | Dx = 1.395 Mg m−3 |
Monoclinic, P21/n | Melting point: 361-363 K K |
Hall symbol: -P 2yn | Mo Kα radiation, λ = 0.71073 Å |
a = 11.374 (3) Å | Cell parameters from 3560 reflections |
b = 3.811 (1) Å | θ = 2.7–27.4° |
c = 15.721 (4) Å | µ = 0.10 mm−1 |
β = 110.419 (10)° | T = 173 K |
V = 638.6 (3) Å3 | Needle, colorless |
Z = 4 | 0.45 × 0.20 × 0.10 mm |
Siemens SMART area-detector diffractometer | 1452 independent reflections |
Radiation source: fine-focus sealed tube | 1237 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
ω scans | θmax = 27.5°, θmin = 1.9° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) | h = −14→14 |
Tmin = 0.98, Tmax = 0.99 | k = −4→4 |
6965 measured reflections | l = −20→20 |
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)] = 0.042 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.118 | H-atom parameters constrained |
S = 1.08 | w = 1/[σ2(Fo2) + (0.063P)2 + 0.146P] where P = (Fo2 + 2Fc2)/3 |
1452 reflections | (Δ/σ)max = 0.001 |
91 parameters | Δρmax = 0.23 e Å−3 |
0 restraints | Δρmin = −0.14 e Å−3 |
C8H6O2 | V = 638.6 (3) Å3 |
Mr = 134.13 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 11.374 (3) Å | µ = 0.10 mm−1 |
b = 3.811 (1) Å | T = 173 K |
c = 15.721 (4) Å | 0.45 × 0.20 × 0.10 mm |
β = 110.419 (10)° |
Siemens SMART area-detector diffractometer | 1452 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) | 1237 reflections with I > 2σ(I) |
Tmin = 0.98, Tmax = 0.99 | Rint = 0.022 |
6965 measured reflections |
R[F2 > 2σ(F2)] = 0.042 | 0 restraints |
wR(F2) = 0.118 | H-atom parameters constrained |
S = 1.08 | Δρmax = 0.23 e Å−3 |
1452 reflections | Δρmin = −0.14 e Å−3 |
91 parameters |
x | y | z | Uiso*/Ueq | ||
C1 | 0.35851 (11) | 0.5573 (3) | 0.62691 (8) | 0.0277 (3) | |
C2 | 0.36368 (11) | 0.6242 (3) | 0.54146 (8) | 0.0276 (3) | |
H2 | 0.4346 | 0.7393 | 0.5356 | 0.033* | |
C3 | 0.26449 (11) | 0.5219 (3) | 0.46424 (8) | 0.0283 (3) | |
C4 | 0.16007 (12) | 0.3563 (3) | 0.47298 (9) | 0.0312 (3) | |
H4 | 0.0929 | 0.2845 | 0.4203 | 0.037* | |
C5 | 0.15386 (12) | 0.2957 (3) | 0.55856 (9) | 0.0327 (3) | |
H5 | 0.0818 | 0.1876 | 0.5644 | 0.039* | |
C6 | 0.25272 (12) | 0.3931 (3) | 0.63500 (9) | 0.0304 (3) | |
H6 | 0.2490 | 0.3485 | 0.6935 | 0.036* | |
C7 | 0.46497 (12) | 0.6640 (4) | 0.70790 (9) | 0.0338 (3) | |
H1 | 0.5316 | 0.7898 | 0.6986 | 0.041* | |
C8 | 0.26791 (13) | 0.5905 (4) | 0.37271 (9) | 0.0348 (3) | |
H3 | 0.2050 | 0.4858 | 0.3224 | 0.042* | |
O1 | 0.47326 (10) | 0.6023 (3) | 0.78532 (6) | 0.0459 (3) | |
O3 | 0.34604 (10) | 0.7722 (3) | 0.35779 (7) | 0.0467 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0301 (6) | 0.0258 (6) | 0.0274 (6) | 0.0036 (5) | 0.0102 (5) | 0.0002 (5) |
C2 | 0.0281 (6) | 0.0272 (6) | 0.0291 (6) | 0.0020 (5) | 0.0121 (5) | 0.0012 (5) |
C3 | 0.0309 (6) | 0.0272 (6) | 0.0272 (6) | 0.0056 (5) | 0.0108 (5) | 0.0016 (5) |
C4 | 0.0286 (6) | 0.0308 (7) | 0.0316 (6) | 0.0016 (5) | 0.0072 (5) | −0.0032 (5) |
C5 | 0.0308 (6) | 0.0300 (7) | 0.0401 (7) | −0.0014 (5) | 0.0160 (5) | −0.0008 (5) |
C6 | 0.0365 (7) | 0.0289 (7) | 0.0298 (6) | 0.0030 (5) | 0.0166 (5) | 0.0022 (5) |
C7 | 0.0343 (7) | 0.0372 (7) | 0.0295 (6) | 0.0020 (5) | 0.0109 (5) | −0.0020 (5) |
C8 | 0.0368 (7) | 0.0395 (8) | 0.0273 (6) | 0.0081 (6) | 0.0101 (5) | 0.0023 (5) |
O1 | 0.0472 (6) | 0.0622 (7) | 0.0262 (5) | 0.0001 (5) | 0.0101 (4) | −0.0001 (5) |
O3 | 0.0534 (7) | 0.0560 (7) | 0.0358 (6) | −0.0003 (5) | 0.0219 (5) | 0.0087 (5) |
C1—C2 | 1.3886 (17) | C4—H4 | 0.9500 |
C1—C6 | 1.4009 (18) | C5—C6 | 1.3797 (19) |
C1—C7 | 1.4754 (18) | C5—H5 | 0.9500 |
C2—C3 | 1.3938 (18) | C6—H6 | 0.9500 |
C2—H2 | 0.9500 | C7—O1 | 1.2106 (16) |
C3—C4 | 1.3934 (18) | C7—H1 | 0.9500 |
C3—C8 | 1.4764 (17) | C8—O3 | 1.2122 (18) |
C4—C5 | 1.3910 (18) | C8—H3 | 0.9500 |
C2—C1—C6 | 119.83 (11) | C6—C5—C4 | 119.80 (12) |
C2—C1—C7 | 119.03 (11) | C6—C5—H5 | 120.1 |
C6—C1—C7 | 121.14 (11) | C4—C5—H5 | 120.1 |
C1—C2—C3 | 119.78 (11) | C5—C6—C1 | 120.39 (11) |
C1—C2—H2 | 120.1 | C5—C6—H6 | 119.8 |
C3—C2—H2 | 120.1 | C1—C6—H6 | 119.8 |
C4—C3—C2 | 119.98 (11) | O1—C7—C1 | 124.52 (13) |
C4—C3—C8 | 119.30 (11) | O1—C7—H1 | 117.7 |
C2—C3—C8 | 120.72 (11) | C1—C7—H1 | 117.7 |
C5—C4—C3 | 120.21 (11) | O3—C8—C3 | 124.06 (12) |
C5—C4—H4 | 119.9 | O3—C8—H3 | 118.0 |
C3—C4—H4 | 119.9 | C3—C8—H3 | 118.0 |
C6—C1—C2—C3 | −1.13 (18) | C4—C5—C6—C1 | 0.95 (19) |
C7—C1—C2—C3 | 179.34 (11) | C2—C1—C6—C5 | 0.34 (18) |
C1—C2—C3—C4 | 0.64 (18) | C7—C1—C6—C5 | 179.86 (12) |
C1—C2—C3—C8 | 179.96 (11) | C2—C1—C7—O1 | −175.92 (13) |
C2—C3—C4—C5 | 0.65 (19) | C6—C1—C7—O1 | 4.6 (2) |
C8—C3—C4—C5 | −178.68 (12) | C4—C3—C8—O3 | 169.90 (13) |
C3—C4—C5—C6 | −1.45 (19) | C2—C3—C8—O3 | −9.4 (2) |
Experimental details
(I) | (IIA) | (IIB) | |
Crystal data | |||
Chemical formula | C8H6O2 | C8H6O2 | C8H6O2 |
Mr | 134.13 | 134.13 | 134.13 |
Crystal system, space group | Orthorhombic, Pna21 | Monoclinic, P21/n | Monoclinic, P21/n |
Temperature (K) | 174 | 174 | 173 |
a, b, c (Å) | 7.282 (2), 13.140 (3), 6.760 (2) | 3.776 (1), 11.171 (3), 15.229 (4) | 11.374 (3), 3.811 (1), 15.721 (4) |
α, β, γ (°) | 90, 90, 90 | 90, 94.98 (1), 90 | 90, 110.419 (10), 90 |
V (Å3) | 646.8 (3) | 640.0 (3) | 638.6 (3) |
Z | 4 | 4 | 4 |
Radiation type | Mo Kα | Mo Kα | Mo Kα |
µ (mm−1) | 0.10 | 0.10 | 0.10 |
Crystal size (mm) | 0.5 × 0.2 × 0.1 | 0.50 × 0.15 × 0.10 | 0.45 × 0.20 × 0.10 |
Data collection | |||
Diffractometer | Siemens SMART area-detector diffractometer | Siemens SMART area-detector diffractometer | Siemens SMART area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) | Multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) | Multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995) |
Tmin, Tmax | 0.97, 0.99 | 0.98, 0.99 | 0.98, 0.99 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7182, 802, 752 | 7258, 1461, 1138 | 6965, 1452, 1237 |
Rint | 0.032 | 0.040 | 0.022 |
(sin θ/λ)max (Å−1) | 0.649 | 0.649 | 0.649 |
Refinement | |||
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.078, 1.05 | 0.039, 0.099, 1.05 | 0.042, 0.118, 1.08 |
No. of reflections | 802 | 1461 | 1452 |
No. of parameters | 91 | 91 | 91 |
No. of restraints | 1 | 0 | 0 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.19, −0.16 | 0.21, −0.19 | 0.23, −0.14 |
Computer programs: SMART (Siemens, 1995), SAINT (Siemens, 1995), SAINT, SHELXTL (Sheldrick, 1997), SHELXTL.
C | H | O | C-H···O | H···O | H···O=C | C···O |
ortho | ||||||
C7i | H1i | O1 | 153 | 2.80 | 132 | 3.670 (3) |
C8ii | H2ii | O1 | 144 | 2.77 | 92 | 3.583 (3) |
C3iii | H3iii | O1 | 131 | 2.66 | 130 | 3.360 (2) |
C4iv | H4iv | O2 | 144 | 2.67 | 103 | 3.482 (2) |
C6v | H6v | O2 | 116 | 2.80 | 98 | 3.323 (2) |
C6vi | H6vi | O2 | 137 | 2.57 | 164 | 3.330 (2) |
meta | polymorph-I | |||||
C8vii | H3vii | O1 | 118 | 2.77 | 130 | 3.318 (2) |
C8viii | H3viii | O1 | 148 | 2.64 | 101 | 3.482 (2) |
C4viii | H4viii | O1 | 143 | 2.72 | 142 | 3.522 (2) |
C5ix | H5ix | O1 | 157 | 2.58 | 124 | 3.470 (2) |
C7x | H1x | O3 | 150 | 2.66 | 154 | 3.517 (2) |
C2x | H2x | O3 | 149 | 2.64 | 146 | 3.485 (2) |
C6xi | H6xi | O3 | 172 | 2.65 | 92 | 3.595 (2) |
meta | polymorph-II | |||||
C4xii | H4xii | O1 | 158 | 2.55 | 141 | 3.449 (2) |
C5xiii | H5xiii | O1 | 128 | 2.67 | 155 | 3.337 (2) |
C6xiii | H6xiii | O1 | 121 | 2.82 | 107 | 3.413 (2) |
C7xiv | H1xiv | O3 | 163 | 2.52 | 168 | 3.443 (2) |
C8xv | H3xv | O3 | 143 | 2.81 | 117 | 3.606 (2) |
para | ||||||
C2A | H2A | O1A | 119 | 2.81 | 109 | 3.395 (2) |
C3A | H3A | O1A | 129 | 2.62 | 159 | 3.312 (2) |
C8B | H4B | O1A | 160 | 2.67 | 117 | 3.580 (2) |
C8B | H4B | O1A | 109 | 2.79 | 130 | 3.226 (2) |
C2B | H2B | O1B | 118 | 2.89 | 111 | 3.457 (2) |
C3B | H3B | O1B | 129 | 2.62 | 161 | 3.327 (2) |
C8A | H4A | O1B | 161 | 2.58 | 131 | 3.521 (2) |
C8A | H4A | O1B | 105 | 2.88 | 122 | 3.279 (2) |
All C-H distances were fixed at 0.95 Å. Symmetry codes: (i) -x, 1-y, 1/2+z; (ii) -x, 1-y, -1/2+z; (iii) 1/2-x, 1/2+y, -1/2+z; (iv) 1/2-x, 1/2+y, 1/2+z; (v) x, y, 1+z; (vi) -1/2+x, 3/2-y, 1+z; (vii) -1/2+x, 3/2-y, -1/2+z; (viii) 1/2+x, 3/2-y, -1/2+z; (ix) 1/2-x, -1/2+y, 3/2-z; (x) 2-x, 2-y, 1-z; (xi) -1/2+x, 3/2-y, 1/2+z; (xii) -1/2+x, 1/2-y, -1/2+z; (xiii) 1/2-x, -1/2+y, 3/2-z; (xiv) 1-x, 2-y, 1-z; (xv) 1/2-x, -1/2+y, 1/2-z. |
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In the structure of p-benzenedicarbaldehyde (Britton, 1998), there are short intermolecular C—H···O═C contacts involving the aldehyde H atoms. The structures of o- and m-benzenedicarbaldehyde, (I) and (II), respectively, have been determined, to look for further examples of such contacts, and the results are presented here. \sch
Views of (I) and the two isomorphs, A and B, of (II) are shown in Fig. 1. The bond lengths and angles are in the normal ranges. At the ring C atoms bonded to the aldehyde groups, the external C—C—C angles are not equal. In the ortho compound, (I), C7—C1—C2 [123.0 (2)°] and C8—C2—C1 [123.2 (2)°] are both 5–6° larger than C7—C1—C6 [117.1 (2)°] and C8—C2—C3 [117.8 (2)°]. This is consistent with the intramolecular hydrogen bonding forcing the groups apart (see below). In both polymorphs of the meta compound, (IIA) and (IIB), the external angles on the O side are about 2° larger than those on the H side. This can be attributed to the greater crowding between the O and ring H atoms than between the aldehyde H and ring H atoms.
There is one intramolecular C—H···O═C contact in the ortho compound, (I) (Fig. 2), with C8—H2···O1 112 (2)°, C8—H2 0.95 (2) Å, H2···O1 2.36 (2) Å, H2···O1═C7 98 (2)° and C8···O1 2.852 (2) Å. The corresponding values in naphthalene-2,3-dicarbaldehyde are 116 (2)°, 1.00 (2) Å, 2.30 (2) Å, 100 (2)° and 2.884 (2) Å (Britton, 1999). The two aldehyde groups are rotated by 13.3 (2) and 25.1 (2)° out of the plane of the benzene ring, compared with 7.2 (2) and 22.7 (2)° in the naphthalene compound. These rotations are both in the direction which increases the H···O distance, which is presumably the reason for the rotations. The smaller angles in the naphthalene compound are consistent with the longer C1—C2 length, 1.441 (2) versus. 1.411 (2) Å.
In the meta compound, (II), where there is less intramolecular crowding, the aldehyde groups are rotated 6.1 (2) and 6.6 (2)° in polymorph A, and 4.5 (2) and 10.1 (2)° in polymorph B.
The intermolecular H···O contacts of less than 2.82 Å are listed in Table 1 for both compounds, as well as for the para isomer (Britton, 1998) for comparison. If approximate linearity for the C—H···O angle and an approximate trigonal angle for H···O═C are taken as expected for a good C—H···O interaction, then none of the interactions in the ortho and meta compounds are as favorable as those in the para compound, although there are a number of H···O distances that are as short as those in the para compound. Overall, the contacts involving the aldehyde H atoms are no shorter than those involving the ring H atoms, suggesting there is no noticeable difference in their abilities to form C—H···O interactions. For an extended discussion of C—H···X interactions, see Desiraju & Steiner (1999).