cis,cis,cis-1,2,4,5-Cyclohexanetetracarboxylic acid, C10H12O8, (I), contains a mirror plane and the cyclohexane ring exhibits a chair conformation. Two crystallographically independent hydrogen bonds form R22(14), R22(16) and R44(16) ring motifs, and propagation of these two hydrogen bonds along the c and b axes generates C22(16) and C22(7) chains. cis,cis,cis-1,2:4,5-Cyclohexanetetracarboxylic dianhydride, C10H8O6, (II), was prepared by the reaction of (I) with acetic anhydride. The cyclohexane ring of (II) exhibits a boat conformation and the dihedral angle between the two anhydro rings is 117.5 (1)°.
Supporting information
CCDC references: 219570; 219571
Compound (I) was prepared by esterifying 1,2,4,5-benzenetetracarboxylic dianhydride with methanol in the presence of Ti(OBu)4 to give 1,2,4,5- benzenetetracarboxylic tetramethyl ester and then hydrogenating the latter at 423 K under 5 MPa hydrogen pressure in the presence of Ru on a carbon support (New Japan Chemical Co. Ltd., 1996). Hydrolysis of the resulting ester in the presence of water and sulfuric acid gave (I). Compound (II) was prepared by the reaction of (I) with acetic anhydride. Crystals of (I) and (II) suitable for X-ray diffraction studies were obtained by slow evaporation of an aqueous solution and an acetic anhydride solution, respectively, at room temperature.
For both compounds, data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1996); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 2000); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003) and ORTEPIII (Burnett et al., 1996); software used to prepare material for publication: SHELXL97, PLATON and PARST (Nardelli, 1995).
(I)
cis,
cis,
cis-1,2,4,5-cyclohexanetetracarboxylic acid
top
Crystal data top
C10H12O8 | ? # Insert any comments here. |
Mr = 260.20 | Dx = 1.559 Mg m−3 |
Orthorhombic, Pbcm | Cu Kα radiation, λ = 1.54178 Å |
Hall symbol: -P 2c 2b | Cell parameters from 25 reflections |
a = 5.9425 (18) Å | θ = 25.1–28.2° |
b = 12.436 (2) Å | µ = 1.21 mm−1 |
c = 14.999 (2) Å | T = 298 K |
V = 1108.5 (4) Å3 | Cubic, colorless |
Z = 4 | 0.20 × 0.20 × 0.20 mm |
F(000) = 544 | |
Data collection top
Rigaku AFC6R diffractometer | 1038 reflections with I > 2σ(I) |
Radiation source: fine-focus rotating anode | Rint = 0.016 |
Graphite monochromator | θmax = 74.9°, θmin = 5.9° |
2θ/ω scans | h = 0→7 |
Absorption correction: psi scan (North et al., 1968) | k = 0→16 |
Tmin = 0.774, Tmax = 0.786 | l = 0→19 |
1188 measured reflections | 3 standard reflections every 150 reflections |
1188 independent reflections | intensity decay: none |
Refinement top
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)] = 0.041 | H-atom parameters constrained |
wR(F2) = 0.113 | w = 1/[σ2(Fo2) + (0.0547P)2 + 0.3575P] where P = (Fo2 + 2Fc2)/3 |
S = 1.11 | (Δ/σ)max < 0.001 |
1188 reflections | Δρmax = 0.27 e Å−3 |
88 parameters | Δρmin = −0.20 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0050 (7) |
Crystal data top
C10H12O8 | V = 1108.5 (4) Å3 |
Mr = 260.20 | Z = 4 |
Orthorhombic, Pbcm | Cu Kα radiation |
a = 5.9425 (18) Å | µ = 1.21 mm−1 |
b = 12.436 (2) Å | T = 298 K |
c = 14.999 (2) Å | 0.20 × 0.20 × 0.20 mm |
Data collection top
Rigaku AFC6R diffractometer | 1038 reflections with I > 2σ(I) |
Absorption correction: psi scan (North et al., 1968) | Rint = 0.016 |
Tmin = 0.774, Tmax = 0.786 | 3 standard reflections every 150 reflections |
1188 measured reflections | intensity decay: none |
1188 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.041 | 0 restraints |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 1.11 | Δρmax = 0.27 e Å−3 |
1188 reflections | Δρmin = −0.20 e Å−3 |
88 parameters | |
Special details top
Experimental. ? #Insert any special details here. |
Refinement. For both compounds, the equivalent reflections, −h, −k, l, were measured up to 2θ =60° in order to obtain the Rint value, but these reflections were not included in the refinement. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.5595 (2) | 0.33961 (9) | 0.41822 (8) | 0.0545 (4) | |
O2 | 0.2624 (2) | 0.40312 (11) | 0.49090 (8) | 0.0573 (4) | |
H2 | 0.3470 | 0.3969 | 0.5338 | 0.086* | |
O3 | 0.46671 (18) | 0.58326 (9) | 0.36509 (8) | 0.0436 (3) | |
O4 | 0.1639 (3) | 0.68604 (11) | 0.36292 (14) | 0.0825 (6) | |
H4 | 0.2543 | 0.7319 | 0.3791 | 0.124* | |
C1 | 0.3669 (4) | 0.37454 (17) | 0.2500 | 0.0387 (5) | |
H1A | 0.4942 | 0.4234 | 0.2500 | 0.046* | |
H1B | 0.4251 | 0.3017 | 0.2500 | 0.046* | |
C2 | 0.2285 (3) | 0.39250 (12) | 0.33446 (10) | 0.0391 (4) | |
H2A | 0.1115 | 0.3370 | 0.3351 | 0.047* | |
C3 | 0.1063 (3) | 0.50196 (12) | 0.33583 (11) | 0.0402 (4) | |
H3 | −0.0019 | 0.4994 | 0.3851 | 0.048* | |
C4 | −0.0297 (4) | 0.5182 (2) | 0.2500 | 0.0451 (6) | |
H4A | −0.0913 | 0.5904 | 0.2500 | 0.054* | |
H4B | −0.1551 | 0.4683 | 0.2500 | 0.054* | |
C5 | 0.3702 (3) | 0.37538 (12) | 0.41726 (10) | 0.0420 (4) | |
C6 | 0.2663 (3) | 0.59341 (12) | 0.35542 (11) | 0.0401 (4) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0694 (9) | 0.0479 (7) | 0.0461 (7) | 0.0179 (6) | −0.0036 (6) | −0.0036 (5) |
O2 | 0.0593 (8) | 0.0766 (9) | 0.0360 (6) | 0.0029 (7) | 0.0040 (6) | −0.0004 (6) |
O3 | 0.0402 (6) | 0.0413 (6) | 0.0492 (7) | −0.0012 (4) | 0.0001 (5) | −0.0061 (5) |
O4 | 0.0626 (9) | 0.0414 (7) | 0.1434 (16) | 0.0141 (6) | −0.0346 (10) | −0.0263 (9) |
C1 | 0.0492 (12) | 0.0316 (10) | 0.0353 (11) | −0.0004 (9) | 0.000 | 0.000 |
C2 | 0.0462 (8) | 0.0332 (7) | 0.0380 (8) | −0.0098 (6) | 0.0027 (6) | 0.0016 (6) |
C3 | 0.0361 (7) | 0.0427 (8) | 0.0416 (8) | −0.0036 (6) | 0.0056 (6) | −0.0001 (6) |
C4 | 0.0303 (10) | 0.0517 (13) | 0.0534 (13) | −0.0059 (10) | 0.000 | 0.000 |
C5 | 0.0567 (10) | 0.0303 (7) | 0.0390 (9) | −0.0042 (7) | 0.0027 (7) | 0.0010 (6) |
C6 | 0.0442 (8) | 0.0353 (8) | 0.0409 (8) | 0.0027 (6) | −0.0018 (7) | −0.0030 (6) |
Geometric parameters (Å, º) top
O1—C5 | 1.210 (2) | C2—C5 | 1.515 (2) |
O2—C5 | 1.322 (2) | C2—C3 | 1.543 (2) |
O2—H2 | 0.8200 | C2—H2A | 0.9800 |
O3—C6 | 1.206 (2) | C3—C6 | 1.511 (2) |
O4—C6 | 1.3077 (19) | C3—C4 | 1.533 (2) |
O4—H4 | 0.8200 | C3—H3 | 0.9800 |
C1—C2i | 1.5267 (19) | C4—C3i | 1.533 (2) |
C1—C2 | 1.5267 (19) | C4—H4A | 0.9700 |
C1—H1A | 0.9700 | C4—H4B | 0.9700 |
C1—H1B | 0.9700 | | |
| | | |
C5—O2—H2 | 109.5 | C4—C3—C2 | 110.67 (14) |
C6—O4—H4 | 109.5 | C6—C3—H3 | 106.9 |
C2i—C1—C2 | 112.13 (19) | C4—C3—H3 | 106.9 |
C2i—C1—H1A | 109.2 | C2—C3—H3 | 106.9 |
C2—C1—H1A | 109.2 | C3i—C4—C3 | 114.19 (18) |
C2i—C1—H1B | 109.2 | C3—C4—H4A | 108.7 |
C2—C1—H1B | 109.2 | C3i—C4—H4A | 108.7 |
H1A—C1—H1B | 107.9 | C3—C4—H4B | 108.7 |
C5—C2—C1 | 111.11 (14) | C3i—C4—H4B | 108.7 |
C5—C2—C3 | 111.99 (12) | H4A—C4—H4B | 107.6 |
C1—C2—C3 | 113.18 (13) | O1—C5—O2 | 122.43 (15) |
C5—C2—H2A | 106.7 | O1—C5—C2 | 125.30 (15) |
C1—C2—H2A | 106.7 | O2—C5—C2 | 112.26 (14) |
C3—C2—H2A | 106.7 | O3—C6—O4 | 122.77 (15) |
C6—C3—C4 | 113.32 (14) | O3—C6—C3 | 124.45 (14) |
C6—C3—C2 | 111.75 (13) | O4—C6—C3 | 112.77 (14) |
| | | |
C2i—C1—C2—C5 | −179.39 (11) | C1—C2—C5—O1 | −8.5 (2) |
C2i—C1—C2—C3 | −52.4 (2) | C3—C2—C5—O1 | −136.13 (16) |
C5—C2—C3—C6 | 51.02 (17) | C1—C2—C5—O2 | 172.26 (15) |
C1—C2—C3—C6 | −75.53 (17) | C3—C2—C5—O2 | 44.60 (18) |
C5—C2—C3—C4 | 178.31 (13) | C4—C3—C6—O3 | −122.89 (18) |
C1—C2—C3—C4 | 51.77 (19) | C2—C3—C6—O3 | 3.0 (2) |
C6i—C3—C4—C3 | 74.0 (2) | C4—C3—C6—O4 | 58.5 (2) |
C2i—C3—C4—C3 | −52.5 (2) | C2—C3—C6—O4 | −175.62 (16) |
Symmetry code: (i) x, y, −z+1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3ii | 0.82 | 1.89 | 2.699 (2) | 167 |
O4—H4···O1iii | 0.82 | 1.83 | 2.653 (2) | 176 |
Symmetry codes: (ii) −x+1, −y+1, −z+1; (iii) −x+1, y+1/2, z. |
(II)
cis,
cis,
cis-1,2,4,5-cyclohexanetetracarboxylic dianhydride
top
Crystal data top
C10H8O6 | ? # Insert any comments here. |
Mr = 224.16 | Dx = 1.527 Mg m−3 |
Orthorhombic, Pna21 | Cu Kα radiation, λ = 1.54178 Å |
Hall symbol: P 2c -2n | Cell parameters from 25 reflections |
a = 13.591 (2) Å | θ = 26.6–28.4° |
b = 9.306 (2) Å | µ = 1.12 mm−1 |
c = 7.711 (3) Å | T = 298 K |
V = 975.2 (5) Å3 | Rod, colorless |
Z = 4 | 0.25 × 0.25 × 0.20 mm |
F(000) = 464 | |
Data collection top
Rigaku AFC6R diffractometer | 984 reflections with I > 2σ(I) |
Radiation source: fine-focus rotating anode | Rint = 0.017 |
Graphite monochromator | θmax = 74.9°, θmin = 5.8° |
2θ/ω scans | h = 0→17 |
Absorption correction: psi scan (North et al., 1968) | k = 0→11 |
Tmin = 0.723, Tmax = 0.799 | l = 0→9 |
1074 measured reflections | 3 standard reflections every 150 reflections |
1074 independent reflections | intensity decay: none |
Refinement top
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.039 | w = 1/[σ2(Fo2) + (0.0664P)2 + 0.1313P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.110 | (Δ/σ)max = 0.007 |
S = 1.07 | Δρmax = 0.19 e Å−3 |
1074 reflections | Δρmin = −0.16 e Å−3 |
146 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
1 restraint | Extinction coefficient: 0.053 (11) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983) |
Secondary atom site location: difference Fourier map | Absolute structure parameter: 0.0 (4) |
Crystal data top
C10H8O6 | V = 975.2 (5) Å3 |
Mr = 224.16 | Z = 4 |
Orthorhombic, Pna21 | Cu Kα radiation |
a = 13.591 (2) Å | µ = 1.12 mm−1 |
b = 9.306 (2) Å | T = 298 K |
c = 7.711 (3) Å | 0.25 × 0.25 × 0.20 mm |
Data collection top
Rigaku AFC6R diffractometer | 984 reflections with I > 2σ(I) |
Absorption correction: psi scan (North et al., 1968) | Rint = 0.017 |
Tmin = 0.723, Tmax = 0.799 | 3 standard reflections every 150 reflections |
1074 measured reflections | intensity decay: none |
1074 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.039 | H-atom parameters constrained |
wR(F2) = 0.110 | Δρmax = 0.19 e Å−3 |
S = 1.07 | Δρmin = −0.16 e Å−3 |
1074 reflections | Absolute structure: Flack (1983) |
146 parameters | Absolute structure parameter: 0.0 (4) |
1 restraint | |
Special details top
Experimental. ? #Insert any special details here. |
Refinement. For both compounds, the equivalent reflections, −h, −k, l, were measured up to 2θ =60° in order to obtain the Rint value, but these reflections were not included in the refinement. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.0649 (2) | 0.8750 (3) | 0.3765 (3) | 0.0820 (7) | |
O2 | 0.1939 (2) | 0.7333 (3) | 0.4120 (3) | 0.0919 (9) | |
O3 | 0.3093 (3) | 0.5875 (5) | 0.5180 (5) | 0.1437 (17) | |
O4 | 0.1157 (2) | 0.4727 (3) | 1.1692 (6) | 0.1178 (13) | |
O5 | −0.01415 (16) | 0.6148 (3) | 1.1308 (4) | 0.0788 (8) | |
O6 | −0.11751 (15) | 0.7871 (3) | 1.0483 (4) | 0.0850 (8) | |
C1 | 0.13272 (19) | 0.8416 (3) | 0.6675 (3) | 0.0457 (6) | |
H1 | 0.1533 | 0.9400 | 0.6945 | 0.055* | |
C2 | 0.2154 (2) | 0.7375 (3) | 0.7165 (4) | 0.0525 (6) | |
H2 | 0.2697 | 0.7913 | 0.7693 | 0.063* | |
C3 | 0.18218 (19) | 0.6205 (3) | 0.8393 (4) | 0.0529 (6) | |
H3A | 0.2382 | 0.5631 | 0.8753 | 0.064* | |
H3B | 0.1354 | 0.5580 | 0.7817 | 0.064* | |
C4 | 0.13404 (17) | 0.6905 (2) | 0.9979 (3) | 0.0443 (6) | |
H4 | 0.1847 | 0.7390 | 1.0670 | 0.053* | |
C5 | 0.05272 (17) | 0.7980 (3) | 0.9529 (3) | 0.0431 (5) | |
H5 | 0.0700 | 0.8927 | 0.9997 | 0.052* | |
C6 | 0.03488 (18) | 0.8107 (3) | 0.7570 (4) | 0.0469 (6) | |
H6A | 0.0071 | 0.7219 | 0.7129 | 0.056* | |
H6B | −0.0113 | 0.8878 | 0.7338 | 0.056* | |
C7 | 0.1230 (2) | 0.8252 (3) | 0.4731 (4) | 0.0615 (8) | |
C8 | 0.2486 (3) | 0.6758 (5) | 0.5462 (5) | 0.0873 (11) | |
C9 | 0.0839 (2) | 0.5798 (4) | 1.1075 (5) | 0.0708 (9) | |
C10 | −0.03653 (18) | 0.7426 (4) | 1.0442 (4) | 0.0582 (7) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.1054 (18) | 0.0974 (17) | 0.0432 (11) | 0.0191 (14) | −0.0082 (13) | 0.0124 (12) |
O2 | 0.1006 (19) | 0.132 (2) | 0.0432 (13) | 0.0411 (18) | 0.0059 (12) | −0.0116 (15) |
O3 | 0.130 (3) | 0.215 (4) | 0.085 (2) | 0.104 (3) | 0.006 (2) | −0.030 (3) |
O4 | 0.0900 (18) | 0.0946 (18) | 0.169 (3) | −0.0099 (15) | −0.015 (2) | 0.082 (2) |
O5 | 0.0572 (11) | 0.0897 (16) | 0.0896 (17) | −0.0190 (11) | 0.0076 (12) | 0.0368 (14) |
O6 | 0.0487 (11) | 0.127 (2) | 0.0795 (17) | 0.0076 (12) | 0.0146 (11) | 0.0118 (17) |
C1 | 0.0523 (13) | 0.0461 (12) | 0.0387 (12) | −0.0042 (11) | 0.0006 (10) | −0.0001 (9) |
C2 | 0.0408 (12) | 0.0692 (16) | 0.0476 (14) | 0.0026 (12) | −0.0014 (10) | −0.0068 (13) |
C3 | 0.0463 (12) | 0.0490 (12) | 0.0635 (17) | 0.0064 (10) | −0.0136 (12) | −0.0027 (13) |
C4 | 0.0386 (11) | 0.0481 (11) | 0.0463 (13) | −0.0084 (9) | −0.0089 (10) | 0.0091 (10) |
C5 | 0.0429 (12) | 0.0472 (12) | 0.0394 (12) | −0.0026 (9) | 0.0009 (10) | 0.0024 (10) |
C6 | 0.0447 (12) | 0.0538 (13) | 0.0422 (13) | 0.0057 (10) | −0.0057 (11) | 0.0029 (11) |
C7 | 0.0737 (19) | 0.0714 (18) | 0.0395 (13) | 0.0020 (14) | 0.0034 (13) | 0.0047 (13) |
C8 | 0.081 (2) | 0.121 (3) | 0.060 (2) | 0.035 (2) | 0.0075 (18) | −0.017 (2) |
C9 | 0.0594 (16) | 0.0703 (16) | 0.083 (2) | −0.0122 (14) | −0.0085 (16) | 0.0330 (18) |
C10 | 0.0450 (13) | 0.0790 (17) | 0.0505 (15) | −0.0083 (13) | 0.0016 (11) | 0.0089 (14) |
Geometric parameters (Å, º) top
O1—C7 | 1.181 (4) | C2—C3 | 1.512 (4) |
O2—C7 | 1.371 (4) | C2—H2 | 0.9800 |
O2—C8 | 1.382 (5) | C3—C4 | 1.532 (4) |
O3—C8 | 1.185 (5) | C3—H3A | 0.9700 |
O4—C9 | 1.185 (4) | C3—H3B | 0.9700 |
O5—C9 | 1.384 (4) | C4—C9 | 1.497 (4) |
O5—C10 | 1.397 (4) | C4—C5 | 1.531 (3) |
O6—C10 | 1.176 (3) | C4—H4 | 0.9800 |
C1—C7 | 1.512 (4) | C5—C10 | 1.494 (3) |
C1—C6 | 1.525 (4) | C5—C6 | 1.535 (4) |
C1—C2 | 1.531 (4) | C5—H5 | 0.9800 |
C1—H1 | 0.9800 | C6—H6A | 0.9700 |
C2—C8 | 1.503 (5) | C6—H6B | 0.9700 |
| | | |
C7—O2—C8 | 111.2 (3) | C3—C4—H4 | 109.2 |
C9—O5—C10 | 110.4 (2) | C10—C5—C4 | 104.7 (2) |
C7—C1—C6 | 110.7 (2) | C10—C5—C6 | 111.2 (2) |
C7—C1—C2 | 104.2 (2) | C4—C5—C6 | 112.8 (2) |
C6—C1—C2 | 114.2 (2) | C10—C5—H5 | 109.3 |
C7—C1—H1 | 109.2 | C4—C5—H5 | 109.3 |
C6—C1—H1 | 109.2 | C6—C5—H5 | 109.3 |
C2—C1—H1 | 109.2 | C1—C6—C5 | 108.8 (2) |
C8—C2—C3 | 111.2 (3) | C1—C6—H6A | 109.9 |
C8—C2—C1 | 104.3 (3) | C5—C6—H6A | 109.9 |
C3—C2—C1 | 113.0 (2) | C1—C6—H6B | 109.9 |
C8—C2—H2 | 109.4 | C5—C6—H6B | 109.9 |
C3—C2—H2 | 109.4 | H6A—C6—H6B | 108.3 |
C1—C2—H2 | 109.4 | O1—C7—O2 | 119.8 (3) |
C2—C3—C4 | 108.74 (19) | O1—C7—C1 | 130.1 (3) |
C2—C3—H3A | 109.9 | O2—C7—C1 | 110.0 (3) |
C4—C3—H3A | 109.9 | O3—C8—O2 | 120.4 (4) |
C2—C3—H3B | 109.9 | O3—C8—C2 | 129.4 (4) |
C4—C3—H3B | 109.9 | O2—C8—C2 | 110.1 (3) |
H3A—C3—H3B | 108.3 | O4—C9—O5 | 119.8 (3) |
C9—C4—C5 | 104.4 (2) | O4—C9—C4 | 129.7 (3) |
C9—C4—C3 | 110.6 (2) | O5—C9—C4 | 110.4 (2) |
C5—C4—C3 | 113.9 (2) | O6—C10—O5 | 119.4 (3) |
C9—C4—H4 | 109.2 | O6—C10—C5 | 130.6 (3) |
C5—C4—H4 | 109.2 | O5—C10—C5 | 110.0 (2) |
| | | |
C7—C1—C2—C8 | 2.3 (3) | C6—C1—C7—O2 | −127.0 (3) |
C6—C1—C2—C8 | 123.2 (3) | C2—C1—C7—O2 | −3.8 (4) |
C7—C1—C2—C3 | −118.6 (3) | C7—O2—C8—O3 | 175.5 (5) |
C6—C1—C2—C3 | 2.3 (3) | C7—O2—C8—C2 | −2.3 (5) |
C8—C2—C3—C4 | −171.0 (2) | C3—C2—C8—O3 | −55.7 (7) |
C1—C2—C3—C4 | −54.1 (3) | C1—C2—C8—O3 | −177.8 (6) |
C2—C3—C4—C9 | 169.8 (2) | C3—C2—C8—O2 | 121.9 (3) |
C2—C3—C4—C5 | 52.5 (3) | C1—C2—C8—O2 | −0.2 (4) |
C9—C4—C5—C10 | 1.6 (3) | C10—O5—C9—O4 | −178.5 (4) |
C3—C4—C5—C10 | 122.3 (2) | C10—O5—C9—C4 | 0.3 (4) |
C9—C4—C5—C6 | −119.5 (3) | C5—C4—C9—O4 | 177.5 (5) |
C3—C4—C5—C6 | 1.3 (3) | C3—C4—C9—O4 | 54.5 (5) |
C7—C1—C6—C5 | 168.5 (2) | C5—C4—C9—O5 | −1.2 (4) |
C2—C1—C6—C5 | 51.4 (3) | C3—C4—C9—O5 | −124.1 (3) |
C10—C5—C6—C1 | −170.0 (2) | C9—O5—C10—O6 | 178.8 (3) |
C4—C5—C6—C1 | −52.7 (3) | C9—O5—C10—C5 | 0.8 (4) |
C8—O2—C7—O1 | −174.1 (4) | C4—C5—C10—O6 | −179.3 (4) |
C8—O2—C7—C1 | 3.9 (4) | C6—C5—C10—O6 | −57.1 (5) |
C6—C1—C7—O1 | 50.8 (5) | C4—C5—C10—O5 | −1.5 (3) |
C2—C1—C7—O1 | 174.0 (3) | C6—C5—C10—O5 | 120.6 (3) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···O3i | 0.98 | 2.45 | 3.320 (5) | 148 |
C2—H2···O4ii | 0.98 | 2.42 | 3.193 (4) | 135 |
C6—H6A···O4iii | 0.97 | 2.49 | 3.406 (4) | 158 |
Symmetry codes: (i) −x+1/2, y+1/2, z+1/2; (ii) −x+1/2, y+1/2, z−1/2; (iii) −x, −y+1, z−1/2. |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | C10H12O8 | C10H8O6 |
Mr | 260.20 | 224.16 |
Crystal system, space group | Orthorhombic, Pbcm | Orthorhombic, Pna21 |
Temperature (K) | 298 | 298 |
a, b, c (Å) | 5.9425 (18), 12.436 (2), 14.999 (2) | 13.591 (2), 9.306 (2), 7.711 (3) |
V (Å3) | 1108.5 (4) | 975.2 (5) |
Z | 4 | 4 |
Radiation type | Cu Kα | Cu Kα |
µ (mm−1) | 1.21 | 1.12 |
Crystal size (mm) | 0.20 × 0.20 × 0.20 | 0.25 × 0.25 × 0.20 |
|
Data collection |
Diffractometer | Rigaku AFC6R diffractometer | Rigaku AFC6R diffractometer |
Absorption correction | Psi scan (North et al., 1968) | Psi scan (North et al., 1968) |
Tmin, Tmax | 0.774, 0.786 | 0.723, 0.799 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1188, 1188, 1038 | 1074, 1074, 984 |
Rint | 0.016 | 0.017 |
(sin θ/λ)max (Å−1) | 0.626 | 0.626 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.041, 0.113, 1.11 | 0.039, 0.110, 1.07 |
No. of reflections | 1188 | 1074 |
No. of parameters | 88 | 146 |
No. of restraints | 0 | 1 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.27, −0.20 | 0.19, −0.16 |
Absolute structure | ? | Flack (1983) |
Absolute structure parameter | ? | 0.0 (4) |
Selected geometric parameters (Å, º) for (I) topC1—C2 | 1.5267 (19) | C3—C4 | 1.533 (2) |
C2—C3 | 1.543 (2) | | |
| | | |
C2i—C1—C2 | 112.13 (19) | C4—C3—C2 | 110.67 (14) |
C1—C2—C3 | 113.18 (13) | C3i—C4—C3 | 114.19 (18) |
| | | |
C1—C2—C5—O1 | −8.5 (2) | C2—C3—C6—O3 | 3.0 (2) |
Symmetry code: (i) x, y, −z+1/2. |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3ii | 0.82 | 1.89 | 2.699 (2) | 167 |
O4—H4···O1iii | 0.82 | 1.83 | 2.653 (2) | 176 |
Symmetry codes: (ii) −x+1, −y+1, −z+1; (iii) −x+1, y+1/2, z. |
Selected geometric parameters (Å, º) for (II) topO2—C7 | 1.371 (4) | C1—C2 | 1.531 (4) |
O2—C8 | 1.382 (5) | C2—C3 | 1.512 (4) |
O5—C9 | 1.384 (4) | C3—C4 | 1.532 (4) |
O5—C10 | 1.397 (4) | C4—C5 | 1.531 (3) |
C1—C6 | 1.525 (4) | C5—C6 | 1.535 (4) |
| | | |
C7—O2—C8 | 111.2 (3) | C2—C3—C4 | 108.74 (19) |
C9—O5—C10 | 110.4 (2) | C5—C4—C3 | 113.9 (2) |
C6—C1—C2 | 114.2 (2) | C4—C5—C6 | 112.8 (2) |
C3—C2—C1 | 113.0 (2) | C1—C6—C5 | 108.8 (2) |
| | | |
C2—C1—C7—O1 | 174.0 (3) | C5—C4—C9—O4 | 177.5 (5) |
C1—C2—C8—O3 | −177.8 (6) | C4—C5—C10—O6 | −179.3 (4) |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···O3i | 0.98 | 2.45 | 3.320 (5) | 148 |
C2—H2···O4ii | 0.98 | 2.42 | 3.193 (4) | 135 |
C6—H6A···O4iii | 0.97 | 2.49 | 3.406 (4) | 158 |
Symmetry codes: (i) −x+1/2, y+1/2, z+1/2; (ii) −x+1/2, y+1/2, z−1/2; (iii) −x, −y+1, z−1/2. |
Over the past 15 years, considerable efforts have been made to obtain polyimide films possessing low linear thermal-expansion coefficients (CTEs) in order to reduce thermal stress (Numata et al., 1986, 1987). Recently, polyimides with low dielectric constants (ε) have also been in demand, in order to increase the signal-propagation rate in chips (Matsuura et al., 1991; Sachdev et al., 1999). We have tried to develop polyimides showing both low CTE and low ε. According to the structure–property relationship, promising as target materials include polyimides with stiff linear-chain structures for low CTE and low polarizability for low ε (Hasegawa 2001). We have highlighted the combination of cycloaliphatic 1,2,4,5-cyclohexanetetracarboxylic anhydride, (II), and rod-like 2,2'-bis(trifluromethyl)benzidine, (III). The polyimide film (IV) resulted in low ε values, as expected, but did not show low CTE (Hasegawa et al., 2001). The present X-ray investigation was undertaken to obtain structural information about (II) and its intermediate, 1,2,4,5-cyclohexanetetracarboxylic acid, (I).
In (I), atoms C1 and C4 lie on a mirror plane (Fig. 1). The cyclohexane ring assumes a chair conformation, with the carboxyl group on atom C2 in an equatorial position and that on C3 in an axial position, resulting in the four carboxyl groups being in a mutually cis conformation, which is roughly similar to that of cis,cis,cis- tetramethyl 1,2,4,5-cyclohexanetetracarboxylate, (V) (Robinson et al., 2000). Among the endocyclic angles, the C3—C4—C3i angle [114.2 (2)°] of (I) (Table 1) and the corresponding angle [114.6 (3)°] of (V) are the largest because of the 1,3-diaxial repulsion, and the angles at atoms with the axial substituents in both structures [110.7 (1)° in (I) and 108.9 (3) and 110.7 (3) ° in (V)] are smaller [symmetry code: (i) x, y, 1/2 − z]. The two carbonyl goups of the carboxyl groups in (I) are synperiplanar with respect to an endocyclic bond [O1—C5—C2—C1 = −8.5 (2)° and O3—C6—C3—C2 = 3.0 (2)°], and all four carbonyl groups in (V) are also synperiplanar, with larger deviations from an eclipsed position [the corresponding torsion angles are −13.0 (6) and 21.4 (5)° for the equatorial carboxyl groups and −19.8 (5) and −25.6 (5)° for the axial ones].
Two crystallographically independent hydrogen bonds (Table 2 and Fig. 2), viz. O2—H2···O3 and O4—H4···O1, form R22(14) rings about an inversion center, R22(16) rings along a 21 screw axis and R44(16) rigns about a twofold axis (Etter, 1990; Bernstein et al., 1995). Propagation of these two hydrogen bonds along the c and b axes generates two chain motifs, viz. C22(16) and C22(7). This results in two-dimensional networks perpendicular to the a axis.
The structure of (II) is shown in Fig. 3. The molecule possesses approximate C2v symmetry. The displacement ellipsoids of atoms O3 and O4 are appreciably larger than those of the other atoms, which may be due to hydrolysis of the anhydro rings, where the hydrogen bonds associated with atoms O3 and O4 may promote the reaction (Table 4 and Fig. 4). Crystals kept at ambient temperature showed degradation of crystallinity in a few months.
The cyclohexane ring of (II) assumes a boat conformation [Cremer & Pople (1975) puckering parameters are Q = 0.749 (2) Å, θ =90.3 (2)° and ϕ = −61.8 (2)°], while the cyclohexane ring of cis-1,2-cyclohexane-dicarboxylic acid anhydride, (VI), adopts a chair conformation (Pawel et al., 1982). The mean torsion angle of the cyclohexane ring of (I) is 52.2 (1)°, and the corresponding value in (VI) is 49 (4)°. The cyclohexane ring of (VI) is largely flattened at the anhydro side of the ring and puckered at the opposite side. Although the anhydro ring of (VI) adopts a slightly distorted envelope conformation, the anhydro rings of (II) assume a favorable planar conformation [maximum deviations are 0.03 Å for C1/C2/C8/O2/C7 and 0.01 Å for C4/C5/C10/O5/C9], as observed in succinic anhydride (Ehrenberg, 1965; Fodor et al., 1984) and 5,6,11,12-tetrahydro-5,12;6, 11-di-o-benzenodibenzo[a,e]cyclooctene-5,6-dicarboxylic anhydride (Cicogna et al., 2002). For (VI), the strain induced from anhydro ring formation is relaxed by the deformations of the anhydro and cyclohexane rings, while for (II), the cyclohexane adopts a boat conformation, because the four carboxyl groups that are mutually in the cis conformation form anhydro rings at either side of the cyclohexane ring.
The dihedral angle between the two anhydro rings is 117.5 (1)°. Hence, the polyimide chain containing (II) as an anhydride monomer is expected to be non-linear. We ascribe the low CTE of the polyimide film (IV) to the non-linearity of the polyimide chain.