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The phase behaviour of 4-[trans-4-(trans-4-propylcyclohexyl)cyclohexyl]benzonitrile, C22H31N, 1, has been examined. This compound has two different solid phases, denoted I and II, and exhibits thermotropic liquid-crystalline behaviour, with a remarkable interval of stability of the mesophase between the lower melting solid phase (75 °C) and the isotropization temperature (247 °C). The crystal and molecular structures of solid phase I have been determined at 173 K. The cyclohexyl rings both adopt the chair conformation and are equatorially substituted. The packing of 1 in the crystalline state is driven by the antiparallel arrangement of cyano dipoles with the formation of close contacts involving the strong cyano acceptor and weak aromatic C—H or aliphatic C—H donors. The crystal packing is discussed and compared with X-ray diffraction data in the liquid-crystalline state. The combination of thermal analysis, optical polarizing microscopy and X-ray diffraction analysis suggests that the mesophase is a partially ordered smectic phase. The lamellar structure of the mesophase is retained in crystalline solid phase II obtained by cooling the liquid-crystalline phase.
Supporting information
CCDC reference: 1857108
Data collection: COLLECT (Nonius, 1999); cell refinement: DIRAX/LSQ (Duisenberg et al., 2000); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and
Mercury (Macrae et al., 2020); software used to prepare material for publication: WinGX (Farrugia, 2012).
4-[
trans-4-(
trans-4-Propylcyclohexyl)cyclohexyl]benzonitrile
top
Crystal data top
C22H31N | Z = 2 |
Mr = 309.48 | F(000) = 340 |
Triclinic, P1 | Dx = 1.132 Mg m−3 |
a = 9.6230 (7) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 10.1300 (18) Å | Cell parameters from 93 reflections |
c = 10.1510 (18) Å | θ = 3.5–23.0° |
α = 104.686 (12)° | µ = 0.06 mm−1 |
β = 103.935 (14)° | T = 173 K |
γ = 98.024 (15)° | Prism, colourless |
V = 907.6 (3) Å3 | 0.40 × 0.40 × 0.30 mm |
Data collection top
Bruker–Nonius KappaCCD diffractometer | 4117 independent reflections |
Radiation source: normal-focus sealed tube | 3129 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.025 |
Detector resolution: 9 pixels mm-1 | θmax = 27.5°, θmin = 2.5° |
CCD rotation images, thick slices scans | h = −10→12 |
Absorption correction: multi-scan (SADABS; Bruker–Nonius, 2002) | k = −13→13 |
Tmin = 0.965, Tmax = 0.971 | l = −13→12 |
12255 measured 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)] = 0.043 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.143 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0719P)2 + 0.1945P] where P = (Fo2 + 2Fc2)/3 |
4117 reflections | (Δ/σ)max < 0.001 |
209 parameters | Δρmax = 0.32 e Å−3 |
0 restraints | Δρmin = −0.15 e Å−3 |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds involving l.s. planes. |
Refinement. Data for single-crystal structure determination were measured on a
Bruker–Nonius Kappa CCD diffractometer equipped with Oxford (Oxford,
United Kingdom) Cryostream 700 apparatus, using graphite-monochromated
Mo Kα radiation (λ = 0.71073 Å). For data collection, a single
crystal of approximate size 0.4 × 0.4 × 0.3 mm was attached to
the tip of a glass fiber with epoxy glue, and data collection was performed at
173 (2) K. Reduction of data and semi-empirical absorption correction were
done using the SADABS program (Bruker–Nonius, 2002). The structure was
solved by direct methods SIR97 program (Altomare et al., 1999)
and refined by the full-matrix least-squares method on F2 using the
SHELXL2015 program (Sheldrick, 2015) with the aid of the program
WinGX (Farrugia, 2012). The analysis of the crystal packing was
performed using the program Mercury (Macrae et al., 2020). |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.84162 (15) | 0.01984 (16) | −0.39658 (15) | 0.0397 (3) | |
H1A | 0.888723 | −0.025297 | −0.328427 | 0.060* | |
H1B | 0.916926 | 0.078691 | −0.419040 | 0.060* | |
H1C | 0.780508 | −0.051747 | −0.483822 | 0.060* | |
C2 | 0.74624 (14) | 0.10988 (13) | −0.33195 (14) | 0.0317 (3) | |
H2A | 0.808502 | 0.182382 | −0.244214 | 0.038* | |
H2B | 0.701566 | 0.157776 | −0.399839 | 0.038* | |
C3 | 0.62548 (13) | 0.02422 (12) | −0.29644 (13) | 0.0280 (3) | |
H3A | 0.671443 | −0.016565 | −0.222359 | 0.034* | |
H3B | 0.570598 | −0.054134 | −0.382398 | 0.034* | |
C4 | 0.51666 (12) | 0.10492 (11) | −0.24414 (12) | 0.0230 (2) | |
H4 | 0.474927 | 0.150023 | −0.317219 | 0.028* | |
C5 | 0.39027 (13) | 0.00589 (12) | −0.22930 (12) | 0.0259 (3) | |
H5A | 0.430384 | −0.044702 | −0.162272 | 0.031* | |
H5B | 0.340118 | −0.064108 | −0.322877 | 0.031* | |
C6 | 0.27836 (12) | 0.08118 (12) | −0.17608 (12) | 0.0253 (2) | |
H6A | 0.202860 | 0.012472 | −0.163207 | 0.030* | |
H6B | 0.228968 | 0.121602 | −0.249001 | 0.030* | |
C7 | 0.34774 (12) | 0.19771 (12) | −0.03552 (11) | 0.0226 (2) | |
H7 | 0.389643 | 0.153353 | 0.038192 | 0.027* | |
C8 | 0.47497 (13) | 0.29588 (12) | −0.05101 (13) | 0.0283 (3) | |
H8A | 0.435337 | 0.345942 | −0.118755 | 0.034* | |
H8B | 0.525248 | 0.366384 | 0.042222 | 0.034* | |
C9 | 0.58641 (13) | 0.21933 (13) | −0.10332 (13) | 0.0287 (3) | |
H9A | 0.663549 | 0.287426 | −0.114815 | 0.034* | |
H9B | 0.633736 | 0.177436 | −0.030810 | 0.034* | |
C10 | 0.23605 (12) | 0.27698 (11) | 0.01610 (11) | 0.0223 (2) | |
H10 | 0.202136 | 0.330148 | −0.051758 | 0.027* | |
C11 | 0.10115 (13) | 0.17884 (13) | 0.01877 (13) | 0.0283 (3) | |
H11A | 0.050446 | 0.117191 | −0.078976 | 0.034* | |
H11B | 0.133433 | 0.118955 | 0.078465 | 0.034* | |
C12 | −0.00672 (12) | 0.25675 (13) | 0.07645 (12) | 0.0283 (3) | |
H12A | −0.089174 | 0.188293 | 0.079434 | 0.034* | |
H12B | −0.047150 | 0.309011 | 0.011295 | 0.034* | |
C13 | 0.06575 (12) | 0.35873 (12) | 0.22571 (11) | 0.0233 (2) | |
H13 | 0.104632 | 0.303059 | 0.289162 | 0.028* | |
C14 | 0.19631 (13) | 0.45952 (12) | 0.22088 (13) | 0.0278 (3) | |
H14A | 0.246601 | 0.523231 | 0.317795 | 0.033* | |
H14B | 0.161054 | 0.516882 | 0.159335 | 0.033* | |
C15 | 0.30514 (12) | 0.38222 (13) | 0.16392 (12) | 0.0281 (3) | |
H15A | 0.347324 | 0.332423 | 0.230929 | 0.034* | |
H15B | 0.386352 | 0.451333 | 0.159835 | 0.034* | |
C16 | −0.04613 (12) | 0.42781 (12) | 0.28390 (11) | 0.0228 (2) | |
C17 | −0.16062 (14) | 0.34635 (13) | 0.30854 (14) | 0.0312 (3) | |
H17 | −0.165307 | 0.248868 | 0.290450 | 0.037* | |
C18 | −0.26768 (14) | 0.40267 (13) | 0.35845 (14) | 0.0309 (3) | |
H18 | −0.345100 | 0.344560 | 0.373460 | 0.037* | |
C19 | −0.26044 (12) | 0.54539 (12) | 0.38634 (11) | 0.0243 (2) | |
C20 | −0.14628 (14) | 0.62888 (13) | 0.36475 (14) | 0.0327 (3) | |
H20 | −0.140452 | 0.726670 | 0.384918 | 0.039* | |
C21 | −0.04058 (14) | 0.57022 (13) | 0.31384 (14) | 0.0318 (3) | |
H21 | 0.036973 | 0.628502 | 0.299196 | 0.038* | |
C22 | −0.37016 (13) | 0.60842 (12) | 0.43798 (12) | 0.0265 (3) | |
N1 | −0.45588 (12) | 0.66094 (11) | 0.47855 (12) | 0.0343 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0299 (7) | 0.0473 (8) | 0.0382 (7) | 0.0073 (6) | 0.0174 (6) | −0.0005 (6) |
C2 | 0.0287 (6) | 0.0330 (6) | 0.0330 (6) | 0.0047 (5) | 0.0166 (5) | 0.0031 (5) |
C3 | 0.0289 (6) | 0.0265 (6) | 0.0324 (6) | 0.0097 (5) | 0.0147 (5) | 0.0078 (5) |
C4 | 0.0233 (5) | 0.0233 (5) | 0.0249 (5) | 0.0065 (4) | 0.0105 (4) | 0.0075 (4) |
C5 | 0.0268 (6) | 0.0217 (5) | 0.0303 (6) | 0.0050 (5) | 0.0129 (5) | 0.0055 (4) |
C6 | 0.0225 (5) | 0.0232 (5) | 0.0285 (6) | 0.0032 (4) | 0.0102 (4) | 0.0032 (4) |
C7 | 0.0204 (5) | 0.0257 (6) | 0.0226 (5) | 0.0062 (4) | 0.0077 (4) | 0.0067 (4) |
C8 | 0.0241 (6) | 0.0258 (6) | 0.0311 (6) | 0.0015 (5) | 0.0124 (5) | −0.0004 (5) |
C9 | 0.0213 (6) | 0.0323 (6) | 0.0305 (6) | 0.0038 (5) | 0.0115 (5) | 0.0033 (5) |
C10 | 0.0195 (5) | 0.0259 (6) | 0.0214 (5) | 0.0057 (4) | 0.0068 (4) | 0.0053 (4) |
C11 | 0.0212 (6) | 0.0290 (6) | 0.0293 (6) | 0.0021 (5) | 0.0095 (5) | −0.0014 (5) |
C12 | 0.0193 (5) | 0.0313 (6) | 0.0285 (6) | 0.0027 (5) | 0.0075 (4) | −0.0002 (5) |
C13 | 0.0211 (5) | 0.0259 (5) | 0.0230 (5) | 0.0055 (4) | 0.0084 (4) | 0.0056 (4) |
C14 | 0.0240 (6) | 0.0273 (6) | 0.0283 (6) | 0.0013 (5) | 0.0116 (5) | −0.0001 (5) |
C15 | 0.0201 (5) | 0.0320 (6) | 0.0266 (6) | 0.0019 (5) | 0.0086 (4) | −0.0004 (5) |
C16 | 0.0218 (5) | 0.0260 (6) | 0.0205 (5) | 0.0054 (4) | 0.0073 (4) | 0.0056 (4) |
C17 | 0.0328 (6) | 0.0224 (6) | 0.0417 (7) | 0.0059 (5) | 0.0203 (5) | 0.0064 (5) |
C18 | 0.0294 (6) | 0.0267 (6) | 0.0388 (7) | 0.0036 (5) | 0.0188 (5) | 0.0064 (5) |
C19 | 0.0237 (5) | 0.0284 (6) | 0.0217 (5) | 0.0085 (5) | 0.0077 (4) | 0.0066 (4) |
C20 | 0.0357 (7) | 0.0255 (6) | 0.0445 (7) | 0.0112 (5) | 0.0205 (6) | 0.0126 (5) |
C21 | 0.0313 (6) | 0.0272 (6) | 0.0431 (7) | 0.0061 (5) | 0.0202 (5) | 0.0124 (5) |
C22 | 0.0273 (6) | 0.0254 (6) | 0.0270 (6) | 0.0053 (5) | 0.0093 (5) | 0.0071 (4) |
N1 | 0.0351 (6) | 0.0303 (5) | 0.0418 (6) | 0.0110 (5) | 0.0190 (5) | 0.0089 (5) |
Geometric parameters (Å, º) top
C1—C2 | 1.5249 (16) | C10—C11 | 1.5312 (16) |
C1—H1A | 0.9800 | C10—H10 | 1.0000 |
C1—H1B | 0.9800 | C11—C12 | 1.5265 (15) |
C1—H1C | 0.9800 | C11—H11A | 0.9900 |
C2—C3 | 1.5206 (16) | C11—H11B | 0.9900 |
C2—H2A | 0.9900 | C12—C13 | 1.5315 (16) |
C2—H2B | 0.9900 | C12—H12A | 0.9900 |
C3—C4 | 1.5276 (14) | C12—H12B | 0.9900 |
C3—H3A | 0.9900 | C13—C16 | 1.5182 (14) |
C3—H3B | 0.9900 | C13—C14 | 1.5232 (16) |
C4—C9 | 1.5224 (16) | C13—H13 | 1.0000 |
C4—C5 | 1.5272 (15) | C14—C15 | 1.5282 (14) |
C4—H4 | 1.0000 | C14—H14A | 0.9900 |
C5—C6 | 1.5277 (14) | C14—H14B | 0.9900 |
C5—H5A | 0.9900 | C15—H15A | 0.9900 |
C5—H5B | 0.9900 | C15—H15B | 0.9900 |
C6—C7 | 1.5304 (16) | C16—C21 | 1.3873 (16) |
C6—H6A | 0.9900 | C16—C17 | 1.3932 (16) |
C6—H6B | 0.9900 | C17—C18 | 1.3829 (15) |
C7—C8 | 1.5313 (15) | C17—H17 | 0.9500 |
C7—C10 | 1.5405 (14) | C18—C19 | 1.3893 (16) |
C7—H7 | 1.0000 | C18—H18 | 0.9500 |
C8—C9 | 1.5268 (15) | C19—C20 | 1.3860 (17) |
C8—H8A | 0.9900 | C19—C22 | 1.4430 (15) |
C8—H8B | 0.9900 | C20—C21 | 1.3860 (16) |
C9—H9A | 0.9900 | C20—H20 | 0.9500 |
C9—H9B | 0.9900 | C21—H21 | 0.9500 |
C10—C15 | 1.5300 (15) | C22—N1 | 1.1438 (15) |
| | | |
C2—C1—H1A | 109.5 | C15—C10—C7 | 111.68 (9) |
C2—C1—H1B | 109.5 | C11—C10—C7 | 112.56 (9) |
H1A—C1—H1B | 109.5 | C15—C10—H10 | 107.8 |
C2—C1—H1C | 109.5 | C11—C10—H10 | 107.8 |
H1A—C1—H1C | 109.5 | C7—C10—H10 | 107.8 |
H1B—C1—H1C | 109.5 | C12—C11—C10 | 112.91 (10) |
C3—C2—C1 | 112.11 (11) | C12—C11—H11A | 109.0 |
C3—C2—H2A | 109.2 | C10—C11—H11A | 109.0 |
C1—C2—H2A | 109.2 | C12—C11—H11B | 109.0 |
C3—C2—H2B | 109.2 | C10—C11—H11B | 109.0 |
C1—C2—H2B | 109.2 | H11A—C11—H11B | 107.8 |
H2A—C2—H2B | 107.9 | C11—C12—C13 | 111.99 (9) |
C2—C3—C4 | 115.12 (10) | C11—C12—H12A | 109.2 |
C2—C3—H3A | 108.5 | C13—C12—H12A | 109.2 |
C4—C3—H3A | 108.5 | C11—C12—H12B | 109.2 |
C2—C3—H3B | 108.5 | C13—C12—H12B | 109.2 |
C4—C3—H3B | 108.5 | H12A—C12—H12B | 107.9 |
H3A—C3—H3B | 107.5 | C16—C13—C14 | 114.86 (9) |
C9—C4—C5 | 109.06 (9) | C16—C13—C12 | 110.77 (9) |
C9—C4—C3 | 113.27 (9) | C14—C13—C12 | 108.66 (9) |
C5—C4—C3 | 110.65 (9) | C16—C13—H13 | 107.4 |
C9—C4—H4 | 107.9 | C14—C13—H13 | 107.4 |
C5—C4—H4 | 107.9 | C12—C13—H13 | 107.4 |
C3—C4—H4 | 107.9 | C13—C14—C15 | 111.68 (9) |
C4—C5—C6 | 112.96 (9) | C13—C14—H14A | 109.3 |
C4—C5—H5A | 109.0 | C15—C14—H14A | 109.3 |
C6—C5—H5A | 109.0 | C13—C14—H14B | 109.3 |
C4—C5—H5B | 109.0 | C15—C14—H14B | 109.3 |
C6—C5—H5B | 109.0 | H14A—C14—H14B | 107.9 |
H5A—C5—H5B | 107.8 | C14—C15—C10 | 113.20 (9) |
C5—C6—C7 | 112.75 (9) | C14—C15—H15A | 108.9 |
C5—C6—H6A | 109.0 | C10—C15—H15A | 108.9 |
C7—C6—H6A | 109.0 | C14—C15—H15B | 108.9 |
C5—C6—H6B | 109.0 | C10—C15—H15B | 108.9 |
C7—C6—H6B | 109.0 | H15A—C15—H15B | 107.8 |
H6A—C6—H6B | 107.8 | C21—C16—C17 | 117.61 (10) |
C6—C7—C8 | 109.04 (9) | C21—C16—C13 | 122.91 (10) |
C6—C7—C10 | 112.92 (9) | C17—C16—C13 | 119.48 (10) |
C8—C7—C10 | 111.98 (9) | C18—C17—C16 | 122.19 (11) |
C6—C7—H7 | 107.6 | C18—C17—H17 | 118.9 |
C8—C7—H7 | 107.6 | C16—C17—H17 | 118.9 |
C10—C7—H7 | 107.6 | C17—C18—C19 | 119.09 (11) |
C9—C8—C7 | 112.88 (9) | C17—C18—H18 | 120.5 |
C9—C8—H8A | 109.0 | C19—C18—H18 | 120.5 |
C7—C8—H8A | 109.0 | C20—C19—C18 | 119.76 (10) |
C9—C8—H8B | 109.0 | C20—C19—C22 | 119.32 (10) |
C7—C8—H8B | 109.0 | C18—C19—C22 | 120.92 (10) |
H8A—C8—H8B | 107.8 | C19—C20—C21 | 120.24 (11) |
C4—C9—C8 | 112.38 (9) | C19—C20—H20 | 119.9 |
C4—C9—H9A | 109.1 | C21—C20—H20 | 119.9 |
C8—C9—H9A | 109.1 | C20—C21—C16 | 121.10 (11) |
C4—C9—H9B | 109.1 | C20—C21—H21 | 119.4 |
C8—C9—H9B | 109.1 | C16—C21—H21 | 119.4 |
H9A—C9—H9B | 107.9 | N1—C22—C19 | 178.58 (12) |
C15—C10—C11 | 108.96 (9) | | |
| | | |
C1—C2—C3—C4 | −174.55 (10) | C11—C12—C13—C14 | 56.51 (12) |
C2—C3—C4—C9 | −64.17 (13) | C16—C13—C14—C15 | 178.88 (9) |
C2—C3—C4—C5 | 173.01 (10) | C12—C13—C14—C15 | −56.44 (12) |
C9—C4—C5—C6 | 54.31 (12) | C13—C14—C15—C10 | 56.92 (13) |
C3—C4—C5—C6 | 179.55 (9) | C11—C10—C15—C14 | −53.11 (13) |
C4—C5—C6—C7 | −55.35 (13) | C7—C10—C15—C14 | −178.08 (9) |
C5—C6—C7—C8 | 53.02 (12) | C14—C13—C16—C21 | 7.75 (16) |
C5—C6—C7—C10 | 178.17 (9) | C12—C13—C16—C21 | −115.82 (13) |
C6—C7—C8—C9 | −53.81 (13) | C14—C13—C16—C17 | −172.51 (10) |
C10—C7—C8—C9 | −179.50 (9) | C12—C13—C16—C17 | 63.92 (14) |
C5—C4—C9—C8 | −54.70 (12) | C21—C16—C17—C18 | 1.20 (18) |
C3—C4—C9—C8 | −178.40 (9) | C13—C16—C17—C18 | −178.55 (11) |
C7—C8—C9—C4 | 56.60 (13) | C16—C17—C18—C19 | −0.62 (19) |
C6—C7—C10—C15 | 174.04 (9) | C17—C18—C19—C20 | −0.41 (18) |
C8—C7—C10—C15 | −62.42 (12) | C17—C18—C19—C22 | 179.75 (11) |
C6—C7—C10—C11 | 51.10 (12) | C18—C19—C20—C21 | 0.80 (19) |
C8—C7—C10—C11 | 174.64 (9) | C22—C19—C20—C21 | −179.35 (11) |
C15—C10—C11—C12 | 52.83 (12) | C19—C20—C21—C16 | −0.2 (2) |
C7—C10—C11—C12 | 177.27 (9) | C17—C16—C21—C20 | −0.79 (18) |
C10—C11—C12—C13 | −56.52 (13) | C13—C16—C21—C20 | 178.96 (11) |
C11—C12—C13—C16 | −176.44 (9) | | |
Phase behaviour of 1 as reported in the literature (Cr is the crystal
phase, Sm is the smectic phase, N is the nematic phase and I is the isotropic
liquid phase) topReference | Phase transition temperatures (°C) |
Kojima et al. (1983) | Cr 73.6 Sm 81.1 N 238.9 I |
Poetsch et al. (1987) | Cr 55 N 184 I |
Sasnovski et al. (1997) | Cr 80 N 247 I |
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