Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801000903/bt6005sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536801000903/bt6005Isup2.hkl |
CCDC reference: 159721
Key indicators
- Single-crystal X-ray study
- T = 296 K
- Mean (C-C) = 0.005 Å
- R factor = 0.059
- wR factor = 0.193
- Data-to-parameter ratio = 21.1
checkCIF results
No syntax errors found ADDSYM reports no extra symmetry
Alert Level C:
PLAT_371 Alert C Long C(sp2)-C(sp1) Bond C(1) - C(2) = 1.44 Ang.
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
1 Alert Level C = Please check
The title compound (CP12OB) was prepared by esterification of 4-cyanophenol with 4-n-dodecanyloxybenzoyl chloride. The single crystals of CP12OB were obtained by recrystallization from ethyl acetate.
The positional parameters of the H atoms were calculated geometrically and refined using a riding model. Their Uiso values were fixed to 1.2 times Ueq of the bonded non-H atoms.
Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SIR97 (Altomare et al., 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Xtal_GX (Hall & du Boulay, 1995); software used to prepare material for publication: SHELXL97.
Fig. 1. The molecular structure of CP12OB showing 50% probability displacement ellipsoids. | |
Fig. 2. Packing diagram viewed down the a axis. H atoms have been omitted for clarity. |
C26H33NO3 | Z = 2 |
Mr = 407.53 | F(000) = 440 |
Triclinic, P1 | Dx = 1.130 Mg m−3 |
a = 11.031 (5) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 16.639 (5) Å | Cell parameters from 18 reflections |
c = 6.813 (5) Å | θ = 9.1–18.0° |
α = 95.381 (5)° | µ = 0.07 mm−1 |
β = 94.530 (5)° | T = 296 K |
γ = 104.686 (5)° | Prism, colorless |
V = 1197.4 (11) Å3 | 0.43 × 0.43 × 0.10 mm |
Enraf-Nonius FR590 diffractometer | 1764 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.039 |
Graphite monochromator | θmax = 28.0°, θmin = 2.8° |
ω–2θ scans | h = −14→14 |
Absorption correction: empirical (using intensity measurements) via ψ scans (North et al., 1968) | k = −21→21 |
Tmin = 0.961, Tmax = 0.991 | l = −8→0 |
6224 measured reflections | 3 standard reflections every 120 min |
5747 independent reflections | intensity decay: 5.7% |
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)] = 0.059 | H-atom parameters constrained |
wR(F2) = 0.193 | w = 1/[σ2(Fo2) + (0.0774P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.91 | (Δ/σ)max < 0.001 |
5747 reflections | Δρmax = 0.17 e Å−3 |
272 parameters | Δρmin = −0.17 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: 0.0080 (18) |
C26H33NO3 | γ = 104.686 (5)° |
Mr = 407.53 | V = 1197.4 (11) Å3 |
Triclinic, P1 | Z = 2 |
a = 11.031 (5) Å | Mo Kα radiation |
b = 16.639 (5) Å | µ = 0.07 mm−1 |
c = 6.813 (5) Å | T = 296 K |
α = 95.381 (5)° | 0.43 × 0.43 × 0.10 mm |
β = 94.530 (5)° |
Enraf-Nonius FR590 diffractometer | 1764 reflections with I > 2σ(I) |
Absorption correction: empirical (using intensity measurements) via ψ scans (North et al., 1968) | Rint = 0.039 |
Tmin = 0.961, Tmax = 0.991 | 3 standard reflections every 120 min |
6224 measured reflections | intensity decay: 5.7% |
5747 independent reflections |
R[F2 > 2σ(F2)] = 0.059 | 0 restraints |
wR(F2) = 0.193 | H-atom parameters constrained |
S = 0.91 | Δρmax = 0.17 e Å−3 |
5747 reflections | Δρmin = −0.17 e Å−3 |
272 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
N1 | −0.4339 (3) | 0.4684 (2) | 1.2208 (4) | 0.1022 (11) | |
O1 | 0.0859 (2) | 0.44265 (15) | 0.6033 (3) | 0.0937 (8) | |
O2 | −0.10191 (18) | 0.34921 (12) | 0.5171 (3) | 0.0693 (6) | |
O3 | 0.1612 (2) | 0.23849 (13) | −0.1957 (3) | 0.0838 (7) | |
C1 | −0.3756 (3) | 0.4506 (2) | 1.1026 (5) | 0.0717 (9) | |
C2 | −0.3025 (3) | 0.42646 (17) | 0.9517 (4) | 0.0592 (8) | |
C3 | −0.1809 (3) | 0.42189 (19) | 1.0048 (4) | 0.0676 (9) | |
H3 | −0.1468 | 0.4350 | 1.1367 | 0.081* | |
C4 | −0.1101 (3) | 0.39797 (19) | 0.8635 (4) | 0.0689 (9) | |
H4 | −0.0288 | 0.3941 | 0.8992 | 0.083* | |
C5 | −0.1612 (3) | 0.38009 (17) | 0.6704 (4) | 0.0573 (8) | |
C6 | −0.2812 (3) | 0.38472 (18) | 0.6149 (4) | 0.0656 (9) | |
H6 | −0.3148 | 0.3718 | 0.4828 | 0.079* | |
C7 | −0.3520 (3) | 0.40885 (19) | 0.7571 (5) | 0.0700 (9) | |
H7 | −0.4330 | 0.4131 | 0.7206 | 0.084* | |
C8 | 0.0215 (3) | 0.3854 (2) | 0.4936 (4) | 0.0645 (9) | |
C9 | 0.0585 (3) | 0.34436 (18) | 0.3163 (4) | 0.0565 (8) | |
C10 | 0.1759 (3) | 0.37957 (18) | 0.2563 (4) | 0.0636 (9) | |
H10 | 0.2296 | 0.4262 | 0.3323 | 0.076* | |
C11 | 0.2143 (3) | 0.34654 (18) | 0.0860 (4) | 0.0645 (9) | |
H11 | 0.2924 | 0.3714 | 0.0461 | 0.077* | |
C12 | 0.1360 (3) | 0.27650 (19) | −0.0241 (4) | 0.0636 (8) | |
C13 | 0.0211 (3) | 0.23955 (19) | 0.0390 (5) | 0.0766 (10) | |
H13 | −0.0305 | 0.1910 | −0.0327 | 0.092* | |
C14 | −0.0177 (3) | 0.27365 (19) | 0.2060 (4) | 0.0705 (9) | |
H14 | −0.0961 | 0.2488 | 0.2450 | 0.085* | |
C15 | 0.2753 (3) | 0.27311 (19) | −0.2774 (4) | 0.0716 (9) | |
H15A | 0.3475 | 0.2752 | −0.1841 | 0.086* | |
H15B | 0.2789 | 0.3294 | −0.3075 | 0.086* | |
C16 | 0.2759 (3) | 0.21705 (18) | −0.4639 (4) | 0.0703 (9) | |
H16A | 0.2057 | 0.2185 | −0.5576 | 0.084* | |
H16B | 0.2630 | 0.1600 | −0.4324 | 0.084* | |
C17 | 0.3964 (3) | 0.24100 (19) | −0.5615 (4) | 0.0676 (9) | |
H17A | 0.4669 | 0.2409 | −0.4670 | 0.081* | |
H17B | 0.4082 | 0.2975 | −0.5964 | 0.081* | |
C18 | 0.3973 (3) | 0.18290 (19) | −0.7463 (4) | 0.0752 (10) | |
H18A | 0.3817 | 0.1262 | −0.7115 | 0.090* | |
H18B | 0.3282 | 0.1846 | −0.8416 | 0.090* | |
C19 | 0.5166 (3) | 0.2023 (2) | −0.8441 (4) | 0.0779 (10) | |
H19A | 0.5862 | 0.2016 | −0.7483 | 0.093* | |
H19B | 0.5314 | 0.2585 | −0.8819 | 0.093* | |
C20 | 0.5168 (3) | 0.1428 (2) | −1.0253 (5) | 0.0823 (10) | |
H20A | 0.4984 | 0.0864 | −0.9879 | 0.099* | |
H20B | 0.4487 | 0.1450 | −1.1221 | 0.099* | |
C21 | 0.6362 (3) | 0.1583 (2) | −1.1232 (5) | 0.0848 (11) | |
H21A | 0.7043 | 0.1554 | −1.0272 | 0.102* | |
H21B | 0.6552 | 0.2147 | −1.1601 | 0.102* | |
C22 | 0.6335 (3) | 0.0987 (2) | −1.3043 (5) | 0.0925 (12) | |
H22A | 0.6062 | 0.0422 | −1.2692 | 0.111* | |
H22B | 0.5698 | 0.1053 | −1.4034 | 0.111* | |
C23 | 0.7510 (3) | 0.1062 (2) | −1.3964 (6) | 0.1068 (13) | |
H23A | 0.8145 | 0.0991 | −1.2975 | 0.128* | |
H23B | 0.7787 | 0.1628 | −1.4304 | 0.128* | |
C24 | 0.7486 (4) | 0.0477 (2) | −1.5768 (6) | 0.1111 (14) | |
H24A | 0.7119 | −0.0087 | −1.5473 | 0.133* | |
H24B | 0.6923 | 0.0593 | −1.6806 | 0.133* | |
C25 | 0.8672 (5) | 0.0489 (3) | −1.6561 (8) | 0.163 (2) | |
H25A | 0.9225 | 0.0358 | −1.5531 | 0.195* | |
H25B | 0.9050 | 0.1058 | −1.6813 | 0.195* | |
C26 | 0.8663 (5) | −0.0062 (3) | −1.8358 (8) | 0.190 (3) | |
H26A | 0.9510 | 0.0003 | −1.8687 | 0.286* | |
H26B | 0.8166 | 0.0079 | −1.9428 | 0.286* | |
H26C | 0.8306 | −0.0632 | −1.8143 | 0.286* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.105 (2) | 0.156 (3) | 0.073 (2) | 0.075 (2) | 0.0354 (18) | 0.016 (2) |
O1 | 0.0800 (16) | 0.1069 (18) | 0.0763 (16) | 0.0007 (14) | 0.0259 (13) | −0.0290 (14) |
O2 | 0.0648 (14) | 0.0844 (14) | 0.0585 (13) | 0.0208 (12) | 0.0190 (11) | −0.0064 (11) |
O3 | 0.0859 (16) | 0.0890 (15) | 0.0721 (15) | 0.0163 (13) | 0.0343 (13) | −0.0158 (12) |
C1 | 0.081 (2) | 0.089 (2) | 0.055 (2) | 0.0378 (19) | 0.0166 (19) | 0.0105 (18) |
C2 | 0.062 (2) | 0.0674 (19) | 0.054 (2) | 0.0241 (16) | 0.0171 (16) | 0.0055 (16) |
C3 | 0.069 (2) | 0.094 (2) | 0.0455 (18) | 0.0304 (18) | 0.0130 (16) | 0.0042 (16) |
C4 | 0.061 (2) | 0.101 (2) | 0.053 (2) | 0.0361 (18) | 0.0075 (16) | 0.0086 (18) |
C5 | 0.059 (2) | 0.0649 (18) | 0.0500 (19) | 0.0188 (15) | 0.0167 (16) | −0.0012 (15) |
C6 | 0.062 (2) | 0.085 (2) | 0.0486 (18) | 0.0211 (17) | 0.0058 (16) | −0.0034 (16) |
C7 | 0.056 (2) | 0.090 (2) | 0.067 (2) | 0.0257 (17) | 0.0124 (18) | 0.0040 (19) |
C8 | 0.058 (2) | 0.078 (2) | 0.056 (2) | 0.0195 (18) | 0.0081 (17) | −0.0023 (18) |
C9 | 0.0598 (19) | 0.0607 (18) | 0.0532 (19) | 0.0226 (16) | 0.0143 (16) | 0.0025 (15) |
C10 | 0.062 (2) | 0.070 (2) | 0.058 (2) | 0.0163 (16) | 0.0135 (16) | −0.0030 (16) |
C11 | 0.063 (2) | 0.068 (2) | 0.065 (2) | 0.0201 (17) | 0.0201 (17) | 0.0040 (17) |
C12 | 0.069 (2) | 0.067 (2) | 0.058 (2) | 0.0231 (17) | 0.0203 (17) | 0.0002 (17) |
C13 | 0.072 (2) | 0.077 (2) | 0.072 (2) | 0.0086 (18) | 0.0196 (19) | −0.0152 (18) |
C14 | 0.064 (2) | 0.077 (2) | 0.069 (2) | 0.0158 (17) | 0.0230 (17) | −0.0043 (18) |
C15 | 0.071 (2) | 0.085 (2) | 0.061 (2) | 0.0245 (18) | 0.0209 (18) | −0.0022 (17) |
C16 | 0.076 (2) | 0.078 (2) | 0.062 (2) | 0.0286 (18) | 0.0224 (17) | 0.0005 (17) |
C17 | 0.074 (2) | 0.083 (2) | 0.0523 (19) | 0.0319 (18) | 0.0160 (17) | 0.0023 (17) |
C18 | 0.088 (2) | 0.086 (2) | 0.059 (2) | 0.0354 (19) | 0.0182 (18) | −0.0014 (17) |
C19 | 0.085 (2) | 0.094 (2) | 0.060 (2) | 0.035 (2) | 0.0192 (18) | −0.0025 (18) |
C20 | 0.090 (3) | 0.094 (2) | 0.069 (2) | 0.034 (2) | 0.028 (2) | −0.0048 (19) |
C21 | 0.085 (2) | 0.104 (3) | 0.070 (2) | 0.032 (2) | 0.0220 (19) | −0.002 (2) |
C22 | 0.099 (3) | 0.109 (3) | 0.074 (2) | 0.035 (2) | 0.034 (2) | −0.006 (2) |
C23 | 0.101 (3) | 0.120 (3) | 0.100 (3) | 0.032 (2) | 0.029 (2) | −0.013 (2) |
C24 | 0.126 (3) | 0.115 (3) | 0.098 (3) | 0.037 (3) | 0.048 (3) | −0.006 (2) |
C25 | 0.170 (5) | 0.140 (4) | 0.197 (6) | 0.047 (4) | 0.115 (5) | 0.016 (4) |
C26 | 0.239 (6) | 0.179 (5) | 0.178 (5) | 0.070 (5) | 0.131 (5) | 0.011 (4) |
N1—C1 | 1.133 (3) | C10—C11 | 1.379 (4) |
O1—C8 | 1.188 (3) | C11—C12 | 1.375 (4) |
O2—C8 | 1.371 (3) | C12—C13 | 1.382 (4) |
O2—C5 | 1.400 (3) | C13—C14 | 1.371 (4) |
O3—C12 | 1.359 (3) | C15—C16 | 1.505 (4) |
O3—C15 | 1.424 (3) | C16—C17 | 1.513 (4) |
C1—C2 | 1.444 (4) | C17—C18 | 1.516 (4) |
C2—C7 | 1.368 (4) | C18—C19 | 1.498 (4) |
C2—C3 | 1.385 (4) | C19—C20 | 1.508 (4) |
C3—C4 | 1.379 (4) | C20—C21 | 1.498 (4) |
C4—C5 | 1.364 (4) | C21—C22 | 1.502 (4) |
C5—C6 | 1.371 (4) | C22—C23 | 1.467 (4) |
C6—C7 | 1.384 (4) | C23—C24 | 1.488 (4) |
C8—C9 | 1.468 (4) | C24—C25 | 1.450 (5) |
C9—C14 | 1.374 (4) | C25—C26 | 1.458 (5) |
C9—C10 | 1.390 (4) | ||
C1—N1—C26 | 3.4 (2) | C11—C10—C9 | 121.2 (3) |
C8—O2—C5 | 121.3 (2) | C12—C11—C10 | 119.4 (3) |
C12—O3—C15 | 119.6 (2) | O3—C12—C11 | 125.4 (3) |
N1—C1—C2 | 179.1 (4) | O3—C12—C13 | 115.0 (3) |
C7—C2—C3 | 119.9 (3) | C11—C12—C13 | 119.6 (3) |
C7—C2—C1 | 120.6 (3) | C14—C13—C12 | 120.8 (3) |
C3—C2—C1 | 119.5 (3) | C13—C14—C9 | 120.4 (3) |
C4—C3—C2 | 120.4 (3) | O3—C15—C16 | 106.8 (2) |
C5—C4—C3 | 118.9 (3) | C15—C16—C17 | 113.8 (2) |
C4—C5—C6 | 121.5 (3) | C16—C17—C18 | 113.4 (2) |
C4—C5—O2 | 123.8 (3) | C19—C18—C17 | 115.3 (3) |
C6—C5—O2 | 114.5 (3) | C18—C19—C20 | 114.6 (3) |
C5—C6—C7 | 119.5 (3) | C21—C20—C19 | 116.2 (3) |
C2—C7—C6 | 119.8 (3) | C20—C21—C22 | 115.1 (3) |
O1—C8—O2 | 122.9 (3) | C23—C22—C21 | 117.6 (3) |
O1—C8—C9 | 126.6 (3) | C22—C23—C24 | 117.8 (3) |
O2—C8—C9 | 110.5 (3) | C25—C24—C23 | 117.9 (4) |
C14—C9—C10 | 118.6 (3) | C24—C25—C26 | 118.7 (5) |
C14—C9—C8 | 123.2 (3) | C25—C26—N1 | 31.5 (3) |
C10—C9—C8 | 118.2 (3) | ||
C7—C2—C3—C4 | −1.4 (5) | C15—O3—C12—C13 | 178.0 (3) |
C1—C2—C3—C4 | 179.2 (3) | C10—C11—C12—O3 | 178.9 (3) |
C2—C3—C4—C5 | 0.9 (5) | C10—C11—C12—C13 | −1.0 (5) |
C3—C4—C5—C6 | −0.6 (5) | O3—C12—C13—C14 | −177.5 (3) |
C3—C4—C5—O2 | −175.0 (3) | C11—C12—C13—C14 | 2.4 (5) |
C8—O2—C5—C4 | −48.2 (4) | C12—C13—C14—C9 | −1.5 (5) |
C8—O2—C5—C6 | 137.0 (3) | C10—C9—C14—C13 | −0.9 (5) |
C4—C5—C6—C7 | 0.6 (5) | C8—C9—C14—C13 | 178.3 (3) |
O2—C5—C6—C7 | 175.6 (3) | C12—O3—C15—C16 | 179.5 (3) |
C3—C2—C7—C6 | 1.4 (5) | O3—C15—C16—C17 | −175.3 (3) |
C1—C2—C7—C6 | −179.1 (3) | C15—C16—C17—C18 | 178.6 (3) |
C5—C6—C7—C2 | −1.1 (5) | C16—C17—C18—C19 | −177.9 (3) |
C5—O2—C8—O1 | 2.2 (5) | C17—C18—C19—C20 | 178.8 (3) |
C5—O2—C8—C9 | −176.8 (2) | C18—C19—C20—C21 | −177.9 (3) |
O1—C8—C9—C14 | 174.1 (3) | C19—C20—C21—C22 | −179.5 (3) |
O2—C8—C9—C14 | −6.9 (4) | C20—C21—C22—C23 | −174.8 (3) |
O1—C8—C9—C10 | −6.7 (5) | C21—C22—C23—C24 | −179.5 (3) |
O2—C8—C9—C10 | 172.3 (3) | C22—C23—C24—C25 | −173.6 (4) |
C14—C9—C10—C11 | 2.3 (4) | C23—C24—C25—C26 | −178.3 (4) |
C8—C9—C10—C11 | −177.0 (3) | C24—C25—C26—N1 | −9.9 (3) |
C9—C10—C11—C12 | −1.3 (5) | C1—N1—C26—C25 | −27 (4) |
C15—O3—C12—C11 | −2.0 (5) |
Experimental details
Crystal data | |
Chemical formula | C26H33NO3 |
Mr | 407.53 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 296 |
a, b, c (Å) | 11.031 (5), 16.639 (5), 6.813 (5) |
α, β, γ (°) | 95.381 (5), 94.530 (5), 104.686 (5) |
V (Å3) | 1197.4 (11) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.07 |
Crystal size (mm) | 0.43 × 0.43 × 0.10 |
Data collection | |
Diffractometer | Enraf-Nonius FR590 diffractometer |
Absorption correction | Empirical (using intensity measurements) via ψ scans (North et al., 1968) |
Tmin, Tmax | 0.961, 0.991 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6224, 5747, 1764 |
Rint | 0.039 |
(sin θ/λ)max (Å−1) | 0.660 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.059, 0.193, 0.91 |
No. of reflections | 5747 |
No. of parameters | 272 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.17, −0.17 |
Computer programs: CAD-4 Software (Enraf-Nonius, 1989), CAD-4 Software, MolEN (Fair, 1990), SIR97 (Altomare et al., 1997), SHELXL97 (Sheldrick, 1997), Xtal_GX (Hall & du Boulay, 1995), SHELXL97.
N1—C1 | 1.133 (3) | O3—C12 | 1.359 (3) |
O1—C8 | 1.188 (3) | C1—C2 | 1.444 (4) |
O2—C8 | 1.371 (3) | C8—C9 | 1.468 (4) |
O2—C5 | 1.400 (3) | ||
N1—C1—C2 | 179.1 (4) | O2—C8—C9 | 110.5 (3) |
C8—O2—C5—C4 | −48.2 (4) | O2—C8—C9—C10 | 172.3 (3) |
C5—O2—C8—O1 | 2.2 (5) | C12—O3—C15—C16 | 179.5 (3) |
C5—O2—C8—C9 | −176.8 (2) |
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Mesomorphic sequences of 4-cyanophenyl 4-n-alkoxybenzoates (CPnOB) are dependent on the length of the alkoxy chains, i.e. crystal-nematic-isotropic for n = 5–8, crystal-smectic A-nematic-isotropic for n = 9–11, and crystal-smectic A-isotropic for n = 12 (Vill, 2000). Although the crystal structures of CPnOB with shorter alkyl chains (n = 5, 6, 7 and 8) have been reported (Baumeister et al., 1981; Iki & Hori, 1995), those with longer alkyl chains have not been elucidated. For CP5OB, the crystal has a non-parallel arrangement of molecular long axes (Baumeister et al., 1981). In the crystals of CP6OB and CP8OB (Iki & Hori, 1995), close contacts between CN groups of a pair of molecules are observed, though in the latter crystal two carbonyloxy groups between another pair of molecules are also closely arranged. For CP7OB (Iki & Hori, 1995), a CN and a carbonyloxy group come close to each other between a pair of molecules. These compounds are enantiotropic nematogens. We now report the structure of 4-cyanophenyl 4-n-dodecanyloxybenzoate (CP12OB), which has a smectic A phase, with the aim of contributing to a deeper understanding the relationships between mesomorphic properties and molecular packings in the lattice.
The intersection angle between the least-squares planes A (defined by C2–C7) and B (defined by C9–C14) is 50.5 (1)°, which is similar to that (49.2°) of CP8OB (Iki & Hori, 1995), while that between the least-squares planes B and C (defined by O1, O2 and C8) is 7.9 (2)°. The paraffin chain has an all-trans conformation and the molecular length of the compound is 27.848 (13) Å for the N1···C26 distance.
Intermolecular close contact between CN groups of a pair of antiparallel molecules is observed in the crystal lattice. The distance for C1—N1i is 3.514 (5) Å [symmetry code: (i) -1 - x, 1 - y, 2 - z], which is similar to that (3.486 Å; Iki & Hori, 1995). Carbonyloxy groups of another pair of antiparallel molecules are also closely arranged. The distances for O1—O1ii, O1—O2ii and O1—C8ii are 3.336 (4), 3.598 (3) and 3.460 (5) Å, respectively [symmetry code: (ii) -x, 1 - y, 1 - z]. In addition, close contacts between a CN and a carbonyloxy group of the other pair of molecules are observed as follows: the distances for C1—O1iii and N1—O1iii are 3.581 (4) and 3.798 (4) Å, respectively [symmetry code: (iii) -x, 1 - y, 2 - z].
Comparing the dipole moments between a CN group (4.0 D) and a COO group (1.8 D) (The Chemical Society of Japan, 1993), antiparallel interactions between two CN groups is expected to be dominant in the crystal lattice. The crystal of CP12OB, therefore, has a distinct layer structure through infinite networks of the CN—CN interaction.