4-Cyano-3-fluoro­phenyl 4′-isobutoxy­biphenyl-4-carboxylate

In the title compound, C₂₄H₂₀FNO₃, the mol­ecule is non-planar, with dihedral angles of 67.9 (1), 48.2 (1) and 20.3 (1)° between the three aromatic rings. The packing is stabilized by C—H...π and π–π inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.038
• wR factor = 0.097
• Data-to-parameter ratio = 8.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C1     -   C2      ..       5.00 su
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C22
PLAT371_ALERT_2_C Long   C(sp2)-C(sp1) Bond  C1     -   C2     ...       1.44 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H14A   ..  CG2     ..       2.92 Ang.
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C24 H20 F N O3

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           26.02
           From the CIF: _reflns_number_total               2315
           Count of symmetry unique reflns         2328
           Completeness (_total/calc)             99.44%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   9 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   4 ALERT type 4 Improvement, methodology, query or suggestion

---

S1. Comment

Recently, liquid crystals including F atoms as substituents have become a current topic because these molecules generally exhibit novel properties (Ozaki et al., 1987; Wu et al., 1992) when compared with the unsubstituted parent compounds, such as low viscosity, high voltage percent retention and high specific resistance. In our research of liquid crystal materials containing fluorine, we have synthesized the title compound, (I). We report its structure (Fig. 1) here.

The bond lengths and angles (Table 1) are within normal ranges (Allen et al., 1987). The molecule is non-planar, and the three benzene rings make dihedral angles of 67.9 (1)° (angle between the C2–C7 and C9–C14 rings), 48.2 (1)° (angle between the C2–C7 and C15–C20 rings) and 20.3 (1)° (angle between theC9–C14 and C15–C20 rings). There exists a weak intramolecular C23—H23A···O3 hydrogen bond, forming a five-membered ring (Table 2). In the crystal structure, the packing is stabilized by C—H···π (Table 2) and π–π interactions involving the three benzene rings.

S2. Experimental

To a solution of 4'-hydroxybiphenyl-4-carboxylic acid (1.0 g, 0.01 mol) in 6.4% KOH solution (10 ml) was added dropwise 1-bromo-2-methylpropane (3.22 g, 0.05 mol) in ethanol (30 ml). The mixture was refluxed for 90 h and extra KOH solution was added to remove the additional products. The mixture was then acidified to give a white precipitate, which was filtered and recrystallized from acetic acid, giving a white powder, identified as 4-isobutoxybiphenyl-4-carboxylic acid. This compound (0.75 g) and DCC (1,3-dicyclohexyl-carbodiimide, 0.6 g) were dissolved in THF (20 ml), and a solution of 2-fluoro-4-hydroxybenzonitrile (0.4 g) and DMAP (4-dimethylamino-pyridine, 0.01 g) in THF (20 ml) was added. The mixture was stirred at 298 K for 140 h and then filtered. Colorless single crystals of (I) suitable for X-ray diffraction study were obtained by slow evaporation of an ethyl acetate/petroleum ether (1:7) solution, over a period of 10 d.

S3. Refinement

All H atoms were placed in idealized positions and constrained to ride on their parent atoms, with C—H distances in the range 0.93–0.98 Å, and with U_iso(H) = 1.2 U_eq(C) (aromatic CH, methine CH and methylene CH₂) or U_iso(H) = 1.5 U_eq(C) (methyl CH₃). The Friedel reflections were merged before the final refinement because of the absence of significant anomalous scattering effects.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); 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, PARST95 (Nardelli, 1995) and PLATON (Spek, 2003).

Figures

Fig. 1. The structure of (I), showing 50% probability displacement ellipsoids and the atom numbering scheme.

4'-Isobutoxy-biphenyl-4-carboxylic acid 4-cyano-3-fluoro-phenyl ester

Crystal data

C24H20FNO3	Dx = 1.279 Mg m^−3
Mr = 389.41	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 4369 reflections
a = 7.1969 (12) Å	θ = 2.6–25.3°
b = 7.8499 (13) Å	µ = 0.09 mm^−1
c = 35.797 (6) Å	T = 293 K
V = 2022.4 (6) Å^3	Block, colorless
Z = 4	0.38 × 0.11 × 0.08 mm
F(000) = 816

Data collection

Siemens SMART 1000 CCD area-detector diffractometer	2315 independent reflections
Radiation source: fine-focus sealed tube	2113 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
Detector resolution: 8.33 pixels mm^-1	θmax = 26.0°, θmin = 2.3°
ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −9→9
Tmin = 0.967, Tmax = 0.993	l = −44→42
11402 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.097	H-atom parameters constrained
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0482P)^2 + 0.199P] where P = (Fo^2 + 2Fc^2)/3
2315 reflections	(Δ/σ)max = 0.006
262 parameters	Δρmax = 0.15 e Å^−3
0 restraints	Δρmin = −0.14 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
F1	0.7228 (2)	0.9655 (3)	0.11394 (5)	0.0908 (6)
O1	0.1278 (2)	0.8971 (2)	0.16705 (4)	0.0580 (4)
O2	0.0380 (3)	1.1606 (2)	0.15092 (4)	0.0657 (5)
O3	−0.8116 (2)	1.0226 (2)	0.39293 (4)	0.0587 (4)
N1	0.7152 (4)	0.8320 (4)	0.02146 (7)	0.0959 (9)
C1	0.6132 (4)	0.8454 (4)	0.04557 (7)	0.0678 (7)
C2	0.4836 (3)	0.8616 (3)	0.07614 (6)	0.0529 (6)
C3	0.5430 (3)	0.9221 (3)	0.11004 (6)	0.0559 (6)
C4	0.4276 (3)	0.9383 (3)	0.14045 (6)	0.0558 (6)
H4A	0.4711	0.9793	0.1632	0.067*
C5	0.2446 (3)	0.8911 (3)	0.13570 (6)	0.0484 (5)
C6	0.1793 (3)	0.8300 (4)	0.10246 (6)	0.0620 (7)
H6A	0.0554	0.7980	0.1001	0.074*
C7	0.2987 (3)	0.8161 (4)	0.07248 (6)	0.0632 (7)
H7A	0.2548	0.7760	0.0497	0.076*
C8	0.0276 (3)	1.0433 (3)	0.17180 (5)	0.0449 (5)
C9	−0.0908 (3)	1.0356 (3)	0.20576 (5)	0.0419 (5)
C10	−0.2386 (3)	1.1480 (3)	0.20845 (6)	0.0481 (5)
H10A	−0.2617	1.2246	0.1892	0.058*
C11	−0.3518 (3)	1.1467 (3)	0.23963 (6)	0.0480 (5)
H11A	−0.4510	1.2224	0.2409	0.058*
C12	−0.3213 (3)	1.0352 (3)	0.26921 (5)	0.0405 (4)
C13	−0.1701 (3)	0.9260 (3)	0.26618 (6)	0.0501 (5)
H13A	−0.1435	0.8523	0.2858	0.060*
C14	−0.0582 (3)	0.9240 (3)	0.23490 (5)	0.0499 (5)
H14A	0.0397	0.8470	0.2334	0.060*
C15	−0.4462 (3)	1.0315 (3)	0.30235 (5)	0.0418 (4)
C16	−0.3923 (3)	0.9600 (3)	0.33602 (5)	0.0497 (5)
H16A	−0.2730	0.9153	0.3381	0.060*
C17	−0.5091 (3)	0.9526 (3)	0.36663 (6)	0.0527 (6)
H17A	−0.4690	0.9025	0.3887	0.063*
C18	−0.6863 (3)	1.0202 (3)	0.36414 (6)	0.0471 (5)
C19	−0.7442 (3)	1.0917 (3)	0.33092 (6)	0.0517 (5)
H19A	−0.8633	1.1370	0.3290	0.062*
C20	−0.6270 (3)	1.0965 (3)	0.30059 (6)	0.0503 (5)
H20A	−0.6690	1.1442	0.2783	0.060*
C21	−0.7725 (3)	0.9223 (3)	0.42536 (6)	0.0579 (6)
H21A	−0.6622	0.9652	0.4377	0.069*
H21B	−0.7501	0.8050	0.4182	0.069*
C22	−0.9366 (3)	0.9315 (3)	0.45154 (6)	0.0558 (6)
H22A	−0.9595	1.0515	0.4575	0.067*
C23	−1.1093 (4)	0.8599 (5)	0.43381 (7)	0.0813 (9)
H23A	−1.1362	0.9213	0.4113	0.122*
H23B	−1.2117	0.8708	0.4508	0.122*
H23C	−1.0901	0.7417	0.4280	0.122*
C24	−0.8860 (4)	0.8395 (5)	0.48754 (6)	0.0793 (8)
H24A	−0.9892	0.8440	0.5045	0.119*
H24B	−0.7801	0.8936	0.4987	0.119*
H24C	−0.8568	0.7228	0.4821	0.119*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0517 (9)	0.1334 (16)	0.0872 (11)	−0.0222 (10)	0.0079 (8)	−0.0115 (11)
O1	0.0623 (10)	0.0595 (9)	0.0523 (8)	0.0080 (8)	0.0190 (8)	0.0064 (7)
O2	0.0835 (12)	0.0565 (9)	0.0572 (9)	0.0025 (10)	0.0228 (9)	0.0095 (8)
O3	0.0568 (10)	0.0735 (11)	0.0459 (8)	0.0159 (9)	0.0129 (7)	0.0087 (8)
N1	0.0954 (19)	0.124 (2)	0.0687 (14)	0.0293 (19)	0.0337 (15)	0.0131 (16)
C1	0.0705 (16)	0.0775 (17)	0.0553 (13)	0.0165 (15)	0.0139 (13)	0.0103 (13)
C2	0.0554 (13)	0.0603 (13)	0.0430 (11)	0.0078 (12)	0.0106 (10)	0.0049 (10)
C3	0.0440 (12)	0.0642 (14)	0.0596 (13)	−0.0040 (12)	0.0073 (10)	0.0041 (12)
C4	0.0557 (13)	0.0644 (14)	0.0473 (12)	−0.0052 (12)	0.0018 (10)	−0.0059 (11)
C5	0.0504 (12)	0.0505 (12)	0.0443 (11)	0.0005 (10)	0.0114 (10)	0.0051 (9)
C6	0.0478 (13)	0.0829 (18)	0.0551 (13)	−0.0094 (13)	0.0013 (11)	−0.0042 (13)
C7	0.0618 (15)	0.0850 (18)	0.0428 (12)	−0.0039 (15)	−0.0015 (11)	−0.0077 (12)
C8	0.0465 (11)	0.0468 (11)	0.0415 (10)	−0.0085 (10)	0.0015 (9)	−0.0054 (9)
C9	0.0422 (11)	0.0460 (10)	0.0375 (10)	−0.0067 (10)	−0.0007 (8)	−0.0044 (8)
C10	0.0544 (12)	0.0477 (11)	0.0422 (10)	0.0017 (11)	0.0007 (10)	0.0061 (9)
C11	0.0460 (11)	0.0497 (11)	0.0482 (11)	0.0100 (10)	0.0035 (9)	0.0025 (10)
C12	0.0417 (10)	0.0423 (10)	0.0375 (9)	−0.0028 (9)	−0.0021 (8)	−0.0024 (8)
C13	0.0509 (12)	0.0556 (13)	0.0438 (11)	0.0118 (11)	0.0040 (10)	0.0097 (10)
C14	0.0442 (11)	0.0561 (12)	0.0493 (11)	0.0089 (11)	0.0031 (9)	0.0032 (10)
C15	0.0422 (10)	0.0413 (10)	0.0418 (10)	0.0025 (10)	0.0017 (9)	−0.0025 (8)
C16	0.0416 (11)	0.0637 (14)	0.0438 (11)	0.0109 (11)	−0.0007 (9)	0.0017 (10)
C17	0.0499 (12)	0.0682 (15)	0.0401 (10)	0.0099 (12)	0.0010 (10)	0.0058 (10)
C18	0.0468 (11)	0.0513 (12)	0.0432 (11)	0.0024 (10)	0.0059 (9)	−0.0026 (9)
C19	0.0446 (11)	0.0585 (13)	0.0521 (12)	0.0129 (11)	0.0046 (10)	0.0051 (10)
C20	0.0518 (12)	0.0562 (13)	0.0430 (11)	0.0093 (11)	0.0007 (10)	0.0073 (10)
C21	0.0583 (13)	0.0688 (15)	0.0465 (12)	0.0129 (13)	0.0069 (11)	0.0054 (11)
C22	0.0563 (13)	0.0697 (15)	0.0413 (10)	0.0100 (13)	0.0086 (10)	0.0025 (11)
C23	0.0678 (17)	0.118 (3)	0.0586 (15)	−0.0118 (19)	0.0054 (14)	0.0107 (16)
C24	0.0797 (18)	0.107 (2)	0.0514 (13)	0.0176 (19)	0.0092 (13)	0.0140 (15)

Geometric parameters (Å, º)

F1—C3	1.345 (3)	C13—C14	1.379 (3)
O1—C8	1.366 (3)	C13—H13A	0.9300
O1—C5	1.403 (2)	C14—H14A	0.9300
O2—C8	1.188 (2)	C15—C16	1.385 (3)
O3—C18	1.370 (2)	C15—C20	1.399 (3)
O3—C21	1.431 (3)	C16—C17	1.383 (3)
N1—C1	1.137 (3)	C16—H16A	0.9300
C1—C2	1.444 (3)	C17—C18	1.384 (3)
C2—C3	1.372 (3)	C17—H17A	0.9300
C2—C7	1.384 (3)	C18—C19	1.380 (3)
C3—C4	1.375 (3)	C19—C20	1.376 (3)
C4—C5	1.378 (3)	C19—H19A	0.9300
C4—H4A	0.9300	C20—H20A	0.9300
C5—C6	1.367 (3)	C21—C22	1.509 (3)
C6—C7	1.379 (3)	C21—H21A	0.9700
C6—H6A	0.9300	C21—H21B	0.9700
C7—H7A	0.9300	C22—C23	1.504 (4)
C8—C9	1.486 (3)	C22—C24	1.521 (3)
C9—C14	1.382 (3)	C22—H22A	0.9800
C9—C10	1.385 (3)	C23—H23A	0.9600
C10—C11	1.382 (3)	C23—H23B	0.9600
C10—H10A	0.9300	C23—H23C	0.9600
C11—C12	1.391 (3)	C24—H24A	0.9600
C11—H11A	0.9300	C24—H24B	0.9600
C12—C13	1.390 (3)	C24—H24C	0.9600
C12—C15	1.488 (3)
C8—O1—C5	116.38 (16)	C16—C15—C20	116.59 (19)
C18—O3—C21	118.26 (16)	C16—C15—C12	122.16 (18)
N1—C1—C2	179.8 (4)	C20—C15—C12	121.22 (18)
C3—C2—C7	118.2 (2)	C17—C16—C15	122.43 (19)
C3—C2—C1	120.0 (2)	C17—C16—H16A	118.8
C7—C2—C1	121.8 (2)	C15—C16—H16A	118.8
F1—C3—C2	118.7 (2)	C18—C17—C16	119.56 (19)
F1—C3—C4	118.4 (2)	C18—C17—H17A	120.2
C2—C3—C4	122.9 (2)	C16—C17—H17A	120.2
C3—C4—C5	117.0 (2)	O3—C18—C19	116.33 (19)
C3—C4—H4A	121.5	O3—C18—C17	124.31 (19)
C5—C4—H4A	121.5	C19—C18—C17	119.36 (19)
C6—C5—C4	122.0 (2)	C20—C19—C18	120.4 (2)
C6—C5—O1	120.1 (2)	C20—C19—H19A	119.8
C4—C5—O1	117.7 (2)	C18—C19—H19A	119.8
C5—C6—C7	119.4 (2)	C19—C20—C15	121.66 (19)
C5—C6—H6A	120.3	C19—C20—H20A	119.2
C7—C6—H6A	120.3	C15—C20—H20A	119.2
C6—C7—C2	120.3 (2)	O3—C21—C22	108.91 (18)
C6—C7—H7A	119.8	O3—C21—H21A	109.9
C2—C7—H7A	119.8	C22—C21—H21A	109.9
O2—C8—O1	122.66 (19)	O3—C21—H21B	109.9
O2—C8—C9	125.6 (2)	C22—C21—H21B	109.9
O1—C8—C9	111.74 (17)	H21A—C21—H21B	108.3
C14—C9—C10	118.79 (19)	C23—C22—C21	111.49 (19)
C14—C9—C8	123.1 (2)	C23—C22—C24	112.2 (2)
C10—C9—C8	118.13 (18)	C21—C22—C24	108.4 (2)
C11—C10—C9	120.27 (19)	C23—C22—H22A	108.2
C11—C10—H10A	119.9	C21—C22—H22A	108.2
C9—C10—H10A	119.9	C24—C22—H22A	108.2
C10—C11—C12	121.8 (2)	C22—C23—H23A	109.5
C10—C11—H11A	119.1	C22—C23—H23B	109.5
C12—C11—H11A	119.1	H23A—C23—H23B	109.5
C13—C12—C11	116.86 (18)	C22—C23—H23C	109.5
C13—C12—C15	121.55 (17)	H23A—C23—H23C	109.5
C11—C12—C15	121.59 (18)	H23B—C23—H23C	109.5
C14—C13—C12	121.86 (19)	C22—C24—H24A	109.5
C14—C13—H13A	119.1	C22—C24—H24B	109.5
C12—C13—H13A	119.1	H24A—C24—H24B	109.5
C13—C14—C9	120.4 (2)	C22—C24—H24C	109.5
C13—C14—H14A	119.8	H24A—C24—H24C	109.5
C9—C14—H14A	119.8	H24B—C24—H24C	109.5
C7—C2—C3—F1	179.5 (3)	C10—C11—C12—C15	−178.58 (19)
C1—C2—C3—F1	0.1 (4)	C11—C12—C13—C14	−2.0 (3)
C7—C2—C3—C4	0.4 (4)	C15—C12—C13—C14	177.3 (2)
C1—C2—C3—C4	−179.0 (2)	C12—C13—C14—C9	2.0 (3)
F1—C3—C4—C5	−179.3 (2)	C10—C9—C14—C13	−0.6 (3)
C2—C3—C4—C5	−0.2 (4)	C8—C9—C14—C13	178.2 (2)
C3—C4—C5—C6	0.3 (4)	C13—C12—C15—C16	19.5 (3)
C3—C4—C5—O1	176.2 (2)	C11—C12—C15—C16	−161.2 (2)
C8—O1—C5—C6	−89.9 (3)	C13—C12—C15—C20	−158.6 (2)
C8—O1—C5—C4	94.1 (3)	C11—C12—C15—C20	20.6 (3)
C4—C5—C6—C7	−0.6 (4)	C20—C15—C16—C17	−0.2 (3)
O1—C5—C6—C7	−176.4 (2)	C12—C15—C16—C17	−178.4 (2)
C5—C6—C7—C2	0.8 (4)	C15—C16—C17—C18	−0.7 (4)
C3—C2—C7—C6	−0.7 (4)	C21—O3—C18—C19	168.2 (2)
C1—C2—C7—C6	178.7 (3)	C21—O3—C18—C17	−12.2 (3)
C5—O1—C8—O2	−0.4 (3)	C16—C17—C18—O3	−178.6 (2)
C5—O1—C8—C9	−179.98 (17)	C16—C17—C18—C19	0.9 (4)
O2—C8—C9—C14	−159.3 (2)	O3—C18—C19—C20	179.3 (2)
O1—C8—C9—C14	20.2 (3)	C17—C18—C19—C20	−0.3 (4)
O2—C8—C9—C10	19.5 (3)	C18—C19—C20—C15	−0.7 (4)
O1—C8—C9—C10	−160.95 (19)	C16—C15—C20—C19	0.9 (3)
C14—C9—C10—C11	−0.6 (3)	C12—C15—C20—C19	179.1 (2)
C8—C9—C10—C11	−179.45 (19)	C18—O3—C21—C22	−174.7 (2)
C9—C10—C11—C12	0.5 (3)	O3—C21—C22—C23	61.7 (3)
C10—C11—C12—C13	0.7 (3)	O3—C21—C22—C24	−174.3 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C23—H23A···.O3	0.96	2.55	2.891 (3)	101
C10—H10A···Cg3^i	0.93	2.78	3.602	148
C14—H14A···Cg2^ii	0.93	2.92	3.725	146

Symmetry codes: (i) −x−1, y+1/2, −z+1/2; (ii) −x, y−1/2, −z+1/2.