supplementary materials


rz2682 scheme

Acta Cryst. (2012). E68, o172    [ doi:10.1107/S160053681105344X ]

Ethyl 4,4''-difluoro-5'-methoxy-1,1':3',1''-terphenyl-4'-carboxylate

H.-K. Fun, T. S. Chia, S. Samshuddin, B. Narayana and B. K. Sarojini

Abstract top

In the title compound, C22H18F2O3, the two fluoro-substituted rings form dihedral angles of 25.89 (15) and 55.00 (12)° with the central benzene ring. The ethoxy group in the molecule is disordered over two positions with a site-occupancy ratio of 0.662 (7):0.338 (7). In the crystal, molecules are linked by C-H...O hydrogen bonds into chains along the a axis. The crystal packing is further stabilized by C-H...[pi] and [pi]-[pi] interactions, with centroid-centroid distances of 3.8605 (15) Å.

Comment top

In continuation of our work on the synthesis of terphenyl esters (Fun et al., 2011; Samshuddin et al., 2011), the title compound was prepared and its crystal structure is reported. The starting material of the title compound was prepared from 4,4'-difluoro chalcone by several steps.

The molecular structure of the title compound is shown in Fig. 1. The mean planes of the two fluoro-substituted phenyl rings (C1–C6 and C13–C18) make dihedral angles of 25.89 (15) and 55.00 (12)°, respectively, with the mean plane of the central benzene ring (C7–C12) in the terphenyl moiety. The ethoxy group (O3/C21/C22) is disordered over two positions with a site-occupancy ratio of 0.662 (7):0.338 (7). Bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable to those observed in a related structure (Fun et al., 2011).

In the crystal structure (Fig. 2), the molecules are interconnected by C12—H12A···O2 hydrogen bonds (Table 1) into chains along the a axis. The crystal structure is further stabilized by C—H···π interactions (Table 1). ππ interactions are also observed with Cg2···Cg3 distance = 3.8605 (15) Å (symmetry code: 1/2+x,1/2-y,-z; Cg2 and Cg3 are the centroids of the C7–C12 and C13—C18 rings, respectively).

Related literature top

For a related structure and background to terphenyls, see: Fun et al. (2011); Samshuddin et al. (2011). For the synthesis, see: Kotnis (1990). For reference bond lengths, see: Allen et al. (1987).

Experimental top

The title compound was prepared by the aromatization of a cyclohexenone derivative, ethyl 4,6-bis(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate, using iodine and methanol at reflux condition (Kotnis, 1990). Single crystals of the product were grown from methanol by slow evaporation method (m.p. 383 K).

Refinement top

All H atoms were positioned geometrically [C—H = 0.93, 0.96 or 0.97 Å] and refined using a riding model with Uiso(H) = 1.2 or 1.5Ueq(C). A rotating group model was applied to the methyl group. The ethoxy unit was disordered over two positions with a site-occupancy ratio of 0.662 (7):0.338 (7). The same Uij parameters were used for atoms pairs C21/C21X and C22/C22X. The C13–C18 benzene ring was refined using a rigid regular hexagon model with a bond length of 1.39 Å. 2085 Friedel pairs were merged in the last refinement cycles.

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound with 50% probability displacement ellipsoids.
[Figure 2] Fig. 2. The crystal packing of the title compound viewed along the b axis. Only the major components of disorder are shown. Intermolecular hydrogen bonds are shown as dashed lines. Hydrogen atoms not involved in hydrogen bonding are omitted for clarity.
Ethyl 4,4''-difluoro-5'-methoxy-1,1':3',1''-terphenyl-4'-carboxylate top
Crystal data top
C22H18F2O3F(000) = 768
Mr = 368.36Dx = 1.319 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 3149 reflections
a = 8.5197 (11) Åθ = 2.3–22.9°
b = 9.5225 (12) ŵ = 0.10 mm1
c = 22.871 (3) ÅT = 296 K
V = 1855.5 (4) Å3Block, colourless
Z = 40.43 × 0.21 × 0.15 mm
Data collection top
Bruker APEX DUO CCD area-detector
diffractometer
3036 independent reflections
Radiation source: fine-focus sealed tube2131 reflections with I > 2σ(I)
graphiteRint = 0.026
φ and ω scansθmax = 30.0°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 1111
Tmin = 0.958, Tmax = 0.986k = 139
11701 measured reflectionsl = 2632
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.057Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.171H-atom parameters constrained
S = 1.10 w = 1/[σ2(Fo2) + (0.0841P)2 + 0.2095P]
where P = (Fo2 + 2Fc2)/3
3036 reflections(Δ/σ)max = 0.011
251 parametersΔρmax = 0.20 e Å3
0 restraintsΔρmin = 0.23 e Å3
Crystal data top
C22H18F2O3V = 1855.5 (4) Å3
Mr = 368.36Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 8.5197 (11) ŵ = 0.10 mm1
b = 9.5225 (12) ÅT = 296 K
c = 22.871 (3) Å0.43 × 0.21 × 0.15 mm
Data collection top
Bruker APEX DUO CCD area-detector
diffractometer
3036 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
2131 reflections with I > 2σ(I)
Tmin = 0.958, Tmax = 0.986Rint = 0.026
11701 measured reflectionsθmax = 30.0°
Refinement top
R[F2 > 2σ(F2)] = 0.057H-atom parameters constrained
wR(F2) = 0.171Δρmax = 0.20 e Å3
S = 1.10Δρmin = 0.23 e Å3
3036 reflectionsAbsolute structure: ?
251 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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 (Å2) top
xyzUiso*/UeqOcc. (<1)
F10.2161 (4)0.4152 (4)0.32486 (9)0.1192 (10)
F20.0906 (3)0.0580 (3)0.15941 (11)0.1145 (10)
O10.2205 (3)0.7197 (2)0.00201 (11)0.0713 (6)
O20.3043 (3)0.4532 (3)0.09557 (11)0.0776 (7)
C10.1600 (4)0.4267 (5)0.26928 (13)0.0778 (11)
C20.0345 (5)0.5148 (5)0.25967 (14)0.0806 (11)
H2A0.01110.56500.29010.097*
C30.0212 (4)0.5260 (4)0.20305 (13)0.0687 (9)
H3A0.10630.58430.19540.082*
C40.0473 (3)0.4518 (3)0.15723 (11)0.0503 (6)
C50.1719 (3)0.3640 (3)0.16957 (13)0.0569 (7)
H5A0.21830.31270.13960.068*
C60.2285 (4)0.3514 (4)0.22611 (14)0.0708 (9)
H6A0.31240.29200.23430.085*
C70.0110 (3)0.4665 (3)0.09605 (11)0.0477 (6)
C80.0859 (3)0.5911 (3)0.07870 (12)0.0524 (6)
H8A0.09740.66440.10520.063*
C90.1428 (3)0.6052 (3)0.02228 (13)0.0528 (6)
C100.1231 (3)0.4972 (3)0.01847 (12)0.0502 (6)
C110.0447 (3)0.3755 (3)0.00194 (12)0.0485 (6)
C120.0081 (3)0.3612 (3)0.05553 (12)0.0493 (6)
H12A0.05740.27830.06670.059*
C130.0119 (3)0.26039 (16)0.04462 (8)0.0530 (6)
C140.0684 (3)0.28881 (19)0.09618 (9)0.0701 (9)
H14A0.09870.38030.10490.084*
C150.1035 (3)0.1805 (3)0.13478 (8)0.0852 (11)
H15A0.15720.19950.16930.102*
C160.0582 (3)0.0438 (2)0.12181 (10)0.0783 (10)
C170.0221 (3)0.01533 (15)0.07024 (10)0.0765 (10)
H17A0.05240.07620.06160.092*
C180.0571 (3)0.12364 (19)0.03165 (8)0.0649 (8)
H18A0.11090.10460.00290.078*
C190.1921 (4)0.5144 (3)0.07789 (14)0.0601 (7)
C200.2508 (5)0.8306 (3)0.04159 (18)0.0758 (10)
H20A0.30450.90510.02160.114*
H20B0.15330.86530.05700.114*
H20C0.31500.79680.07310.114*
O30.0943 (6)0.5935 (6)0.1127 (2)0.0681 (13)0.662 (7)
C210.1430 (9)0.6182 (10)0.1721 (3)0.101 (2)0.662 (7)
H21A0.05020.63540.19560.122*0.662 (7)
H21B0.19200.53330.18680.122*0.662 (7)
C220.2433 (17)0.7258 (11)0.1799 (5)0.162 (5)0.662 (7)
H22A0.28980.71910.21810.243*0.662 (7)
H22B0.18750.81300.17660.243*0.662 (7)
H22C0.32410.72190.15070.243*0.662 (7)
O3X0.1537 (10)0.6375 (9)0.1002 (4)0.0542 (19)0.338 (7)
C21X0.231 (2)0.674 (2)0.1527 (5)0.101 (2)0.338 (7)
H21C0.22590.77430.15950.122*0.338 (7)
H21D0.34050.64550.15150.122*0.338 (7)
C22X0.1341 (17)0.586 (2)0.2049 (6)0.101 (2)0.338 (7)
H22D0.18940.59480.24130.152*0.338 (7)
H22E0.12690.48880.19430.152*0.338 (7)
H22F0.03050.62460.20900.152*0.338 (7)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
F10.1238 (19)0.184 (3)0.0495 (10)0.031 (2)0.0206 (13)0.0071 (15)
F20.1106 (19)0.1178 (18)0.115 (2)0.0261 (17)0.0049 (16)0.0635 (17)
O10.0911 (15)0.0529 (12)0.0699 (13)0.0167 (12)0.0212 (13)0.0061 (11)
O20.0827 (15)0.0703 (13)0.0798 (15)0.0215 (13)0.0310 (13)0.0108 (12)
C10.074 (2)0.114 (3)0.0449 (15)0.001 (2)0.0088 (15)0.0080 (18)
C20.084 (2)0.107 (3)0.0504 (17)0.017 (2)0.0000 (16)0.0070 (18)
C30.0666 (18)0.089 (2)0.0507 (15)0.0189 (18)0.0031 (14)0.0025 (16)
C40.0518 (13)0.0517 (14)0.0472 (13)0.0015 (12)0.0013 (11)0.0051 (12)
C50.0565 (14)0.0635 (17)0.0508 (15)0.0046 (14)0.0029 (12)0.0042 (13)
C60.0681 (18)0.085 (2)0.0596 (18)0.0133 (18)0.0115 (15)0.0120 (17)
C70.0479 (12)0.0482 (13)0.0469 (13)0.0001 (11)0.0008 (11)0.0041 (11)
C80.0566 (14)0.0483 (14)0.0522 (14)0.0011 (12)0.0040 (12)0.0003 (12)
C90.0550 (13)0.0480 (15)0.0553 (15)0.0007 (12)0.0057 (12)0.0081 (12)
C100.0521 (13)0.0463 (13)0.0522 (14)0.0074 (11)0.0063 (11)0.0060 (11)
C110.0507 (12)0.0452 (13)0.0495 (13)0.0053 (11)0.0055 (11)0.0033 (11)
C120.0523 (13)0.0455 (13)0.0501 (13)0.0040 (12)0.0024 (11)0.0061 (11)
C130.0533 (13)0.0534 (14)0.0524 (14)0.0017 (12)0.0082 (12)0.0002 (12)
C140.0736 (19)0.073 (2)0.0636 (18)0.0121 (18)0.0029 (16)0.0092 (16)
C150.071 (2)0.119 (3)0.066 (2)0.004 (2)0.0070 (18)0.017 (2)
C160.0675 (18)0.083 (2)0.085 (2)0.0157 (19)0.0109 (18)0.030 (2)
C170.089 (2)0.0574 (18)0.083 (2)0.0118 (18)0.013 (2)0.0115 (17)
C180.0804 (19)0.0503 (15)0.0639 (18)0.0037 (15)0.0085 (16)0.0022 (14)
C190.0694 (17)0.0488 (15)0.0621 (17)0.0097 (14)0.0164 (14)0.0082 (13)
C200.084 (2)0.0539 (17)0.090 (2)0.0160 (17)0.009 (2)0.0042 (17)
O30.067 (3)0.088 (3)0.049 (2)0.010 (2)0.006 (2)0.020 (2)
C210.093 (3)0.159 (7)0.053 (3)0.015 (4)0.010 (3)0.033 (4)
C220.229 (13)0.114 (7)0.142 (9)0.014 (8)0.090 (9)0.010 (6)
O3X0.054 (4)0.059 (4)0.049 (4)0.004 (3)0.003 (3)0.004 (3)
C21X0.093 (3)0.159 (7)0.053 (3)0.015 (4)0.010 (3)0.033 (4)
C22X0.093 (3)0.159 (7)0.053 (3)0.015 (4)0.010 (3)0.033 (4)
Geometric parameters (Å, °) top
F1—C11.362 (4)C14—C151.3900
F2—C161.325 (3)C14—H14A0.9300
O1—C91.357 (3)C15—C161.3900
O1—C201.415 (4)C15—H15A0.9300
O2—C191.191 (4)C16—C171.3900
C1—C61.353 (5)C17—C181.3900
C1—C21.376 (5)C17—H17A0.9300
C2—C31.383 (5)C18—H18A0.9300
C2—H2A0.9300C19—O3X1.320 (9)
C3—C41.392 (4)C19—O31.377 (5)
C3—H3A0.9300C20—H20A0.9600
C4—C51.381 (4)C20—H20B0.9600
C4—C71.491 (4)C20—H20C0.9600
C5—C61.385 (4)O3—C211.440 (8)
C5—H5A0.9300C21—C221.346 (14)
C6—H6A0.9300C21—H21A0.9700
C7—C121.375 (4)C21—H21B0.9700
C7—C81.404 (4)C22—H22A0.9600
C8—C91.385 (4)C22—H22B0.9600
C8—H8A0.9300C22—H22C0.9600
C9—C101.398 (4)O3X—C21X1.414 (16)
C10—C111.390 (4)C21X—C22X1.68 (3)
C10—C191.490 (4)C21X—H21C0.9700
C11—C121.396 (4)C21X—H21D0.9700
C11—C131.494 (3)C22X—H22D0.9600
C12—H12A0.9300C22X—H22E0.9600
C13—C141.3900C22X—H22F0.9600
C13—C181.3900
C9—O1—C20118.0 (2)C16—C15—C14120.0
C6—C1—F1119.2 (3)C16—C15—H15A120.0
C6—C1—C2122.8 (3)C14—C15—H15A120.0
F1—C1—C2118.0 (3)F2—C16—C17120.7 (2)
C1—C2—C3117.6 (3)F2—C16—C15119.3 (2)
C1—C2—H2A121.2C17—C16—C15120.0
C3—C2—H2A121.2C16—C17—C18120.0
C2—C3—C4121.5 (3)C16—C17—H17A120.0
C2—C3—H3A119.3C18—C17—H17A120.0
C4—C3—H3A119.3C17—C18—C13120.0
C5—C4—C3118.4 (3)C17—C18—H18A120.0
C5—C4—C7120.3 (3)C13—C18—H18A120.0
C3—C4—C7121.3 (3)O2—C19—O3X120.2 (5)
C6—C5—C4120.7 (3)O2—C19—O3123.9 (3)
C6—C5—H5A119.6O2—C19—C10125.0 (3)
C4—C5—H5A119.6O3X—C19—C10110.6 (4)
C1—C6—C5119.0 (3)O3—C19—C10110.4 (3)
C1—C6—H6A120.5O1—C20—H20A109.5
C5—C6—H6A120.5O1—C20—H20B109.5
C12—C7—C8118.6 (2)H20A—C20—H20B109.5
C12—C7—C4121.6 (2)O1—C20—H20C109.5
C8—C7—C4119.7 (2)H20A—C20—H20C109.5
C9—C8—C7120.3 (3)H20B—C20—H20C109.5
C9—C8—H8A119.9C19—O3—C21117.4 (5)
C7—C8—H8A119.9C22—C21—O3115.7 (10)
O1—C9—C8124.6 (3)C22—C21—H21A108.4
O1—C9—C10114.9 (2)O3—C21—H21A108.4
C8—C9—C10120.5 (3)C22—C21—H21B108.4
C11—C10—C9119.3 (2)O3—C21—H21B108.4
C11—C10—C19122.0 (2)H21A—C21—H21B107.4
C9—C10—C19118.7 (2)C19—O3X—C21X115.5 (10)
C10—C11—C12119.5 (2)O3X—C21X—C22X104.7 (15)
C10—C11—C13121.6 (2)O3X—C21X—H21C110.8
C12—C11—C13118.9 (2)C22X—C21X—H21C110.8
C7—C12—C11121.7 (2)O3X—C21X—H21D110.8
C7—C12—H12A119.2C22X—C21X—H21D110.8
C11—C12—H12A119.2H21C—C21X—H21D108.9
C14—C13—C18120.0C21X—C22X—H22D109.5
C14—C13—C11120.24 (15)C21X—C22X—H22E109.5
C18—C13—C11119.72 (15)H22D—C22X—H22E109.5
C13—C14—C15120.0C21X—C22X—H22F109.5
C13—C14—H14A120.0H22D—C22X—H22F109.5
C15—C14—H14A120.0H22E—C22X—H22F109.5
C6—C1—C2—C30.5 (6)C10—C11—C12—C72.1 (4)
F1—C1—C2—C3179.9 (4)C13—C11—C12—C7176.5 (2)
C1—C2—C3—C40.4 (6)C10—C11—C13—C1455.1 (3)
C2—C3—C4—C51.1 (5)C12—C11—C13—C14123.4 (2)
C2—C3—C4—C7178.7 (3)C10—C11—C13—C18127.1 (2)
C3—C4—C5—C60.8 (5)C12—C11—C13—C1854.4 (3)
C7—C4—C5—C6178.9 (3)C18—C13—C14—C150.0
F1—C1—C6—C5179.6 (4)C11—C13—C14—C15177.8 (2)
C2—C1—C6—C50.7 (6)C13—C14—C15—C160.0
C4—C5—C6—C10.1 (6)C14—C15—C16—F2179.1 (2)
C5—C4—C7—C1226.1 (4)C14—C15—C16—C170.0
C3—C4—C7—C12154.1 (3)F2—C16—C17—C18179.1 (2)
C5—C4—C7—C8153.1 (3)C15—C16—C17—C180.0
C3—C4—C7—C826.6 (4)C16—C17—C18—C130.0
C12—C7—C8—C91.7 (4)C14—C13—C18—C170.0
C4—C7—C8—C9179.0 (2)C11—C13—C18—C17177.8 (2)
C20—O1—C9—C82.3 (5)C11—C10—C19—O270.4 (4)
C20—O1—C9—C10177.3 (3)C9—C10—C19—O2107.4 (4)
C7—C8—C9—O1178.1 (3)C11—C10—C19—O3X132.9 (5)
C7—C8—C9—C101.5 (4)C9—C10—C19—O3X49.3 (6)
O1—C9—C10—C11179.9 (2)C11—C10—C19—O3100.0 (4)
C8—C9—C10—C110.4 (4)C9—C10—C19—O382.2 (4)
O1—C9—C10—C192.2 (4)O2—C19—O3—C218.6 (9)
C8—C9—C10—C19177.4 (3)O3X—C19—O3—C2184.6 (11)
C9—C10—C11—C122.2 (4)C10—C19—O3—C21179.1 (6)
C19—C10—C11—C12175.6 (3)C19—O3—C21—C2283.5 (10)
C9—C10—C11—C13176.3 (2)O2—C19—O3X—C21X13.1 (13)
C19—C10—C11—C135.9 (4)O3—C19—O3X—C21X93.4 (14)
C8—C7—C12—C110.1 (4)C10—C19—O3X—C21X171.1 (10)
C4—C7—C12—C11179.2 (2)C19—O3X—C21X—C22X79.9 (12)
Hydrogen-bond geometry (Å, °) top
Cg2 and Cg3 are the centroids of the C7–C12 and C13–C18 rings, respectively.
D—H···AD—HH···AD···AD—H···A
C12—H12A···O2i0.932.593.515 (3)179.
C5—H5A···Cg3ii0.932.923.589 (3)130
C20—H20A···Cg2iii0.962.833.710 (4)152
Symmetry codes: (i) x−1/2, −y+1/2, −z; (ii) −x−1, y+1/2, −z+1/2; (iii) −x, y+3/2, −z+1/2.
Table 1
Hydrogen-bond geometry (Å, °)
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Cg2 and Cg3 are the centroids of the C7–C12 and C13–C18 rings, respectively.
D—H···AD—HH···AD···AD—H···A
C12—H12A···O2i0.932.593.515 (3)179.
C5—H5A···Cg3ii0.932.923.589 (3)130
C20—H20A···Cg2iii0.962.833.710 (4)152
Symmetry codes: (i) x−1/2, −y+1/2, −z; (ii) −x−1, y+1/2, −z+1/2; (iii) −x, y+3/2, −z+1/2.
Acknowledgements top

HKF and TSC thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). TSC thanks the Malaysian Government and USM for the award of the post of Research Officer under the Research University Grant (1001/PSKBP/8630013). BN thanks the UGC for financial assistance through the SAP and BSR one-time grant for the purchase of chemicals. SS thanks Mangalore University for research facilities.

references
References top

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