Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104032913/av1218sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270104032913/av1218Isup2.hkl |
CCDC reference: 268118
The title compound was obtained as described previously by Cristau et al. (1997). Crystallization in Et2O/n-hexane yielded single crystals of (I) suitable for X-ray diffraction.
One of the phosphonate ethoxy groups exhibits orientational disorder and was refined over two positions using SADI and DFIX restraints. The final occupancy was 0.64 (1) for C15 and C16, and 0.36 (1) for C15B and C16B. H atoms were positioned geometrically and allowed to ride on their respective parent atoms, with C—H distances of 0.93 (aromatic CH), 0.97 (CH2) or 0.96 Å (CH3), and Uiso(H) equal to 1.2 (CH and CH2) or 1.5 (CH3) times Ueq of the parent atom.
Data collection: SMART-NT (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Bruker, 1999); program(s) used to refine structure: SHELXTL; molecular graphics: PLATON (Spek, 2003) and SCHAKAL97 (Keller, 1997); software used to prepare material for publication: SHELXTL.
C16H24IO3P | F(000) = 848 |
Mr = 422.22 | Dx = 1.489 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 1006 reflections |
a = 11.7324 (18) Å | θ = 2.4–27.4° |
b = 12.3985 (19) Å | µ = 1.79 mm−1 |
c = 13.228 (2) Å | T = 293 K |
β = 101.817 (3)° | Irregular, colourless |
V = 1883.4 (5) Å3 | 0.48 × 0.42 × 0.26 mm |
Z = 4 |
Bruker SMART CCD area-detector diffractometer | 3693 independent reflections |
Radiation source: fine-focus sealed tube | 2988 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.019 |
ϕ and ω scans | θmax = 26.0°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | h = −13→14 |
Tmin = 0.480, Tmax = 0.653 | k = −13→15 |
10404 measured reflections | l = −12→16 |
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)] = 0.031 | H-atom parameters constrained |
wR(F2) = 0.086 | w = 1/[σ2(Fo2) + (0.0411P)2 + 1.3932P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max = 0.001 |
3693 reflections | Δρmax = 0.70 e Å−3 |
212 parameters | Δρmin = −0.42 e Å−3 |
57 restraints | Extinction correction: SHELXTL (Bruker, 1999), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0031 (4) |
C16H24IO3P | V = 1883.4 (5) Å3 |
Mr = 422.22 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 11.7324 (18) Å | µ = 1.79 mm−1 |
b = 12.3985 (19) Å | T = 293 K |
c = 13.228 (2) Å | 0.48 × 0.42 × 0.26 mm |
β = 101.817 (3)° |
Bruker SMART CCD area-detector diffractometer | 3693 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | 2988 reflections with I > 2σ(I) |
Tmin = 0.480, Tmax = 0.653 | Rint = 0.019 |
10404 measured reflections |
R[F2 > 2σ(F2)] = 0.031 | 57 restraints |
wR(F2) = 0.086 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.70 e Å−3 |
3693 reflections | Δρmin = −0.42 e Å−3 |
212 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 | Occ. (<1) | |
I | 0.27698 (2) | −0.178181 (18) | 0.656147 (19) | 0.06326 (13) | |
P | 0.40374 (9) | 0.04203 (8) | 0.76022 (7) | 0.0584 (2) | |
O1 | 0.3245 (3) | 0.0983 (2) | 0.8130 (2) | 0.0811 (8) | |
O2 | 0.5034 (2) | 0.1114 (2) | 0.7321 (2) | 0.0762 (8) | |
O3 | 0.4605 (3) | −0.0509 (3) | 0.8301 (3) | 0.1104 (12) | |
C1 | 0.3381 (3) | −0.0192 (3) | 0.6392 (3) | 0.0506 (7) | |
C2 | 0.3205 (3) | 0.0287 (3) | 0.5463 (2) | 0.0517 (7) | |
C3 | 0.2686 (4) | −0.0282 (3) | 0.4461 (3) | 0.0667 (10) | |
H3A | 0.3053 | −0.0014 | 0.3917 | 0.080* | |
H3B | 0.2848 | −0.1048 | 0.4538 | 0.080* | |
C4 | 0.1394 (4) | −0.0114 (3) | 0.4154 (3) | 0.0750 (11) | |
H4A | 0.1226 | 0.0651 | 0.4169 | 0.090* | |
H4B | 0.1018 | −0.0469 | 0.4652 | 0.090* | |
C5 | 0.0886 (4) | −0.0562 (4) | 0.3064 (4) | 0.0912 (14) | |
H5A | 0.1269 | −0.0209 | 0.2570 | 0.109* | |
H5B | 0.1058 | −0.1327 | 0.3053 | 0.109* | |
C6 | −0.0356 (5) | −0.0410 (5) | 0.2744 (5) | 0.122 (2) | |
H6A | −0.0737 | −0.0688 | 0.3266 | 0.183* | |
H6B | −0.0633 | −0.0787 | 0.2107 | 0.183* | |
H6C | −0.0524 | 0.0345 | 0.2646 | 0.183* | |
C7 | 0.3448 (3) | 0.1452 (3) | 0.5334 (3) | 0.0521 (8) | |
C8 | 0.4251 (4) | 0.1779 (3) | 0.4756 (3) | 0.0685 (10) | |
H8 | 0.4662 | 0.1265 | 0.4463 | 0.082* | |
C9 | 0.4443 (4) | 0.2865 (4) | 0.4614 (4) | 0.0865 (14) | |
H9 | 0.4993 | 0.3075 | 0.4237 | 0.104* | |
C10 | 0.3830 (4) | 0.3637 (4) | 0.5025 (4) | 0.0824 (12) | |
H10 | 0.3958 | 0.4365 | 0.4920 | 0.099* | |
C11 | 0.3031 (4) | 0.3327 (3) | 0.5589 (3) | 0.0724 (11) | |
H11 | 0.2616 | 0.3847 | 0.5869 | 0.087* | |
C12 | 0.2835 (3) | 0.2242 (3) | 0.5745 (3) | 0.0599 (9) | |
H12 | 0.2288 | 0.2042 | 0.6129 | 0.072* | |
C13 | 0.5489 (5) | 0.2053 (4) | 0.7904 (5) | 0.1054 (18) | |
H13A | 0.5718 | 0.1868 | 0.8630 | 0.126* | |
H13B | 0.4892 | 0.2605 | 0.7832 | 0.126* | |
C14 | 0.6483 (5) | 0.2460 (5) | 0.7537 (5) | 0.122 (2) | |
H14A | 0.7059 | 0.1902 | 0.7583 | 0.183* | |
H14B | 0.6809 | 0.3063 | 0.7953 | 0.183* | |
H14C | 0.6244 | 0.2685 | 0.6832 | 0.183* | |
C15 | 0.5622 (6) | −0.1068 (6) | 0.8245 (5) | 0.107 (3) | 0.642 (10) |
H15A | 0.5910 | −0.0797 | 0.7657 | 0.128* | 0.642 (10) |
H15B | 0.5424 | −0.1822 | 0.8112 | 0.128* | 0.642 (10) |
C16 | 0.6548 (7) | −0.1009 (9) | 0.9137 (7) | 0.117 (4) | 0.642 (10) |
H16A | 0.7198 | −0.1427 | 0.9021 | 0.175* | 0.642 (10) |
H16B | 0.6284 | −0.1289 | 0.9726 | 0.175* | 0.642 (10) |
H16C | 0.6782 | −0.0271 | 0.9263 | 0.175* | 0.642 (10) |
C15B | 0.5569 (11) | −0.0557 (9) | 0.9104 (9) | 0.123 (6) | 0.358 (10) |
H15C | 0.5326 | −0.0361 | 0.9737 | 0.147* | 0.358 (10) |
H15D | 0.6125 | −0.0019 | 0.8981 | 0.147* | 0.358 (10) |
C16B | 0.6157 (14) | −0.1589 (12) | 0.9260 (14) | 0.121 (6) | 0.358 (10) |
H16D | 0.6725 | −0.1575 | 0.9895 | 0.182* | 0.358 (10) |
H16E | 0.6536 | −0.1731 | 0.8696 | 0.182* | 0.358 (10) |
H16F | 0.5598 | −0.2147 | 0.9293 | 0.182* | 0.358 (10) |
U11 | U22 | U33 | U12 | U13 | U23 | |
I | 0.0801 (2) | 0.04690 (16) | 0.06561 (19) | 0.00041 (11) | 0.02164 (13) | 0.00068 (10) |
P | 0.0695 (6) | 0.0540 (5) | 0.0488 (5) | 0.0020 (4) | 0.0054 (4) | 0.0006 (4) |
O1 | 0.100 (2) | 0.083 (2) | 0.0645 (17) | −0.0024 (16) | 0.0270 (15) | −0.0218 (15) |
O2 | 0.0742 (17) | 0.0814 (19) | 0.0712 (17) | −0.0172 (15) | 0.0104 (14) | −0.0137 (15) |
O3 | 0.129 (3) | 0.083 (2) | 0.099 (3) | 0.008 (2) | −0.026 (2) | 0.0217 (19) |
C1 | 0.0580 (19) | 0.0449 (17) | 0.0508 (18) | 0.0039 (14) | 0.0152 (15) | −0.0023 (14) |
C2 | 0.0543 (18) | 0.0545 (19) | 0.0488 (18) | 0.0044 (15) | 0.0159 (14) | −0.0045 (15) |
C3 | 0.087 (3) | 0.060 (2) | 0.052 (2) | 0.000 (2) | 0.0130 (18) | −0.0044 (17) |
C4 | 0.086 (3) | 0.064 (2) | 0.071 (3) | −0.005 (2) | 0.006 (2) | −0.0004 (19) |
C5 | 0.098 (3) | 0.077 (3) | 0.092 (3) | 0.005 (3) | 0.002 (3) | −0.017 (3) |
C6 | 0.097 (4) | 0.101 (4) | 0.150 (5) | 0.006 (3) | −0.016 (4) | −0.040 (4) |
C7 | 0.0559 (19) | 0.0551 (19) | 0.0455 (17) | −0.0007 (15) | 0.0109 (15) | 0.0026 (14) |
C8 | 0.070 (2) | 0.073 (3) | 0.070 (2) | 0.0108 (19) | 0.029 (2) | 0.0089 (19) |
C9 | 0.085 (3) | 0.084 (3) | 0.101 (4) | −0.007 (2) | 0.045 (3) | 0.022 (3) |
C10 | 0.093 (3) | 0.063 (3) | 0.095 (3) | −0.005 (2) | 0.029 (3) | 0.019 (2) |
C11 | 0.091 (3) | 0.054 (2) | 0.076 (3) | 0.007 (2) | 0.026 (2) | 0.0015 (18) |
C12 | 0.066 (2) | 0.059 (2) | 0.061 (2) | 0.0003 (17) | 0.0256 (17) | 0.0021 (17) |
C13 | 0.100 (4) | 0.085 (3) | 0.133 (5) | −0.026 (3) | 0.027 (3) | −0.041 (3) |
C14 | 0.089 (3) | 0.119 (5) | 0.164 (6) | −0.036 (3) | 0.040 (4) | −0.061 (4) |
C15 | 0.127 (6) | 0.098 (6) | 0.087 (5) | 0.049 (5) | 0.002 (4) | −0.008 (4) |
C16 | 0.116 (6) | 0.124 (8) | 0.100 (6) | 0.046 (6) | −0.001 (5) | 0.006 (6) |
C15B | 0.141 (11) | 0.132 (10) | 0.088 (9) | 0.068 (9) | 0.007 (9) | 0.029 (8) |
C16B | 0.176 (13) | 0.097 (10) | 0.076 (8) | 0.044 (9) | −0.008 (9) | 0.023 (8) |
I—C1 | 2.125 (3) | C8—H8 | 0.9300 |
P—O1 | 1.451 (3) | C9—C10 | 1.373 (7) |
P—O3 | 1.541 (3) | C9—H9 | 0.9300 |
P—O2 | 1.557 (3) | C10—C11 | 1.367 (6) |
P—C1 | 1.797 (3) | C10—H10 | 0.9300 |
O2—C13 | 1.438 (5) | C11—C12 | 1.387 (5) |
O3—C15B | 1.384 (5) | C11—H11 | 0.9300 |
O3—C15 | 1.395 (4) | C12—H12 | 0.9300 |
C1—C2 | 1.342 (5) | C13—C14 | 1.443 (7) |
C2—C7 | 1.489 (5) | C13—H13A | 0.9700 |
C2—C3 | 1.515 (5) | C13—H13B | 0.9700 |
C3—C4 | 1.501 (6) | C14—H14A | 0.9600 |
C3—H3A | 0.9700 | C14—H14B | 0.9600 |
C3—H3B | 0.9700 | C14—H14C | 0.9600 |
C4—C5 | 1.547 (6) | C15—C16 | 1.433 (5) |
C4—H4A | 0.9700 | C15—H15A | 0.9700 |
C4—H4B | 0.9700 | C15—H15B | 0.9700 |
C5—C6 | 1.444 (7) | C16—H16A | 0.9600 |
C5—H5A | 0.9700 | C16—H16B | 0.9600 |
C5—H5B | 0.9700 | C16—H16C | 0.9600 |
C6—H6A | 0.9600 | C15B—C16B | 1.448 (5) |
C6—H6B | 0.9600 | C15B—H15C | 0.9700 |
C6—H6C | 0.9600 | C15B—H15D | 0.9700 |
C7—C8 | 1.390 (5) | C16B—H16D | 0.9600 |
C7—C12 | 1.390 (5) | C16B—H16E | 0.9600 |
C8—C9 | 1.385 (6) | C16B—H16F | 0.9600 |
O1—P—O3 | 108.2 (2) | C10—C9—H9 | 119.6 |
O1—P—O2 | 115.87 (17) | C8—C9—H9 | 119.6 |
O3—P—O2 | 107.62 (19) | C11—C10—C9 | 119.5 (4) |
O1—P—C1 | 115.64 (17) | C11—C10—H10 | 120.2 |
O3—P—C1 | 105.80 (18) | C9—C10—H10 | 120.2 |
O2—P—C1 | 103.07 (15) | C10—C11—C12 | 120.5 (4) |
C13—O2—P | 122.2 (3) | C10—C11—H11 | 119.8 |
C15B—O3—C15 | 56.4 (7) | C12—C11—H11 | 119.8 |
C15B—O3—P | 132.6 (5) | C11—C12—C7 | 120.6 (4) |
C15—O3—P | 127.5 (4) | C11—C12—H12 | 119.7 |
C2—C1—P | 125.9 (3) | C7—C12—H12 | 119.7 |
C2—C1—I | 121.0 (3) | O2—C13—C14 | 109.8 (4) |
P—C1—I | 112.95 (17) | O2—C13—H13A | 109.7 |
C1—C2—C7 | 122.5 (3) | C14—C13—H13A | 109.7 |
C1—C2—C3 | 123.6 (3) | O2—C13—H13B | 109.7 |
C7—C2—C3 | 113.8 (3) | C14—C13—H13B | 109.7 |
C4—C3—C2 | 112.0 (3) | H13A—C13—H13B | 108.2 |
C4—C3—H3A | 109.2 | C13—C14—H14A | 109.5 |
C2—C3—H3A | 109.2 | C13—C14—H14B | 109.5 |
C4—C3—H3B | 109.2 | H14A—C14—H14B | 109.5 |
C2—C3—H3B | 109.2 | C13—C14—H14C | 109.5 |
H3A—C3—H3B | 107.9 | H14A—C14—H14C | 109.5 |
C3—C4—C5 | 112.2 (4) | H14B—C14—H14C | 109.5 |
C3—C4—H4A | 109.2 | O3—C15—C16 | 116.3 (6) |
C5—C4—H4A | 109.2 | O3—C15—H15A | 108.2 |
C3—C4—H4B | 109.2 | C16—C15—H15A | 108.2 |
C5—C4—H4B | 109.2 | O3—C15—H15B | 108.2 |
H4A—C4—H4B | 107.9 | C16—C15—H15B | 108.2 |
C6—C5—C4 | 113.5 (5) | H15A—C15—H15B | 107.4 |
C6—C5—H5A | 108.9 | C15—C16—H16A | 109.5 |
C4—C5—H5A | 108.9 | C15—C16—H16B | 109.5 |
C6—C5—H5B | 108.9 | H16A—C16—H16B | 109.5 |
C4—C5—H5B | 108.9 | C15—C16—H16C | 109.5 |
H5A—C5—H5B | 107.7 | H16A—C16—H16C | 109.5 |
C5—C6—H6A | 109.5 | H16B—C16—H16C | 109.5 |
C5—C6—H6B | 109.5 | O3—C15B—C16B | 115.9 (7) |
H6A—C6—H6B | 109.5 | O3—C15B—H15C | 108.3 |
C5—C6—H6C | 109.5 | C16B—C15B—H15C | 108.3 |
H6A—C6—H6C | 109.5 | O3—C15B—H15D | 108.3 |
H6B—C6—H6C | 109.5 | C16B—C15B—H15D | 108.3 |
C8—C7—C12 | 118.3 (3) | H15C—C15B—H15D | 107.4 |
C8—C7—C2 | 120.9 (3) | C15B—C16B—H16D | 109.5 |
C12—C7—C2 | 120.8 (3) | C15B—C16B—H16E | 109.5 |
C9—C8—C7 | 120.3 (4) | H16D—C16B—H16E | 109.5 |
C9—C8—H8 | 119.8 | C15B—C16B—H16F | 109.5 |
C7—C8—H8 | 119.8 | H16D—C16B—H16F | 109.5 |
C10—C9—C8 | 120.7 (4) | H16E—C16B—H16F | 109.5 |
O1—P—O2—C13 | 27.2 (5) | C7—C2—C3—C4 | −82.5 (4) |
O3—P—O2—C13 | −93.9 (4) | C2—C3—C4—C5 | 172.3 (4) |
C1—P—O2—C13 | 154.6 (4) | C3—C4—C5—C6 | −179.8 (5) |
O1—P—O3—C15B | −85.4 (10) | C1—C2—C7—C8 | 120.0 (4) |
O2—P—O3—C15B | 40.5 (10) | C3—C2—C7—C8 | −63.0 (4) |
C1—P—O3—C15B | 150.2 (10) | C1—C2—C7—C12 | −63.3 (5) |
O1—P—O3—C15 | −161.4 (5) | C3—C2—C7—C12 | 113.7 (4) |
O2—P—O3—C15 | −35.5 (5) | C12—C7—C8—C9 | 1.1 (6) |
C1—P—O3—C15 | 74.2 (5) | C2—C7—C8—C9 | 177.9 (4) |
O1—P—C1—C2 | 88.5 (3) | C7—C8—C9—C10 | −1.2 (7) |
O3—P—C1—C2 | −151.9 (3) | C8—C9—C10—C11 | 0.7 (8) |
O2—P—C1—C2 | −39.0 (3) | C9—C10—C11—C12 | −0.1 (7) |
O1—P—C1—I | −87.4 (2) | C10—C11—C12—C7 | 0.1 (6) |
O3—P—C1—I | 32.2 (2) | C8—C7—C12—C11 | −0.6 (6) |
O2—P—C1—I | 145.11 (17) | C2—C7—C12—C11 | −177.4 (4) |
P—C1—C2—C7 | −5.6 (5) | P—O2—C13—C14 | 173.8 (4) |
I—C1—C2—C7 | 170.0 (2) | C15B—O3—C15—C16 | −1.7 (10) |
P—C1—C2—C3 | 177.7 (3) | P—O3—C15—C16 | 119.2 (8) |
I—C1—C2—C3 | −6.7 (5) | C15—O3—C15B—C16B | −39.6 (14) |
C1—C2—C3—C4 | 94.4 (4) | P—O3—C15B—C16B | −152.1 (12) |
D—H···A | D—H | H···A | D···A | D—H···A |
C14—H14C···Cg | 0.96 | 3.38 | 3.870 (7) | 131 |
C14—H14B···Cgi | 0.96 | 3.36 | 3.870 (7) | 116 |
Symmetry code: (i) x+1/2, −y+1/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C16H24IO3P |
Mr | 422.22 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 11.7324 (18), 12.3985 (19), 13.228 (2) |
β (°) | 101.817 (3) |
V (Å3) | 1883.4 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.79 |
Crystal size (mm) | 0.48 × 0.42 × 0.26 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 1999) |
Tmin, Tmax | 0.480, 0.653 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10404, 3693, 2988 |
Rint | 0.019 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.031, 0.086, 1.05 |
No. of reflections | 3693 |
No. of parameters | 212 |
No. of restraints | 57 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.70, −0.42 |
Computer programs: SMART-NT (Bruker, 1998), SAINT-Plus (Bruker, 1999), SAINT-Plus, SHELXTL (Bruker, 1999), SHELXTL, PLATON (Spek, 2003) and SCHAKAL97 (Keller, 1997).
D—H···A | D—H | H···A | D···A | D—H···A |
C14—H14C···Cg | 0.96 | 3.38 | 3.870 (7) | 131 |
C14—H14B···Cgi | 0.96 | 3.36 | 3.870 (7) | 116 |
Symmetry code: (i) x+1/2, −y+1/2, z+1/2. |
For the last three decades, there has been considerable interest in the synthesis and characterization of alkenylphosphonates, due to their wide range of applications as polymer additives, flame-retardants and intermediates for drugs, and as a useful tool in organic transformations (Minami & Motoyoshiya, 1992). However, very few vinylphosphonate structures have been characterized by X-ray crystallography to date. As part of an ongoing study of phosphoorganic biomolecules, we previously reported a facile procedure for the stereoselective preparation of alkenylphosphonates by carbocupration of 1-alkynylphosphonates in diethylether, followed by hydrolysis or reaction with various electrophiles (Cristau et al., 1994, 1997). Here, we report the structure of the title compound, (I), which has been determined by X-ray crystallographic methods.
The crystal structure of (I) is composed of independent molecules, in which the phosphonate ethoxy group facing the I atom is disordered over two orientations. In contrast, the other ethoxy group (atoms C13 and C14) does not exhibit disorder. This is due to restraints placed on it by the geometry of the molecule, in particular the arrangement of O atoms around the C1—P bond, leading to it facing the phenyl ring (Fig. 1). In addition, extrapolating the structure indicates that this ethoxy group is sandwiched between two phenyl rings (one intra- and one intermolecular), preventing disorder (Fig. 2). This constrained environment also leads to two C—H···π interactions. One of these acts in an intramolecular manner between the ethoxy group and the phenyl ring of the molecule [C14—H14C 0.96 Å, H14C···π 3.38 Å, C14—H14C···π 131° and C14···π 3.870 (7) Å]. The other C—H···π interaction occurs between the same ethoxy group and phenyl ring but as an intermolecular interaction [C14—H14B 0.96 Å, H14B···π 3.36 Å, C14—H14B···π 116° and C14···π 3.870 (7) Å; Fig. 2].
Despite the rotational restraint imposed by the double bond (C1═C2), the deviations from zero in the torsion angles I—C1—C2—C3 [−6.7 (5)°] and P—C1—C2—C7 [−5.6 (5)°] indicate that there is some deviation from planarity around C1═C2. This is most probably due to some steric interaction between I and C3, and P and C7.
Examining the crystal packing of (I) indicates that molecules related by the twofold screw axis are held together by an I···O interaction [I···O1 3.076 (3) Å, C1—I···O1 176.17 (12)° and I···O1—P 143.20 (16)°]. This leads to a chain of molecules running along the b axis (Fig. 3). While many examples of general I···O interactions can be found in the Cambridge Structural Database (CSD, Version 5.25, update 3 of July 2004; Allen, 2002), very few examples involving C—I···O—P interactions exist. A search of the CSD for an interaction between C—I and O—P yielded only 16 hits with I···O distances less than 4 Å. Only two of these have I···O distances less than 3.3 Å [2.921 Å in ICYGET10 (Reference?) and 2.941 Å in HXMIPX (Reference?)], and both structure determinations date back to the 1970's. In general, the effect of I···O interactions has not been widely discussed in the literature and is sufficiently rare that it is highlighted by current IUCr validation programs as an unlikely interaction. However, the effect of I···O interactions, together with other weak interactions, on the crystal packing of some iodo-nitroarenesulfonamides and iodo-nitroanilines has been discussed in detail by Kelly et al. (2002) and Garden et al. (2002).