The title compound, C
34H
26N
4·2CH
2Cl
2, lies about an inversion center. The solvent molecules interact with the benzene molecule both through C—H
N hydrogen bonding to span pyridine N atoms of adjacent vinyl groups, possibly stabilizing the rotational conformation observed, and through a π interaction between a dichloromethane Cl atom and a pyridyl ring C—C bond of a
c-glide-related molecule. The benzene molecules form stacks along the
a axis such that two of the four olefin groups are properly oriented for photoreactivity (2+2 cyclodimerization).
Supporting information
CCDC reference: 208013
In a heavy-walled flask, 0.30 g (0.52 mmol) of 1,2,4,5-tetraiodobenzene, 0.67 ml (6.2 mmol) of 2-vinylpyridine, 0.0046 g (4 mol%) of palladium(II) acetate, 0.0063 g (4 mol%) of tri(ο-tolyl)phosphine, 0.21 g (2.6 mmol) of sodium acetate and 15 ml of dimethylformamide were sealed under nitrogen and heated to 403 K with stirring for 4 d. The reaction mixture was quenched with water, extracted with dichloromethane, dried with magnesium sulfate and filtered. Following column chromatography (silica gel, hexane/dichloromethane), the resultant mixture was dissolved in dichloromethane and the solvent was allowed to slowly evaporate in a refrigerator. Several diffraction quality crystals were removed from the solution.
Data collection: CrystalClear(Rigaku Corp., 2001); cell refinement: CrystalClear (Rigaku Corp., 2001); data reduction: CrystalClear (Rigaku Corp., 2001); program(s) used to solve structure: SHELXTL, (Sheldrick,2000); program(s) used to refine structure: SHELXTL (Sheldrick, 2000); molecular graphics: SHELXTL (Sheldrick, 2000); software used to prepare material for publication: SHELXTL (Sheldrick, 2000).
1,2,4,5-tetrakis(2'-vinylpyridyl)benzene-dichloromethane (1:2)
top
Crystal data top
C34H26N4·2CH2Cl2 | F(000) = 684 |
Mr = 660.44 | Dx = 1.339 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 8789 reflections |
a = 8.928 (2) Å | θ = 2.8–26.4° |
b = 18.596 (4) Å | µ = 0.39 mm−1 |
c = 10.015 (2) Å | T = 298 K |
β = 99.822 (6)° | Rod, yellow |
V = 1638.4 (6) Å3 | 0.41 × 0.14 × 0.12 mm |
Z = 2 | |
Data collection top
Mercury AFC8S diffractometer | 3339 independent reflections |
Radiation source: fine-focus sealed tube | 2172 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.086 |
ω scans | θmax = 26.4°, θmin = 3.0° |
Absorption correction: multi-scan (REQABA; Jacobson, 1998) | h = −10→11 |
Tmin = 0.676, Tmax = 1.000 | k = −23→23 |
15828 measured reflections | l = −12→12 |
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)] = 0.065 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.137 | All H-atom parameters refined |
S = 0.99 | w = 1/[σ2(Fo2) + (0.0125P)2 + 1.973P] where P = (Fo2 + 2Fc2)/3 |
3339 reflections | (Δ/σ)max < 0.001 |
259 parameters | Δρmax = 0.18 e Å−3 |
0 restraints | Δρmin = −0.28 e Å−3 |
Crystal data top
C34H26N4·2CH2Cl2 | V = 1638.4 (6) Å3 |
Mr = 660.44 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.928 (2) Å | µ = 0.39 mm−1 |
b = 18.596 (4) Å | T = 298 K |
c = 10.015 (2) Å | 0.41 × 0.14 × 0.12 mm |
β = 99.822 (6)° | |
Data collection top
Mercury AFC8S diffractometer | 3339 independent reflections |
Absorption correction: multi-scan (REQABA; Jacobson, 1998) | 2172 reflections with I > 2σ(I) |
Tmin = 0.676, Tmax = 1.000 | Rint = 0.086 |
15828 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.065 | 0 restraints |
wR(F2) = 0.137 | All H-atom parameters refined |
S = 0.99 | Δρmax = 0.18 e Å−3 |
3339 reflections | Δρmin = −0.28 e Å−3 |
259 parameters | |
Special details top
Experimental. REQABA Empirical Absorption Correction, Version 1.1, R·A·Jacobson, Molecular Structure Corp. 1996–1998 |
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
N1 | −0.0891 (3) | 0.63113 (15) | 0.4618 (3) | 0.0548 (7) | |
N2 | 0.2441 (4) | 0.67215 (17) | 0.0440 (3) | 0.0634 (8) | |
C1 | 0.4369 (3) | 0.54020 (16) | 0.3839 (3) | 0.0408 (7) | |
C2 | 0.3587 (3) | 0.53603 (16) | 0.4954 (3) | 0.0409 (7) | |
C3 | 0.4262 (4) | 0.49630 (17) | 0.6081 (3) | 0.0447 (7) | |
H1 | 0.367 (3) | 0.4935 (16) | 0.683 (3) | 0.052 (9)* | |
C4 | 0.2099 (4) | 0.57042 (18) | 0.4919 (3) | 0.0466 (7) | |
H2 | 0.165 (4) | 0.5930 (18) | 0.404 (4) | 0.066 (10)* | |
C5 | 0.1285 (4) | 0.57177 (19) | 0.5897 (4) | 0.0529 (8) | |
H3 | 0.168 (4) | 0.5526 (18) | 0.676 (4) | 0.067 (11)* | |
C6 | −0.0233 (3) | 0.60410 (17) | 0.5814 (3) | 0.0469 (7) | |
C7 | −0.0950 (4) | 0.6056 (2) | 0.6927 (4) | 0.0648 (10) | |
H4 | −0.047 (4) | 0.587 (2) | 0.775 (4) | 0.077 (13)* | |
C8 | −0.2377 (5) | 0.6352 (2) | 0.6832 (5) | 0.0739 (12) | |
H5 | −0.285 (5) | 0.635 (2) | 0.762 (5) | 0.105 (15)* | |
C9 | −0.3043 (5) | 0.6629 (2) | 0.5623 (5) | 0.0685 (11) | |
H6 | −0.406 (5) | 0.681 (2) | 0.544 (4) | 0.097 (14)* | |
C10 | −0.2282 (4) | 0.6597 (2) | 0.4557 (4) | 0.0634 (10) | |
H7 | −0.265 (4) | 0.6750 (18) | 0.367 (4) | 0.061 (11)* | |
C11 | 0.3776 (4) | 0.58315 (18) | 0.2636 (3) | 0.0455 (7) | |
H8 | 0.287 (4) | 0.6096 (18) | 0.269 (3) | 0.068 (11)* | |
C12 | 0.4348 (4) | 0.5911 (2) | 0.1521 (3) | 0.0566 (9) | |
H9 | 0.533 (5) | 0.569 (2) | 0.140 (4) | 0.087 (13)* | |
C13 | 0.3722 (4) | 0.63698 (19) | 0.0368 (3) | 0.0496 (8) | |
C14 | 0.4410 (5) | 0.6431 (3) | −0.0756 (4) | 0.0910 (16) | |
H10 | 0.525 (6) | 0.617 (3) | −0.075 (5) | 0.13 (2)* | |
C15 | 0.3791 (6) | 0.6869 (3) | −0.1812 (5) | 0.0929 (17) | |
H11 | 0.425 (6) | 0.693 (3) | −0.247 (6) | 0.14 (2)* | |
C16 | 0.2519 (5) | 0.7233 (2) | −0.1738 (4) | 0.0693 (11) | |
H12 | 0.208 (4) | 0.754 (2) | −0.251 (4) | 0.081 (12)* | |
C17 | 0.1882 (6) | 0.7145 (2) | −0.0602 (4) | 0.0780 (13) | |
H13 | 0.108 (5) | 0.735 (2) | −0.053 (4) | 0.083 (14)* | |
Cl1 | −0.18376 (12) | 0.52390 (6) | 0.04942 (11) | 0.0779 (3) | |
Cl2 | −0.14710 (16) | 0.67646 (6) | 0.10044 (15) | 0.1020 (5) | |
H15 | 0.023 (5) | 0.591 (2) | 0.104 (4) | 0.083 (13)* | |
H14 | −0.062 (5) | 0.585 (2) | 0.230 (5) | 0.102 (16)* | |
C18 | −0.0699 (5) | 0.5913 (2) | 0.1369 (5) | 0.0692 (11) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0459 (16) | 0.0631 (18) | 0.0565 (17) | 0.0064 (14) | 0.0121 (13) | −0.0004 (14) |
N2 | 0.078 (2) | 0.068 (2) | 0.0463 (16) | 0.0220 (17) | 0.0193 (15) | 0.0163 (14) |
C1 | 0.0435 (16) | 0.0441 (16) | 0.0357 (15) | −0.0024 (13) | 0.0090 (12) | 0.0023 (13) |
C2 | 0.0373 (15) | 0.0478 (17) | 0.0379 (16) | −0.0005 (13) | 0.0079 (13) | −0.0002 (13) |
C3 | 0.0440 (16) | 0.0544 (18) | 0.0378 (16) | 0.0023 (14) | 0.0131 (14) | 0.0019 (14) |
C4 | 0.0435 (17) | 0.0555 (19) | 0.0413 (17) | 0.0051 (15) | 0.0085 (14) | 0.0037 (15) |
C5 | 0.0514 (19) | 0.061 (2) | 0.0478 (19) | 0.0098 (16) | 0.0136 (16) | 0.0106 (17) |
C6 | 0.0438 (17) | 0.0470 (18) | 0.0523 (19) | −0.0003 (14) | 0.0149 (15) | −0.0004 (15) |
C7 | 0.057 (2) | 0.082 (3) | 0.060 (2) | 0.014 (2) | 0.0250 (19) | 0.009 (2) |
C8 | 0.068 (3) | 0.085 (3) | 0.078 (3) | 0.009 (2) | 0.038 (2) | −0.004 (2) |
C9 | 0.051 (2) | 0.074 (3) | 0.085 (3) | 0.002 (2) | 0.024 (2) | −0.013 (2) |
C10 | 0.053 (2) | 0.072 (3) | 0.064 (2) | 0.0056 (19) | 0.0060 (19) | 0.001 (2) |
C11 | 0.0408 (16) | 0.0564 (19) | 0.0407 (17) | 0.0068 (15) | 0.0109 (14) | 0.0060 (14) |
C12 | 0.0446 (18) | 0.082 (2) | 0.0447 (19) | 0.0163 (18) | 0.0121 (15) | 0.0153 (18) |
C13 | 0.0469 (17) | 0.066 (2) | 0.0360 (16) | −0.0001 (16) | 0.0067 (14) | 0.0061 (15) |
C14 | 0.064 (3) | 0.153 (5) | 0.061 (3) | 0.033 (3) | 0.026 (2) | 0.043 (3) |
C15 | 0.077 (3) | 0.149 (5) | 0.058 (3) | 0.012 (3) | 0.023 (2) | 0.044 (3) |
C16 | 0.089 (3) | 0.068 (2) | 0.049 (2) | 0.004 (2) | 0.008 (2) | 0.0189 (19) |
C17 | 0.097 (3) | 0.081 (3) | 0.060 (3) | 0.037 (3) | 0.024 (2) | 0.017 (2) |
Cl1 | 0.0684 (6) | 0.0810 (7) | 0.0859 (7) | −0.0008 (5) | 0.0178 (5) | −0.0120 (6) |
Cl2 | 0.1131 (10) | 0.0724 (7) | 0.1217 (11) | 0.0125 (7) | 0.0236 (8) | 0.0075 (7) |
C18 | 0.065 (3) | 0.075 (3) | 0.066 (3) | 0.006 (2) | 0.007 (2) | −0.002 (2) |
Geometric parameters (Å, º) top
N1—C6 | 1.338 (4) | C9—H6 | 0.96 (4) |
N1—C10 | 1.342 (4) | C10—H7 | 0.93 (3) |
N2—C13 | 1.330 (4) | C11—C12 | 1.313 (4) |
N2—C17 | 1.335 (5) | C11—H8 | 0.96 (4) |
C1—C3i | 1.388 (4) | C12—C13 | 1.468 (4) |
C1—C2 | 1.417 (4) | C12—H9 | 0.99 (4) |
C1—C11 | 1.467 (4) | C13—C14 | 1.376 (5) |
C2—C3 | 1.397 (4) | C14—C15 | 1.374 (6) |
C2—C4 | 1.469 (4) | C14—H10 | 0.90 (5) |
C3—C1i | 1.388 (4) | C15—C16 | 1.335 (6) |
C3—H1 | 0.99 (3) | C15—H11 | 0.84 (6) |
C4—C5 | 1.316 (4) | C16—C17 | 1.366 (6) |
C4—H2 | 1.00 (3) | C16—H12 | 0.98 (4) |
C5—C6 | 1.472 (4) | C17—H13 | 0.82 (4) |
C5—H3 | 0.94 (3) | Cl1—C18 | 1.752 (4) |
C6—C7 | 1.378 (5) | Cl2—C18 | 1.741 (4) |
C7—C8 | 1.376 (5) | Cl2—C9ii | 3.295 (4) |
C7—H4 | 0.92 (4) | Cl2—C10ii | 3.399 (4) |
C8—C9 | 1.356 (6) | C18—H15 | 0.94 (4) |
C8—H5 | 0.96 (5) | C18—H14 | 0.93 (5) |
C9—C10 | 1.361 (5) | | |
| | | |
C6—N1—C10 | 116.8 (3) | C9—C10—H7 | 126 (2) |
C13—N2—C17 | 117.3 (3) | C12—C11—C1 | 128.4 (3) |
C3i—C1—C2 | 118.4 (3) | C12—C11—H8 | 117 (2) |
C3i—C1—C11 | 120.3 (3) | C1—C11—H8 | 115 (2) |
C2—C1—C11 | 121.3 (3) | C11—C12—C13 | 125.7 (3) |
C3—C2—C1 | 117.6 (3) | C11—C12—H9 | 123 (2) |
C3—C2—C4 | 120.9 (3) | C13—C12—H9 | 111 (2) |
C1—C2—C4 | 121.5 (3) | N2—C13—C14 | 120.8 (3) |
C1i—C3—C2 | 124.0 (3) | N2—C13—C12 | 117.3 (3) |
C1i—C3—H1 | 120.5 (18) | C14—C13—C12 | 121.9 (3) |
C2—C3—H1 | 115.4 (18) | C15—C14—C13 | 120.1 (4) |
C5—C4—C2 | 127.0 (3) | C15—C14—H10 | 124 (4) |
C5—C4—H2 | 117 (2) | C13—C14—H10 | 116 (4) |
C2—C4—H2 | 116 (2) | C16—C15—C14 | 119.5 (4) |
C4—C5—C6 | 125.8 (3) | C16—C15—H11 | 121 (4) |
C4—C5—H3 | 121 (2) | C14—C15—H11 | 120 (4) |
C6—C5—H3 | 114 (2) | C15—C16—C17 | 117.7 (4) |
N1—C6—C7 | 121.5 (3) | C15—C16—H12 | 118 (2) |
N1—C6—C5 | 117.6 (3) | C17—C16—H12 | 124 (2) |
C7—C6—C5 | 120.9 (3) | N2—C17—C16 | 124.7 (4) |
C8—C7—C6 | 120.3 (4) | N2—C17—H13 | 114 (3) |
C8—C7—H4 | 120 (2) | C16—C17—H13 | 121 (3) |
C6—C7—H4 | 120 (2) | Cl2—C18—Cl1 | 111.8 (2) |
C9—C8—C7 | 118.3 (4) | Cl2—C18—H15 | 106 (3) |
C9—C8—H5 | 124 (3) | Cl1—C18—H15 | 107 (2) |
C7—C8—H5 | 118 (3) | Cl2—C18—H14 | 106 (3) |
C8—C9—C10 | 118.8 (4) | Cl1—C18—H14 | 111 (3) |
C8—C9—H6 | 124 (3) | H15—C18—H14 | 115 (4) |
C10—C9—H6 | 117 (3) | C18—Cl2—C9ii | 174.1 (2) |
N1—C10—C9 | 124.3 (4) | C18—Cl2—C10ii | 162.3 (2) |
N1—C10—H7 | 110 (2) | | |
| | | |
C3i—C1—C2—C3 | 1.2 (5) | C7—C8—C9—C10 | 0.5 (6) |
C11—C1—C2—C3 | −177.4 (3) | C6—N1—C10—C9 | 0.3 (6) |
C3i—C1—C2—C4 | −177.1 (3) | C8—C9—C10—N1 | −0.5 (6) |
C11—C1—C2—C4 | 4.2 (4) | C3i—C1—C11—C12 | 2.9 (5) |
C1—C2—C3—C1i | −1.3 (5) | C2—C1—C11—C12 | −178.5 (4) |
C4—C2—C3—C1i | 177.1 (3) | C1—C11—C12—C13 | −177.8 (3) |
C3—C2—C4—C5 | 3.5 (5) | C17—N2—C13—C14 | −1.5 (6) |
C1—C2—C4—C5 | −178.2 (3) | C17—N2—C13—C12 | 179.3 (4) |
C2—C4—C5—C6 | −177.3 (3) | C11—C12—C13—N2 | −1.9 (6) |
C10—N1—C6—C7 | −0.1 (5) | C11—C12—C13—C14 | 178.9 (4) |
C10—N1—C6—C5 | 179.3 (3) | N2—C13—C14—C15 | 1.1 (8) |
C4—C5—C6—N1 | 4.0 (5) | C12—C13—C14—C15 | −179.7 (5) |
C4—C5—C6—C7 | −176.6 (4) | C13—C14—C15—C16 | 0.0 (9) |
N1—C6—C7—C8 | 0.1 (6) | C14—C15—C16—C17 | −0.5 (8) |
C5—C6—C7—C8 | −179.2 (4) | C13—N2—C17—C16 | 0.9 (7) |
C6—C7—C8—C9 | −0.4 (7) | C15—C16—C17—N2 | 0.1 (8) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, −y+3/2, z−1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C18—H14···N1 | 0.93 (5) | 2.52 (5) | 3.371 (6) | 152 (4) |
C18—H15···N2 | 0.94 (4) | 2.64 (4) | 3.445 (6) | 144 (3) |
C16—H12···N2ii | 0.98 (4) | 2.54 (4) | 3.420 (5) | 149 (3) |
C5—H3···Cl1iii | 0.94 (3) | 3.08 (4) | 3.982 (4) | 161 (3) |
C12—H9···Cl1iv | 0.99 (4) | 2.95 (4) | 3.926 (4) | 167 (3) |
Symmetry codes: (ii) x, −y+3/2, z−1/2; (iii) −x, −y+1, −z+1; (iv) x+1, y, z. |
Experimental details
Crystal data |
Chemical formula | C34H26N4·2CH2Cl2 |
Mr | 660.44 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 298 |
a, b, c (Å) | 8.928 (2), 18.596 (4), 10.015 (2) |
β (°) | 99.822 (6) |
V (Å3) | 1638.4 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.39 |
Crystal size (mm) | 0.41 × 0.14 × 0.12 |
|
Data collection |
Diffractometer | Mercury AFC8S diffractometer |
Absorption correction | Multi-scan (REQABA; Jacobson, 1998) |
Tmin, Tmax | 0.676, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15828, 3339, 2172 |
Rint | 0.086 |
(sin θ/λ)max (Å−1) | 0.625 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.065, 0.137, 0.99 |
No. of reflections | 3339 |
No. of parameters | 259 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.18, −0.28 |
Selected geometric parameters (Å, º) topN1—C6 | 1.338 (4) | C6—C7 | 1.378 (5) |
N1—C10 | 1.342 (4) | C7—C8 | 1.376 (5) |
C1—C3i | 1.388 (4) | C8—C9 | 1.356 (6) |
C1—C2 | 1.417 (4) | C9—C10 | 1.361 (5) |
C1—C11 | 1.467 (4) | Cl1—C18 | 1.752 (4) |
C2—C3 | 1.397 (4) | Cl2—C18 | 1.741 (4) |
C2—C4 | 1.469 (4) | Cl2—C9ii | 3.295 (4) |
C4—C5 | 1.316 (4) | Cl2—C10ii | 3.399 (4) |
C5—C6 | 1.472 (4) | | |
| | | |
C6—N1—C10 | 116.8 (3) | N1—C6—C5 | 117.6 (3) |
C13—N2—C17 | 117.3 (3) | C7—C6—C5 | 120.9 (3) |
C3i—C1—C2 | 118.4 (3) | N1—C10—C9 | 124.3 (4) |
C3i—C1—C11 | 120.3 (3) | C12—C11—C1 | 128.4 (3) |
C2—C1—C11 | 121.3 (3) | C11—C12—C13 | 125.7 (3) |
C3—C2—C1 | 117.6 (3) | N2—C13—C14 | 120.8 (3) |
C3—C2—C4 | 120.9 (3) | N2—C13—C12 | 117.3 (3) |
C1—C2—C4 | 121.5 (3) | N2—C17—C16 | 124.7 (4) |
C1i—C3—C2 | 124.0 (3) | Cl2—C18—Cl1 | 111.8 (2) |
C5—C4—C2 | 127.0 (3) | C18—Cl2—C9ii | 174.1 (2) |
C4—C5—C6 | 125.8 (3) | C18—Cl2—C10ii | 162.3 (2) |
N1—C6—C7 | 121.5 (3) | | |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, −y+3/2, z−1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C18—H14···N1 | 0.93 (5) | 2.52 (5) | 3.371 (6) | 152 (4) |
C18—H15···N2 | 0.94 (4) | 2.64 (4) | 3.445 (6) | 144 (3) |
C16—H12···N2ii | 0.98 (4) | 2.54 (4) | 3.420 (5) | 149 (3) |
C5—H3···Cl1iii | 0.94 (3) | 3.08 (4) | 3.982 (4) | 161 (3) |
C12—H9···Cl1iv | 0.99 (4) | 2.95 (4) | 3.926 (4) | 167 (3) |
Symmetry codes: (ii) x, −y+3/2, z−1/2; (iii) −x, −y+1, −z+1; (iv) x+1, y, z. |
Polyvinyl aromatic polymers have been researched extensively as potentially active materials in optoelectronic devices (Bao et al., 1998). Monomeric precursors incorporate vinyl groups that photopolymerize through [2 + 2] cycloaddition, ultimately breaking the conjugation between aromatized systems (Hasegawa et al., 1969). We are investigating pyridyl diolefins as halogen-bonding donors and as bridging ligands for metal complexation. Specifically, we are interested in the role that the acceptor molecules or metal centers in these complexes play in orientation of the olefins to control photoactivity. The title compound, (I), offers the possibility of crosslinking in two dimensions to give a layered polymer with sustainable cavities. However, when (I) crystallizes as the methylene chloride solvate reported here, only one pair of para-olefin groups is properly oriented for photoactivity.
The 1,2,4,5-tetrakis(2-vinylpyridyl)benzene molecule is situated about an inversion center at the mid-point of the cell (see Fig. 1). The molecule is approximately planar (r.m.s. = 0.127 Å) with a slightly bowed shape. The pyridyl rings in the 2 and 4 positions, which are associated with atoms N1 and N2A, are displaced to the same side of the central benzene plane by 0.367 (3) and 0.203 (3) Å, respectively, and have dihedral angles to the central ring of 9.3 (2)° and 4.5 (2)°.
The methylene chloride solvent molecules span the two adjacent pyridyl rings on either side of the benzene ring through C—H···N interactions. Compound (I) has the potential for a wide variety of rotational conformers (one alternative is shown in the scheme), and this solvent interaction may act to stabilize the conformation observed. One of the Cl atoms (Cl1) of each of the two solvent molecules extends, approximately normal, from the molecular plane into a hydrophobic cavity of the molecules above and below the solvent molecule in the stack. Weak C—H···Cl interactions are present between two of the C/H groups in the cavity and this Cl atom. The resulting one-dimensional stacks pack in herringbone fashion, with adjacent stacks related by glide-plane symmetry (Fig. 2). There are also close contacts between atom Cl2 of the solvent molecule and the C9—C10 bonding pair of the glide-related stack (at x, 1.5 − y, −0.5 + z), with Cl···C distances of 3.295 (4) and 3.399 (4) Å, respectively, and a Cl···Centroid(C9—C10) distance of 3.278 (4) Å. This Cl-π interaction is very similar to many others that have been observed (Irving, 1997; Irving & Irving, 1994). There is one weak intramolecular contact between the proton on C11 and N2 (H···N = 2.51 (3) Å).
As a result of the crystal packing, molecules stacked along the a axis have inversion-related olefins (associated with C4 and C5) in close contact (centroid-to-centroid distance of 3.993 (6) Å) and exactly parallel. This distance is somewhat longer than that observed in related compounds – 3.910 Å in 1,4-bis[2-(2-pyridyl)vinyl]benzene (Nakanishi et al., 1972), 3.939 Å in 2,5-distyrylpyrazine (Sasada et al., 1971), and 3.846 (7)–3.941 (6) Å in a mixed crystal of these two compounds (Nakanishi et al., 1979) – but like these compounds (Hasegawa et al., 1973), (I) should be suitable for photoactivity by solid-state polymerization.
We have also prepared a chloroform solvate of 1,2,4,5-tetrakis(2-vinylpyridyl)benzene, but attempts to structurally characterize it have been unsuccessful because of its rapid solvent loss. Continuing investigation of 1,2,4,5-tetrakis(2-vinylpyridyl)benzene will focus on its potential for photoactivity, its solvent-inclusion behavior and the role that the solvent might play in isolating other rotational conformations.