Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807042304/ng2317sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807042304/ng2317Isup2.hkl |
CCDC reference: 663686
2,6-Bis(4-benzyloxystyryl)biphenyl, 1, (0.56 g, 1.0 mmol) and 10% palladium on charcoal (0.10 g, 0.1 mmol) in ethyl acetate (50 cm3) were rocked under hydrogen at 40 psi at room temperature for 48 h. The solution was filtered through a short celite pad and concentrated in vacuo to yield a yellow solid. Flash chromatography, eluting in hexane-ethyl acetate (4:1), afforded 2,6-bis[2-(4-benzyloxyphenyl)ethyl]biphenyl (0.23 g, 41%) as a white solid: mp 133–134 °C [Found: C, 87.3%; H, 6.65%; M+ 574.2872 (ESI). C42H38O2 requires C, 87.8%; H, 6.7%; M+ 574.2862]; νmax(KBr)/cm-1 3029 2956 2921 2865 (C—H), 1611 1582 1513 (aromatic), 1455, 1246, 1175, 1025; δH(400 MHz; CDCl3) 7.39 (10H, m, ArH), 7.35 (2H, m, ArH), 7.31 (2H, m, ArH), 7.16 (1H, s, ArH), 6.78 (8H, m, ArH), 5.00 (4H, s, CH2O), 2.59 (8H, m, CH2CH2); δC(101 MHz; CDCl3) 156.9, 141.4, 140.1, 139.8, 137.2, 134.4, 129.6, 129.2, 128.5, 128.1, 127.8, 127.4, 126.8, 114.6, 70.0 (OCH2), 37.0 (CH2CH2), 36.5 (CH2CH2). Colourless crystals of (I) were obtained as needles from ethyl acetate layered with hexane.
All H-atoms were positioned geometrically and refined using a riding model with d(C—H) = 0.95 Å, Uiso=1.2Ueq (C) for aromatic and 0.99 Å, Uiso = 1.2Ueq (C) for CH2 groups. In the final difference Fourier map, two peaks of approximately 0.7 e Å-3 are found close to C7 and O8 but no chemical significance could be attached to them.
Auxetic materials are those with a negative Poisson ratio, i.e. they expand sideways upon stretching (Evans et al., 1991). A common theme in auxetic materials is that of the re-entrant structural motif. In this way, any force along one axis gets transmitted in a lateral fashion to a perpendicular axis. We were interested to see if such a unit could be deliberately designed into a polymer backbone. Computer simulations of such structures suggest that, under ideal situations, the resulting material should be auxetic (Evans et al., 1991; Aldred & Moratti, 2005). While rigid auxetic molecular structures are not too hard to design (Evans et al., 1991), ideally they should have some flexibility in order to accommodate chain motion and resultant strain.
By using a 1,2,3-trisubstituted phenyl ring and 1,2-ethane linkers it was hoped to get some flexibility as well as enforcing a re-entrant structure. In order to determine suitable polymer backbones, model oligomers were synthesized for structural analysis and monomer (I) was obtained from the hydrogenation of the Wittig-produced diene.
In (I), the biphenyl system is linked symmetrically at the 2 and 6-positions via two ethandiyl chains to two benzyloxyphenyl units. In the solid state, both the ethandiyl and benzyl ether linkages stayed trans - reinforcing the overall re-entrant structure of the central 1,2,3-phenyl linkage. The rings of the biphenyl group are almost orthogonal with a dihedral angle of 85.34 (8)° between them. The rings of the two benzyloxybenzene groups are inclined at 58.99 (10)° C1···C6/C9···C14 and 33.22 (13)° C31···C36/C39···C44 respectively.
In the crystal, molecules form inversion related dimers through C—H···O hydrogen bonds and are further linked into a three dimensional network by a series of C—H···π interactions. Fig 2, Table 1.
For information on auxetic materials, see: Evans et al. (1991); Aldred & Moratti (2005). No structures of benzyloxy ethyl benzene derivatives of biphenyl have been reported previously but two molecules with linked benzyloxybenzene systems are known; see Roesky et al. (1997); Cannon et al. (1989).
Data collection: COLLECT (Nonius, 1998); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick 1997); program(s) used to refine structure: SHELXL97 (Sheldrick 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997), enCIFer (Allen et al., 2004) and PLATON (Spek, 2003).
C42H38O2 | Z = 2 |
Mr = 574.72 | F(000) = 612 |
Triclinic, P1 | Dx = 1.183 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 10.0431 (3) Å | Cell parameters from 12508 reflections |
b = 10.2145 (3) Å | θ = 1.0–27.5° |
c = 16.4136 (5) Å | µ = 0.07 mm−1 |
α = 100.213 (2)° | T = 180 K |
β = 98.218 (2)° | Plate, colourless |
γ = 98.642 (2)° | 0.30 × 0.18 × 0.05 mm |
V = 1613.22 (8) Å3 |
Nonius KappaCCD diffractometer | 7345 independent reflections |
Radiation source: fine-focus sealed tube | 5114 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.045 |
Thin–slice ω and φ scans | θmax = 27.5°, θmin = 3.6° |
Absorption correction: multi-scan (SORTAV; Blessing, 1995) | h = −13→12 |
Tmin = 0.971, Tmax = 0.980 | k = −13→13 |
22105 measured reflections | l = −20→21 |
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)] = 0.066 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.169 | H-atom parameters constrained |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0633P)2 + 0.8567P] where P = (Fo2 + 2Fc2)/3 |
7345 reflections | (Δ/σ)max = 0.005 |
397 parameters | Δρmax = 0.73 e Å−3 |
0 restraints | Δρmin = −0.44 e Å−3 |
C42H38O2 | γ = 98.642 (2)° |
Mr = 574.72 | V = 1613.22 (8) Å3 |
Triclinic, P1 | Z = 2 |
a = 10.0431 (3) Å | Mo Kα radiation |
b = 10.2145 (3) Å | µ = 0.07 mm−1 |
c = 16.4136 (5) Å | T = 180 K |
α = 100.213 (2)° | 0.30 × 0.18 × 0.05 mm |
β = 98.218 (2)° |
Nonius KappaCCD diffractometer | 7345 independent reflections |
Absorption correction: multi-scan (SORTAV; Blessing, 1995) | 5114 reflections with I > 2σ(I) |
Tmin = 0.971, Tmax = 0.980 | Rint = 0.045 |
22105 measured reflections |
R[F2 > 2σ(F2)] = 0.066 | 0 restraints |
wR(F2) = 0.169 | H-atom parameters constrained |
S = 1.02 | Δρmax = 0.73 e Å−3 |
7345 reflections | Δρmin = −0.44 e Å−3 |
397 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 | ||
C1 | 1.0625 (3) | 0.8508 (2) | −0.04760 (14) | 0.0504 (6) | |
C2 | 0.9489 (2) | 0.8225 (2) | −0.11049 (17) | 0.0565 (6) | |
H2A | 0.8618 | 0.7890 | −0.0985 | 0.068* | |
C3 | 0.9602 (3) | 0.8420 (2) | −0.19012 (16) | 0.0593 (7) | |
H3A | 0.8811 | 0.8228 | −0.2326 | 0.071* | |
C4 | 1.0842 (3) | 0.8888 (3) | −0.20805 (16) | 0.0618 (7) | |
H4A | 1.0918 | 0.9019 | −0.2632 | 0.074* | |
C5 | 1.1969 (3) | 0.9168 (3) | −0.1476 (2) | 0.0681 (8) | |
H5A | 1.2834 | 0.9494 | −0.1606 | 0.082* | |
C6 | 1.1873 (3) | 0.8983 (3) | −0.06724 (17) | 0.0610 (7) | |
H6A | 1.2671 | 0.9183 | −0.0252 | 0.073* | |
C7 | 1.0563 (3) | 0.8383 (3) | 0.04239 (17) | 0.0665 (7) | |
H7A | 1.1471 | 0.8740 | 0.0781 | 0.080* | |
H7B | 0.9896 | 0.8912 | 0.0645 | 0.080* | |
O8 | 1.0169 (2) | 0.70361 (19) | 0.04364 (12) | 0.0808 (6) | |
C9 | 0.9942 (3) | 0.6682 (3) | 0.11879 (15) | 0.0539 (6) | |
C10 | 1.0227 (2) | 0.7547 (2) | 0.19627 (16) | 0.0537 (6) | |
H10A | 1.0600 | 0.8475 | 0.2014 | 0.064* | |
C11 | 0.9958 (2) | 0.7036 (2) | 0.26760 (14) | 0.0468 (5) | |
H11A | 1.0156 | 0.7627 | 0.3212 | 0.056* | |
C12 | 0.94126 (19) | 0.5692 (2) | 0.26109 (12) | 0.0374 (4) | |
C13 | 0.9127 (3) | 0.4867 (2) | 0.18170 (14) | 0.0516 (6) | |
H13A | 0.8740 | 0.3940 | 0.1757 | 0.062* | |
C14 | 0.9387 (3) | 0.5350 (3) | 0.11136 (16) | 0.0634 (7) | |
H14A | 0.9182 | 0.4760 | 0.0578 | 0.076* | |
C15 | 0.91479 (19) | 0.5109 (2) | 0.33682 (13) | 0.0399 (5) | |
H15A | 0.9742 | 0.5691 | 0.3876 | 0.048* | |
H15B | 0.9404 | 0.4202 | 0.3304 | 0.048* | |
C16 | 0.76568 (18) | 0.49849 (19) | 0.34982 (11) | 0.0323 (4) | |
H16A | 0.7423 | 0.5899 | 0.3622 | 0.039* | |
H16B | 0.7049 | 0.4472 | 0.2974 | 0.039* | |
C17 | 0.74155 (16) | 0.42761 (18) | 0.42112 (11) | 0.0285 (4) | |
C18 | 0.74898 (16) | 0.49903 (17) | 0.50373 (11) | 0.0270 (4) | |
C19 | 0.73258 (17) | 0.42965 (18) | 0.56915 (11) | 0.0287 (4) | |
C20 | 0.70909 (18) | 0.28851 (19) | 0.55089 (12) | 0.0337 (4) | |
H20A | 0.6985 | 0.2405 | 0.5948 | 0.040* | |
C21 | 0.70094 (19) | 0.21757 (19) | 0.46983 (12) | 0.0359 (4) | |
H21A | 0.6846 | 0.1215 | 0.4583 | 0.043* | |
C22 | 0.71646 (18) | 0.28627 (19) | 0.40563 (12) | 0.0335 (4) | |
H22A | 0.7100 | 0.2368 | 0.3500 | 0.040* | |
C23 | 0.77486 (18) | 0.65079 (17) | 0.52238 (10) | 0.0286 (4) | |
C24 | 0.90739 (19) | 0.72428 (19) | 0.53862 (12) | 0.0355 (4) | |
H24A | 0.9825 | 0.6779 | 0.5369 | 0.043* | |
C25 | 0.9312 (2) | 0.8645 (2) | 0.55727 (13) | 0.0440 (5) | |
H25A | 1.0223 | 0.9135 | 0.5687 | 0.053* | |
C26 | 0.8231 (2) | 0.9328 (2) | 0.55932 (13) | 0.0481 (5) | |
H26A | 0.8394 | 1.0289 | 0.5723 | 0.058* | |
C27 | 0.6912 (2) | 0.8613 (2) | 0.54248 (13) | 0.0449 (5) | |
H27A | 0.6166 | 0.9084 | 0.5435 | 0.054* | |
C28 | 0.6665 (2) | 0.7211 (2) | 0.52408 (12) | 0.0368 (4) | |
H28A | 0.5751 | 0.6728 | 0.5126 | 0.044* | |
C29 | 0.73770 (18) | 0.50279 (19) | 0.65846 (11) | 0.0323 (4) | |
H29A | 0.7910 | 0.5953 | 0.6668 | 0.039* | |
H29B | 0.7857 | 0.4549 | 0.6977 | 0.039* | |
C30 | 0.5957 (2) | 0.5116 (2) | 0.67939 (12) | 0.0417 (5) | |
H30A | 0.5488 | 0.5614 | 0.6409 | 0.050* | |
H30B | 0.5418 | 0.4190 | 0.6694 | 0.050* | |
C31 | 0.59842 (19) | 0.5813 (2) | 0.76926 (12) | 0.0386 (4) | |
C32 | 0.5546 (2) | 0.7035 (2) | 0.78777 (13) | 0.0449 (5) | |
H32A | 0.5268 | 0.7472 | 0.7433 | 0.054* | |
C33 | 0.5504 (2) | 0.7636 (2) | 0.86958 (13) | 0.0477 (5) | |
H33A | 0.5187 | 0.8470 | 0.8807 | 0.057* | |
C34 | 0.5919 (2) | 0.7027 (2) | 0.93522 (13) | 0.0423 (5) | |
C35 | 0.6418 (2) | 0.5836 (2) | 0.91888 (14) | 0.0489 (5) | |
H35A | 0.6744 | 0.5428 | 0.9637 | 0.059* | |
C36 | 0.6437 (2) | 0.5239 (2) | 0.83581 (14) | 0.0461 (5) | |
H36A | 0.6770 | 0.4414 | 0.8247 | 0.055* | |
O37 | 0.57941 (18) | 0.76905 (16) | 1.01376 (9) | 0.0546 (4) | |
C38 | 0.6185 (2) | 0.7105 (2) | 1.08315 (13) | 0.0486 (5) | |
H38A | 0.7189 | 0.7159 | 1.0935 | 0.058* | |
H38B | 0.5746 | 0.6140 | 1.0714 | 0.058* | |
C39 | 0.5748 (2) | 0.7855 (2) | 1.15913 (13) | 0.0405 (5) | |
C40 | 0.4617 (3) | 0.8461 (3) | 1.15324 (16) | 0.0568 (6) | |
H40A | 0.4097 | 0.8432 | 1.0996 | 0.068* | |
C41 | 0.4231 (3) | 0.9115 (3) | 1.22520 (19) | 0.0696 (8) | |
H41A | 0.3447 | 0.9534 | 1.2210 | 0.084* | |
C42 | 0.4987 (3) | 0.9157 (3) | 1.30297 (18) | 0.0741 (8) | |
H42A | 0.4726 | 0.9604 | 1.3525 | 0.089* | |
C43 | 0.6112 (3) | 0.8553 (3) | 1.30865 (16) | 0.0708 (8) | |
H43A | 0.6635 | 0.8583 | 1.3622 | 0.085* | |
C44 | 0.6488 (3) | 0.7907 (2) | 1.23758 (14) | 0.0535 (6) | |
H44A | 0.7271 | 0.7488 | 1.2423 | 0.064* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0693 (15) | 0.0448 (12) | 0.0490 (13) | 0.0197 (11) | 0.0214 (11) | 0.0242 (10) |
C2 | 0.0458 (13) | 0.0459 (13) | 0.0817 (18) | 0.0012 (10) | 0.0177 (12) | 0.0235 (12) |
C3 | 0.0687 (16) | 0.0458 (13) | 0.0548 (15) | 0.0080 (12) | −0.0095 (12) | 0.0059 (11) |
C4 | 0.092 (2) | 0.0542 (15) | 0.0516 (14) | 0.0225 (14) | 0.0245 (14) | 0.0269 (12) |
C5 | 0.0565 (15) | 0.0621 (16) | 0.098 (2) | 0.0035 (12) | 0.0314 (15) | 0.0411 (15) |
C6 | 0.0521 (14) | 0.0575 (15) | 0.0701 (17) | 0.0041 (11) | −0.0069 (12) | 0.0234 (13) |
C7 | 0.0829 (19) | 0.0562 (15) | 0.0645 (16) | 0.0079 (14) | 0.0212 (14) | 0.0207 (13) |
O8 | 0.1388 (19) | 0.0630 (12) | 0.0708 (12) | 0.0393 (12) | 0.0610 (13) | 0.0414 (10) |
C9 | 0.0708 (16) | 0.0608 (15) | 0.0518 (14) | 0.0327 (12) | 0.0333 (12) | 0.0330 (12) |
C10 | 0.0473 (13) | 0.0518 (13) | 0.0716 (16) | 0.0091 (10) | 0.0173 (11) | 0.0322 (12) |
C11 | 0.0405 (11) | 0.0545 (13) | 0.0476 (12) | 0.0068 (10) | 0.0092 (9) | 0.0163 (10) |
C12 | 0.0322 (10) | 0.0480 (11) | 0.0418 (11) | 0.0169 (8) | 0.0138 (8) | 0.0213 (9) |
C13 | 0.0767 (16) | 0.0423 (12) | 0.0493 (13) | 0.0229 (11) | 0.0294 (12) | 0.0198 (10) |
C14 | 0.110 (2) | 0.0508 (14) | 0.0480 (13) | 0.0344 (14) | 0.0382 (14) | 0.0226 (11) |
C15 | 0.0328 (10) | 0.0563 (13) | 0.0385 (11) | 0.0140 (9) | 0.0107 (8) | 0.0224 (9) |
C16 | 0.0294 (9) | 0.0399 (10) | 0.0297 (9) | 0.0095 (8) | 0.0054 (7) | 0.0098 (8) |
C17 | 0.0217 (8) | 0.0338 (9) | 0.0318 (9) | 0.0079 (7) | 0.0051 (7) | 0.0088 (7) |
C18 | 0.0208 (8) | 0.0294 (9) | 0.0317 (9) | 0.0052 (7) | 0.0044 (7) | 0.0084 (7) |
C19 | 0.0220 (8) | 0.0338 (9) | 0.0317 (9) | 0.0055 (7) | 0.0049 (7) | 0.0097 (7) |
C20 | 0.0313 (9) | 0.0340 (10) | 0.0387 (10) | 0.0050 (8) | 0.0075 (8) | 0.0147 (8) |
C21 | 0.0345 (10) | 0.0277 (9) | 0.0451 (11) | 0.0053 (8) | 0.0042 (8) | 0.0083 (8) |
C22 | 0.0313 (9) | 0.0349 (10) | 0.0329 (9) | 0.0074 (8) | 0.0048 (7) | 0.0024 (8) |
C23 | 0.0316 (9) | 0.0305 (9) | 0.0249 (8) | 0.0062 (7) | 0.0046 (7) | 0.0082 (7) |
C24 | 0.0336 (10) | 0.0355 (10) | 0.0386 (10) | 0.0047 (8) | 0.0044 (8) | 0.0138 (8) |
C25 | 0.0468 (12) | 0.0362 (11) | 0.0445 (12) | −0.0030 (9) | −0.0012 (9) | 0.0128 (9) |
C26 | 0.0694 (15) | 0.0280 (10) | 0.0433 (12) | 0.0065 (10) | 0.0016 (11) | 0.0066 (9) |
C27 | 0.0549 (13) | 0.0388 (11) | 0.0450 (12) | 0.0197 (10) | 0.0102 (10) | 0.0086 (9) |
C28 | 0.0352 (10) | 0.0382 (11) | 0.0394 (10) | 0.0111 (8) | 0.0088 (8) | 0.0085 (8) |
C29 | 0.0296 (9) | 0.0377 (10) | 0.0304 (9) | 0.0041 (8) | 0.0055 (7) | 0.0105 (8) |
C30 | 0.0323 (10) | 0.0532 (13) | 0.0378 (11) | 0.0060 (9) | 0.0075 (8) | 0.0044 (9) |
C31 | 0.0298 (10) | 0.0466 (11) | 0.0383 (11) | 0.0021 (8) | 0.0090 (8) | 0.0074 (9) |
C32 | 0.0419 (11) | 0.0568 (13) | 0.0374 (11) | 0.0141 (10) | 0.0052 (9) | 0.0100 (10) |
C33 | 0.0524 (13) | 0.0510 (13) | 0.0414 (12) | 0.0172 (10) | 0.0088 (10) | 0.0064 (10) |
C34 | 0.0450 (12) | 0.0455 (12) | 0.0365 (11) | 0.0059 (9) | 0.0148 (9) | 0.0040 (9) |
C35 | 0.0620 (14) | 0.0513 (13) | 0.0409 (12) | 0.0156 (11) | 0.0190 (10) | 0.0167 (10) |
C36 | 0.0543 (13) | 0.0420 (12) | 0.0476 (12) | 0.0129 (10) | 0.0211 (10) | 0.0108 (10) |
O37 | 0.0773 (11) | 0.0561 (10) | 0.0343 (8) | 0.0223 (8) | 0.0144 (7) | 0.0073 (7) |
C38 | 0.0509 (13) | 0.0589 (14) | 0.0421 (12) | 0.0187 (11) | 0.0142 (10) | 0.0139 (10) |
C39 | 0.0440 (11) | 0.0396 (11) | 0.0388 (11) | 0.0039 (9) | 0.0134 (9) | 0.0088 (9) |
C40 | 0.0518 (14) | 0.0674 (16) | 0.0504 (14) | 0.0153 (12) | 0.0079 (11) | 0.0069 (12) |
C41 | 0.0597 (16) | 0.0670 (17) | 0.084 (2) | 0.0177 (13) | 0.0278 (15) | 0.0017 (15) |
C42 | 0.095 (2) | 0.0669 (18) | 0.0559 (16) | 0.0004 (16) | 0.0405 (16) | −0.0080 (13) |
C43 | 0.097 (2) | 0.0713 (18) | 0.0383 (13) | 0.0064 (16) | 0.0100 (14) | 0.0059 (12) |
C44 | 0.0592 (14) | 0.0558 (14) | 0.0474 (13) | 0.0101 (11) | 0.0089 (11) | 0.0163 (11) |
C1—C6 | 1.377 (3) | C23—C24 | 1.390 (3) |
C1—C2 | 1.382 (3) | C23—C28 | 1.392 (2) |
C1—C7 | 1.514 (3) | C24—C25 | 1.387 (3) |
C2—C3 | 1.375 (4) | C24—H24A | 0.9500 |
C2—H2A | 0.9500 | C25—C26 | 1.378 (3) |
C3—C4 | 1.357 (4) | C25—H25A | 0.9500 |
C3—H3A | 0.9500 | C26—C27 | 1.377 (3) |
C4—C5 | 1.352 (4) | C26—H26A | 0.9500 |
C4—H4A | 0.9500 | C27—C28 | 1.386 (3) |
C5—C6 | 1.380 (4) | C27—H27A | 0.9500 |
C5—H5A | 0.9500 | C28—H28A | 0.9500 |
C6—H6A | 0.9500 | C29—C30 | 1.525 (3) |
C7—O8 | 1.378 (3) | C29—H29A | 0.9900 |
C7—H7A | 0.9900 | C29—H29B | 0.9900 |
C7—H7B | 0.9900 | C30—C31 | 1.515 (3) |
O8—C9 | 1.385 (3) | C30—H30A | 0.9900 |
C9—C14 | 1.368 (4) | C30—H30B | 0.9900 |
C9—C10 | 1.379 (3) | C31—C36 | 1.382 (3) |
C10—C11 | 1.407 (3) | C31—C32 | 1.384 (3) |
C10—H10A | 0.9500 | C32—C33 | 1.383 (3) |
C11—C12 | 1.379 (3) | C32—H32A | 0.9500 |
C11—H11A | 0.9500 | C33—C34 | 1.381 (3) |
C12—C13 | 1.386 (3) | C33—H33A | 0.9500 |
C12—C15 | 1.510 (3) | C34—O37 | 1.378 (2) |
C13—C14 | 1.376 (3) | C34—C35 | 1.381 (3) |
C13—H13A | 0.9500 | C35—C36 | 1.396 (3) |
C14—H14A | 0.9500 | C35—H35A | 0.9500 |
C15—C16 | 1.532 (3) | C36—H36A | 0.9500 |
C15—H15A | 0.9900 | O37—C38 | 1.412 (3) |
C15—H15B | 0.9900 | C38—C39 | 1.501 (3) |
C16—C17 | 1.510 (2) | C38—H38A | 0.9900 |
C16—H16A | 0.9900 | C38—H38B | 0.9900 |
C16—H16B | 0.9900 | C39—C40 | 1.373 (3) |
C17—C22 | 1.398 (2) | C39—C44 | 1.380 (3) |
C17—C18 | 1.407 (2) | C40—C41 | 1.386 (4) |
C18—C19 | 1.403 (2) | C40—H40A | 0.9500 |
C18—C23 | 1.501 (2) | C41—C42 | 1.379 (4) |
C19—C20 | 1.396 (2) | C41—H41A | 0.9500 |
C19—C29 | 1.513 (2) | C42—C43 | 1.366 (4) |
C20—C21 | 1.382 (3) | C42—H42A | 0.9500 |
C20—H20A | 0.9500 | C43—C44 | 1.367 (4) |
C21—C22 | 1.380 (3) | C43—H43A | 0.9500 |
C21—H21A | 0.9500 | C44—H44A | 0.9500 |
C22—H22A | 0.9500 | ||
C6—C1—C2 | 118.1 (2) | C24—C23—C28 | 118.52 (17) |
C6—C1—C7 | 118.3 (2) | C24—C23—C18 | 120.83 (16) |
C2—C1—C7 | 123.6 (2) | C28—C23—C18 | 120.64 (16) |
C3—C2—C1 | 120.8 (2) | C25—C24—C23 | 120.76 (18) |
C3—C2—H2A | 119.6 | C25—C24—H24A | 119.6 |
C1—C2—H2A | 119.6 | C23—C24—H24A | 119.6 |
C4—C3—C2 | 120.1 (2) | C26—C25—C24 | 120.11 (19) |
C4—C3—H3A | 120.0 | C26—C25—H25A | 119.9 |
C2—C3—H3A | 120.0 | C24—C25—H25A | 119.9 |
C5—C4—C3 | 120.1 (2) | C27—C26—C25 | 119.73 (19) |
C5—C4—H4A | 119.9 | C27—C26—H26A | 120.1 |
C3—C4—H4A | 119.9 | C25—C26—H26A | 120.1 |
C4—C5—C6 | 120.5 (2) | C26—C27—C28 | 120.54 (19) |
C4—C5—H5A | 119.7 | C26—C27—H27A | 119.7 |
C6—C5—H5A | 119.7 | C28—C27—H27A | 119.7 |
C1—C6—C5 | 120.3 (2) | C27—C28—C23 | 120.33 (19) |
C1—C6—H6A | 119.8 | C27—C28—H28A | 119.8 |
C5—C6—H6A | 119.8 | C23—C28—H28A | 119.8 |
O8—C7—C1 | 108.3 (2) | C19—C29—C30 | 112.53 (15) |
O8—C7—H7A | 110.0 | C19—C29—H29A | 109.1 |
C1—C7—H7A | 110.0 | C30—C29—H29A | 109.1 |
O8—C7—H7B | 110.0 | C19—C29—H29B | 109.1 |
C1—C7—H7B | 110.0 | C30—C29—H29B | 109.1 |
H7A—C7—H7B | 108.4 | H29A—C29—H29B | 107.8 |
C7—O8—C9 | 118.7 (2) | C31—C30—C29 | 113.37 (16) |
C14—C9—C10 | 120.3 (2) | C31—C30—H30A | 108.9 |
C14—C9—O8 | 114.2 (2) | C29—C30—H30A | 108.9 |
C10—C9—O8 | 125.5 (2) | C31—C30—H30B | 108.9 |
C9—C10—C11 | 119.1 (2) | C29—C30—H30B | 108.9 |
C9—C10—H10A | 120.4 | H30A—C30—H30B | 107.7 |
C11—C10—H10A | 120.4 | C36—C31—C32 | 117.61 (19) |
C12—C11—C10 | 121.1 (2) | C36—C31—C30 | 120.93 (19) |
C12—C11—H11A | 119.4 | C32—C31—C30 | 121.46 (19) |
C10—C11—H11A | 119.4 | C33—C32—C31 | 121.4 (2) |
C11—C12—C13 | 117.58 (19) | C33—C32—H32A | 119.3 |
C11—C12—C15 | 122.25 (19) | C31—C32—H32A | 119.3 |
C13—C12—C15 | 120.16 (19) | C34—C33—C32 | 120.2 (2) |
C14—C13—C12 | 122.0 (2) | C34—C33—H33A | 119.9 |
C14—C13—H13A | 119.0 | C32—C33—H33A | 119.9 |
C12—C13—H13A | 119.0 | O37—C34—C35 | 125.08 (19) |
C9—C14—C13 | 119.8 (2) | O37—C34—C33 | 115.36 (19) |
C9—C14—H14A | 120.1 | C35—C34—C33 | 119.56 (19) |
C13—C14—H14A | 120.1 | C34—C35—C36 | 119.3 (2) |
C12—C15—C16 | 113.56 (15) | C34—C35—H35A | 120.4 |
C12—C15—H15A | 108.9 | C36—C35—H35A | 120.4 |
C16—C15—H15A | 108.9 | C31—C36—C35 | 121.8 (2) |
C12—C15—H15B | 108.9 | C31—C36—H36A | 119.1 |
C16—C15—H15B | 108.9 | C35—C36—H36A | 119.1 |
H15A—C15—H15B | 107.7 | C34—O37—C38 | 117.91 (17) |
C17—C16—C15 | 111.51 (14) | O37—C38—C39 | 108.87 (17) |
C17—C16—H16A | 109.3 | O37—C38—H38A | 109.9 |
C15—C16—H16A | 109.3 | C39—C38—H38A | 109.9 |
C17—C16—H16B | 109.3 | O37—C38—H38B | 109.9 |
C15—C16—H16B | 109.3 | C39—C38—H38B | 109.9 |
H16A—C16—H16B | 108.0 | H38A—C38—H38B | 108.3 |
C22—C17—C18 | 118.59 (16) | C40—C39—C44 | 119.0 (2) |
C22—C17—C16 | 119.16 (16) | C40—C39—C38 | 122.1 (2) |
C18—C17—C16 | 122.20 (16) | C44—C39—C38 | 118.9 (2) |
C19—C18—C17 | 120.59 (16) | C39—C40—C41 | 120.2 (2) |
C19—C18—C23 | 119.48 (15) | C39—C40—H40A | 119.9 |
C17—C18—C23 | 119.92 (15) | C41—C40—H40A | 119.9 |
C20—C19—C18 | 118.82 (16) | C42—C41—C40 | 119.8 (3) |
C20—C19—C29 | 119.04 (16) | C42—C41—H41A | 120.1 |
C18—C19—C29 | 122.13 (16) | C40—C41—H41A | 120.1 |
C21—C20—C19 | 120.95 (17) | C43—C42—C41 | 119.8 (2) |
C21—C20—H20A | 119.5 | C43—C42—H42A | 120.1 |
C19—C20—H20A | 119.5 | C41—C42—H42A | 120.1 |
C22—C21—C20 | 120.01 (17) | C42—C43—C44 | 120.2 (3) |
C22—C21—H21A | 120.0 | C42—C43—H43A | 119.9 |
C20—C21—H21A | 120.0 | C44—C43—H43A | 119.9 |
C21—C22—C17 | 121.04 (17) | C43—C44—C39 | 120.9 (2) |
C21—C22—H22A | 119.5 | C43—C44—H44A | 119.5 |
C17—C22—H22A | 119.5 | C39—C44—H44A | 119.5 |
C6—C1—C2—C3 | −0.4 (4) | C16—C17—C22—C21 | 176.61 (16) |
C7—C1—C2—C3 | 176.8 (2) | C19—C18—C23—C24 | 94.7 (2) |
C1—C2—C3—C4 | 0.5 (4) | C17—C18—C23—C24 | −85.2 (2) |
C2—C3—C4—C5 | −0.2 (4) | C19—C18—C23—C28 | −85.1 (2) |
C3—C4—C5—C6 | 0.0 (4) | C17—C18—C23—C28 | 95.0 (2) |
C2—C1—C6—C5 | 0.2 (4) | C28—C23—C24—C25 | 0.9 (3) |
C7—C1—C6—C5 | −177.2 (2) | C18—C23—C24—C25 | −178.87 (17) |
C4—C5—C6—C1 | 0.1 (4) | C23—C24—C25—C26 | −0.5 (3) |
C6—C1—C7—O8 | −116.2 (3) | C24—C25—C26—C27 | −0.2 (3) |
C2—C1—C7—O8 | 66.5 (3) | C25—C26—C27—C28 | 0.5 (3) |
C1—C7—O8—C9 | −175.3 (2) | C26—C27—C28—C23 | 0.0 (3) |
C7—O8—C9—C14 | 171.9 (2) | C24—C23—C28—C27 | −0.7 (3) |
C7—O8—C9—C10 | −8.0 (4) | C18—C23—C28—C27 | 179.12 (17) |
C14—C9—C10—C11 | 1.0 (4) | C20—C19—C29—C30 | −82.1 (2) |
O8—C9—C10—C11 | −179.1 (2) | C18—C19—C29—C30 | 97.1 (2) |
C9—C10—C11—C12 | −0.3 (3) | C19—C29—C30—C31 | 178.50 (17) |
C10—C11—C12—C13 | −0.6 (3) | C29—C30—C31—C36 | −66.3 (3) |
C10—C11—C12—C15 | 178.38 (19) | C29—C30—C31—C32 | 114.4 (2) |
C11—C12—C13—C14 | 0.8 (3) | C36—C31—C32—C33 | −2.8 (3) |
C15—C12—C13—C14 | −178.2 (2) | C30—C31—C32—C33 | 176.6 (2) |
C10—C9—C14—C13 | −0.8 (4) | C31—C32—C33—C34 | 0.8 (3) |
O8—C9—C14—C13 | 179.3 (2) | C32—C33—C34—O37 | −178.05 (19) |
C12—C13—C14—C9 | −0.1 (4) | C32—C33—C34—C35 | 2.0 (3) |
C11—C12—C15—C16 | 98.6 (2) | O37—C34—C35—C36 | 177.3 (2) |
C13—C12—C15—C16 | −82.4 (2) | C33—C34—C35—C36 | −2.7 (3) |
C12—C15—C16—C17 | 174.56 (17) | C32—C31—C36—C35 | 2.0 (3) |
C15—C16—C17—C22 | −83.3 (2) | C30—C31—C36—C35 | −177.3 (2) |
C15—C16—C17—C18 | 94.1 (2) | C34—C35—C36—C31 | 0.7 (3) |
C22—C17—C18—C19 | 0.5 (2) | C35—C34—O37—C38 | −0.9 (3) |
C16—C17—C18—C19 | −176.86 (15) | C33—C34—O37—C38 | 179.1 (2) |
C22—C17—C18—C23 | −179.60 (15) | C34—O37—C38—C39 | −170.58 (18) |
C16—C17—C18—C23 | 3.1 (2) | O37—C38—C39—C40 | 30.2 (3) |
C17—C18—C19—C20 | 0.2 (2) | O37—C38—C39—C44 | −151.5 (2) |
C23—C18—C19—C20 | −179.76 (15) | C44—C39—C40—C41 | 0.1 (4) |
C17—C18—C19—C29 | −179.03 (15) | C38—C39—C40—C41 | 178.4 (2) |
C23—C18—C19—C29 | 1.1 (2) | C39—C40—C41—C42 | 0.0 (4) |
C18—C19—C20—C21 | −0.5 (3) | C40—C41—C42—C43 | 0.0 (4) |
C29—C19—C20—C21 | 178.72 (16) | C41—C42—C43—C44 | −0.1 (4) |
C19—C20—C21—C22 | 0.2 (3) | C42—C43—C44—C39 | 0.2 (4) |
C20—C21—C22—C17 | 0.5 (3) | C40—C39—C44—C43 | −0.2 (4) |
C18—C17—C22—C21 | −0.8 (3) | C38—C39—C44—C43 | −178.6 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C14—H14A···O8i | 0.95 | 2.48 | 3.326 (4) | 149 |
C2—H2A···Cg5ii | 0.95 | 2.78 | 3.644 (2) | 152 |
C7—H7B···Cg1iii | 0.99 | 2.68 | 3.575 (3) | 150 |
C13—H13A···Cg1iv | 0.95 | 2.82 | 3.620 (2) | 143 |
C28—H28A···Cg3v | 0.95 | 2.98 | 3.865 (2) | 155 |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) x, y, z+1; (iii) −x, −y, −z+2; (iv) −x, −y+1, −z+2; (v) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C42H38O2 |
Mr | 574.72 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 180 |
a, b, c (Å) | 10.0431 (3), 10.2145 (3), 16.4136 (5) |
α, β, γ (°) | 100.213 (2), 98.218 (2), 98.642 (2) |
V (Å3) | 1613.22 (8) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.07 |
Crystal size (mm) | 0.30 × 0.18 × 0.05 |
Data collection | |
Diffractometer | Nonius KappaCCD |
Absorption correction | Multi-scan (SORTAV; Blessing, 1995) |
Tmin, Tmax | 0.971, 0.980 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 22105, 7345, 5114 |
Rint | 0.045 |
(sin θ/λ)max (Å−1) | 0.651 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.066, 0.169, 1.02 |
No. of reflections | 7345 |
No. of parameters | 397 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.73, −0.44 |
Computer programs: COLLECT (Nonius, 1998), SCALEPACK (Otwinowski & Minor, 1997), SCALEPACK and DENZO (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick 1997), SHELXL97 (Sheldrick 1997), ORTEP-3 (Farrugia, 1997), SHELXL97 (Sheldrick, 1997), enCIFer (Allen et al., 2004) and PLATON (Spek, 2003).
D—H···A | D—H | H···A | D···A | D—H···A |
C14—H14A···O8i | 0.95 | 2.48 | 3.326 (4) | 148.5 |
C2—H2A···Cg5ii | 0.95 | 2.78 | 3.644 (2) | 152 |
C7—H7B···Cg1iii | 0.99 | 2.68 | 3.575 (3) | 150 |
C13—H13A···Cg1iv | 0.95 | 2.82 | 3.620 (2) | 143 |
C28—H28A···Cg3v | 0.95 | 2.98 | 3.865 (2) | 155 |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) x, y, z+1; (iii) −x, −y, −z+2; (iv) −x, −y+1, −z+2; (v) −x+1, −y+1, −z+1. |
Auxetic materials are those with a negative Poisson ratio, i.e. they expand sideways upon stretching (Evans et al., 1991). A common theme in auxetic materials is that of the re-entrant structural motif. In this way, any force along one axis gets transmitted in a lateral fashion to a perpendicular axis. We were interested to see if such a unit could be deliberately designed into a polymer backbone. Computer simulations of such structures suggest that, under ideal situations, the resulting material should be auxetic (Evans et al., 1991; Aldred & Moratti, 2005). While rigid auxetic molecular structures are not too hard to design (Evans et al., 1991), ideally they should have some flexibility in order to accommodate chain motion and resultant strain.
By using a 1,2,3-trisubstituted phenyl ring and 1,2-ethane linkers it was hoped to get some flexibility as well as enforcing a re-entrant structure. In order to determine suitable polymer backbones, model oligomers were synthesized for structural analysis and monomer (I) was obtained from the hydrogenation of the Wittig-produced diene.
In (I), the biphenyl system is linked symmetrically at the 2 and 6-positions via two ethandiyl chains to two benzyloxyphenyl units. In the solid state, both the ethandiyl and benzyl ether linkages stayed trans - reinforcing the overall re-entrant structure of the central 1,2,3-phenyl linkage. The rings of the biphenyl group are almost orthogonal with a dihedral angle of 85.34 (8)° between them. The rings of the two benzyloxybenzene groups are inclined at 58.99 (10)° C1···C6/C9···C14 and 33.22 (13)° C31···C36/C39···C44 respectively.
In the crystal, molecules form inversion related dimers through C—H···O hydrogen bonds and are further linked into a three dimensional network by a series of C—H···π interactions. Fig 2, Table 1.