4,4′-Bis[2-(3,5-dimeth­oxy­phen­yl)ethen­yl]biphen­yl

Alain Collas; Matthias Zeller; Frank Blockhuys

doi:10.1107/S1600536811012888

. 2011 Apr 13;67(Pt 5):o1112–o1113. doi: 10.1107/S1600536811012888

4,4′-Bis[2-(3,5-dimethoxyphenyl)ethenyl]biphenyl

Alain Collas ^a, Matthias Zeller ^b, Frank Blockhuys ^a,^*

PMCID: PMC3089291 PMID: 21754429

Abstract

The title compound, C₃₂H₃₀O₄, crystallizes with three different conformers of the same molecule in the asymmetric unit, which explains the unusually large unit cell volume. The supramolecular structure is based on interactions involving the methoxy groups [C⋯O contacts between 3.090 (2) and 3.204 (2) Å, and C—H⋯O contacts between (normalized) 2.40 and 2.71 Å], π–π stacking of the electron-rich methoxy-substituted rings [centroid–centroid distances of 3.6454 (9)–3.738 (1) Å] and C—H⋯π contacts (normalized, 2.62–2.97Å).

Related literature

For related methoxy-substituted biphenyls with 4,4′-bis(2-phenylethenyl) substitution, see: Vande Velde et al. (2002 ▶) [CSD refcode: MODDUE] and Li & Jian (2009 ▶) [CSD refcode: POWYUW]. For a study on the blue-light-emitting properties of a related compound, see: Jin et al. (2002 ▶). For the conformations of methoxybenzenes, see: Vande Velde et al. (2007 ▶). For the preparation, see: Jin et al. (2002 ▶.

Experimental

Crystal data

C₃₂H₃₀O₄
M _r = 478.56
Monoclinic,
a = 11.8208 (13) Å
b = 27.896 (3) Å
c = 22.875 (3) Å
β = 99.723 (2)°
V = 7434.8 (14) Å³
Z = 12
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 100 K
0.55 × 0.45 × 0.15 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.956, T _max = 0.988
74405 measured reflections
18422 independent reflections
13284 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.060
wR(F ²) = 0.181
S = 1.03
18422 reflections
985 parameters
H-atom parameters constrained
Δρ_max = 0.68 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811012888/vm2079sup1.cif

e-67-o1112-sup1.cif^{(54KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811012888/vm2079Isup2.hkl

e-67-o1112-Isup2.hkl^{(882.2KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Relevant C—H⋯π contacts in the crystal packing of the title compound (Å, °).

Cg(X1), Cg(X2), Cg(X3) and Cg(X4) are the centroids of the C1X–C6X, C9X–C14X, C15X–C20X and C23X–C28X rings, respectively, where X = A, B, C, D.

Entry	D	H	A	H⋯A	D—H⋯A
1	C10A	H10A	Cg(B4)ⁱ	2.62	148
2	C17A	H17A	Cg(B3)ⁱ	2.86	150
3	C19A	H19A	Cg(C4)ⁱⁱ	2.80	143
4	C29A	H29A	Cg(A3)ⁱⁱⁱ	2.79	147
5	C10B	H10B	Cg(C1)ⁱⁱⁱ	2.84	148
6	C14B	H14B	Cg(A2)^iv	2.97	147
7	C19B	H19B	Cg(A1)^iv	2.67	149
8	C31B	H31F	Cg(B2)ⁱⁱⁱ	2.80	148
9	C10C	H10C	Cg(B1)^iv	2.70	148
10	C19C	H19C	Cg(A4)^v	2.85	152
11	C29C	H29G	Cg(C3)ⁱ	2.76	143
12	C31C	H31G	Cg(C2)ⁱⁱⁱ	2.78	140

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Symmetry codes: (i) x + 1, y, z; (ii) −x + 1, y + Inline graphic , −z + ; (iii) x − 1, y, z; (iv) x, y, z; (v) −x + 2, y − , −z + .

Table 2. Relevant π–π contacts in the crystal packing of the title compound (Å, °).

The angle related to a pair of centroids is defined as the angle between the Cg(I)⋯Cg(J) vector and the normal to plane I. Centroids as in Table 1.

Entry	Cg(I)	Cg(J)	Cg⋯Cg	Angle
1	Cg(A1)	Cg(A1)^vi	3.738 (1)	26.65
2	Cg(A4)	Cg(A4)^vii	3.6454 (9)	25.18
3	Cg(B1)	Cg(C4)^viii	3.713 (1)	25.39
4	Cg(B4)	Cg(C1)^ix	3.697 (1)	26.83
5	Cg(C1)	Cg(B4)^x	3.697 (1)	25.86
6	Cg(C4)	Cg(B1)^xi	3.713 (1)	25.72

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Symmetry codes: (vi) −x, −y + 1, −z; (vii) −x + 3, −y + 1, −z + 1; (viii) x + 1, −y + Inline graphic , z + ; (ix) x − 2, −y + , z − ; (x) x + 2, −y + , z + ; (xi) x − 1, −y + , z − .

Table 3. Relevant short contacts involving the methoxy groups in the crystal packing of the title compound (Å, °).

Entry	D	X	A	X⋯A	D–X⋯A
1	O2A	C30A	O1C^ix	3.139 (2)	175.28 (12)
2	O3A	C31A	O4C^x	3.090 (2)	160.33 (12)
3	C32A	H32A	O2C^vii	2.71	120
4	C32A	H32c	O3A^vii	2.55	142
5	C15B	C16B	O1Bⁱⁱⁱ	3.204 (2)	108.54 (9)
6	O1B	C29B	O4A^vii	3.171 (2)	143.57 (12)
7	O2B	C30B	O3B^x	3.171 (2)	171.88 (12)
8	O4B	C32B	O1A^xii	3.102 (2)	174.13 (12)
9	C31B	H31D	O2C^ix	2.68	139
10	O2C	C30C	O3C^x	3.152 (2)	161.25 (11)
11	C29C	H29H	O4B^x	2.67	141
12	C31C	H31I	O2B^xi	2.70	143
13	C32C	H32G	O1B^xi	2.40	144
14	C32C	H32I	O4C^xiii	2.69	124

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Symmetry codes: (xii) −x − 1, −y + 1, −z; (xiii) −x, −y, −z.

Acknowledgments

AC wishes to thank the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT) for a predoctoral grant. The X-ray diffractometer was funded by NSF Grant 0087210, Ohio Board of Regents Grant CAP-491, and by Youngstown State University.

supplementary crystallographic information

Comment

The title compound was synthesized with its use as the active component in an organic blue-light-emitting diode in mind (Jin et al., 2002). Three conformers of the same molecule are present in the asymmetric unit, displaying different conformations of the methoxy groups and the biphenyl moiety; the molecules have been labeled A, B and C and the numbering scheme is given in Fig. 1. Fig. 2 presents a packing diagram. Molecules A and B have non-planar biphenyl units, with dihedral angles of 30.97 (7)° and 30.51 (7)°, respectively, while the same moiety in molecule C is virtually planar [4.22 (8)°]. In each of the three molecules the methoxy groups are oriented differently: their precise orientations do not have a large influence on the relative stability of the conformer (Vande Velde et al., 2007) but are merely due to the intermolecular contacts they are involved in. The three crystallographically independent molecules are held together by three C–H···π interactions involving aromatic hydrogen atoms. Rings 1 and 2 of molecule A are contacted by H14B and H19B (Table 1, entries 6 and 7) and ring 1 of molecule B is contacted by H10C (Table 1, entry 9). Additionally, molecule A is involved in two methoxy···methoxy contacts (Table 3, entries 1 and 2), two C–H···O contacts involving the methoxy group in the 3-position (Table 3, entries 3 and 4), four C–H···π interactions involving aromatic hydrogen atoms (Table 1, entries 1–4) and two π–π contacts with a symmetry-related A molecule (Table 2, entries 1 and 2). The supramolecular organization of molecule B is based on four methoxy···methoxy contacts (Table 3, entries 5–8), one contact involving the hydrogen atoms of the methoxy group in the 3-position (Table 3, entry 9), two additional C—H···π interactions (Table 1, entries 5 and 8) and two π–π contacts involving the methoxy-substituted rings (1 and 4) of molecules B and C (Table 2, entries 3 and 4). Molecule C participates in five contacts involving the methoxy groups, of which one is a methoxy···methoxy contact (Table 3, entry 10) and four are initiated by hydrogen atoms of the methoxy groups (Table 3, entries 11–14). Two contacts involve the π-systems of the methoxy-substituted rings of molecules B and C (Table 2, entries 5 and 6). Finally, it can be clearly seen from Table 2 that all three molecules are engaged in π–π stacking of the electron-rich methoxy-substituted rings 1 and 4.

Experimental

The title compound was prepared as is outlined in Yin et al. (2002). Crystals suitable for the diffraction experiment were grown by slow evaporation of an acetone solution. M.p. (uncorrected) 452 K. ¹H NMR (CDCl₃, 400 MHz, TMS): δ 3.83 (s, OCH₃), 6.41 (t, 2.2 Hz, H4, H26), 6.69 (d, 2.2 Hz, H2, H6, H24, H28), 7.06 (d, 16.3 Hz, H7/H22 or H8/H21), 7.11 (d, 16.3 Hz, H7/H22 or H8/H21), 7.56 (d, 8.4 Hz, H10, H14, H17, H19), 7.61 (d, 8.4 Hz, H11, H13, H17, H19) p.p.m. ¹³C NMR (CDCl₃, 100 MHz, TMS): δ 55.40 (C29, C30, C31, C32), 100.12 (C4, C26), 104.69 (C2, C6, C24, C28), 127.08 (C10, C14, C17, C19), 127.09 (C11, C13, C16, C20), 128.71 (C7/C22 or C8/C21), 128.81 (C7/C22 or C8/C21), 136.32 (C9, C18), 139.38 (C12, C15), 139.83 (C1, C23), 161.06 (C3, C5, C25, C27) p.p.m.