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2,5-Dieth­oxy-1,4-bis­[(trimethyl­silyl)ethyn­yl]benzene, C20H30O2Si2, (I), constitutes one of the first structurally characterized examples of a family of compounds, viz. the 2,5-dialk­oxy-1,4-bis­[(trimethyl­silyl)ethyn­yl]benzene derivatives, used in the preparation of oligo(phenyl­ene­ethynylene)s via Pd/Cu-catalysed cross-coupling. 2,5-Dieth­oxy-1,4-diethynylbenzene, C14H14O2, (II), results from protodesilylation of (I). 1,4-Diethynyl-2,5-bis­(hept­yloxy)benzene, C24H34O2, (III), is a long alk­yloxy chain analogue of (II). The molecules of compounds (I)-(III) are located on sites with crystallographic inversion symmetry. The large substituents either in the alkynyl group or in the benzene ring have a marked effect on the packing and inter­molecular inter­actions of adjacent mol­ecules. All the compounds exhibit weak inter­molecular inter­actions that are only slightly shorter than the sum of the van der Waals radii of the inter­acting atoms. Compound (I) displays C-H...[pi] inter­actions between the methyl­ene H atoms and the acetyl­enic C atom. Compound (II) shows [pi]-[pi] inter­actions between the acetyl­enic C atoms, complemented by C-H...[pi] inter­actions between the methyl H atoms and the acetyl­enic C atoms. Unlike (I) or (II), compound (III) has weak nonclassical hydrogen-bond-type inter­actions between the acetyl­enic H atoms and the ether O atoms.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270107065523/sk3181sup1.cif
Contains datablocks global, I, II, III

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270107065523/sk3181Isup2.hkl
Contains datablock I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270107065523/sk3181IIsup3.hkl
Contains datablock II

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270107065523/sk3181IIIsup4.hkl
Contains datablock III

CCDC references: 681533; 681534; 681535

Comment top

Among the variety of highly conjugated polymers, those composed of alternating aryl and ethynyl units, such as the oligo(phenyleneethynylene)s (OPEs), a type of monodisperse and shaped-persistent oligomer, have been the object of increasing interest in academic and industrial research laboratories owing to their potential applications as molecular wires (Kushmerick et al., 2002; Tour, 2000; Reinerth et al., 1998; Cygan et al., 1998; Bumm et al.,1996), rectifiers (Dhirani et al., 1997), data storage systems (Reed et al., 2001; Feringa et al., 1993), photoluminescent and electroluminescent devices (Yamaguchi et al., 2005), and nonlinear optical materials (Koynov et al., 2005; Meier et al., 2001). Modification of OPEs is needed in order to improve both processability and long-term stability. One of the methods for improving their stability and solubility is the attachment of long linear alkoxy side chains to the main backbone. Additionally, alkoxy side chains can also lead to highly ordered supramolecular architectures and reduce the HOMO–LUMO gap and the band gap in the solid state (Wackerly & Moore, 2006; Jiang et al., 2004; Zhou et al., 2004; Zhou, Liu et al., 2003; Zhou, Zhao et al., 2003; Meier et al., 2001; Perahia et al., 2001; Müllen & Rabe, 1998). A possible way to synthesize OPEs with alkoxy side chains is by using a two-step Sonogashira–Hagihara reaction; a palladium-catalyzed cross-coupling condensation between 2,5-bis(alkoxy)benzene halides and terminal trimethylsilylacetylenes or 2-methylbut-3-yn-2-ol as the protecting group precursors in the presence of CuI, followed by a base-promoted deprotection of the capped acetylides (Tykwinski, 2003; Sonogashira, 2002; Takahashi et al. 1980; Zhao et al.,2007). The structure of trimethylsilylated 1,4-diethynylbenzene (Weiss et al., 1997; Ahmed et al.,1972) and 2,5-bis(alkoxy) ring-substituted derivatives, 1,4-bis(ethynyl)-2,5-bis(methoxy)benzene and 1,4-bis(ethynyl)-2,5-bis(octyloxy)benzene (Khan et al. 2003) are known. The X-ray structures of 1,4-bis(trimethylsilylethynyl)naphthalene and 9,10-bis(trimethylsilylethynyl)anthracene were reported by Khan et al. (2004).

Compound (I) is symmetrical and shows the expected planar overall structure (Fig. 1). The bond distances and angles do not show any abnormal values. The prevailing intermolecular interactions (defined to be shorter than the sum of the van der Waals radii of the interacting atoms) in compound (I) is the C–H···π interaction between the methylene H atoms of the ethoxy group and the terminal acetylenic C atom (C6—H6B···C1), with an interaction distance of 2.86 Å and angle 153°, the C···C distance being 3.772 (4) Å (Fig. 2, only the stronger interactions shown). One molecule of (I) has these interactions to four separate molecules [(1 - x, -1/2 + y, 1/2 - z), (x, -1/2 - y, 1/2 + z); (1 - x, 1/2 + y, -1/2 - z) and (x, 1/2 - y, 1/2 + z)]. Another but weaker intermolecular interaction is also present between the H atoms of the adjacent trimethylsilyl groups, [H8A···H9B(1 - x, 1/2 - y, 1/2 + z)] with a contact distance of 2.39 Å.

Compound (II) does not have the bulky trimethylsilyl groups and thus shows different packing behaviour. Like (I), compound (II) is symmetrical and planar with no abnormal bond distances and angles (Fig. 3). The absence of the bulky trimethylsilyl group allows the molecules a closer approach and completely different packing results with interactions to eight separate molecules [(-x, 1 - y, -z), (-x,-1 - y, -z), (x,-1/2 - y, -1/2 + z), (-x, -1/2 + y, 1/2 - z), (x, 1/2 - y, -1/2 + z) and (-1 + x, y, -1 + z)]. The molecules of (II) are arranged in planes with ππ interactions between the acetylenic C1 atoms of adjacent molecules, the C1···C1 distance being 3.224 (2) Å. In addition to the ππ interactions, in-plane C—H···π interaction between the acetylenic atom C1 and the methyl atom H7B exist, the contact distance C1··· H7B(x, -1 + y, z) being 2.88 Å (Fig. 4). These planes stack on top of each other with a twist angle of 36.7° between the planes. The C–H···π interactions between the planes are mediated through methylene H atoms (H6A) and the phenyl π system(C4) of adjacent molecules, the contact distance H6A···C4(x, -1/2 - y, -1/2 + z) being 2.85 Å.

The long heptyloxy chain has an opposite effect on the packing when compared with compound (II). Compound (III) is symmetrical and planar, like the other two compounds, and the bond distances and angles within the molecule are normal (Fig. 5). Unlike (I) and (II), compound (III) exhibits, as the only sufficiently short intermolecular interaction, a nonclassical hydrogen bond between the molecules (Fig. 6). The contact distance between atoms H1 and O1(-1/2 + x, 3/2 - y, z) is 2.54 Å, with an angle of 161° and C···O distance of 3.449 (2) Å. Similar contact distances are frequently found in nonclassical hydrogen bonds. As in (I), each molecule of (III) interacts with four other molecules [(-1/2 - x, -1/2 + y, -z), (-1/2 + x, 3/2 - y, -z), (-1/2 - x, -1/2 + y, -z) and (1/2 + x, 3/2 - y, z)]. Even though the bond lengths in all three compounds do not show abnormal values, there is a significant variation in the bond lengths of the central benzene ring typical for this type of symmetrical tetrasubstituted benzenes. The bond length of the unsubstituted atom C4 and the alkoxy-substituted atom C5 is on avarage 0.034 Å [for (I)], 0.015 Å [for (II)] and 0.010 Å [for (III)] shorter than the other bond lengths in the benzene ring.

Related literature top

For related literature, see: Ahmed et al. (1972); Bumm et al. (1996); Cygan et al. (1998); Dhirani et al. (1997); Feringa et al. (1993); Jiang et al. (2004); Khan et al. (2003, 2004); Koynov et al. (2005); Kushmerick et al. (2002); Müllen & Rabe (1998); Meier et al. (2001); Perahia et al. (2001); Reed et al. (2001); Reinerth et al. (1998); Sonogashira (2002); Takahashi et al. (1980); Tour (2000); Tykwinski (2003); Wackerly & Moore (2006); Weder & Wrighton (1996); Weiss et al. (1997); Yamaguchi et al. (2005); Zhao et al. (2007); Zhou, Liu et al. (2003); Zhou, Zhao et al. (2003); Zhou et al. (2004).

Experimental top

Compound (I) was obtained by Sonogashira cross-coupling (Weder & Wrighton, 1996) of 1,4-diethoxy-2,5-diiodobenzene (1.50 g, 3.59 mmol) with TMSA [give name in full] (1.5 ml, 10.54 mmol) in dried tetrahydrofuran (20 ml) and DIEA [in full] (25 ml). The reaction was catalysed by PdCl2(PPh3)2 (0.293 g, 0.42 mmol) and CuI (0.06 g, 0.32 mmol). After 16 h of stirring at 318 K under nitrogen atmosphere, the dark-brown mixture was filtered and evaporated under vacuum. Purification over column chromatography (silica gel S60, CH2Cl2/cyclohexane 1:3) gave a dark-yellow solid that was further purified by sublimation. The resulting solid was dissolved in CH2Cl2, forming a light-yellow solution which was slowly evaporated in air at room temperature, affording yellow crystals in 35% yield (m.p. 305–309 K). 1H NMR (500 MHz, CDCl3): δ 6.89 (2H, s, Ar), 4.02 (4H, q, CH2, JHH = 14 Hz), 1.40 (4H, t, Me, JHH = 14 Hz), 0.29 (18H, s, Me); 13C NMR (126 MHz, CDCl3): 153.97, 117.75, 101.06, 100.24, 65.30, 14.79, 0.058; IR (KBr): 2969 (s), 2151 (s), 1499 (s), 1394 (s), 1213 (sh),1043 (s), 840 (br), 760 (s).

Compound (II) was obtained by adding K2CO3 (1.61 g, 11.6 mmol) to (I) (1.91 g, 5.3 mmol) in a purged Schlenk tube. Degassed CH2Cl2 (7 ml) and MeOH (3 ml) were then added to the solids, forming a yellow solution, and stirring was begun. After 4 h at room temperature, the now fuzzy [cloudy?] yellow mixture was filtrated and evaporated under vacuum, yielding a light-yellow solid. Yellow crystals suitable for X-ray diffraction were obtained as previously described for compound (I) (yield 73.8%, m.p 347–348 K). 1H NMR (500 MHz, CDCl3): δ 6.89 (2H, s, Ar), 4.07 (4H, q, CH2, JHH = 14 Hz), 3.40 (2H, s, H—CC), 1.43 (6H, t, CH3, JHH = 14 Hz); 13C NMR (126 MHz, CDCl3): 153.83, 117.92, 113.36, 82.42, 79.79, 65.20, 14.75; IR (KBr): 3288 (s), 2984 (s), 2932 (s), 2883 (s), 2107 (s), 1932 (s), 1496 (m), 1218 (m), 1040 (s), 674 (m). MS (ESI): 158 [M+– (C2H5)2 + H2], 214 (M+) m/z.

Compound (III) was prepared by refluxing 4,4'-[2,5-bis(heptyloxy)-1,4-phenylene]bis(2-methylbut-3-yn-2-ol) in toluene with high excess of NaOH for 4 h. After this, the still hot solution was filtered and concentrated under vacuum. Good quality single crystals were obtained by allowing the yellow solution to cool to room temperature (yield 99%, m.p. 346–347 K). 1H NMR (250 MHz, CDCl3): δ 6.95 (2H, s, Ar), 3.97 (4H, t, CH2, JHH = 27 Hz), 3.32 (2H, s, H—CC), 1.76 (4H, Q, CH2, JHH = 27 Hz), 1.469–1.257 [16H, (CH2)4], 0.89 (3H, d, CH3, JHH = 9); 13C NMR (65 MHz, CDCl3): 153.86, 117.64, 113.15, 82.23, 79.65, 69.54, 31.62, 28.99, 28.85, 25.72, 22.44, 13.93; IR (KBr): 3265 (s), 2927 (s), 2932 (s), 2866 (s), 2105 (w), 1497 (s), 1275 (m). MS (ESI): 158 [M+– (C2H5)2 + H2], 354 (M+) m/z.

Refinement top

All non-H atoms were refined anisotropically. The H atoms were visible in electron density maps, but were placed in idealized positions and allowed to ride on their parent atoms at distances of 0.95 Å (aromatic and acetylinic), 0.98 Å (methyl) and 0.99 Å (methylene) with Uiso(H) of 1.2 times Ueq(C).

Computing details top

For all compounds, data collection: Collect (Hooft, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO and SCALEPACK (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 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. An ORTEP-3 plot (Farrugia, 1997) of (I) (50% probability displacement ellipsoids).
[Figure 2] Fig. 2. The packing (Macrae et al., 2006) of (I)·For clarity, only the C—H···π interactions are shown.
[Figure 3] Fig. 3. An ORTEP-3 plot (Farrugia, 1997) of (II)(50% probability displacement ellipsoids).
[Figure 4] Fig. 4. The packing (Macrae et al., 2006) of (II),showing the in-plane interactions.
[Figure 5] Fig. 5. An ORTEP-3 plot (Farrugia, 1997) of (III) (50% probability displacement ellipsoids).
[Figure 6] Fig. 6. The packing (Macrae et al., 2006) of (III), showing the C—H···O interactions.
(I) 2,5-Diethoxy-1,4-bis[(trimethylsilyl)ethynyl]benzene top
Crystal data top
C20H30O2Si2Z = 2
Mr = 358.62F(000) = 388
Monoclinic, P21/cDx = 1.024 Mg m3
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 10.132 (1) ŵ = 0.16 mm1
b = 9.887 (2) ÅT = 173 K
c = 12.169 (4) ÅPrism, colourless
β = 107.46 (2)°0.25 × 0.2 × 0.15 mm
V = 1162.9 (5) Å3
Data collection top
Nonius KappaCCD
diffractometer
Rint = 0.039
CCD rotation images, thick slices scansθmax = 25.0°, θmin = 3.7°
9367 measured reflectionsh = 1212
2032 independent reflectionsk = 1111
1568 reflections with I > 2σ(I)l = 1412
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.048 w = 1/[σ2(Fo2) + (0.1372P)2 + 1.7989P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.175(Δ/σ)max < 0.001
S = 0.76Δρmax = 0.21 e Å3
2032 reflectionsΔρmin = 0.52 e Å3
113 parameters
Crystal data top
C20H30O2Si2V = 1162.9 (5) Å3
Mr = 358.62Z = 2
Monoclinic, P21/cMo Kα radiation
a = 10.132 (1) ŵ = 0.16 mm1
b = 9.887 (2) ÅT = 173 K
c = 12.169 (4) Å0.25 × 0.2 × 0.15 mm
β = 107.46 (2)°
Data collection top
Nonius KappaCCD
diffractometer
1568 reflections with I > 2σ(I)
9367 measured reflectionsRint = 0.039
2032 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0480 restraints
wR(F2) = 0.175H-atom parameters constrained
S = 0.76Δρmax = 0.21 e Å3
2032 reflectionsΔρmin = 0.52 e Å3
113 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Si10.09344 (8)0.40623 (7)0.25610 (6)0.0386 (3)
O10.3962 (2)0.0057 (2)0.24102 (16)0.0480 (6)
C10.2172 (3)0.2749 (3)0.1776 (2)0.0397 (6)
C20.3001 (3)0.1920 (3)0.1246 (2)0.0388 (6)
C30.4012 (3)0.0942 (2)0.0618 (2)0.0369 (6)
C40.5473 (3)0.1011 (3)0.0606 (2)0.0388 (6)
H40.57970.17010.10040.047*
C50.4500 (3)0.0083 (3)0.1227 (2)0.0378 (6)
C60.4329 (3)0.1148 (3)0.3058 (2)0.0503 (8)
H6A0.40410.20270.28150.06*
H6B0.53420.11670.29210.06*
C70.3585 (4)0.0899 (4)0.4333 (3)0.0644 (10)
H7A0.25820.09120.44630.097*
H7B0.38360.1610.47950.097*
H7C0.38590.00170.4560.097*
C80.0214 (4)0.4469 (3)0.1647 (3)0.0560 (8)
H8A0.06920.36460.15260.084*
H8B0.08980.51490.20380.084*
H8C0.03480.48230.09020.084*
C90.1951 (3)0.5596 (3)0.2748 (3)0.0500 (8)
H9A0.25280.59070.19920.075*
H9B0.13110.63180.31230.075*
H9C0.25420.53590.32260.075*
C100.0067 (4)0.3383 (4)0.4007 (3)0.0705 (11)
H10A0.05730.31360.44380.106*
H10B0.07110.40750.44330.106*
H10C0.05880.25810.39060.106*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Si10.0506 (5)0.0277 (4)0.0322 (4)0.0066 (3)0.0048 (3)0.0040 (3)
O10.0575 (13)0.0509 (12)0.0336 (10)0.0183 (10)0.0107 (9)0.0026 (8)
C10.0505 (16)0.0324 (13)0.0347 (13)0.0043 (12)0.0103 (12)0.0037 (11)
C20.0492 (16)0.0315 (13)0.0364 (14)0.0035 (12)0.0138 (12)0.0032 (11)
C30.0443 (14)0.0291 (13)0.0376 (14)0.0045 (11)0.0127 (12)0.0082 (10)
C40.0464 (15)0.0334 (14)0.0378 (14)0.0060 (11)0.0147 (12)0.0030 (11)
C50.0452 (15)0.0337 (14)0.0347 (13)0.0044 (11)0.0125 (11)0.0059 (11)
C60.0544 (18)0.0551 (18)0.0386 (16)0.0086 (14)0.0099 (13)0.0075 (13)
C70.066 (2)0.086 (3)0.0393 (17)0.0170 (19)0.0137 (16)0.0046 (16)
C80.0604 (19)0.0397 (16)0.072 (2)0.0078 (15)0.0252 (17)0.0059 (15)
C90.066 (2)0.0383 (15)0.0457 (17)0.0014 (14)0.0174 (15)0.0063 (13)
C100.098 (3)0.0478 (19)0.0456 (18)0.0036 (19)0.0087 (18)0.0024 (15)
Geometric parameters (Å, º) top
Si1—C11.858 (3)C6—H6A0.99
Si1—C101.872 (3)C6—H6B0.99
Si1—C81.878 (3)C7—H7A0.98
Si1—C91.885 (3)C7—H7B0.98
O1—C51.379 (3)C7—H7C0.98
O1—C61.449 (3)C8—H8A0.98
C1—C21.212 (4)C8—H8B0.98
C2—C31.449 (4)C8—H8C0.98
C3—C4i1.424 (4)C9—H9A0.98
C3—C51.428 (4)C9—H9B0.98
C4—C51.392 (4)C9—H9C0.98
C4—C3i1.424 (4)C10—H10A0.98
C4—H40.95C10—H10B0.98
C6—C71.528 (4)C10—H10C0.98
C1—Si1—C10108.91 (15)C6—C7—H7A109.5
C1—Si1—C8106.71 (14)C6—C7—H7B109.5
C10—Si1—C8112.06 (19)H7A—C7—H7B109.5
C1—Si1—C9108.38 (14)C6—C7—H7C109.5
C10—Si1—C9109.69 (16)H7A—C7—H7C109.5
C8—Si1—C9110.95 (15)H7B—C7—H7C109.5
C5—O1—C6118.0 (2)Si1—C8—H8A109.5
C2—C1—Si1178.2 (3)Si1—C8—H8B109.5
C1—C2—C3178.9 (3)H8A—C8—H8B109.5
C4i—C3—C5120.1 (2)Si1—C8—H8C109.5
C4i—C3—C2119.9 (2)H8A—C8—H8C109.5
C5—C3—C2120.0 (2)H8B—C8—H8C109.5
C5—C4—C3i120.9 (2)Si1—C9—H9A109.5
C5—C4—H4119.6Si1—C9—H9B109.5
C3i—C4—H4119.6H9A—C9—H9B109.5
O1—C5—C4124.9 (2)Si1—C9—H9C109.5
O1—C5—C3116.1 (2)H9A—C9—H9C109.5
C4—C5—C3119.0 (2)H9B—C9—H9C109.5
O1—C6—C7107.7 (2)Si1—C10—H10A109.5
O1—C6—H6A110.2Si1—C10—H10B109.5
C7—C6—H6A110.2H10A—C10—H10B109.5
O1—C6—H6B110.2Si1—C10—H10C109.5
C7—C6—H6B110.2H10A—C10—H10C109.5
H6A—C6—H6B108.5H10B—C10—H10C109.5
C6—O1—C5—C46.2 (4)C2—C3—C5—O10.6 (4)
C6—O1—C5—C3174.4 (2)C4i—C3—C5—C40.5 (4)
C3i—C4—C5—O1178.8 (2)C2—C3—C5—C4180.0 (2)
C3i—C4—C5—C30.5 (4)C5—O1—C6—C7178.9 (3)
C4i—C3—C5—O1178.9 (2)
Symmetry code: (i) x+1, y, z.
(II) 2,5-Diethoxy-1,4-diethynylbenzene top
Crystal data top
C14H14O2Z = 2
Mr = 214.25F(000) = 228
Monoclinic, P21/cDx = 1.177 Mg m3
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 9.748 (2) ŵ = 0.08 mm1
b = 8.890 (2) ÅT = 173 K
c = 7.566 (2) ÅBlock, colourless
β = 112.74 (3)°0.3 × 0.2 × 0.2 mm
V = 604.7 (3) Å3
Data collection top
Nonius KappaCCD
diffractometer
Rint = 0.024
CCD rotation images, thick slices scansθmax = 25.0°, θmin = 3.7°
4943 measured reflectionsh = 1110
1045 independent reflectionsk = 910
910 reflections with I > 2σ(I)l = 78
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.038 w = 1/[σ2(Fo2) + (0.0343P)2 + 0.258P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.095(Δ/σ)max < 0.001
S = 1.07Δρmax = 0.14 e Å3
1045 reflectionsΔρmin = 0.19 e Å3
74 parameters
Crystal data top
C14H14O2V = 604.7 (3) Å3
Mr = 214.25Z = 2
Monoclinic, P21/cMo Kα radiation
a = 9.748 (2) ŵ = 0.08 mm1
b = 8.890 (2) ÅT = 173 K
c = 7.566 (2) Å0.3 × 0.2 × 0.2 mm
β = 112.74 (3)°
Data collection top
Nonius KappaCCD
diffractometer
910 reflections with I > 2σ(I)
4943 measured reflectionsRint = 0.024
1045 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.095H-atom parameters constrained
S = 1.07Δρmax = 0.14 e Å3
1045 reflectionsΔρmin = 0.19 e Å3
74 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.21490 (11)0.20584 (11)0.21994 (14)0.0314 (3)
C10.38489 (18)0.13769 (18)0.4200 (2)0.0430 (4)
H10.47390.17090.51950.052*
C20.27296 (16)0.09599 (16)0.2948 (2)0.0321 (4)
C30.13512 (15)0.04637 (16)0.14445 (19)0.0265 (3)
C40.02968 (15)0.15371 (16)0.03503 (19)0.0279 (4)
H40.05050.25780.05890.033*
C50.10497 (15)0.10871 (16)0.10794 (19)0.0259 (3)
C60.19286 (16)0.36579 (15)0.1785 (2)0.0297 (4)
H6A0.1020.40110.19450.036*
H6B0.18220.38630.04520.036*
C70.32904 (17)0.44534 (18)0.3193 (2)0.0375 (4)
H7A0.34110.41990.45050.056*
H7B0.31650.55430.30070.056*
H7C0.41740.41320.29760.056*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0307 (6)0.0224 (5)0.0325 (6)0.0064 (4)0.0029 (4)0.0030 (4)
C10.0368 (9)0.0312 (9)0.0441 (10)0.0007 (7)0.0030 (8)0.0029 (7)
C20.0323 (8)0.0234 (7)0.0358 (8)0.0040 (6)0.0079 (7)0.0044 (6)
C30.0254 (7)0.0259 (8)0.0262 (7)0.0030 (6)0.0078 (6)0.0018 (6)
C40.0297 (8)0.0216 (7)0.0296 (8)0.0021 (6)0.0085 (6)0.0011 (6)
C50.0261 (7)0.0249 (7)0.0254 (7)0.0071 (5)0.0085 (6)0.0049 (5)
C60.0322 (8)0.0228 (8)0.0315 (8)0.0041 (6)0.0095 (6)0.0023 (6)
C70.0358 (8)0.0273 (8)0.0437 (9)0.0083 (6)0.0092 (7)0.0064 (6)
Geometric parameters (Å, º) top
O1—C51.3820 (16)C4—H40.95
O1—C61.4541 (17)C5—C4i1.398 (2)
C1—C21.194 (2)C6—C71.518 (2)
C1—H10.95C6—H6A0.99
C2—C31.454 (2)C6—H6B0.99
C3—C41.412 (2)C7—H7A0.98
C3—C51.414 (2)C7—H7B0.98
C4—C5i1.398 (2)C7—H7C0.98
C5—O1—C6117.64 (11)O1—C6—C7106.75 (12)
C2—C1—H1180O1—C6—H6A110.4
C1—C2—C3178.93 (17)C7—C6—H6A110.4
C4—C3—C5119.67 (12)O1—C6—H6B110.4
C4—C3—C2119.80 (13)C7—C6—H6B110.4
C5—C3—C2120.54 (12)H6A—C6—H6B108.6
C5i—C4—C3120.86 (13)C6—C7—H7A109.5
C5i—C4—H4119.6C6—C7—H7B109.5
C3—C4—H4119.6H7A—C7—H7B109.5
O1—C5—C4i124.68 (13)C6—C7—H7C109.5
O1—C5—C3115.84 (12)H7A—C7—H7C109.5
C4i—C5—C3119.47 (12)H7B—C7—H7C109.5
C5—C3—C4—C5i0.6 (2)C2—C3—C5—O11.41 (19)
C2—C3—C4—C5i178.77 (13)C4—C3—C5—C4i0.6 (2)
C6—O1—C5—C4i3.9 (2)C2—C3—C5—C4i178.77 (13)
C6—O1—C5—C3175.96 (12)C5—O1—C6—C7179.40 (12)
C4—C3—C5—O1179.22 (12)
Symmetry code: (i) x, y, z.
(III) 1,4-Diethynyl-2,5-bis(heptyloxy)benzene top
Crystal data top
C24H34O2F(000) = 388
Mr = 354.51Dx = 1.075 Mg m3
Monoclinic, P21/aMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yabCell parameters from 8991 reflections
a = 6.7246 (2) Åθ = 2.9–27.9°
b = 16.7456 (5) ŵ = 0.07 mm1
c = 9.8026 (3) ÅT = 173 K
β = 97.320 (2)°Prism, colourless
V = 1094.85 (6) Å30.6 × 0.5 × 0.4 mm
Z = 2
Data collection top
Nonius KappaCCD
diffractometer
Rint = 0.026
CCD rotation images, thick slices scansθmax = 25.0°, θmin = 3.2°
3729 measured reflectionsh = 77
1920 independent reflectionsk = 1919
1458 reflections with I > 2σ(I)l = 1111
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.044 w = 1/[σ2(Fo2) + (0.0396P)2 + 0.355P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.107(Δ/σ)max < 0.001
S = 0.99Δρmax = 0.10 e Å3
1920 reflectionsΔρmin = 0.18 e Å3
119 parameters
Crystal data top
C24H34O2V = 1094.85 (6) Å3
Mr = 354.51Z = 2
Monoclinic, P21/aMo Kα radiation
a = 6.7246 (2) ŵ = 0.07 mm1
b = 16.7456 (5) ÅT = 173 K
c = 9.8026 (3) Å0.6 × 0.5 × 0.4 mm
β = 97.320 (2)°
Data collection top
Nonius KappaCCD
diffractometer
1458 reflections with I > 2σ(I)
3729 measured reflectionsRint = 0.026
1920 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0440 restraints
wR(F2) = 0.107H-atom parameters constrained
S = 0.99Δρmax = 0.10 e Å3
1920 reflectionsΔρmin = 0.18 e Å3
119 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.22444 (16)0.59123 (6)0.19897 (12)0.0447 (3)
C10.2060 (3)0.71184 (10)0.11340 (19)0.0489 (4)
H10.2580.7620.1370.059*
C20.1414 (2)0.64950 (9)0.08414 (17)0.0400 (4)
C30.0684 (2)0.57332 (9)0.04310 (16)0.0378 (4)
C40.1849 (2)0.52880 (9)0.05744 (16)0.0396 (4)
H40.31160.54880.09660.047*
C50.1185 (2)0.54417 (9)0.10110 (16)0.0378 (4)
C60.4182 (2)0.56259 (10)0.25708 (17)0.0440 (4)
H6A0.50730.55840.18440.053*
H6B0.40530.50890.29720.053*
C70.5066 (2)0.61981 (10)0.36713 (18)0.0450 (4)
H7A0.41490.62490.4380.054*
H7B0.52130.67320.32610.054*
C80.7103 (2)0.59062 (10)0.43384 (17)0.0451 (4)
H8A0.6950.53630.4710.054*
H8B0.80170.58680.36250.054*
C90.8053 (3)0.64423 (10)0.54912 (18)0.0462 (4)
H9A0.82240.69830.51160.055*
H9B0.71290.64870.61970.055*
C101.0073 (2)0.61477 (10)0.61750 (17)0.0449 (4)
H10A0.99060.56030.65350.054*
H10B1.10030.61120.54710.054*
C111.1015 (3)0.66726 (10)0.73425 (18)0.0474 (4)
H11A1.00860.67120.80460.057*
H11B1.12010.72170.69840.057*
C121.3033 (3)0.63598 (12)0.80199 (19)0.0564 (5)
H12A1.28570.58250.83940.085*
H12B1.35650.6720.87660.085*
H12C1.39730.63330.73350.085*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0424 (7)0.0353 (6)0.0564 (7)0.0031 (5)0.0065 (5)0.0027 (5)
C10.0466 (10)0.0371 (9)0.0642 (12)0.0030 (8)0.0123 (8)0.0027 (8)
C20.0370 (9)0.0364 (9)0.0488 (10)0.0005 (7)0.0134 (7)0.0042 (7)
C30.0413 (9)0.0290 (8)0.0459 (9)0.0007 (7)0.0161 (7)0.0058 (7)
C40.0395 (9)0.0324 (8)0.0487 (10)0.0027 (7)0.0129 (7)0.0074 (7)
C50.0386 (9)0.0312 (8)0.0457 (9)0.0015 (7)0.0140 (7)0.0048 (7)
C60.0412 (9)0.0399 (9)0.0526 (10)0.0045 (7)0.0120 (8)0.0033 (8)
C70.0449 (10)0.0401 (9)0.0520 (10)0.0023 (8)0.0135 (8)0.0002 (8)
C80.0480 (10)0.0417 (9)0.0471 (10)0.0045 (8)0.0123 (8)0.0015 (8)
C90.0492 (10)0.0390 (9)0.0525 (11)0.0023 (8)0.0150 (8)0.0001 (8)
C100.0463 (10)0.0431 (9)0.0473 (10)0.0028 (8)0.0136 (8)0.0022 (8)
C110.0564 (11)0.0378 (9)0.0498 (10)0.0031 (8)0.0133 (8)0.0052 (8)
C120.0564 (12)0.0599 (12)0.0531 (11)0.0043 (9)0.0079 (9)0.0040 (9)
Geometric parameters (Å, º) top
O1—C51.369 (2)C8—C91.519 (2)
O1—C61.436 (2)C8—H8A0.99
C1—C21.180 (2)C8—H8B0.99
C1—H10.95C9—C101.519 (2)
C2—C31.442 (2)C9—H9A0.99
C3—C41.394 (2)C9—H9B0.99
C3—C51.399 (2)C10—C111.516 (2)
C4—C5i1.387 (2)C10—H10A0.99
C4—H40.95C10—H10B0.99
C5—C4i1.387 (2)C11—C121.525 (2)
C6—C71.507 (2)C11—H11A0.99
C6—H6A0.99C11—H11B0.99
C6—H6B0.99C12—H12A0.98
C7—C81.522 (2)C12—H12B0.98
C7—H7A0.99C12—H12C0.98
C7—H7B0.99
C5—O1—C6116.78 (12)C9—C8—H8B108.8
C2—C1—H1180C7—C8—H8B108.8
C1—C2—C3177.56 (19)H8A—C8—H8B107.7
C4—C3—C5119.69 (14)C10—C9—C8113.85 (14)
C4—C3—C2119.30 (14)C10—C9—H9A108.8
C5—C3—C2121.00 (15)C8—C9—H9A108.8
C5i—C4—C3121.01 (15)C10—C9—H9B108.8
C5i—C4—H4119.5C8—C9—H9B108.8
C3—C4—H4119.5H9A—C9—H9B107.7
O1—C5—C4i124.33 (15)C11—C10—C9114.15 (14)
O1—C5—C3116.36 (13)C11—C10—H10A108.7
C4i—C5—C3119.31 (15)C9—C10—H10A108.7
O1—C6—C7109.07 (13)C11—C10—H10B108.7
O1—C6—H6A109.9C9—C10—H10B108.7
C7—C6—H6A109.9H10A—C10—H10B107.6
O1—C6—H6B109.9C10—C11—C12113.10 (15)
C7—C6—H6B109.9C10—C11—H11A109
H6A—C6—H6B108.3C12—C11—H11A109
C6—C7—C8110.78 (13)C10—C11—H11B109
C6—C7—H7A109.5C12—C11—H11B109
C8—C7—H7A109.5H11A—C11—H11B107.8
C6—C7—H7B109.5C11—C12—H12A109.5
C8—C7—H7B109.5C11—C12—H12B109.5
H7A—C7—H7B108.1H12A—C12—H12B109.5
C9—C8—C7113.59 (14)C11—C12—H12C109.5
C9—C8—H8A108.8H12A—C12—H12C109.5
C7—C8—H8A108.8H12B—C12—H12C109.5
C5—C3—C4—C5i0.0 (2)C2—C3—C5—C4i179.02 (14)
C2—C3—C4—C5i179.04 (14)C5—O1—C6—C7177.11 (13)
C6—O1—C5—C4i1.1 (2)O1—C6—C7—C8178.67 (13)
C6—O1—C5—C3178.76 (13)C6—C7—C8—C9178.17 (14)
C4—C3—C5—O1179.89 (13)C7—C8—C9—C10179.16 (14)
C2—C3—C5—O10.9 (2)C8—C9—C10—C11179.03 (14)
C4—C3—C5—C4i0.0 (2)C9—C10—C11—C12179.48 (14)
Symmetry code: (i) x, y+1, z.

Experimental details

(I)(II)(III)
Crystal data
Chemical formulaC20H30O2Si2C14H14O2C24H34O2
Mr358.62214.25354.51
Crystal system, space groupMonoclinic, P21/cMonoclinic, P21/cMonoclinic, P21/a
Temperature (K)173173173
a, b, c (Å)10.132 (1), 9.887 (2), 12.169 (4)9.748 (2), 8.890 (2), 7.566 (2)6.7246 (2), 16.7456 (5), 9.8026 (3)
β (°) 107.46 (2) 112.74 (3) 97.320 (2)
V3)1162.9 (5)604.7 (3)1094.85 (6)
Z222
Radiation typeMo KαMo KαMo Kα
µ (mm1)0.160.080.07
Crystal size (mm)0.25 × 0.2 × 0.150.3 × 0.2 × 0.20.6 × 0.5 × 0.4
Data collection
DiffractometerNonius KappaCCD
diffractometer
Nonius KappaCCD
diffractometer
Nonius KappaCCD
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
9367, 2032, 1568 4943, 1045, 910 3729, 1920, 1458
Rint0.0390.0240.026
(sin θ/λ)max1)0.5950.5950.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.048, 0.175, 0.76 0.038, 0.095, 1.07 0.044, 0.107, 0.99
No. of reflections203210451920
No. of parameters11374119
H-atom treatmentH-atom parameters constrainedH-atom parameters constrainedH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.21, 0.520.14, 0.190.10, 0.18

Computer programs: Collect (Hooft, 1998), HKL SCALEPACK (Otwinowski & Minor, 1997), HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

 

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