organic compounds
1,3,5-Trichloro-2,4,6-tris(dichloromethyl)benzene
aUniversity Mainz, Duesbergweg 10-14, 55099 Mainz, Germany
*Correspondence e-mail: detert@uni-mainz.de
The 9H3Cl9, contains one molecule. Two slightly different conformations with nearly C3h symmetry are mutually disordered in a 1:1 ratio. This disorder enhances the overall structural symmetry to D3h.
of the title compound, CKeywords: crystal structure; chlorinated hydrocarbon; disorder.
CCDC reference: 1532083
Structure description
The title compound (Fig. 1) is a central intermediate for star-shaped conjugated oligomers (Demenev et al., 2010; Detert et al., 2010). A bromo derivative has been reported by Holst et al. (2011). This compound combines our interest in perchloro hydrocarbons (Detert et al., 2009; Schollmeyer & Detert, 2017) and star-shaped discotic liquid crystals (Rieth et al., 2014; Glang et al., 2014).
The C3h symmetry occur in a 1:1 ratio (Fig. 2). This disorder enhances the symmetry of the overall structure to D3h. Assuming the D3h symmetry for one nondisordered molecule, the will rise from P43 to P43212. However, then the is not stable and the molecular symmetry is in contradiction to the chemistry. Distances between H atoms and ring-bound Cl atoms are 2.262 Å for H7⋯Cl3 and also for H8⋯Cl6, but the spacing between H9 and Cl9 is 2.43 Å. Similarly, two C—H bonds are nearly coplanar with the ring (H8—C8—C3—C4 = −3° and H9—C9—C5—C6 = 3°), whereas H7—C7—C1—C2 is twisted by −9°.
contains one molecule of the title compound and two very similar conformations with nearlySynthesis and crystallization
The title compound was prepared according to Veciana et al. (1993) and Taerum et al. (2009) with the modification that a steel bomb (2.2 × 25 cm) was used as reaction vessel. This allows scale-up to 3.0 g (16.5 mmol, 1.0 equivalent) 1,3,5-trichlorbenzene in 30 ml absolute chloroform with 2.7 g (19.8 mmol, 1.2 equivalents) AlCl3, and frequent pressure reduction was not necessary. The temperature was regulated with ISOHEAT (typ: MIL-HT–H, P = 175 W) by a heat panel (JUMBO iTRON 16). The reaction mixture was heated slowly (over 3 h) to 383 K and held at 383 K for 67 h with magnetic stirring. After cooling to room temperature, the pressure was reduced through a swagelok valve (SS-41GS2). Purification was carried out according to Taerum et al. (2009). The title compound was obtained after (SiO2, petroleum ether) in 31.6% yield (2.2 g, 5.2 mmol) as colourless crystals (m.p. 453–457 K). Crystallization from acetonitrile and chloroform resulted in single crystals.
Refinement
Crystal data, data collection and structure . The site-occupancy factors [0.501 (6)/0.499 (6)] for the disordered atoms were refined using one common parameter. Disordered phenyl rings were refined assuming a regular six-membered ring with C—C = 1.39 Å. Their displacement parameters were refined using a RIGU restraint.
details are summarized in Table 1Structural data
CCDC reference: 1532083
https://doi.org/10.1107/S2414314617002279/bt4040sup1.cif
contains datablocks I, New_Global_Publ_Block. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617002279/bt4040Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314617002279/bt4040Isup3.cml
Data collection: X-AREA (Stoe & Cie, 1999); cell
X-AREA (Stoe & Cie, 1999); data reduction: X-RED (Stoe & Cie, 1999); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015b).C9H3Cl9 | Dx = 1.968 Mg m−3 |
Mr = 430.16 | Mo Kα radiation, λ = 0.71073 Å |
Tetragonal, P43 | Cell parameters from 56414 reflections |
a = 9.5435 (2) Å | θ = 2.5–28.2° |
c = 15.9424 (4) Å | µ = 1.71 mm−1 |
V = 1452.01 (7) Å3 | T = 120 K |
Z = 4 | Block, colourless |
F(000) = 840 | 0.43 × 0.33 × 0.13 mm |
Stoe IPDS 2T diffractometer | 3561 independent reflections |
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus | 3429 reflections with I > 2σ(I) |
Detector resolution: 6.67 pixels mm-1 | Rint = 0.018 |
rotation method scans | θmax = 28.3°, θmin = 2.5° |
Absorption correction: integration (X-RED; Stoe & Cie, 1999) | h = −12→12 |
Tmin = 0.496, Tmax = 0.813 | k = −12→12 |
34268 measured reflections | l = −21→21 |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.055 | w = 1/[σ2(Fo2) + (0.0519P)2 + 3.8476P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.135 | (Δ/σ)max < 0.001 |
S = 1.11 | Δρmax = 1.11 e Å−3 |
3561 reflections | Δρmin = −0.67 e Å−3 |
248 parameters | Absolute structure: Flack x determined using 1575 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013) |
73 restraints | Absolute structure parameter: −0.04 (3) |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
C1 | 0.5937 (17) | 0.1944 (16) | −0.0704 (8) | 0.034 (4) | 0.501 (6) |
C2 | 0.5029 (16) | 0.0821 (18) | −0.0594 (9) | 0.027 (3) | 0.501 (6) |
C3 | 0.5150 (15) | −0.0029 (15) | 0.0110 (10) | 0.024 (3) | 0.501 (6) |
C4 | 0.6180 (16) | 0.0245 (14) | 0.0704 (8) | 0.018 (3) | 0.501 (6) |
C5 | 0.7089 (14) | 0.1368 (15) | 0.0594 (8) | 0.026 (3) | 0.501 (6) |
C6 | 0.6967 (15) | 0.2218 (13) | −0.0110 (9) | 0.030 (4) | 0.501 (6) |
C1A | 0.6360 (16) | 0.2079 (15) | −0.0608 (9) | 0.030 (3) | 0.499 (6) |
C2A | 0.5235 (16) | 0.1174 (18) | −0.0722 (9) | 0.023 (3) | 0.499 (6) |
C3A | 0.4956 (15) | 0.0141 (15) | −0.0130 (10) | 0.024 (3) | 0.499 (6) |
C4A | 0.5803 (17) | 0.0014 (14) | 0.0576 (9) | 0.026 (3) | 0.499 (6) |
C5A | 0.6928 (15) | 0.0919 (17) | 0.0689 (8) | 0.031 (4) | 0.499 (6) |
C6A | 0.7206 (13) | 0.1952 (15) | 0.0097 (10) | 0.029 (3) | 0.499 (6) |
C7 | 0.5684 (19) | 0.2814 (16) | −0.1497 (10) | 0.042 (4) | 0.501 (6) |
H7 | 0.4779 | 0.2467 | −0.1736 | 0.050* | 0.501 (6) |
C7A | 0.6720 (15) | 0.3144 (14) | −0.1321 (9) | 0.033 (3) | 0.499 (6) |
H7A | 0.7628 | 0.3585 | −0.1153 | 0.040* | 0.499 (6) |
Cl1 | 0.7014 (2) | 0.2405 (2) | −0.22796 (11) | 0.0453 (4) | |
Cl2 | 0.5463 (3) | 0.4547 (2) | −0.13480 (17) | 0.0650 (7) | |
Cl3 | 0.3692 (5) | 0.0489 (5) | −0.1302 (3) | 0.0491 (13) | 0.501 (6) |
Cl3A | 0.4128 (3) | 0.1317 (4) | −0.15464 (19) | 0.0310 (9) | 0.499 (6) |
C8 | 0.4159 (15) | −0.1286 (16) | 0.0251 (12) | 0.042 (4) | 0.501 (6) |
H8 | 0.4500 | −0.1737 | 0.0779 | 0.050* | 0.501 (6) |
C8A | 0.3712 (15) | −0.0836 (15) | −0.0272 (12) | 0.041 (4) | 0.499 (6) |
H8A | 0.3261 | −0.0495 | −0.0800 | 0.049* | 0.499 (6) |
Cl4 | 0.2420 (2) | −0.0756 (2) | 0.0476 (2) | 0.0665 (8) | |
Cl5 | 0.4243 (2) | −0.2580 (2) | −0.0493 (2) | 0.0662 (8) | |
Cl6 | 0.6317 (4) | −0.0872 (3) | 0.15285 (19) | 0.0312 (9) | 0.501 (6) |
Cl6A | 0.5491 (5) | −0.1308 (5) | 0.1285 (3) | 0.0486 (13) | 0.499 (6) |
C9A | 0.8142 (14) | 0.1718 (15) | 0.1307 (9) | 0.034 (3) | 0.501 (6) |
H9A | 0.8586 | 0.2626 | 0.1141 | 0.041* | 0.501 (6) |
C9 | 0.7810 (16) | 0.0677 (19) | 0.1479 (10) | 0.041 (3) | 0.499 (6) |
H9 | 0.7469 | −0.0227 | 0.1722 | 0.050* | 0.499 (6) |
Cl7 | 0.7406 (2) | 0.2015 (2) | 0.22621 (11) | 0.0454 (4) | |
Cl8 | 0.9548 (2) | 0.0463 (3) | 0.13319 (16) | 0.0649 (7) | |
Cl9 | 0.8193 (6) | 0.3484 (5) | −0.0272 (4) | 0.0571 (14) | 0.501 (6) |
Cl9A | 0.8484 (5) | 0.3195 (6) | 0.0255 (4) | 0.0561 (14) | 0.499 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.054 (10) | 0.032 (7) | 0.016 (6) | 0.006 (6) | −0.003 (6) | −0.006 (5) |
C2 | 0.036 (8) | 0.028 (9) | 0.017 (6) | 0.012 (5) | −0.004 (6) | 0.000 (5) |
C3 | 0.027 (7) | 0.024 (6) | 0.021 (8) | 0.004 (5) | −0.001 (5) | 0.000 (5) |
C4 | 0.014 (7) | 0.025 (6) | 0.017 (5) | −0.002 (4) | 0.001 (4) | 0.001 (4) |
C5 | 0.028 (6) | 0.029 (8) | 0.022 (7) | −0.012 (5) | 0.005 (5) | 0.001 (5) |
C6 | 0.043 (8) | 0.026 (6) | 0.020 (7) | 0.004 (6) | 0.003 (5) | 0.006 (5) |
C1A | 0.036 (8) | 0.030 (6) | 0.024 (7) | −0.009 (5) | −0.002 (5) | −0.002 (5) |
C2A | 0.028 (6) | 0.018 (7) | 0.023 (6) | 0.002 (5) | 0.000 (5) | −0.003 (4) |
C3A | 0.019 (5) | 0.030 (7) | 0.023 (8) | 0.000 (5) | −0.003 (5) | −0.004 (5) |
C4A | 0.024 (8) | 0.032 (7) | 0.022 (7) | 0.008 (5) | −0.002 (5) | 0.002 (6) |
C5A | 0.029 (7) | 0.047 (10) | 0.017 (6) | 0.001 (6) | 0.005 (5) | 0.004 (6) |
C6A | 0.028 (6) | 0.037 (8) | 0.022 (7) | 0.002 (6) | −0.002 (5) | 0.000 (5) |
C7 | 0.059 (10) | 0.035 (7) | 0.030 (7) | 0.012 (7) | 0.007 (6) | −0.001 (5) |
C7A | 0.037 (7) | 0.032 (6) | 0.031 (7) | −0.022 (5) | 0.007 (5) | 0.001 (5) |
Cl1 | 0.0480 (10) | 0.0552 (11) | 0.0328 (9) | −0.0015 (8) | 0.0136 (8) | 0.0089 (7) |
Cl2 | 0.103 (2) | 0.0362 (10) | 0.0560 (14) | 0.0163 (10) | 0.0161 (13) | 0.0138 (9) |
Cl3 | 0.045 (2) | 0.064 (3) | 0.038 (2) | 0.002 (2) | −0.0137 (17) | −0.0075 (19) |
Cl3A | 0.0238 (14) | 0.0446 (19) | 0.0247 (14) | −0.0102 (13) | −0.0052 (11) | −0.0027 (13) |
C8 | 0.032 (7) | 0.032 (7) | 0.062 (11) | −0.002 (5) | −0.018 (7) | −0.014 (7) |
C8A | 0.029 (6) | 0.031 (7) | 0.062 (11) | −0.003 (5) | 0.012 (7) | 0.020 (7) |
Cl4 | 0.0398 (10) | 0.0459 (11) | 0.114 (2) | −0.0037 (8) | 0.0262 (12) | 0.0030 (12) |
Cl5 | 0.0459 (11) | 0.0401 (10) | 0.113 (2) | −0.0039 (8) | −0.0033 (12) | −0.0263 (12) |
Cl6 | 0.045 (2) | 0.0239 (14) | 0.0249 (14) | −0.0102 (13) | 0.0030 (13) | 0.0046 (11) |
Cl6A | 0.064 (3) | 0.045 (2) | 0.037 (2) | 0.002 (2) | 0.0071 (19) | 0.0139 (17) |
C9A | 0.033 (6) | 0.039 (7) | 0.030 (7) | −0.022 (5) | −0.001 (5) | −0.007 (5) |
C9 | 0.036 (7) | 0.057 (10) | 0.031 (7) | 0.008 (7) | 0.004 (6) | −0.007 (6) |
Cl7 | 0.0553 (11) | 0.0479 (10) | 0.0328 (9) | −0.0013 (8) | −0.0093 (7) | −0.0136 (8) |
Cl8 | 0.0360 (10) | 0.102 (2) | 0.0565 (14) | 0.0165 (10) | −0.0139 (9) | −0.0162 (13) |
Cl9 | 0.072 (3) | 0.047 (2) | 0.051 (3) | −0.022 (2) | 0.020 (3) | 0.0154 (19) |
Cl9A | 0.047 (2) | 0.071 (3) | 0.051 (3) | −0.021 (2) | −0.0149 (19) | −0.020 (3) |
C1—C2 | 1.3900 | C5A—C6A | 1.3900 |
C1—C6 | 1.3900 | C5A—C9 | 1.532 (19) |
C1—C7 | 1.531 (18) | C6A—Cl9A | 1.719 (9) |
C2—C3 | 1.3900 | C7—Cl2 | 1.684 (15) |
C2—Cl3 | 1.732 (9) | C7—Cl1 | 1.822 (16) |
C3—C4 | 1.3900 | C7—H7 | 1.0000 |
C3—C8 | 1.544 (17) | C7A—Cl1 | 1.706 (14) |
C4—C5 | 1.3900 | C7A—Cl2 | 1.799 (16) |
C4—Cl6 | 1.697 (9) | C7A—H7A | 1.0000 |
C5—C6 | 1.3900 | C8—Cl5 | 1.714 (16) |
C5—C9A | 1.553 (16) | C8—Cl4 | 1.772 (15) |
C6—Cl9 | 1.701 (10) | C8—H8 | 1.0000 |
C1A—C2A | 1.3900 | C8A—Cl4 | 1.718 (15) |
C1A—C6A | 1.3900 | C8A—Cl5 | 1.775 (15) |
C1A—C7A | 1.563 (16) | C8A—H8A | 1.0000 |
C2A—C3A | 1.3900 | C9A—Cl7 | 1.701 (14) |
C2A—Cl3A | 1.692 (9) | C9A—Cl8 | 1.799 (16) |
C3A—C4A | 1.3900 | C9A—H9A | 1.0000 |
C3A—C8A | 1.527 (17) | C9—Cl8 | 1.688 (15) |
C4A—C5A | 1.3900 | C9—Cl7 | 1.827 (16) |
C4A—Cl6A | 1.720 (9) | C9—H9 | 1.0000 |
C2—C1—C6 | 120.0 | C1—C7—Cl2 | 115.8 (12) |
C2—C1—C7 | 115.1 (12) | C1—C7—Cl1 | 109.8 (11) |
C6—C1—C7 | 124.9 (12) | Cl2—C7—Cl1 | 113.2 (10) |
C3—C2—C1 | 120.0 | C1—C7—H7 | 105.7 |
C3—C2—Cl3 | 118.7 (9) | Cl2—C7—H7 | 105.7 |
C1—C2—Cl3 | 121.2 (9) | Cl1—C7—H7 | 105.7 |
C2—C3—C4 | 120.0 | C1A—C7A—Cl1 | 114.8 (10) |
C2—C3—C8 | 121.3 (11) | C1A—C7A—Cl2 | 110.8 (11) |
C4—C3—C8 | 118.7 (11) | Cl1—C7A—Cl2 | 113.3 (8) |
C5—C4—C3 | 120.0 | C1A—C7A—H7A | 105.7 |
C5—C4—Cl6 | 122.3 (8) | Cl1—C7A—H7A | 105.7 |
C3—C4—Cl6 | 117.7 (8) | Cl2—C7A—H7A | 105.7 |
C6—C5—C4 | 120.0 | C3—C8—Cl5 | 115.5 (13) |
C6—C5—C9A | 121.3 (10) | C3—C8—Cl4 | 112.4 (11) |
C4—C5—C9A | 118.5 (10) | Cl5—C8—Cl4 | 112.9 (7) |
C5—C6—C1 | 120.0 | C3—C8—H8 | 104.9 |
C5—C6—Cl9 | 118.7 (9) | Cl5—C8—H8 | 104.9 |
C1—C6—Cl9 | 121.1 (9) | Cl4—C8—H8 | 104.9 |
C2A—C1A—C6A | 120.0 | C3A—C8A—Cl4 | 115.3 (13) |
C2A—C1A—C7A | 118.6 (10) | C3A—C8A—Cl5 | 112.3 (11) |
C6A—C1A—C7A | 121.1 (10) | Cl4—C8A—Cl5 | 112.6 (7) |
C3A—C2A—C1A | 120.0 | C3A—C8A—H8A | 105.1 |
C3A—C2A—Cl3A | 117.7 (8) | Cl4—C8A—H8A | 105.1 |
C1A—C2A—Cl3A | 122.2 (8) | Cl5—C8A—H8A | 105.1 |
C4A—C3A—C2A | 120.0 | C5—C9A—Cl7 | 115.0 (10) |
C4A—C3A—C8A | 121.3 (11) | C5—C9A—Cl8 | 110.9 (10) |
C2A—C3A—C8A | 118.7 (11) | Cl7—C9A—Cl8 | 113.5 (8) |
C3A—C4A—C5A | 120.0 | C5—C9A—H9A | 105.5 |
C3A—C4A—Cl6A | 119.7 (9) | Cl7—C9A—H9A | 105.5 |
C5A—C4A—Cl6A | 120.3 (9) | Cl8—C9A—H9A | 105.5 |
C6A—C5A—C4A | 120.0 | C5A—C9—Cl8 | 116.3 (11) |
C6A—C5A—C9 | 124.0 (12) | C5A—C9—Cl7 | 109.9 (11) |
C4A—C5A—C9 | 116.0 (12) | Cl8—C9—Cl7 | 112.8 (9) |
C5A—C6A—C1A | 120.0 | C5A—C9—H9 | 105.6 |
C5A—C6A—Cl9A | 121.7 (9) | Cl8—C9—H9 | 105.6 |
C1A—C6A—Cl9A | 118.0 (9) | Cl7—C9—H9 | 105.6 |
C6—C1—C2—C3 | 0.0 | C3A—C4A—C5A—C6A | 0.0 |
C7—C1—C2—C3 | −179.1 (14) | Cl6A—C4A—C5A—C6A | 177.6 (12) |
C6—C1—C2—Cl3 | 177.6 (14) | C3A—C4A—C5A—C9 | −179.1 (14) |
C7—C1—C2—Cl3 | −1.6 (12) | Cl6A—C4A—C5A—C9 | −1.5 (12) |
C1—C2—C3—C4 | 0.0 | C4A—C5A—C6A—C1A | 0.0 |
Cl3—C2—C3—C4 | −177.6 (13) | C9—C5A—C6A—C1A | 179.0 (15) |
C1—C2—C3—C8 | −179.9 (15) | C4A—C5A—C6A—Cl9A | 174.0 (12) |
Cl3—C2—C3—C8 | 2.5 (13) | C9—C5A—C6A—Cl9A | −7.0 (14) |
C2—C3—C4—C5 | 0.0 | C2A—C1A—C6A—C5A | 0.0 |
C8—C3—C4—C5 | 179.9 (15) | C7A—C1A—C6A—C5A | −174.7 (15) |
C2—C3—C4—Cl6 | −177.5 (12) | C2A—C1A—C6A—Cl9A | −174.2 (11) |
C8—C3—C4—Cl6 | 2.4 (13) | C7A—C1A—C6A—Cl9A | 11.0 (14) |
C3—C4—C5—C6 | 0.0 | C2—C1—C7—Cl2 | 125.8 (11) |
Cl6—C4—C5—C6 | 177.4 (12) | C6—C1—C7—Cl2 | −53.3 (18) |
C3—C4—C5—C9A | 174.9 (14) | C2—C1—C7—Cl1 | −104.4 (11) |
Cl6—C4—C5—C9A | −7.8 (13) | C6—C1—C7—Cl1 | 76.5 (14) |
C4—C5—C6—C1 | 0.0 | C2A—C1A—C7A—Cl1 | −55.8 (14) |
C9A—C5—C6—C1 | −174.7 (14) | C6A—C1A—C7A—Cl1 | 119.0 (11) |
C4—C5—C6—Cl9 | −174.2 (11) | C2A—C1A—C7A—Cl2 | 74.1 (12) |
C9A—C5—C6—Cl9 | 11.1 (13) | C6A—C1A—C7A—Cl2 | −111.2 (11) |
C2—C1—C6—C5 | 0.0 | C2—C3—C8—Cl5 | 62.3 (14) |
C7—C1—C6—C5 | 179.0 (15) | C4—C3—C8—Cl5 | −117.6 (12) |
C2—C1—C6—Cl9 | 174.0 (12) | C2—C3—C8—Cl4 | −69.3 (15) |
C7—C1—C6—Cl9 | −6.9 (15) | C4—C3—C8—Cl4 | 110.8 (11) |
C6A—C1A—C2A—C3A | 0.0 | C4A—C3A—C8A—Cl4 | 62.0 (15) |
C7A—C1A—C2A—C3A | 174.8 (15) | C2A—C3A—C8A—Cl4 | −117.9 (11) |
C6A—C1A—C2A—Cl3A | 177.5 (14) | C4A—C3A—C8A—Cl5 | −68.9 (15) |
C7A—C1A—C2A—Cl3A | −7.7 (13) | C2A—C3A—C8A—Cl5 | 111.2 (11) |
C1A—C2A—C3A—C4A | 0.0 | C6—C5—C9A—Cl7 | 118.7 (10) |
Cl3A—C2A—C3A—C4A | −177.6 (13) | C4—C5—C9A—Cl7 | −56.1 (14) |
C1A—C2A—C3A—C8A | 179.9 (15) | C6—C5—C9A—Cl8 | −110.8 (10) |
Cl3A—C2A—C3A—C8A | 2.3 (13) | C4—C5—C9A—Cl8 | 74.4 (11) |
C2A—C3A—C4A—C5A | 0.0 | C6A—C5A—C9—Cl8 | −53.2 (17) |
C8A—C3A—C4A—C5A | −179.9 (15) | C4A—C5A—C9—Cl8 | 125.8 (11) |
C2A—C3A—C4A—Cl6A | −177.6 (12) | C6A—C5A—C9—Cl7 | 76.5 (13) |
C8A—C3A—C4A—Cl6A | 2.5 (14) | C4A—C5A—C9—Cl7 | −104.5 (11) |
References
Demenev, A., Eichhorn, S. H., Taerum, T., Perepichka, D. F., Patwardhan, S., Grozema, F. C., Siebbeles, L. D. A. & Klenkler, R. (2010). Chem. Mater. 22, 1420–1428. CrossRef CAS Google Scholar
Detert, H., Lehmann, M. & Meier, H. (2010). Materials, 3, 3218–3330. Web of Science CrossRef CAS Google Scholar
Detert, H., Lenoir, D. & Zipse, H. (2009). Eur. J. Org. Chem. pp. 1181–1190. Web of Science CSD CrossRef Google Scholar
Glang, S., Rieth, T., Borchmann, D., Fortunati, I., Signorini, R. & Detert, H. (2014). Eur. J. Org. Chem. pp. 3116–3126. Web of Science CrossRef Google Scholar
Holst, C., Schollmeyer, D. & Meier, H. (2011). Z. Naturforsch. Teil B, 66, 935–938. CrossRef CAS Google Scholar
Parsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249–259. Web of Science CrossRef CAS IUCr Journals Google Scholar
Rieth, T., Marszalek, T., Pisula, W. & Detert, H. (2014). Chemistry, 20, 5000–5006. CrossRef CAS Google Scholar
Schollmeyer, D. & Detert, H. (2017). Tetrahedron Lett. 58, 843–846. CrossRef CAS Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Stoe & Cie (1999). X-AREA and X-RED. Stoe & Cie, Darmstadt, Germany. Google Scholar
Taerum, T., Lukoyanova, O., Wylie, R. G. & Perepichka, D. F. (2009). Org. Lett. 11, 3230–3233. CrossRef CAS Google Scholar
Veciana, J., Rovira, C., Ventosa, N., Crespo, M. I. & Palacio, F. (1993). J. Am. Chem. Soc. 115, 57–64. CrossRef CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.