Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270106005063/ln3003sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270106005063/ln3003IIsup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270106005063/ln3003IVsup3.hkl |
CCDC references: 605682; 605683
The diol (II) was prepared from 1,2-cyclohexanedione (1) by reaction with sodium acetylide, as described by Ried & Schmidt (1957). The spectroscopic data (Hamann, 1992) were consistent with literature values. Single crystals were obtained from benzene–petroleum ether (Ratio?). Diol (IV) was prepared from 1,4-cyclohexanedione (3) and propargyl bromide, as described by Cognacq et al. (1967). It formed an oil that crystallized slowly. Analytical and spectroscopic data agree with those of the original reference.
Methylene H atoms were included in calculated positions and refined using a riding model, with fixed C—H bond lengths of 0.99 Å and with Uiso(H) = 1.2Ueq(C). Other H atoms were located in difference syntheses and refined freely, but with C—H (acetylenic) and O—H bond distances each restrained to be equal within a notional s.u. of 0.02 Å.
The title compounds, (II) and (IV), respectively, are related trans-cyclohexane-1,2-diols that we have used as synthetic intermediates. Compound (II) is a long-known (Ried & Schmidt, 1957) bis-propargylic diol that we used in our studies (Eshdat et al., 2002) of novel cross-conjugated enynes. Similarly, compound (IV) is a known (Cognacq et al., 1967) compound that we used in our studies of semicyclic olefins and allenes (Hopf et al., 2002). The structures of both compounds were confirmed by X-ray crystal structure determination and proved to display a variety of secondary contacts, not only the expected classical hydrogen bonds but also interactions involving the C≡C—H moieties.
Compound (II) crystallizes with two independent molecules in the asymmetric unit, which are closely similar (a least-squares fit of all non-H atoms gives an r.m.s. deviation of 0.044 Å). The hydroxy groups occupy equatorial and the propargyl groups the axial positions of the cyclohexyl rings (Fig. 1). Primes indicate atoms of the second molecule, which is inverted with respect to the first in the coordinates chosen for the asymmetric unit [to give a hydrogen bond (see below) between both independent molecules without transformation]. The one major difference lies in the configuration of the OH groups, whereby C1'—C2'—O2'—H02' is a trans-periplanar group [the O—H bond is parallel to the C1'—C2' ring bond, torsion angle -177 (2)°] and all other analogous groups are gauche; the corresponding torsion angles (all involving the ring bonds C1—C2 or C1'—C2') involving atoms H01, H01' and H02 are 72 (2), -77 (2) and 76 (2)°, respectively. The molecular dimensions may be regarded as normal. The rings display the usual chair form [absolute torsion angles 54.4 (2)–57.8 (2)°].
The molecular packing of (II) is puzzling at first sight. The molecules associate via two classical hydrogen bonds (Table 2) involving O2—H02 and O2'—H02' as donors, to form chains of graph set C22(7) (Etter, 1990) parallel to the short c axis (Fig. 2; neighbouring chains define layers parallel to the ac plane). However, O1—H01 and O1'—H01' do not take part in such interactions. Closer inspection shows that these OH groups form `weak' intermolecular hydrogen bonds (Desiraju & Steiner, 1999) to the alkyne triple bonds, with both interactions being within the asymmetric unit: O1—H01···midpoint(C9'≡C10'), H···acceptor 2.60 Å and angle 162°; O1'—H01'···midpoint(C9≡C10), H···acceptor 2.71 Å and angle 111°. The latter interaction is admittedly a borderline case in view of its narrow angle.
Acetylenic H atoms represent a fairly acidic form of CH group and can also act as hydrogen-bond donors (Desiraju & Steiner, 1999); as a concrete example, we have drawn attention to C≡C—H···Cl—Au interactions (Bardají et al., 2002). In the current structure, three of the four C≡C—H groups act in this way (Table 2) to connect the classical hydrogen-bonded layers in the third dimension parallel to the long b axis (Fig. 3).
All four O atoms are thus topologically different as regards their hydrogen-bonding behaviour, which may be summarized as follows (D = donor, A = acceptor, C = classical, W = `weak'): O1 WD,WA; O2 CD,CA,WA; O3 CA,WD; O4 CD,WA. One might speculate that the `extra' interaction for atom O2 is connected with its different C—C—O—H torsion angle (see above).
Compound (IV) also crystallizes with two symmetry-independent molecules, which, however, display inversion symmetry [molecule 1 about (1, 1/2, 1) and molecule 2 about (1/2, 1/2, 1/2)] (Fig. 4). A least-squares fit of the ring atoms of the asymmetric unit gives an r.m.s. deviation of 0.07 Å. As in (II), the OH groups of the two molecules are oriented differently; in molecule 2, the C2'—C1'—O1'—H01' torsion angle is 42 (1)° and the OH group is very approximately parallel to the propargyl group (see Fig. 4, bottom left), whereas in molecule 1 the corresponding angle is 171 (1)° and the corresponding groups point in widely disparate directions. The asymmetric unit also contains a molecule of water, which was presumably absorbed from the atmosphere during the slow crystallization of the oily product. In contrast with (II), the hydroxy groups are axial and the propynyl groups equatorial.
The contribution of classical hydrogen bonds to the packing of (IV) is shown in Fig. 5. Both independent OH groups and one water H atom, H03, act as hydrogen-bond donors (Table 4; for a discussion of atom H04, see below) and the overall effect is to form a layer structure parallel to the ac plane. The two independent rings thus formed are both of graph set R66(22).
The second water H atom, H04, appears at first sight to make no significant contacts at all. However, it projects away from the layer shown in Fig. 5 and makes contacts of 3.03 and 3.04 Å (angles at H04: 114 and 157°, respectively) to the midpoints of the triple bonds C5≡C6 and C5'≡C6' in the neighbouring layer at (x, 1 + y, z) (Fig. 6a). For a three-centre contact, these very long distances may still indicate a significant interaction.
The acetylenic H atom, H6, of (IV) makes a short (2.37 Å) `weak' hydrogen bond with atom O1' in the neighbouring layer at (x, -1 + y, z). The corresponding contact from atom H6' to atom O1 is, however, very long and bent (Table 4); again, the explanation may be sought in a three-centre interaction, the other branch of which is a C—H···π interaction to the midpoint of C5≡C6 (2.74 Å and 166°). The operator is (-1 + x, y, z) for both branches, so that the system forms part of the layer structure, but this is not easy to recognize in Fig. 5; it is depicted for clarity in Fig. 6(b).
For both compounds, data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.
C10H12O2 | F(000) = 704 |
Mr = 164.20 | Dx = 1.235 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 10.563 (3) Å | Cell parameters from 46 reflections |
b = 23.839 (6) Å | θ = 8.5–11.5° |
c = 7.025 (2) Å | µ = 0.09 mm−1 |
β = 93.46 (2)° | T = 153 K |
V = 1765.8 (8) Å3 | Prism, colourless |
Z = 8 | 0.45 × 0.40 × 0.40 mm |
Stoe STADI-4 diffractometer | Rint = 0.028 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 3.0° |
Graphite monochromator | h = −12→11 |
ω/θ scans | k = −28→9 |
4400 measured reflections | l = −8→8 |
3131 independent reflections | 3 standard reflections every 60 min |
2380 reflections with I > 2σ(I) | intensity decay: none |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.045 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.103 | w = 1/[σ2(Fo2) + (0.0332P)2 + 0.7551P] where P = (Fo2 + 2Fc2)/3 |
S = 1.08 | (Δ/σ)max < 0.001 |
3131 reflections | Δρmax = 0.18 e Å−3 |
250 parameters | Δρmin = −0.18 e Å−3 |
12 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0080 (10) |
C10H12O2 | V = 1765.8 (8) Å3 |
Mr = 164.20 | Z = 8 |
Monoclinic, P21/c | Mo Kα radiation |
a = 10.563 (3) Å | µ = 0.09 mm−1 |
b = 23.839 (6) Å | T = 153 K |
c = 7.025 (2) Å | 0.45 × 0.40 × 0.40 mm |
β = 93.46 (2)° |
Stoe STADI-4 diffractometer | Rint = 0.028 |
4400 measured reflections | 3 standard reflections every 60 min |
3131 independent reflections | intensity decay: none |
2380 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.045 | 12 restraints |
wR(F2) = 0.103 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.08 | Δρmax = 0.18 e Å−3 |
3131 reflections | Δρmin = −0.18 e Å−3 |
250 parameters |
Experimental. 1,1-Diphenyl-2,2-bis(trimethylsilylethynyl)ethene |
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 | 0.83692 (18) | 0.62268 (8) | 0.3713 (3) | 0.0236 (4) | |
C2 | 0.74653 (17) | 0.60275 (7) | 0.5244 (3) | 0.0204 (4) | |
C3 | 0.81572 (19) | 0.60515 (8) | 0.7221 (3) | 0.0266 (4) | |
H3A | 0.8384 | 0.6445 | 0.7530 | 0.032* | |
H3B | 0.7583 | 0.5916 | 0.8186 | 0.032* | |
C4 | 0.93575 (19) | 0.56940 (9) | 0.7314 (3) | 0.0324 (5) | |
H4A | 0.9803 | 0.5735 | 0.8587 | 0.039* | |
H4B | 0.9125 | 0.5294 | 0.7136 | 0.039* | |
C5 | 1.02384 (19) | 0.58691 (9) | 0.5787 (3) | 0.0347 (5) | |
H5A | 1.0974 | 0.5611 | 0.5810 | 0.042* | |
H5B | 1.0561 | 0.6252 | 0.6066 | 0.042* | |
C6 | 0.95592 (18) | 0.58596 (9) | 0.3813 (3) | 0.0293 (5) | |
H6A | 0.9319 | 0.5469 | 0.3480 | 0.035* | |
H6B | 1.0145 | 0.5994 | 0.2864 | 0.035* | |
C7 | 0.86975 (18) | 0.68239 (8) | 0.4052 (3) | 0.0267 (4) | |
C8 | 0.8953 (2) | 0.73001 (10) | 0.4312 (3) | 0.0384 (5) | |
H8 | 0.916 (3) | 0.7683 (8) | 0.458 (4) | 0.063 (8)* | |
C9 | 0.70117 (17) | 0.54546 (8) | 0.4804 (3) | 0.0229 (4) | |
C10 | 0.6578 (2) | 0.50046 (9) | 0.4479 (3) | 0.0318 (5) | |
H10 | 0.622 (2) | 0.4647 (9) | 0.419 (4) | 0.064 (8)* | |
O1 | 0.77933 (14) | 0.61563 (6) | 0.18327 (18) | 0.0299 (4) | |
H01 | 0.724 (2) | 0.6401 (9) | 0.171 (4) | 0.049 (8)* | |
O2 | 0.63907 (12) | 0.63975 (6) | 0.52862 (19) | 0.0239 (3) | |
H02 | 0.593 (2) | 0.6317 (11) | 0.433 (3) | 0.058 (8)* | |
C1' | 0.37595 (17) | 0.61074 (8) | 0.1025 (3) | 0.0226 (4) | |
C2' | 0.43125 (17) | 0.64112 (8) | −0.0689 (3) | 0.0238 (4) | |
C3' | 0.32330 (19) | 0.66407 (8) | −0.2016 (3) | 0.0299 (5) | |
H3'1 | 0.3597 | 0.6856 | −0.3056 | 0.036* | |
H3'2 | 0.2747 | 0.6323 | −0.2599 | 0.036* | |
C4' | 0.2336 (2) | 0.70171 (9) | −0.0983 (3) | 0.0359 (5) | |
H4'1 | 0.2793 | 0.7360 | −0.0539 | 0.043* | |
H4'2 | 0.1624 | 0.7132 | −0.1879 | 0.043* | |
C5' | 0.1817 (2) | 0.67186 (9) | 0.0713 (3) | 0.0342 (5) | |
H5'1 | 0.1270 | 0.6403 | 0.0256 | 0.041* | |
H5'2 | 0.1290 | 0.6982 | 0.1413 | 0.041* | |
C6' | 0.28866 (19) | 0.64962 (8) | 0.2053 (3) | 0.0286 (5) | |
H6'1 | 0.3384 | 0.6815 | 0.2603 | 0.034* | |
H6'2 | 0.2522 | 0.6291 | 0.3116 | 0.034* | |
C7' | 0.30831 (19) | 0.55942 (8) | 0.0360 (3) | 0.0258 (4) | |
C8' | 0.2575 (2) | 0.51775 (9) | −0.0130 (3) | 0.0342 (5) | |
H8' | 0.221 (2) | 0.4837 (8) | −0.056 (3) | 0.045 (7)* | |
C9' | 0.51511 (19) | 0.68756 (8) | 0.0020 (3) | 0.0285 (5) | |
C10' | 0.5809 (2) | 0.72564 (9) | 0.0496 (3) | 0.0375 (5) | |
H10' | 0.627 (2) | 0.7584 (9) | 0.084 (4) | 0.069 (9)* | |
O1' | 0.47707 (13) | 0.59540 (6) | 0.2389 (2) | 0.0308 (4) | |
H01' | 0.513 (2) | 0.5674 (9) | 0.197 (4) | 0.059 (9)* | |
O2' | 0.50258 (14) | 0.60008 (6) | −0.1628 (2) | 0.0314 (4) | |
H02' | 0.535 (2) | 0.6170 (10) | −0.251 (3) | 0.060 (9)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0239 (10) | 0.0260 (10) | 0.0209 (9) | −0.0010 (8) | 0.0010 (8) | −0.0004 (8) |
C2 | 0.0177 (9) | 0.0215 (9) | 0.0217 (9) | 0.0019 (8) | −0.0001 (7) | −0.0014 (8) |
C3 | 0.0281 (11) | 0.0319 (11) | 0.0195 (9) | −0.0012 (9) | −0.0023 (8) | −0.0003 (8) |
C4 | 0.0267 (11) | 0.0371 (12) | 0.0322 (11) | 0.0016 (9) | −0.0081 (9) | 0.0028 (9) |
C5 | 0.0209 (11) | 0.0371 (12) | 0.0453 (13) | 0.0040 (9) | −0.0033 (9) | 0.0026 (10) |
C6 | 0.0231 (11) | 0.0321 (11) | 0.0333 (11) | 0.0004 (9) | 0.0066 (9) | −0.0008 (9) |
C7 | 0.0234 (10) | 0.0290 (11) | 0.0278 (10) | −0.0013 (9) | 0.0018 (8) | 0.0033 (9) |
C8 | 0.0396 (13) | 0.0291 (13) | 0.0461 (13) | −0.0084 (10) | −0.0003 (10) | 0.0014 (10) |
C9 | 0.0187 (9) | 0.0273 (11) | 0.0228 (9) | 0.0024 (8) | 0.0010 (8) | 0.0013 (8) |
C10 | 0.0268 (11) | 0.0263 (11) | 0.0427 (13) | −0.0023 (9) | 0.0057 (10) | −0.0024 (10) |
O1 | 0.0325 (8) | 0.0375 (9) | 0.0195 (7) | 0.0018 (7) | 0.0004 (6) | −0.0016 (6) |
O2 | 0.0185 (7) | 0.0281 (7) | 0.0250 (7) | 0.0044 (6) | −0.0006 (6) | −0.0021 (6) |
C1' | 0.0205 (9) | 0.0252 (10) | 0.0216 (9) | −0.0035 (8) | −0.0040 (7) | 0.0014 (8) |
C2' | 0.0197 (9) | 0.0253 (10) | 0.0265 (10) | −0.0021 (8) | 0.0013 (8) | −0.0009 (8) |
C3' | 0.0315 (12) | 0.0308 (11) | 0.0268 (11) | −0.0044 (9) | −0.0018 (9) | 0.0069 (9) |
C4' | 0.0303 (12) | 0.0306 (11) | 0.0459 (13) | 0.0030 (9) | −0.0058 (10) | 0.0079 (10) |
C5' | 0.0247 (11) | 0.0347 (12) | 0.0433 (12) | 0.0041 (9) | 0.0022 (9) | −0.0037 (10) |
C6' | 0.0276 (11) | 0.0318 (11) | 0.0269 (10) | −0.0037 (9) | 0.0051 (8) | −0.0036 (9) |
C7' | 0.0276 (11) | 0.0271 (11) | 0.0227 (10) | −0.0029 (9) | 0.0005 (8) | 0.0042 (8) |
C8' | 0.0432 (13) | 0.0308 (12) | 0.0284 (11) | −0.0130 (11) | 0.0003 (10) | 0.0024 (9) |
C9' | 0.0233 (10) | 0.0300 (11) | 0.0323 (11) | −0.0028 (9) | 0.0028 (9) | 0.0022 (9) |
C10' | 0.0322 (12) | 0.0319 (12) | 0.0484 (14) | −0.0089 (10) | 0.0022 (10) | −0.0015 (10) |
O1' | 0.0284 (8) | 0.0325 (9) | 0.0301 (8) | −0.0013 (7) | −0.0106 (6) | 0.0028 (7) |
O2' | 0.0316 (8) | 0.0297 (8) | 0.0343 (8) | 0.0003 (6) | 0.0127 (7) | −0.0025 (7) |
C1—O1 | 1.430 (2) | C1'—O1' | 1.438 (2) |
C1—C7 | 1.481 (3) | C1'—C7' | 1.478 (3) |
C1—C6 | 1.530 (3) | C1'—C6' | 1.520 (3) |
C1—C2 | 1.555 (3) | C1'—C2' | 1.549 (3) |
C2—O2 | 1.439 (2) | C2'—O2' | 1.422 (2) |
C2—C9 | 1.474 (3) | C2'—C9' | 1.485 (3) |
C2—C3 | 1.531 (3) | C2'—C3' | 1.530 (3) |
C3—C4 | 1.526 (3) | C3'—C4' | 1.521 (3) |
C3—H3A | 0.9900 | C3'—H3'1 | 0.9900 |
C3—H3B | 0.9900 | C3'—H3'2 | 0.9900 |
C4—C5 | 1.520 (3) | C4'—C5' | 1.519 (3) |
C4—H4A | 0.9900 | C4'—H4'1 | 0.9900 |
C4—H4B | 0.9900 | C4'—H4'2 | 0.9900 |
C5—C6 | 1.523 (3) | C5'—C6' | 1.522 (3) |
C5—H5A | 0.9900 | C5'—H5'1 | 0.9900 |
C5—H5B | 0.9900 | C5'—H5'2 | 0.9900 |
C6—H6A | 0.9900 | C6'—H6'1 | 0.9900 |
C6—H6B | 0.9900 | C6'—H6'2 | 0.9900 |
C7—C8 | 1.178 (3) | C7'—C8' | 1.171 (3) |
C8—H8 | 0.954 (18) | C8'—H8' | 0.940 (17) |
C9—C10 | 1.183 (3) | C9'—C10' | 1.179 (3) |
C10—H10 | 0.950 (18) | C10'—H10' | 0.944 (18) |
O1—H01 | 0.829 (18) | O1'—H01' | 0.832 (19) |
O2—H02 | 0.828 (19) | O2'—H02' | 0.832 (19) |
O1—C1—C7 | 110.12 (15) | O1'—C1'—C7' | 108.99 (15) |
O1—C1—C6 | 106.12 (15) | O1'—C1'—C6' | 106.61 (15) |
C7—C1—C6 | 111.03 (16) | C7'—C1'—C6' | 111.05 (16) |
O1—C1—C2 | 110.98 (15) | O1'—C1'—C2' | 109.68 (15) |
C7—C1—C2 | 109.26 (15) | C7'—C1'—C2' | 109.82 (15) |
C6—C1—C2 | 109.30 (15) | C6'—C1'—C2' | 110.61 (15) |
O2—C2—C9 | 108.99 (15) | O2'—C2'—C9' | 110.29 (15) |
O2—C2—C3 | 106.99 (14) | O2'—C2'—C3' | 111.08 (16) |
C9—C2—C3 | 110.86 (15) | C9'—C2'—C3' | 110.21 (16) |
O2—C2—C1 | 110.19 (14) | O2'—C2'—C1' | 105.92 (15) |
C9—C2—C1 | 110.08 (15) | C9'—C2'—C1' | 109.46 (16) |
C3—C2—C1 | 109.67 (15) | C3'—C2'—C1' | 109.79 (15) |
C4—C3—C2 | 111.60 (16) | C4'—C3'—C2' | 112.54 (16) |
C4—C3—H3A | 109.3 | C4'—C3'—H3'1 | 109.1 |
C2—C3—H3A | 109.3 | C2'—C3'—H3'1 | 109.1 |
C4—C3—H3B | 109.3 | C4'—C3'—H3'2 | 109.1 |
C2—C3—H3B | 109.3 | C2'—C3'—H3'2 | 109.1 |
H3A—C3—H3B | 108.0 | H3'1—C3'—H3'2 | 107.8 |
C5—C4—C3 | 111.02 (17) | C5'—C4'—C3' | 111.27 (17) |
C5—C4—H4A | 109.4 | C5'—C4'—H4'1 | 109.4 |
C3—C4—H4A | 109.4 | C3'—C4'—H4'1 | 109.4 |
C5—C4—H4B | 109.4 | C5'—C4'—H4'2 | 109.4 |
C3—C4—H4B | 109.4 | C3'—C4'—H4'2 | 109.4 |
H4A—C4—H4B | 108.0 | H4'1—C4'—H4'2 | 108.0 |
C4—C5—C6 | 111.33 (17) | C4'—C5'—C6' | 111.02 (17) |
C4—C5—H5A | 109.4 | C4'—C5'—H5'1 | 109.4 |
C6—C5—H5A | 109.4 | C6'—C5'—H5'1 | 109.4 |
C4—C5—H5B | 109.4 | C4'—C5'—H5'2 | 109.4 |
C6—C5—H5B | 109.4 | C6'—C5'—H5'2 | 109.4 |
H5A—C5—H5B | 108.0 | H5'1—C5'—H5'2 | 108.0 |
C5—C6—C1 | 111.96 (16) | C1'—C6'—C5' | 111.56 (16) |
C5—C6—H6A | 109.2 | C1'—C6'—H6'1 | 109.3 |
C1—C6—H6A | 109.2 | C5'—C6'—H6'1 | 109.3 |
C5—C6—H6B | 109.2 | C1'—C6'—H6'2 | 109.3 |
C1—C6—H6B | 109.2 | C5'—C6'—H6'2 | 109.3 |
H6A—C6—H6B | 107.9 | H6'1—C6'—H6'2 | 108.0 |
C8—C7—C1 | 179.5 (2) | C8'—C7'—C1' | 177.8 (2) |
C7—C8—H8 | 177.6 (16) | C7'—C8'—H8' | 176.3 (15) |
C10—C9—C2 | 176.1 (2) | C10'—C9'—C2' | 176.7 (2) |
C9—C10—H10 | 178.7 (17) | C9'—C10'—H10' | 174.6 (17) |
C1—O1—H01 | 105.7 (18) | C1'—O1'—H01' | 107.8 (19) |
C2—O2—H02 | 105.5 (18) | C2'—O2'—H02' | 105.4 (19) |
O1—C1—C2—O2 | −68.27 (19) | O1'—C1'—C2'—O2' | 67.18 (18) |
C7—C1—C2—O2 | 53.3 (2) | C7'—C1'—C2'—O2' | −52.58 (19) |
C6—C1—C2—O2 | 175.02 (14) | C6'—C1'—C2'—O2' | −175.51 (15) |
O1—C1—C2—C9 | 52.0 (2) | O1'—C1'—C2'—C9' | −51.7 (2) |
C7—C1—C2—C9 | 173.59 (15) | C7'—C1'—C2'—C9' | −171.47 (16) |
C6—C1—C2—C9 | −64.7 (2) | C6'—C1'—C2'—C9' | 65.6 (2) |
O1—C1—C2—C3 | 174.20 (15) | O1'—C1'—C2'—C3' | −172.81 (15) |
C7—C1—C2—C3 | −64.18 (19) | C7'—C1'—C2'—C3' | 67.4 (2) |
C6—C1—C2—C3 | 57.49 (19) | C6'—C1'—C2'—C3' | −55.5 (2) |
O2—C2—C3—C4 | −177.28 (15) | O2'—C2'—C3'—C4' | 171.72 (16) |
C9—C2—C3—C4 | 64.0 (2) | C9'—C2'—C3'—C4' | −65.7 (2) |
C1—C2—C3—C4 | −57.8 (2) | C1'—C2'—C3'—C4' | 54.9 (2) |
C2—C3—C4—C5 | 56.2 (2) | C2'—C3'—C4'—C5' | −55.0 (2) |
C3—C4—C5—C6 | −54.4 (2) | C3'—C4'—C5'—C6' | 54.8 (2) |
C4—C5—C6—C1 | 56.0 (2) | O1'—C1'—C6'—C5' | 176.34 (15) |
O1—C1—C6—C5 | −176.97 (16) | C7'—C1'—C6'—C5' | −65.1 (2) |
C7—C1—C6—C5 | 63.4 (2) | C2'—C1'—C6'—C5' | 57.2 (2) |
C2—C1—C6—C5 | −57.2 (2) | C4'—C5'—C6'—C1' | −56.7 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H02···O1′ | 0.83 (2) | 1.98 (2) | 2.787 (2) | 166 (3) |
O2′—H02′···O2i | 0.83 (2) | 2.02 (2) | 2.837 (2) | 165 (3) |
C10—H10···O2′ii | 0.95 (2) | 2.66 (2) | 3.495 (3) | 147 (2) |
C8′—H8′···O1ii | 0.94 (2) | 2.53 (2) | 3.411 (3) | 156 (2) |
C10′—H10′···O2iii | 0.94 (2) | 2.46 (2) | 3.272 (3) | 144 (2) |
Symmetry codes: (i) x, y, z−1; (ii) −x+1, −y+1, −z; (iii) x, −y+3/2, z−1/2. |
C12H18O3 | Z = 2 |
Mr = 210.26 | F(000) = 228 |
Triclinic, P1 | Dx = 1.222 Mg m−3 |
a = 6.6112 (18) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 7.2474 (19) Å | Cell parameters from 56 reflections |
c = 12.577 (3) Å | θ = 10–11.5° |
α = 93.384 (16)° | µ = 0.09 mm−1 |
β = 102.410 (16)° | T = 153 K |
γ = 102.309 (16)° | Prism, yellow |
V = 571.5 (3) Å3 | 0.70 × 0.60 × 0.25 mm |
Stoe STADI-4 diffractometer | Rint = 0.021 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 3.2° |
Graphite monochromator | h = −7→7 |
ω/θ scans | k = −8→8 |
2374 measured reflections | l = −13→14 |
2022 independent reflections | 3 standard reflections every 60 min |
1849 reflections with I > 2σ(I) | intensity decay: none |
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)] = 0.034 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.084 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0362P)2 + 0.2046P] where P = (Fo2 + 2Fc2)/3 |
2022 reflections | (Δ/σ)max < 0.001 |
160 parameters | Δρmax = 0.20 e Å−3 |
7 restraints | Δρmin = −0.20 e Å−3 |
C12H18O3 | γ = 102.309 (16)° |
Mr = 210.26 | V = 571.5 (3) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.6112 (18) Å | Mo Kα radiation |
b = 7.2474 (19) Å | µ = 0.09 mm−1 |
c = 12.577 (3) Å | T = 153 K |
α = 93.384 (16)° | 0.70 × 0.60 × 0.25 mm |
β = 102.410 (16)° |
Stoe STADI-4 diffractometer | Rint = 0.021 |
2374 measured reflections | 3 standard reflections every 60 min |
2022 independent reflections | intensity decay: none |
1849 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.034 | 7 restraints |
wR(F2) = 0.084 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.20 e Å−3 |
2022 reflections | Δρmin = −0.20 e Å−3 |
160 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 | ||
O1 | 0.84693 (14) | 0.39717 (13) | 0.82084 (7) | 0.0223 (2) | |
H01 | 0.730 (3) | 0.414 (3) | 0.7798 (14) | 0.047 (5)* | |
C1 | 0.81482 (19) | 0.36043 (17) | 0.92784 (10) | 0.0196 (3) | |
C2 | 1.01113 (19) | 0.30015 (17) | 0.98931 (10) | 0.0216 (3) | |
H2A | 1.0331 | 0.1909 | 0.9457 | 0.026* | |
H2B | 0.9864 | 0.2578 | 1.0598 | 0.026* | |
C3 | 0.78829 (19) | 0.53954 (17) | 0.98833 (10) | 0.0212 (3) | |
H3A | 0.6681 | 0.5832 | 0.9440 | 0.025* | |
H3B | 0.7528 | 0.5087 | 1.0588 | 0.025* | |
C4 | 0.6122 (2) | 0.20182 (18) | 0.91501 (11) | 0.0243 (3) | |
H4A | 0.5899 | 0.1765 | 0.9886 | 0.029* | |
H4B | 0.4884 | 0.2466 | 0.8754 | 0.029* | |
C5 | 0.6205 (2) | 0.02421 (19) | 0.85603 (11) | 0.0249 (3) | |
C6 | 0.6284 (2) | −0.1173 (2) | 0.80689 (12) | 0.0296 (3) | |
H6 | 0.633 (3) | −0.230 (2) | 0.7677 (14) | 0.046 (5)* | |
O1' | 0.49797 (14) | 0.45806 (12) | 0.67637 (7) | 0.0216 (2) | |
H01' | 0.383 (3) | 0.477 (3) | 0.6934 (15) | 0.049 (5)* | |
C1' | 0.44261 (19) | 0.34810 (17) | 0.57046 (10) | 0.0193 (3) | |
C2' | 0.27312 (19) | 0.41941 (18) | 0.49225 (10) | 0.0206 (3) | |
H2'1 | 0.1468 | 0.4108 | 0.5237 | 0.025* | |
H2'2 | 0.2287 | 0.3366 | 0.4219 | 0.025* | |
C3' | 0.64711 (19) | 0.37550 (18) | 0.52919 (10) | 0.0206 (3) | |
H3'1 | 0.7588 | 0.3389 | 0.5842 | 0.025* | |
H3'2 | 0.6207 | 0.2906 | 0.4606 | 0.025* | |
C4' | 0.3643 (2) | 0.13701 (18) | 0.58442 (11) | 0.0238 (3) | |
H4'1 | 0.3150 | 0.0628 | 0.5112 | 0.029* | |
H4'2 | 0.4850 | 0.0905 | 0.6260 | 0.029* | |
C5' | 0.1907 (2) | 0.10345 (18) | 0.64148 (11) | 0.0265 (3) | |
C6' | 0.0553 (2) | 0.0849 (2) | 0.69061 (13) | 0.0354 (4) | |
H6' | −0.049 (3) | 0.073 (3) | 0.7311 (15) | 0.053 (5)* | |
O3 | 0.17155 (17) | 0.58949 (16) | 0.73225 (10) | 0.0375 (3) | |
H03 | 0.070 (3) | 0.536 (3) | 0.7641 (17) | 0.071 (7)* | |
H04 | 0.179 (4) | 0.711 (2) | 0.739 (2) | 0.097 (9)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0185 (5) | 0.0289 (5) | 0.0189 (5) | 0.0044 (4) | 0.0042 (4) | 0.0032 (4) |
C1 | 0.0181 (6) | 0.0219 (6) | 0.0185 (6) | 0.0035 (5) | 0.0044 (5) | 0.0027 (5) |
C2 | 0.0223 (6) | 0.0198 (6) | 0.0223 (6) | 0.0059 (5) | 0.0039 (5) | 0.0011 (5) |
C3 | 0.0184 (6) | 0.0243 (7) | 0.0218 (6) | 0.0077 (5) | 0.0043 (5) | 0.0024 (5) |
C4 | 0.0211 (7) | 0.0247 (7) | 0.0262 (7) | 0.0020 (5) | 0.0071 (5) | 0.0019 (5) |
C5 | 0.0197 (6) | 0.0257 (7) | 0.0261 (7) | −0.0007 (5) | 0.0037 (5) | 0.0063 (6) |
C6 | 0.0292 (7) | 0.0230 (7) | 0.0338 (8) | 0.0009 (6) | 0.0066 (6) | 0.0027 (6) |
O1' | 0.0201 (5) | 0.0253 (5) | 0.0193 (5) | 0.0062 (4) | 0.0044 (4) | −0.0005 (4) |
C1' | 0.0198 (6) | 0.0198 (6) | 0.0185 (6) | 0.0054 (5) | 0.0042 (5) | 0.0007 (5) |
C2' | 0.0168 (6) | 0.0239 (6) | 0.0211 (6) | 0.0049 (5) | 0.0042 (5) | 0.0013 (5) |
C3' | 0.0186 (6) | 0.0233 (6) | 0.0216 (6) | 0.0085 (5) | 0.0044 (5) | 0.0036 (5) |
C4' | 0.0246 (7) | 0.0220 (7) | 0.0264 (7) | 0.0071 (5) | 0.0077 (5) | 0.0036 (5) |
C5' | 0.0282 (7) | 0.0215 (7) | 0.0283 (7) | 0.0036 (5) | 0.0053 (6) | 0.0033 (5) |
C6' | 0.0321 (8) | 0.0365 (8) | 0.0381 (8) | 0.0028 (6) | 0.0141 (7) | 0.0054 (7) |
O3 | 0.0317 (6) | 0.0352 (6) | 0.0502 (7) | 0.0050 (5) | 0.0224 (5) | 0.0035 (5) |
O1—C1 | 1.4381 (15) | O1'—H01' | 0.867 (15) |
O1—H01 | 0.871 (15) | C1'—C2' | 1.5242 (17) |
C1—C2 | 1.5242 (17) | C1'—C3' | 1.5284 (17) |
C1—C3 | 1.5273 (17) | C1'—C4' | 1.5403 (18) |
C1—C4 | 1.5396 (17) | C2'—C3'ii | 1.5279 (18) |
C2—C3i | 1.5270 (18) | C2'—H2'1 | 0.9900 |
C2—H2A | 0.9900 | C2'—H2'2 | 0.9900 |
C2—H2B | 0.9900 | C3'—H3'1 | 0.9900 |
C3—H3A | 0.9900 | C3'—H3'2 | 0.9900 |
C3—H3B | 0.9900 | C4'—C5' | 1.4654 (19) |
C4—C5 | 1.4646 (19) | C4'—H4'1 | 0.9900 |
C4—H4A | 0.9900 | C4'—H4'2 | 0.9900 |
C4—H4B | 0.9900 | C5'—C6' | 1.182 (2) |
C5—C6 | 1.182 (2) | C6'—H6' | 0.932 (16) |
C6—H6 | 0.939 (16) | O3—H03 | 0.884 (16) |
O1'—C1' | 1.4437 (15) | O3—H04 | 0.872 (17) |
C1—O1—H01 | 109.5 (12) | O1'—C1'—C2' | 110.06 (10) |
O1—C1—C2 | 107.03 (10) | O1'—C1'—C3' | 106.34 (10) |
O1—C1—C3 | 110.20 (10) | C2'—C1'—C3' | 110.48 (10) |
C2—C1—C3 | 110.23 (10) | O1'—C1'—C4' | 108.92 (10) |
O1—C1—C4 | 108.81 (10) | C2'—C1'—C4' | 111.30 (10) |
C2—C1—C4 | 111.28 (10) | C3'—C1'—C4' | 109.61 (10) |
C3—C1—C4 | 109.25 (10) | C1'—C2'—C3'ii | 112.21 (10) |
C1—C2—C3i | 112.44 (10) | C1'—C2'—H2'1 | 109.2 |
C1—C2—H2A | 109.1 | C3'ii—C2'—H2'1 | 109.2 |
C3i—C2—H2A | 109.1 | C1'—C2'—H2'2 | 109.2 |
C1—C2—H2B | 109.1 | C3'ii—C2'—H2'2 | 109.2 |
C3i—C2—H2B | 109.1 | H2'1—C2'—H2'2 | 107.9 |
H2A—C2—H2B | 107.8 | C2'ii—C3'—C1' | 112.22 (10) |
C2i—C3—C1 | 112.33 (10) | C2'ii—C3'—H3'1 | 109.2 |
C2i—C3—H3A | 109.1 | C1'—C3'—H3'1 | 109.2 |
C1—C3—H3A | 109.1 | C2'ii—C3'—H3'2 | 109.2 |
C2i—C3—H3B | 109.1 | C1'—C3'—H3'2 | 109.2 |
C1—C3—H3B | 109.1 | H3'1—C3'—H3'2 | 107.9 |
H3A—C3—H3B | 107.9 | C5'—C4'—C1' | 113.00 (11) |
C5—C4—C1 | 113.46 (11) | C5'—C4'—H4'1 | 109.0 |
C5—C4—H4A | 108.9 | C1'—C4'—H4'1 | 109.0 |
C1—C4—H4A | 108.9 | C5'—C4'—H4'2 | 109.0 |
C5—C4—H4B | 108.9 | C1'—C4'—H4'2 | 109.0 |
C1—C4—H4B | 108.9 | H4'1—C4'—H4'2 | 107.8 |
H4A—C4—H4B | 107.7 | C6'—C5'—C4' | 176.68 (15) |
C6—C5—C4 | 178.75 (14) | C5'—C6'—H6' | 178.2 (12) |
C5—C6—H6 | 179.4 (11) | H03—O3—H04 | 107 (2) |
C1'—O1'—H01' | 109.5 (12) | ||
O1—C1—C2—C3i | 66.02 (13) | O1'—C1'—C2'—C3'ii | 63.20 (13) |
C3—C1—C2—C3i | −53.83 (14) | C3'—C1'—C2'—C3'ii | −53.94 (14) |
C4—C1—C2—C3i | −175.21 (10) | C4'—C1'—C2'—C3'ii | −175.95 (10) |
O1—C1—C3—C2i | −64.15 (13) | O1'—C1'—C3'—C2'ii | −65.47 (13) |
C2—C1—C3—C2i | 53.77 (15) | C2'—C1'—C3'—C2'ii | 53.94 (15) |
C4—C1—C3—C2i | 176.35 (10) | C4'—C1'—C3'—C2'ii | 176.94 (10) |
O1—C1—C4—C5 | 58.64 (14) | O1'—C1'—C4'—C5' | 54.05 (14) |
C2—C1—C4—C5 | −59.06 (14) | C2'—C1'—C4'—C5' | −67.47 (14) |
C3—C1—C4—C5 | 179.00 (11) | C3'—C1'—C4'—C5' | 170.01 (11) |
Symmetry codes: (i) −x+2, −y+1, −z+2; (ii) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H01···O1′ | 0.87 (2) | 1.88 (2) | 2.7470 (14) | 172 (2) |
O1′—H01′···O3 | 0.87 (2) | 1.90 (2) | 2.7399 (15) | 164 (2) |
O3—H03···O1iii | 0.88 (2) | 1.90 (2) | 2.7795 (15) | 174 (2) |
C6—H6···O1′iv | 0.94 (2) | 2.37 (2) | 3.2516 (19) | 156 (2) |
C6′—H6′···O1iii | 0.93 (2) | 2.83 (2) | 3.4004 (19) | 121 (1) |
Symmetry codes: (iii) x−1, y, z; (iv) x, y−1, z. |
Experimental details
(II) | (IV) | |
Crystal data | ||
Chemical formula | C10H12O2 | C12H18O3 |
Mr | 164.20 | 210.26 |
Crystal system, space group | Monoclinic, P21/c | Triclinic, P1 |
Temperature (K) | 153 | 153 |
a, b, c (Å) | 10.563 (3), 23.839 (6), 7.025 (2) | 6.6112 (18), 7.2474 (19), 12.577 (3) |
α, β, γ (°) | 90, 93.46 (2), 90 | 93.384 (16), 102.410 (16), 102.309 (16) |
V (Å3) | 1765.8 (8) | 571.5 (3) |
Z | 8 | 2 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.09 | 0.09 |
Crystal size (mm) | 0.45 × 0.40 × 0.40 | 0.70 × 0.60 × 0.25 |
Data collection | ||
Diffractometer | Stoe STADI-4 | Stoe STADI-4 |
Absorption correction | – | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4400, 3131, 2380 | 2374, 2022, 1849 |
Rint | 0.028 | 0.021 |
(sin θ/λ)max (Å−1) | 0.596 | 0.595 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.045, 0.103, 1.08 | 0.034, 0.084, 1.05 |
No. of reflections | 3131 | 2022 |
No. of parameters | 250 | 160 |
No. of restraints | 12 | 7 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.18, −0.18 | 0.20, −0.20 |
Computer programs: DIF4 (Stoe & Cie, 1992), DIF4, REDU4 (Stoe & Cie, 1992), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), XP (Siemens, 1994), SHELXL97.
C1—O1 | 1.430 (2) | C1'—O1' | 1.438 (2) |
C2—O2 | 1.439 (2) | C2'—O2' | 1.422 (2) |
C7—C8 | 1.178 (3) | C7'—C8' | 1.171 (3) |
C9—C10 | 1.183 (3) | C9'—C10' | 1.179 (3) |
C8—C7—C1 | 179.5 (2) | C8'—C7'—C1' | 177.8 (2) |
C10—C9—C2 | 176.1 (2) | C10'—C9'—C2' | 176.7 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H02···O1' | 0.828 (19) | 1.976 (19) | 2.787 (2) | 166 (3) |
O2'—H02'···O2i | 0.832 (19) | 2.02 (2) | 2.837 (2) | 165 (3) |
C10—H10···O2'ii | 0.950 (18) | 2.66 (2) | 3.495 (3) | 147 (2) |
C8'—H8'···O1ii | 0.940 (17) | 2.529 (19) | 3.411 (3) | 156 (2) |
C10'—H10'···O2iii | 0.944 (18) | 2.46 (2) | 3.272 (3) | 144 (2) |
Symmetry codes: (i) x, y, z−1; (ii) −x+1, −y+1, −z; (iii) x, −y+3/2, z−1/2. |
O1—C1 | 1.4381 (15) | O1'—C1' | 1.4437 (15) |
C5—C6 | 1.182 (2) | C5'—C6' | 1.182 (2) |
C6—C5—C4 | 178.75 (14) | C6'—C5'—C4' | 176.68 (15) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H01···O1' | 0.871 (15) | 1.882 (15) | 2.7470 (14) | 172.2 (17) |
O1'—H01'···O3 | 0.867 (15) | 1.895 (15) | 2.7399 (15) | 164.4 (17) |
O3—H03···O1i | 0.884 (16) | 1.899 (16) | 2.7795 (15) | 174 (2) |
C6—H6···O1'ii | 0.939 (16) | 2.370 (17) | 3.2516 (19) | 156.3 (15) |
C6'—H6'···O1i | 0.932 (16) | 2.825 (18) | 3.4004 (19) | 121.0 (14) |
Symmetry codes: (i) x−1, y, z; (ii) x, y−1, z. |
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The title compounds, (II) and (IV), respectively, are related trans-cyclohexane-1,2-diols that we have used as synthetic intermediates. Compound (II) is a long-known (Ried & Schmidt, 1957) bis-propargylic diol that we used in our studies (Eshdat et al., 2002) of novel cross-conjugated enynes. Similarly, compound (IV) is a known (Cognacq et al., 1967) compound that we used in our studies of semicyclic olefins and allenes (Hopf et al., 2002). The structures of both compounds were confirmed by X-ray crystal structure determination and proved to display a variety of secondary contacts, not only the expected classical hydrogen bonds but also interactions involving the C≡C—H moieties.
Compound (II) crystallizes with two independent molecules in the asymmetric unit, which are closely similar (a least-squares fit of all non-H atoms gives an r.m.s. deviation of 0.044 Å). The hydroxy groups occupy equatorial and the propargyl groups the axial positions of the cyclohexyl rings (Fig. 1). Primes indicate atoms of the second molecule, which is inverted with respect to the first in the coordinates chosen for the asymmetric unit [to give a hydrogen bond (see below) between both independent molecules without transformation]. The one major difference lies in the configuration of the OH groups, whereby C1'—C2'—O2'—H02' is a trans-periplanar group [the O—H bond is parallel to the C1'—C2' ring bond, torsion angle -177 (2)°] and all other analogous groups are gauche; the corresponding torsion angles (all involving the ring bonds C1—C2 or C1'—C2') involving atoms H01, H01' and H02 are 72 (2), -77 (2) and 76 (2)°, respectively. The molecular dimensions may be regarded as normal. The rings display the usual chair form [absolute torsion angles 54.4 (2)–57.8 (2)°].
The molecular packing of (II) is puzzling at first sight. The molecules associate via two classical hydrogen bonds (Table 2) involving O2—H02 and O2'—H02' as donors, to form chains of graph set C22(7) (Etter, 1990) parallel to the short c axis (Fig. 2; neighbouring chains define layers parallel to the ac plane). However, O1—H01 and O1'—H01' do not take part in such interactions. Closer inspection shows that these OH groups form `weak' intermolecular hydrogen bonds (Desiraju & Steiner, 1999) to the alkyne triple bonds, with both interactions being within the asymmetric unit: O1—H01···midpoint(C9'≡C10'), H···acceptor 2.60 Å and angle 162°; O1'—H01'···midpoint(C9≡C10), H···acceptor 2.71 Å and angle 111°. The latter interaction is admittedly a borderline case in view of its narrow angle.
Acetylenic H atoms represent a fairly acidic form of CH group and can also act as hydrogen-bond donors (Desiraju & Steiner, 1999); as a concrete example, we have drawn attention to C≡C—H···Cl—Au interactions (Bardají et al., 2002). In the current structure, three of the four C≡C—H groups act in this way (Table 2) to connect the classical hydrogen-bonded layers in the third dimension parallel to the long b axis (Fig. 3).
All four O atoms are thus topologically different as regards their hydrogen-bonding behaviour, which may be summarized as follows (D = donor, A = acceptor, C = classical, W = `weak'): O1 WD,WA; O2 CD,CA,WA; O3 CA,WD; O4 CD,WA. One might speculate that the `extra' interaction for atom O2 is connected with its different C—C—O—H torsion angle (see above).
Compound (IV) also crystallizes with two symmetry-independent molecules, which, however, display inversion symmetry [molecule 1 about (1, 1/2, 1) and molecule 2 about (1/2, 1/2, 1/2)] (Fig. 4). A least-squares fit of the ring atoms of the asymmetric unit gives an r.m.s. deviation of 0.07 Å. As in (II), the OH groups of the two molecules are oriented differently; in molecule 2, the C2'—C1'—O1'—H01' torsion angle is 42 (1)° and the OH group is very approximately parallel to the propargyl group (see Fig. 4, bottom left), whereas in molecule 1 the corresponding angle is 171 (1)° and the corresponding groups point in widely disparate directions. The asymmetric unit also contains a molecule of water, which was presumably absorbed from the atmosphere during the slow crystallization of the oily product. In contrast with (II), the hydroxy groups are axial and the propynyl groups equatorial.
The contribution of classical hydrogen bonds to the packing of (IV) is shown in Fig. 5. Both independent OH groups and one water H atom, H03, act as hydrogen-bond donors (Table 4; for a discussion of atom H04, see below) and the overall effect is to form a layer structure parallel to the ac plane. The two independent rings thus formed are both of graph set R66(22).
The second water H atom, H04, appears at first sight to make no significant contacts at all. However, it projects away from the layer shown in Fig. 5 and makes contacts of 3.03 and 3.04 Å (angles at H04: 114 and 157°, respectively) to the midpoints of the triple bonds C5≡C6 and C5'≡C6' in the neighbouring layer at (x, 1 + y, z) (Fig. 6a). For a three-centre contact, these very long distances may still indicate a significant interaction.
The acetylenic H atom, H6, of (IV) makes a short (2.37 Å) `weak' hydrogen bond with atom O1' in the neighbouring layer at (x, -1 + y, z). The corresponding contact from atom H6' to atom O1 is, however, very long and bent (Table 4); again, the explanation may be sought in a three-centre interaction, the other branch of which is a C—H···π interaction to the midpoint of C5≡C6 (2.74 Å and 166°). The operator is (-1 + x, y, z) for both branches, so that the system forms part of the layer structure, but this is not easy to recognize in Fig. 5; it is depicted for clarity in Fig. 6(b).