Enantio­tropic phase transition and twinning in 2,2,3,3,4,4-hexa­fluoro­pentane-1,5-diol

Four crystal structure determinations of 2,2,3,3,4,4-hexa­fluoro­pentane-1,5-diol (HFPD), C₅H₆F₆O₂, were conducted on a single specimen by varying the temperature. Two polymorphs of HFPD were found to be enantio­tropically related as phases (I) and (II), both in the space group P1. These structures contain closely related R₄⁴(20) sheets. A structure determination was completed on form (Ia) at 283 K. Form (Ia) was then supercooled below the phase transition temperature at 279 to 173 K to give form (Ib) for a second structure determination. Metastable form (Ib) was transformed by momentary warming and recooling to give form (II) for a third structure determination at 173 K. Form (II) transformed to form (Ic) upon warming to 283 K. Enantio­tropic phase transitions between phases (I) and (II) were confirmed with X-ray powder diffraction and differential scanning calorimetry. Form (Ia) was found as a twin by nonmerohedry by a reflection in (011). This twinning persists in all phases described. Additional twinning was found after the phase (I) to phase (II) transformation. These two additional twin components are related to the first pair by a 180° rotation about the (012) plane. This latter pair of twins persisted as the specimen was warmed back to form (Ic) at 283 K.

S1. Comment

Enantiotropic phase transitions provide important information regarding the physical properties of the same material in different crystalline forms. These require two polymorphs that are each thermodynamically stable over a range of temperature and pressure, where variation of either will lead to a phase transition to the other polymorph (Herbstein, 2006). Single-crystal-to-single-crystal transitions of crystalline solids have been observed for solid-state phase transitions of enantiotropic polymorphs (Caira et al., 2004; Lim & Jeong, 2001; Asadov, 1967), pressure-dependent transitions between polymorphs (Fabbiani et al., 2005), solid-state geometric isomerizations (Agmon & Kaftory, 1994), topochemical reactions (Enkelmann & Wegner, 1993), solid-state polymerizations (Okada et al., 1994) and pseudo-polymorphic transitions of guest-inclusion compounds (Atwood et al., 2002; Ananchenko et al., 2006). There are reports of enantiotropic phase transitions accompanying a change of crystal system and space group while becoming twinned (Choe et al., 2000; Colombo et al., 2000; Guzei et al., 2009; Jadzewski et al., 2001; Reger et al., 2001; Schweitzer et al. 2000). In the majority of these reports, the higher-temperature phase is also the higher-symmetry minimal nonisomorphic supergroup of the pair, while the lower-temperature phase becomes twinned in a maximal nonisomorphic subgroup. The present study is quite different, because there is no change in symmetry as the phase (I) to phase (II) transition occurs, but rather a sliding of the two unique diol molecules within the unit cell to the other polymorphic form.

The material of interest in this study, 2,2,3,3,4,4-hexafluoropentane-1,5-diol, HFPD, has been used as a reagent to prepare fluorinated polymers and as a precursor to cyclic and acyclic polyfluorosiloxanes (Johncock & Hewins, 1975; Elias et al., 1994; Adhikari et al., 1999; Patel et al., 1994). The solid-state chemistry of fluorocarbons has been a subject of interest because of their unique properties in molecular solids (Reichenbächer et al., 2005). HFPD has also been crystallized within the channels of nanocrystals (Ha et al., 2005), where the initial report of the cell constants for both HFPD phases was presented.

Displacement ellipsoid drawings of all four structure determinations are shown in Fig. 1. All C—C, C—O and C—F distances of the two unique HFPD molecules appear to be in normal ranges for all four structure determinations presented here. However, the basic structural features of these two HFPD polymorphs are unique among reported diol structures (Allen, 2002). The space group for both is P1, with Z = 2 and Z' = 2. The molecules are arranged in intersecting C₁¹(2) and C₁¹(8) chains to form infinite R₄⁴(20) sheets (Bernstein et al. 1995; Etter, 1990; Etter et al., 1990; Grell et al., 1999). Both phases exhibit strong pseudo-symmetry as a pseudo c-glide reflection perpendicular to the a-axis and pseudo-twofold symmetry perpendicular to the layers.

Initial twinned-crystal diffraction studies (not presented here) suggested the phase transition temperature was below the 283 K used for forms (Ia) and (Ic), and above the 173 K used for form (Ib) and (II). This was later confirmed by other means (see below). The packing diagrams for forms (Ib) and (II) at 173 K are shown in Fig. 2. The crystal structures of both phases (I) and (II) of HFPD are composed of stacked infinite molecular sheets. These sheets, parallel to the (012) planes of each polymorph, have in-plane hydrogen bonding between primary hydroxyl groups. The hydrogen bonds, along with corrected H-atom positions based on normalized O—H distances, are presented in Table 1. The hydrogen-bonding network forms a rigid substructure that does not appear to change appreciably throughout the course of the study. Hydrogen bonds are reported with both distances and angles derived from riding O-bound H-atom positions (Sheldrick, 2008) and with normalized H-atom positions (Thalladi et al., 1998). The only minor differences are observed as slightly shorter D···A and H···A normalized distances for forms (Ib) and (II), both at 173 K. The phase transition does not impose any substantial change on the hydrogen-bonding scheme, even though the unit cell undergoes a radical change.

The torsion angle analyses for each HFPD backbone are presented in Table 2. These vary considerably from planar zigzag hydrocarbon chains, where the expected values are approximately 180° (Dunitz, 2004). There are two types in this list. The first type incorporates the O atom of a hydroxyl group, a –CH₂– group and the two adjacent –CF₂– groups. The other type has a –CH₂– group and three adjacent –CF₂– groups. The average O—C—C—C torsion angle is 176.9 (11)°, while the average C—C—C—C torsion angle is 169.1 (15)°. Each of the two unique molecules is twisted by a different angle, averaging 25.7 (5) and 30.6 (12)° for respective molecules over the four structures presented here. This implies each HFPD molecule is twisted considerably from the aforementioned zigzag hydrocarbon chains. This twisting imposes chirality on each HFPD molecule. Given the presence of the pseudo-glide reflection operation and the two unique HFPD molecules in the unit cell, each HFPD molecule is a pseudo-enantiomer of the other. While respective molecules have about a 5° difference in the twist of the diol fragments, the weighted r.m.s. deviations for superposition of the enantiomers for all non-H atoms are 0.0393 for (Ia), 0.0474 for (Ib), 0.0399 for (II) and 0.0387 Å for (Ic).

The hydroxyl functionalities for phases (I) and (II) are effectively enclosed within the substructure, preventing non-bonded contacts with any F atoms. Similarly, the F atoms only take part in non-bonded contacts with C—F F atoms and C—H H atoms. This is strikingly similar to the property of mutual phobicity between fluorocarbons and hydrocarbons as described by Dunitz (2004). These functional groups tend to segregate within crystal structures when no overriding structural feature imposes an unfavorable contact. It appears the same reasoning is applicable to HFPD, which has the three different functional groups of hydroxyl, hydrocarbon and fluorocarbon.

While non-bonded contacts between hydroxyl groups and both hydrocarbon and fluorocarbon groups are surprisingly absent due to the efficient packing, there is a mixture of both F···F and C—H···F close contacts that appears to govern the enantiotropic phase transition. Table 3 presents all significant F···F non-bonded contacts throughout this study. Pairs of C—F bonds involved in single F···F intermolecular contacts are tracked through all structure determinations if at least one is less than 3.10 Å. All of these F···F intermolecular contacts shrink by 1.2 (4)% upon cooling of form (Ia) at 283 K to form (Ib) at 173 K, which follows the contraction of the unit-cell volume. The average F···F intermolecular contacts increase from 3.1 (5) Å in form (Ib) to 3.3 (6) Å in form (II), due to a lack of one less than 3.10 Å in form (II). Two of the eight F···F intermolecular contacts in this group for both forms (Ib) and (II) are less than 2.90 Å, which is considered to be the limit for an F···F van der Waals contact (Rowland & Taylor, 1996; Bondi, 1964). Overall, the F···F intermolecular contacts are more favorable for form (II) at 173 K.

A similar situation is found for C—H···F close contacts in this study. Table 4 presents all significant C—H···F close contacts throughout the series. Form (Ia) at 283 K has three C—H···F close contacts less than 2.54 Å, one of which is less than 2.42 Å. C—H···F close contacts may be mildly stabilizing at distances greater than 2.54 Å (Rowland & Taylor, 1996), but rarely ever form (Dunitz & Taylor, 1997). In the few confirmed instances, the lower limit of a C—H···F close contact is approximately 2.36 Å when the hybridization of the C—H fragment is either sp² or sp³ (Thalladi et al., 1998; Howard et al., 1996). Upon cooling form (Ia) to the metastable form (Ib) at 173 K, these three close contacts decrease on average by 0.06 (2) Å. The shortest of the three C—H···F close contacts is within the van der Waals limit at 2.348 Å. These C—H···F close contacts provide addtional impetus for the enantiotropic phase transition to form (II). All C—H···F close contacts in form (II) are found in a narrower range of 2.535–2.628 Å, thereby avoiding any of the short C—H···F close contacts found in form (Ib). The result of the enantiotropic phase change is a slight increase in the density of form (II) of about 1.1% at this temperature.

The enantiotropic phase transition of HFPD was confirmed with differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). By DSC analyses, the room-temperature stable phase (I) of HFPD transformed to the low-temperature stable phase (II) by cooling to 253 K, as exhibited in Fig. 3. Phase (II) reversibly transformed to phase (I) at 275–283 K by heating. Phase (I) melted to a liquid phase at 354 K. The enthalpy change of the phase transition of phase (II) to phase (I) was 0.44 (1) kJ mol^-1, while the enthalpy change on melting phase (I) to a liquid phase was 29.7 (3) kJ mol^-1. The observed enthalpy change for the solid-state phase transition is relatively small compared with other organic crystal structures (Yu et al., 2000; Cingolani & Berchiesi, 1974; Petropavlov et al., 1988; Steele et al., 2002). Typical values of enthalpy changes for similar phase transitions fall in the range 1–10 kJ mol^-1, which is larger than the observed enthalpy change from phase (II) to (I) of HFPD. The small value of the enthalpy change can be attributed to the modest change in the crystal structure during the solid-state transition. Temperature-dependent XRD confirmed the phase transition between phases (I) and (II) that was observed in the single-crystal of HFPD, as depicted in Fig. 4. Although the reflections of the (012) and (101) planes of phases (I) and (II) are nearly indistinguishable by 2θ positions alone, disappearance of the 010, 002 and 101 reflections of phase (I) and appearance of the corresponding reflections of phase (II) were clearly observed at 263–253 K during cooling from room temperature to 243 K. The reflections of phase (I) were obtained again when the crystalline powder was heated to room temperature.

It is of interest to compare these polymorphic HFPD diol structures with studies of the packing motifs of all diol structures (Taylor & Macrae, 2001). Both primary mono-alcohols and primary–primary diols are much more likely to form chain structures rather than ring structures. Chains are also favored for any diol with one primary alcohol. When considering all diols, including secondary and tertiary, the frequencies of chain and ring structures are very similar. The HFPD polymorphs break this trend because these form two-dimensional sheets, despite being primary–primary diols. One point in common with primary–primary diol ring structures is that virtually all ring structures have four hydrogen bonds. A study of vicinal diols restates the observation that Z' > 1 structures are relatively common if each O atom is involved in more than one hydrogen bond (Brock, 2002).

The single specimen examined as part of this study, and a number of other unreported investigations of HFPD by the authors, were always twinned by nonmerohedry. These specimens were crystallized at temperatures higher than the phase transition, whether these were prepared by recrystallization from methanol, as was done in this study, or by sublimation. Diagrams of the twinning domains are presented in Fig. 5 for phase (I) and Fig. 6 for phase (II). Each twin domain depicted in these two diagrams is drawn with the (012) plane in the page and with the [100] axis parallel to the horizontal axis. The O atoms of each of the unique HFPD molecules are indicated, while the unit-cell axes are shown on the right.

The two twin components of form (Ia) refined to a 0.724 (5):0.276 (5) ratio, with the second twin component corresponding to a 180° rotation about the [100] axis, as shown in Fig. 5(a) and (b). However, the assignment of the twin law does not take into account the possibility of racemic twinning in addition to this twin domain found by nonmerohedry. A twin law with only a 180° rotation about the [100] axis does not bring the composition plane into registry with the reference twin domain unless the enantiomorph is used. Therefore, the permutation of the twofold rotation in [100] and the inversion necessary to provide the enantiomorph is effectively a reflection in the (011) plane. Diffraction data acquired with molybdenum radiation prevents the determination of absolute configuration when F is the heaviest atom. However, this twin law provides for a seamless composition plane, or interface, between the respective twin domains. Form (Ib) can be isolated by carefully cooling the specimen to 173 K, which will preserve the same two twin domains as in form (Ia), but these refined to a 0.597 (5):0.403 (5) ratio. It appears that there is some conversion of the reference individual to the minor individual as the temperature is reduced. A momentary warming by blocking the cryostat flow and recooling causes the phase transition from form (Ib) to form (II). Form (II) contains the same two twin domains as form (Ib), as shown in Fig. 6(a) and (b), but two additional twin components are discovered, concomitant with the enantiotropic phase transition, as shown in Fig. 6(c) and (d). The ratio of twin components for form (II) is 0.339 (6):0.408 (6):0.141 (5):0.112 (4). It is presumed that the appearance of the third and fourth twin components is due to deformation in conjunction with the (Ib) to (II) phase transition. The relationship between twin component pairs 1 and 3 and 2 and 4 is a 180° rotation about the perpendicular to the (012) plane, thereby exploiting the twofold pseudosymmetry within the layer structure. The relationship between twin component pair 3 and 4 is the same as that between pair 1 and 2, described above. Finally, when form (II) is warmed back to 283 K, all four twin domains present are retained in form (Ic) after the phase (II) to phase (I) transition occurs. The ratio of twin components for (Ic) is 0.333 (6):0.434 (6):0.110 (5):0.122 (4). These two additional twin domains present in (Ic) are shown in Fig. 5(c) and 5(d).

The phase transition between phases (I) and (II) is accomplished by a sliding of the (012) layers in the [013] direction, as shown in Fig. 7. The contraction of the unit cell in form (Ia) on cooling to form (Ib), coupled with several unfavorable close contacts in form (Ib), as discussed above, precipitates the phase transition to form (II), whereby all layers slide by approximately 1.83 (5) Å.

S2. Experimental

HFPD (98% pure) was purchased from Aldrich (Milwaukee, Wisconsin, USA) and used without further purification. Twinned crystals of HFPD were grown by slow evaporation of a methanol solution under ambient conditions. A specimen was glued with epoxy cement to the tip of a 0.15 mm glass fiber and mounted on a Bruker SMART 1000 CCD Platform diffractometer equipped with an Oxford Cryosystems Cryostream 600 cryostat. Form (Ia) was placed on the diffractometer at 283 K and the data collected. Form (Ib) was obtained by supercooling the metastable phase (I) at 1 K min^-1 to 173 K. This crystalline phase persisted throughout the data collection at 173 K. In order to obtain phase (II) at 173 K, the flow of the cryostat was blocked to allow the specimen to warm to room temperature for about 1 s, then the blockage was removed, which allowed the specimen to return to 173 K. Initial indexing revealed that the phase change to phase (II) had taken place. Data collection on phase (II) was completed. After this the cryostat was warmed at 1 K min^-1 to 283 K. The specimen returned to phase (I) and a final data collection on form (Ic) was completed.

DSC measurements were obtained from a fine-powdered sample of HFPD using a TA Instruments Q1000 DSC with a 5 K min^-1 temperature ramp. Temperature-dependent XRD data were collected from a fine-powdered sample of HFPD on a Bruker GADDS microdiffractometer with Cu Kα radiation, coupled to a locally built cryostat with an Omega temperature controller.

S3. Refinement

Aliphatic H atoms were treated as riding on the host C atoms, with C—H = 0.96 Å and U_iso(H) = 1.2U_eq(C) for forms (Ia) and (Ic), and with C—H = 0.98 Å and U_iso(H) = 1.2U_eq(C) for forms (Ib) and (II). Hydroxyl H atoms were initially located in the difference Fourier maps and thereafter treated as idealized, torsionally refined on the host O atoms with O—H = 0.82 Å and U_iso(H) = 1.5U_eq(O) for forms (Ia) and (Ic), and with O—H = 0.84 Å and U_iso(H) = 1.5U_eq(O) for forms (Ib) and (II).

Computing details

For all compounds, data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 2007); data reduction: SHELXL97 (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXL97 (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. Views of the two independent molecules of each of the four forms of HFPD, with the atom-numbering schemes. (a) (Ia) at 283 K. (b) (Ib) at 173 K. (c) (II) at 173 K. (d) (Ic) at 283 K. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Both unique molecules are shown in the same relative orientation for phases (I) and (II), as viewed along the [100] axis.
	Fig. 2. Packing diagrams for (a) (Ib) and (b) (II), both at 173 K, viewed with respect to the (012) plane and with the [100] axis parallel to the horizontal axis. The hydrogen-bonding network (dashed lines) is preserved through the phase transition.
	Fig. 3. Differential scanning calorimetry analysis of HFPD in phase (I). The cooling cycle shows a more sluggish phase transition than the warming cycle.
	Fig. 4. Temperature-dependent X-ray powder diffraction study of the phase (I) to phase (II) transition. Phase (I) persists from 283 to 263 K, then completely transforms to phase (II). Warming to 298 K restores HFPD to phase (I). Major calculated reflection positions for phase (I) (top) and phase (II) (bottom) are shown.
	Fig. 5. Phase (I) twin domains. (a) Reference individual. (b) 180° rotation about the [100] axis plus inversion to enantiomorph or a reflection in the (011) plane. (c) 180° rotation about the (012) plane. (d) Reflection in the (011) plane followed by a 180° rotation about the (012) plane. [Symmetry codes: (i) x, y + 1, z; (ii) 1 - x, -y - 1, -z; (iii) x - 1, y - 1, z + 1; (iv) -x, 1 - y, -z - 1; (v) -x, -y, -z.]
	Fig. 6. Phase (II) twin domains. (a) Reference individual. (b) 180° rotation about the [100] axis plus inversion to enantiomorph or a reflection in the (011) plane. (c) 180° rotation about the (012) plane. (d) Reflection in the (011) plane followed by a 180° rotation about the (012) plane. [Symmetry codes: (i) x, y + 1, z; (ii) 1 - x, -y - 1, -z; (iii) x - 1, y - 1, z + 1; (iv) -x, 1 - y, -z - 1; (v) -x, -y, -z.]
	Fig. 7. The superposition of (012) layers of (Ib) and (II), presented to illustrate the sliding of the layers during the enantiotropic phase transition of HFPD. Basal layers (not shown here) were overlayed to yield an r.m.s. deviation of 0.16 Å for respective pairs of O atoms. A composite image is shown, containing (012) layers for (Ib) and (II) above the basal layer, with the [100] axis horizontal and the [013] axis vertical. Molecules of form (Ib) are drawn with dashed bonds and molecules of form (II) are drawn with solid bonds. Each layer slides 1.83 (5) Å along the [013] axis in the (012) plane, based on the translation of respective pairs of O atoms in forms (Ib) and (II).

(Ia) 2,2,3,3,4,4-hexafluoropentane-1,5-diol

Crystal data

C5H6F6O2	Z = 2
Mr = 212.10	F(000) = 212
Triclinic, P1	Dx = 1.852 Mg m^−3
Hall symbol: P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.9343 (10) Å	Cell parameters from 2985 reflections
b = 6.8918 (14) Å	θ = 3.1–27.3°
c = 11.342 (2) Å	µ = 0.23 mm^−1
α = 81.943 (3)°	T = 283 K
β = 85.847 (3)°	Block, colourless
γ = 86.529 (3)°	0.35 × 0.20 × 0.17 mm
V = 380.41 (13) Å^3

Data collection

Bruker SMART 1000 CCD Platform diffractometer	1721 independent reflections
Radiation source: normal-focus sealed tube	1419 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
ω and ϕ scans	θmax = 27.5°, θmin = 1.8°
Absorption correction: multi-scan (TWINABS, Version 2008/1; Sheldrick, 2008)	h = −6→6
Tmin = 0.924, Tmax = 0.962	k = −8→8
4125 measured reflections	l = 0→14

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.085	w = 1/[σ^2(Fo^2) + (0.0415P)^2 + 0.0467P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max < 0.001
1721 reflections	Δρmax = 0.18 e Å^−3
240 parameters	Δρmin = −0.17 e Å^−3
3 restraints	Absolute structure: Flack (1983), with Friedel pairs merged
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.2 (9)

Special details

Experimental. Cell Refinement: Component Input RLV.Excl Used WorstRes BestRes Min.2 T h Max.2 T h 1.1 (1) 1735 0 1735 6.8149 0.7751 5.978 54.578 1.2 (2) 1250 0 1250 6.2110 0.7751 6.560 54.578 A l l 2985 0 2985 6.8149 0.7751 5.978 54.578

Orientation ('UB') matrix (Component 1.1 (1)): 0.0162457 0.1294415 0.0284999 0.0405288 - 0.0689863 0.0808592 0.1987223 - 0.0041799 - 0.0247312

Orientation ('UB') matrix (Component 1.2 (2)): 0.0474380 - 0.1294389 - 0.0285336 0.0559408 0.0690027 - 0.0808352 0.1897823 0.0039865 0.0247708

Rotated from first domain by 179.8 degrees about reciprocal axis 1.000 0.083 0.167 and real axis 1.000 - 0.003 - 0.001

Twin Law (SAINT V7.34 A, final) Transforms h1.1(1)->h1.2(2) 1.00009 - 0.00091 0.00018 0.16753 - 1.00005 0.00028 0.33368 - 0.00111 - 0.99974

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
F1	0.3765 (5)	0.3523 (3)	0.90099 (18)	0.0563 (6)
F2	−0.0362 (5)	0.4571 (3)	0.86504 (19)	0.0584 (6)
F3	0.5165 (4)	0.3433 (3)	0.67348 (18)	0.0526 (5)
F4	0.0988 (4)	0.3953 (3)	0.62393 (17)	0.0519 (5)
F5	0.4549 (5)	0.7076 (3)	0.76595 (17)	0.0522 (5)
F6	0.0646 (4)	0.7516 (3)	0.68813 (19)	0.0512 (5)
O1	0.0272 (5)	0.0550 (4)	0.9524 (2)	0.0562 (7)
H1A	0.1665	0.0221	0.9870	0.084*
O2	0.4688 (5)	0.9323 (3)	0.5413 (3)	0.0549 (7)
H2A	0.3260	0.9856	0.5175	0.082*
C1	0.0965 (8)	0.1346 (5)	0.8331 (3)	0.0462 (8)
H1C	−0.0575	0.1306	0.7851	0.055*
H1B	0.2469	0.0567	0.8008	0.055*
C2	0.1757 (7)	0.3437 (4)	0.8276 (3)	0.0351 (7)
C3	0.2749 (6)	0.4355 (4)	0.7014 (3)	0.0340 (6)
C4	0.3128 (7)	0.6583 (4)	0.6782 (3)	0.0360 (7)
C5	0.4488 (8)	0.7260 (5)	0.5572 (3)	0.0462 (8)
H5A	0.6291	0.6626	0.5505	0.055*
H5B	0.3440	0.6893	0.4954	0.055*
F7	0.5778 (5)	0.3478 (3)	0.39487 (19)	0.0582 (6)
F8	0.9767 (5)	0.4681 (3)	0.37434 (19)	0.0611 (6)
F9	0.5653 (5)	0.3397 (3)	0.1640 (2)	0.0574 (6)
F10	0.9901 (4)	0.4079 (3)	0.13014 (18)	0.0544 (6)
F11	0.4958 (5)	0.7054 (3)	0.26218 (18)	0.0592 (6)
F12	0.9052 (5)	0.7597 (3)	0.1881 (2)	0.0588 (6)
O3	0.9736 (5)	0.0629 (4)	0.4573 (2)	0.0557 (7)
H3A	0.8233	0.0396	0.4902	0.084*
O4	0.5230 (5)	0.9298 (3)	0.0374 (2)	0.0515 (6)
H4A	0.6651	0.9849	0.0172	0.077*
C6	0.9447 (8)	0.1424 (5)	0.3375 (3)	0.0500 (9)
H6A	0.8318	0.0603	0.3010	0.060*
H6B	1.1219	0.1444	0.2945	0.060*
C7	0.8167 (7)	0.3490 (5)	0.3285 (3)	0.0374 (7)
C8	0.7630 (6)	0.4399 (4)	0.2002 (3)	0.0357 (7)
C9	0.6836 (7)	0.6604 (4)	0.1766 (3)	0.0364 (7)
C10	0.5773 (8)	0.7240 (5)	0.0538 (3)	0.0446 (8)
H10B	0.7115	0.6881	−0.0073	0.053*
H10A	0.4122	0.6581	0.0469	0.053*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0692 (14)	0.0586 (13)	0.0408 (11)	−0.0200 (10)	−0.0213 (10)	0.0108 (9)
F2	0.0677 (14)	0.0506 (12)	0.0477 (12)	0.0152 (10)	0.0187 (11)	0.0059 (9)
F3	0.0527 (12)	0.0384 (11)	0.0598 (13)	0.0091 (9)	0.0147 (10)	0.0027 (9)
F4	0.0701 (14)	0.0490 (12)	0.0385 (11)	−0.0176 (10)	−0.0159 (10)	0.0000 (9)
F5	0.0735 (15)	0.0394 (11)	0.0453 (11)	−0.0121 (10)	−0.0187 (10)	0.0004 (8)
F6	0.0446 (11)	0.0391 (10)	0.0632 (13)	0.0102 (9)	0.0036 (9)	0.0071 (9)
O1	0.0499 (15)	0.0498 (15)	0.0603 (17)	−0.0061 (12)	−0.0028 (12)	0.0242 (12)
O2	0.0514 (15)	0.0392 (13)	0.0668 (17)	−0.0063 (11)	−0.0057 (13)	0.0202 (12)
C1	0.054 (2)	0.0359 (18)	0.0461 (19)	−0.0071 (15)	−0.0054 (16)	0.0077 (14)
C2	0.0404 (16)	0.0312 (15)	0.0318 (15)	−0.0002 (12)	−0.0018 (13)	0.0010 (12)
C3	0.0381 (16)	0.0317 (16)	0.0313 (15)	0.0004 (12)	−0.0028 (12)	−0.0013 (12)
C4	0.0389 (16)	0.0289 (16)	0.0386 (16)	−0.0003 (13)	−0.0054 (13)	0.0014 (13)
C5	0.049 (2)	0.0396 (18)	0.0452 (19)	−0.0052 (15)	0.0008 (15)	0.0105 (14)
F7	0.0599 (13)	0.0578 (13)	0.0476 (11)	0.0072 (10)	0.0146 (10)	0.0121 (9)
F8	0.0879 (16)	0.0501 (12)	0.0477 (12)	−0.0182 (11)	−0.0308 (11)	0.0048 (9)
F9	0.0689 (15)	0.0390 (11)	0.0672 (14)	−0.0118 (10)	−0.0328 (12)	0.0015 (10)
F10	0.0584 (13)	0.0554 (13)	0.0428 (11)	0.0154 (10)	0.0070 (9)	0.0033 (9)
F11	0.0799 (16)	0.0458 (12)	0.0445 (11)	0.0172 (11)	0.0110 (11)	0.0038 (9)
F12	0.0654 (14)	0.0392 (11)	0.0728 (15)	−0.0166 (10)	−0.0277 (12)	0.0068 (10)
O3	0.0521 (15)	0.0493 (16)	0.0578 (16)	−0.0015 (12)	−0.0087 (12)	0.0225 (12)
O4	0.0486 (14)	0.0383 (13)	0.0605 (16)	0.0024 (11)	−0.0047 (12)	0.0169 (11)
C6	0.053 (2)	0.0425 (19)	0.050 (2)	0.0009 (16)	−0.0096 (16)	0.0101 (15)
C7	0.0428 (17)	0.0367 (17)	0.0310 (15)	−0.0052 (13)	−0.0035 (13)	0.0033 (13)
C8	0.0400 (16)	0.0339 (16)	0.0327 (15)	−0.0051 (13)	−0.0045 (13)	0.0001 (12)
C9	0.0408 (16)	0.0323 (16)	0.0349 (15)	−0.0016 (13)	−0.0033 (13)	0.0003 (12)
C10	0.052 (2)	0.0387 (18)	0.0391 (17)	−0.0019 (15)	−0.0089 (15)	0.0097 (14)

Geometric parameters (Å, º)

F1—C2	1.348 (4)	F7—C7	1.352 (4)
F2—C2	1.347 (4)	F8—C7	1.351 (4)
F3—C3	1.355 (4)	F9—C8	1.348 (4)
F4—C3	1.346 (4)	F10—C8	1.352 (4)
F5—C4	1.351 (4)	F11—C9	1.348 (4)
F6—C4	1.353 (4)	F12—C9	1.348 (4)
O1—C1	1.413 (4)	O3—C6	1.406 (4)
O1—H1A	0.8200	O3—H3A	0.8200
O2—C5	1.417 (4)	O4—C10	1.416 (4)
O2—H2A	0.8200	O4—H4A	0.8200
C1—C2	1.508 (5)	C6—C7	1.515 (5)
C1—H1C	0.9700	C6—H6A	0.9700
C1—H1B	0.9700	C6—H6B	0.9700
C2—C3	1.540 (4)	C7—C8	1.536 (4)
C3—C4	1.541 (4)	C8—C9	1.538 (4)
C4—C5	1.508 (5)	C9—C10	1.521 (4)
C5—H5A	0.9700	C10—H10B	0.9700
C5—H5B	0.9700	C10—H10A	0.9700
C1—O1—H1A	109.5	C6—O3—H3A	109.5
C5—O2—H2A	109.5	C10—O4—H4A	109.5
O1—C1—C2	110.1 (3)	O3—C6—C7	110.9 (3)
O1—C1—H1C	109.6	O3—C6—H6A	109.5
C2—C1—H1C	109.6	C7—C6—H6A	109.5
O1—C1—H1B	109.6	O3—C6—H6B	109.5
C2—C1—H1B	109.6	C7—C6—H6B	109.5
H1C—C1—H1B	108.2	H6A—C6—H6B	108.0
F2—C2—F1	107.0 (3)	F8—C7—F7	106.5 (3)
F2—C2—C1	110.6 (3)	F8—C7—C6	110.5 (3)
F1—C2—C1	110.0 (2)	F7—C7—C6	109.4 (3)
F2—C2—C3	107.9 (2)	F8—C7—C8	108.2 (2)
F1—C2—C3	108.0 (3)	F7—C7—C8	108.4 (3)
C1—C2—C3	113.2 (2)	C6—C7—C8	113.6 (2)
F4—C3—F3	107.0 (2)	F9—C8—F10	107.1 (2)
F4—C3—C2	108.4 (3)	F9—C8—C7	107.2 (2)
F3—C3—C2	107.5 (2)	F10—C8—C7	107.9 (2)
F4—C3—C4	107.2 (2)	F9—C8—C9	108.6 (3)
F3—C3—C4	107.8 (2)	F10—C8—C9	107.2 (2)
C2—C3—C4	118.5 (2)	C7—C8—C9	118.3 (2)
F5—C4—F6	106.3 (2)	F11—C9—F12	106.9 (3)
F5—C4—C5	110.8 (3)	F11—C9—C10	110.2 (3)
F6—C4—C5	109.3 (3)	F12—C9—C10	109.6 (3)
F5—C4—C3	108.5 (2)	F11—C9—C8	108.8 (2)
F6—C4—C3	108.1 (2)	F12—C9—C8	107.9 (2)
C5—C4—C3	113.5 (3)	C10—C9—C8	113.2 (3)
O2—C5—C4	110.1 (3)	O4—C10—C9	109.4 (3)
O2—C5—H5A	109.6	O4—C10—H10B	109.8
C4—C5—H5A	109.6	C9—C10—H10B	109.8
O2—C5—H5B	109.6	O4—C10—H10A	109.8
C4—C5—H5B	109.6	C9—C10—H10A	109.8
H5A—C5—H5B	108.2	H10B—C10—H10A	108.2
O1—C1—C2—F2	−63.2 (3)	O3—C6—C7—F8	61.7 (4)
O1—C1—C2—F1	54.8 (4)	O3—C6—C7—F7	−55.2 (4)
O1—C1—C2—C3	175.6 (3)	O3—C6—C7—C8	−176.4 (3)
F2—C2—C3—F4	−75.9 (3)	F8—C7—C8—F9	−168.9 (3)
F1—C2—C3—F4	168.8 (3)	F7—C7—C8—F9	−53.8 (3)
C1—C2—C3—F4	46.7 (3)	C6—C7—C8—F9	68.0 (3)
F2—C2—C3—F3	168.7 (3)	F8—C7—C8—F10	76.0 (3)
F1—C2—C3—F3	53.4 (3)	F7—C7—C8—F10	−168.9 (3)
C1—C2—C3—F3	−68.6 (3)	C6—C7—C8—F10	−47.1 (3)
F2—C2—C3—C4	46.4 (4)	F8—C7—C8—C9	−45.8 (4)
F1—C2—C3—C4	−68.9 (3)	F7—C7—C8—C9	69.3 (3)
C1—C2—C3—C4	169.1 (3)	C6—C7—C8—C9	−168.9 (3)
F4—C3—C4—F5	170.8 (3)	F9—C8—C9—F11	77.7 (3)
F3—C3—C4—F5	−74.3 (3)	F10—C8—C9—F11	−166.9 (3)
C2—C3—C4—F5	47.8 (4)	C7—C8—C9—F11	−44.7 (4)
F4—C3—C4—F6	55.9 (3)	F9—C8—C9—F12	−166.7 (3)
F3—C3—C4—F6	170.8 (3)	F10—C8—C9—F12	−51.3 (3)
C2—C3—C4—F6	−67.0 (3)	C7—C8—C9—F12	70.9 (3)
F4—C3—C4—C5	−65.5 (3)	F9—C8—C9—C10	−45.2 (4)
F3—C3—C4—C5	49.3 (3)	F10—C8—C9—C10	70.2 (3)
C2—C3—C4—C5	171.5 (3)	C7—C8—C9—C10	−167.6 (3)
F5—C4—C5—O2	−59.3 (3)	F11—C9—C10—O4	61.0 (4)
F6—C4—C5—O2	57.5 (4)	F12—C9—C10—O4	−56.4 (4)
C3—C4—C5—O2	178.3 (3)	C8—C9—C10—O4	−176.9 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O4^i	0.82	1.93	2.740 (3)	168
O2—H2A···O3^ii	0.82	1.93	2.742 (4)	169
O3—H3A···O2^iii	0.82	1.96	2.758 (4)	165
O4—H4A···O1^iv	0.82	1.94	2.746 (4)	166

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

(Ib) 2,2,3,3,4,4-hexafluoropentane-1,5-diol

Crystal data

C5H6F6O2	Z = 2
Mr = 212.10	F(000) = 212
Triclinic, P1	Dx = 1.893 Mg m^−3
Hall symbol: P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.8848 (12) Å	Cell parameters from 2983 reflections
b = 6.8723 (16) Å	θ = 3.0–27.3°
c = 11.259 (3) Å	µ = 0.23 mm^−1
α = 82.261 (3)°	T = 173 K
β = 84.711 (3)°	Block, colourless
γ = 85.640 (3)°	0.35 × 0.20 × 0.17 mm
V = 372.16 (15) Å^3

Data collection

Bruker SMART 1000 CCD Platform diffractometer	1686 independent reflections
Radiation source: normal-focus sealed tube	1480 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.033
ω and ϕ scans	θmax = 27.5°, θmin = 1.8°
Absorption correction: multi-scan (TWINABS, Version 2008/1; Sheldrick, 2008)	h = −6→6
Tmin = 0.923, Tmax = 0.961	k = −8→8
3947 measured reflections	l = 0→14

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.041	H-atom parameters constrained
wR(F^2) = 0.122	w = 1/[σ^2(Fo^2) + (0.0854P)^2 + 0.0298P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
1686 reflections	Δρmax = 0.40 e Å^−3
240 parameters	Δρmin = −0.29 e Å^−3
3 restraints	Absolute structure: Flack (1983), with Friedel pairs merged
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.3 (10)

Special details

Experimental. Component Input RLV.Excl Used WorstRes BestRes Min.2 T h Max.2 T h 1.1 (1) 1605 0 1605 6.7955 0.7737 5.995 54.686 1.2 (2) 1378 0 1378 6.7955 0.7766 5.995 54.465 A l l 2983 0 2983 6.7955 0.7737 5.995 54.686

Orientation ('UB') matrix (Component 1.1 (1)): 0.0133849 0.1289912 0.0302185 0.0377542 - 0.0706471 0.0810191 0.2020896 - 0.0050161 - 0.0247419

Orientation ('UB') matrix (Component 1.2 (2)): 0.0537601 - 0.1289860 - 0.0302345 0.0571219 0.0706611 - 0.0810090 0.1905037 0.0049533 0.0247554

Twin Law (Cell_Now): Rotated from first domain by 179.9 degrees about reciprocal axis 1.000 0.099 0.215 and real axis 1.000 - 0.004 0.001

Twin Law (SAINT V7.34 A, final) Transforms h1.1(1)->h1.2(2) 1.00006 - 0.00028 0.00005 0.21342 - 1.00016 0.00006 0.42525 - 0.00073 - 0.99977

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
F1	0.3711 (6)	0.3503 (4)	0.9025 (2)	0.0301 (6)
F2	−0.0469 (6)	0.4571 (4)	0.8647 (2)	0.0317 (6)
F3	0.5296 (5)	0.3425 (3)	0.6734 (2)	0.0286 (6)
F4	0.1100 (6)	0.3939 (3)	0.6206 (2)	0.0290 (6)
F5	0.4496 (6)	0.7080 (3)	0.7693 (2)	0.0294 (6)
F6	0.0585 (5)	0.7516 (3)	0.6880 (2)	0.0278 (5)
O1	0.0202 (6)	0.0523 (5)	0.9502 (3)	0.0313 (7)
H1A	0.1620	0.0160	0.9864	0.047*
O2	0.4757 (7)	0.9336 (4)	0.5440 (3)	0.0317 (7)
H2A	0.3269	0.9882	0.5207	0.048*
C1	0.0978 (9)	0.1320 (6)	0.8312 (4)	0.0255 (9)
H1C	−0.0564	0.1276	0.7806	0.031*
H1B	0.2574	0.0522	0.7986	0.031*
C2	0.1729 (8)	0.3420 (6)	0.8264 (3)	0.0195 (8)
C3	0.2815 (8)	0.4349 (5)	0.6998 (3)	0.0198 (8)
C4	0.3145 (9)	0.6584 (5)	0.6790 (3)	0.0210 (8)
C5	0.4612 (9)	0.7262 (6)	0.5574 (4)	0.0256 (9)
H5A	0.6494	0.6617	0.5515	0.031*
H5B	0.3598	0.6891	0.4926	0.031*
F7	0.5710 (6)	0.3459 (4)	0.3951 (2)	0.0324 (6)
F8	0.9717 (6)	0.4723 (4)	0.3751 (2)	0.0339 (6)
F9	0.5703 (5)	0.3388 (3)	0.1626 (2)	0.0312 (6)
F10	1.0003 (5)	0.4075 (4)	0.1284 (2)	0.0299 (6)
F11	0.4882 (6)	0.7061 (4)	0.2649 (2)	0.0352 (7)
F12	0.9030 (6)	0.7614 (4)	0.1871 (2)	0.0329 (6)
O3	0.9808 (7)	0.0655 (5)	0.4580 (3)	0.0324 (7)
H3A	0.8349	0.0132	0.4865	0.049*
O4	0.5126 (6)	0.9315 (4)	0.0388 (3)	0.0278 (7)
H4A	0.6568	0.9883	0.0133	0.042*
C6	0.9560 (10)	0.1436 (6)	0.3373 (4)	0.0271 (9)
H6A	0.8453	0.0580	0.2993	0.033*
H6B	1.1410	0.1468	0.2934	0.033*
C7	0.8193 (9)	0.3494 (6)	0.3286 (3)	0.0219 (8)
C8	0.7674 (8)	0.4399 (5)	0.1990 (3)	0.0206 (8)
C9	0.6794 (9)	0.6611 (5)	0.1765 (3)	0.0211 (8)
C10	0.5725 (9)	0.7241 (6)	0.0538 (3)	0.0232 (8)
H10B	0.7128	0.6877	−0.0101	0.028*
H10A	0.4038	0.6562	0.0473	0.028*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0343 (15)	0.0326 (13)	0.0233 (12)	−0.0104 (11)	−0.0121 (10)	0.0073 (10)
F2	0.0336 (14)	0.0283 (13)	0.0274 (13)	0.0073 (11)	0.0089 (11)	0.0048 (10)
F3	0.0267 (13)	0.0230 (12)	0.0317 (13)	0.0060 (10)	0.0075 (10)	0.0014 (10)
F4	0.0394 (15)	0.0294 (13)	0.0201 (12)	−0.0114 (11)	−0.0097 (11)	−0.0003 (10)
F5	0.0404 (16)	0.0222 (12)	0.0272 (12)	−0.0053 (10)	−0.0125 (11)	−0.0006 (9)
F6	0.0233 (12)	0.0243 (12)	0.0325 (13)	0.0045 (10)	−0.0005 (10)	0.0034 (10)
O1	0.0248 (17)	0.0320 (17)	0.0327 (18)	−0.0053 (13)	−0.0034 (13)	0.0148 (13)
O2	0.0274 (17)	0.0222 (15)	0.0418 (18)	−0.0015 (12)	−0.0046 (14)	0.0103 (13)
C1	0.030 (2)	0.0212 (19)	0.024 (2)	−0.0084 (16)	−0.0036 (17)	0.0051 (16)
C2	0.0162 (18)	0.0231 (19)	0.0183 (16)	0.0010 (14)	−0.0033 (14)	0.0008 (14)
C3	0.0185 (19)	0.0219 (19)	0.0188 (17)	−0.0013 (14)	−0.0024 (15)	−0.0013 (14)
C4	0.024 (2)	0.0166 (18)	0.0222 (18)	0.0003 (15)	−0.0044 (15)	−0.0004 (14)
C5	0.025 (2)	0.0218 (19)	0.027 (2)	−0.0026 (16)	0.0006 (17)	0.0071 (16)
F7	0.0298 (15)	0.0341 (14)	0.0264 (12)	0.0059 (11)	0.0077 (10)	0.0102 (10)
F8	0.0476 (17)	0.0296 (13)	0.0266 (13)	−0.0086 (12)	−0.0181 (12)	0.0025 (10)
F9	0.0380 (16)	0.0224 (12)	0.0358 (14)	−0.0077 (11)	−0.0180 (12)	0.0001 (10)
F10	0.0294 (14)	0.0320 (13)	0.0243 (12)	0.0063 (11)	0.0031 (10)	0.0021 (10)
F11	0.0462 (18)	0.0293 (13)	0.0245 (12)	0.0120 (12)	0.0063 (12)	0.0029 (10)
F12	0.0346 (15)	0.0246 (12)	0.0413 (15)	−0.0108 (11)	−0.0168 (12)	0.0041 (11)
O3	0.0283 (18)	0.0314 (18)	0.0335 (17)	−0.0029 (13)	−0.0061 (14)	0.0129 (13)
O4	0.0230 (16)	0.0228 (14)	0.0343 (16)	−0.0012 (11)	−0.0064 (13)	0.0114 (12)
C6	0.030 (2)	0.0194 (19)	0.030 (2)	0.0013 (16)	−0.0062 (17)	0.0046 (16)
C7	0.022 (2)	0.0226 (19)	0.0197 (17)	−0.0039 (15)	−0.0030 (15)	0.0032 (14)
C8	0.0169 (18)	0.0233 (19)	0.0210 (18)	−0.0005 (14)	−0.0039 (15)	0.0004 (14)
C9	0.0213 (19)	0.0210 (18)	0.0210 (17)	−0.0026 (15)	−0.0064 (15)	0.0011 (14)
C10	0.029 (2)	0.0209 (19)	0.0183 (17)	−0.0008 (16)	−0.0064 (16)	0.0055 (15)

Geometric parameters (Å, º)

F1—C2	1.360 (5)	F7—C7	1.365 (5)
F2—C2	1.357 (5)	F8—C7	1.352 (5)
F3—C3	1.352 (5)	F9—C8	1.352 (5)
F4—C3	1.347 (4)	F10—C8	1.349 (5)
F5—C4	1.355 (5)	F11—C9	1.352 (5)
F6—C4	1.362 (5)	F12—C9	1.358 (5)
O1—C1	1.408 (5)	O3—C6	1.405 (5)
O1—H1A	0.8400	O3—H3A	0.8400
O2—C5	1.419 (5)	O4—C10	1.424 (5)
O2—H2A	0.8400	O4—H4A	0.8400
C1—C2	1.508 (6)	C6—C7	1.512 (5)
C1—H1C	0.9900	C6—H6A	0.9900
C1—H1B	0.9900	C6—H6B	0.9900
C2—C3	1.546 (5)	C7—C8	1.543 (5)
C3—C4	1.541 (5)	C8—C9	1.542 (5)
C4—C5	1.518 (6)	C9—C10	1.519 (5)
C5—H5A	0.9900	C10—H10B	0.9900
C5—H5B	0.9900	C10—H10A	0.9900
C1—O1—H1A	109.5	C6—O3—H3A	109.5
C5—O2—H2A	109.5	C10—O4—H4A	109.5
O1—C1—C2	110.6 (3)	O3—C6—C7	110.7 (3)
O1—C1—H1C	109.5	O3—C6—H6A	109.5
C2—C1—H1C	109.5	C7—C6—H6A	109.5
O1—C1—H1B	109.5	O3—C6—H6B	109.5
C2—C1—H1B	109.5	C7—C6—H6B	109.5
H1C—C1—H1B	108.1	H6A—C6—H6B	108.1
F2—C2—F1	106.5 (3)	F8—C7—F7	106.8 (3)
F2—C2—C1	110.8 (4)	F8—C7—C6	111.0 (3)
F1—C2—C1	109.6 (3)	F7—C7—C6	109.2 (3)
F2—C2—C3	108.1 (3)	F8—C7—C8	108.0 (3)
F1—C2—C3	107.9 (3)	F7—C7—C8	107.8 (3)
C1—C2—C3	113.7 (3)	C6—C7—C8	113.7 (3)
F4—C3—F3	107.5 (3)	F10—C8—F9	107.4 (3)
F4—C3—C4	107.7 (3)	F10—C8—C9	107.9 (3)
F3—C3—C4	108.1 (3)	F9—C8—C9	108.1 (3)
F4—C3—C2	107.9 (3)	F10—C8—C7	107.7 (3)
F3—C3—C2	107.2 (3)	F9—C8—C7	107.2 (3)
C4—C3—C2	118.1 (3)	C9—C8—C7	118.1 (3)
F5—C4—F6	106.5 (3)	F11—C9—F12	106.6 (3)
F5—C4—C5	110.9 (3)	F11—C9—C10	110.7 (3)
F6—C4—C5	109.6 (3)	F12—C9—C10	109.7 (3)
F5—C4—C3	108.8 (3)	F11—C9—C8	108.9 (3)
F6—C4—C3	108.0 (3)	F12—C9—C8	107.3 (3)
C5—C4—C3	112.8 (3)	C10—C9—C8	113.3 (3)
O2—C5—C4	109.3 (3)	O4—C10—C9	109.1 (3)
O2—C5—H5A	109.8	O4—C10—H10B	109.9
C4—C5—H5A	109.8	C9—C10—H10B	109.9
O2—C5—H5B	109.8	O4—C10—H10A	109.9
C4—C5—H5B	109.8	C9—C10—H10A	109.9
H5A—C5—H5B	108.3	H10B—C10—H10A	108.3
O1—C1—C2—F2	−62.4 (4)	O3—C6—C7—F8	61.8 (5)
O1—C1—C2—F1	54.9 (4)	O3—C6—C7—F7	−55.7 (5)
O1—C1—C2—C3	175.7 (3)	O3—C6—C7—C8	−176.2 (3)
F2—C2—C3—F4	−76.6 (4)	F8—C7—C8—F10	77.1 (4)
F1—C2—C3—F4	168.6 (3)	F7—C7—C8—F10	−167.8 (3)
C1—C2—C3—F4	46.8 (4)	C6—C7—C8—F10	−46.5 (4)
F2—C2—C3—F3	168.0 (3)	F8—C7—C8—F9	−167.6 (3)
F1—C2—C3—F3	53.2 (3)	F7—C7—C8—F9	−52.5 (4)
C1—C2—C3—F3	−68.6 (4)	C6—C7—C8—F9	68.8 (4)
F2—C2—C3—C4	45.7 (5)	F8—C7—C8—C9	−45.3 (5)
F1—C2—C3—C4	−69.1 (4)	F7—C7—C8—C9	69.8 (4)
C1—C2—C3—C4	169.1 (3)	C6—C7—C8—C9	−168.9 (3)
F4—C3—C4—F5	170.4 (3)	F10—C8—C9—F11	−165.6 (3)
F3—C3—C4—F5	−73.8 (4)	F9—C8—C9—F11	78.6 (4)
C2—C3—C4—F5	48.0 (5)	C7—C8—C9—F11	−43.2 (5)
F4—C3—C4—F6	55.2 (4)	F10—C8—C9—F12	−50.6 (4)
F3—C3—C4—F6	171.0 (3)	F9—C8—C9—F12	−166.4 (3)
C2—C3—C4—F6	−67.2 (4)	C7—C8—C9—F12	71.8 (4)
F4—C3—C4—C5	−66.1 (4)	F10—C8—C9—C10	70.7 (4)
F3—C3—C4—C5	49.7 (4)	F9—C8—C9—C10	−45.1 (4)
C2—C3—C4—C5	171.5 (3)	C7—C8—C9—C10	−167.0 (3)
F5—C4—C5—O2	−59.4 (4)	F11—C9—C10—O4	60.7 (4)
F6—C4—C5—O2	57.9 (4)	F12—C9—C10—O4	−56.7 (4)
C3—C4—C5—O2	178.2 (3)	C8—C9—C10—O4	−176.5 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O4^i	0.84	1.89	2.717 (4)	169
O2—H2A···O3^ii	0.84	1.90	2.732 (5)	169
O3—H3A···O2^iii	0.84	1.91	2.740 (5)	171
O4—H4A···O1^iv	0.84	1.91	2.733 (4)	166

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

(II) 2,2,3,3,4,4-hexafluoropentane-1,5-diol

Crystal data

C5H6F6O2	Z = 2
Mr = 212.10	F(000) = 212
Triclinic, P1	Dx = 1.914 Mg m^−3
Hall symbol: P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.8641 (12) Å	Cell parameters from 2983 reflections
b = 5.7380 (14) Å	θ = 3.7–26.4°
c = 13.325 (3) Å	µ = 0.24 mm^−1
α = 82.814 (3)°	T = 173 K
β = 87.274 (3)°	Block, colourless
γ = 86.435 (4)°	0.35 × 0.20 × 0.17 mm
V = 367.98 (16) Å^3

Data collection

Bruker SMART 1000 CCD Platform diffractometer	1652 independent reflections
Radiation source: normal-focus sealed tube	1289 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.050
ω and ϕ scans	θmax = 27.5°, θmin = 1.5°
Absorption correction: multi-scan (TWINABS, Version 2008/1; Sheldrick, 2008)	h = −6→6
Tmin = 0.922, Tmax = 0.961	k = −7→7
5181 measured reflections	l = 0→17

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.054	H-atom parameters constrained
wR(F^2) = 0.138	w = 1/[σ^2(Fo^2) + (0.0784P)^2 + 0.0456P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
1652 reflections	Δρmax = 0.39 e Å^−3
242 parameters	Δρmin = −0.39 e Å^−3
3 restraints	Absolute structure: Flack (1983), with how many Friedel pairs?
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.8 (14)

Special details

Experimental. Component Input RLV.Excl Used WorstRes BestRes Min.2 T h Max.2 T h 1.1 (1) 908 0 908 5.4700 0.7982 7.450 52.874 1.2 (2) 897 0 897 5.4700 0.8086 7.450 52.143 1.3 (3) 604 0 604 6.6051 0.8188 6.168 51.445 1.4 (4) 559 0 559 6.6051 0.8188 6.168 51.445 A l l 2968 0 2968 6.6051 0.7982 6.168 52.874

Rotated from first domain by 179.9 degrees about reciprocal axis 1.000 0.050 0.132 and real axis 1.000 - 0.011 - 0.001

Twin law to convert hkl from first to 1.001 - 0.023 - 0.002 this domain (SHELXL TWIN matrix): 0.101 - 1.001 0.001 0.264 - 0.009 - 1.000

Rotated from first domain by 179.7 degrees about reciprocal axis 0.006 0.500 1.000 and real axis -0.100 1.000 0.354

Twin law to convert hkl from first to -1.001 0.017 0.003 this domain (SHELXL TWIN matrix): -0.122 0.170 0.415 - 0.221 2.344 - 0.169

Rotated from first domain by 178.8 degrees about reciprocal axis 0.001 - 0.355 1.000 and real axis 0.003 1.000 - 0.499

Twin law to convert hkl from first to -1.001 0.012 0.005 this domain (SHELXL TWIN matrix): -0.018 - 0.168 - 0.414 - 0.047 - 2.340 0.169

Transforms h1.1(1)->h1.2(2) 0.99992 - 0.00149 0.00057 0.14591 - 0.99984 - 0.00021 0.26476 0.00010 - 1.00010

Transforms h1.1(1)->h1.3(3) -0.99962 - 0.00371 0.00198 - 0.00894 - 0.16980 - 0.41492 0.03379 - 2.33871 0.16956

Transforms h1.1(1)->h1.4(4) -0.99930 - 0.00421 0.00197 - 0.13586 0.16973 0.41551 - 0.29414 2.33869 - 0.16941

Transforms h1.2(2)->h1.3(3) -0.99978 0.00520 - 0.00255 - 0.14358 0.17009 0.41476 - 0.26254 2.33946 - 0.17018

Transforms h1.2(2)->h1.4(4) -0.99954 0.00570 - 0.00255 - 0.00110 - 0.16980 - 0.41543 0.00218 - 2.33904 0.16989

Transforms h1.3(3)->h1.4(4) 0.99969 0.00010 0.00021 0.14486 - 1.00079 - 0.00014 0.26043 0.00071 - 1.00045

SAINT V7.34 A final UB matrices:

Orientation ('UB') matrix (Component 1.1 (1)): -0.0496655 - 0.1562083 - 0.0173567 - 0.0403009 0.0728058 - 0.0702953 0.1959462 - 0.0352862 - 0.0220666

Orientation ('UB') matrix (Component 1.2 (2)): -0.0770598 0.1563497 0.0172780 - 0.0482976 - 0.0727383 0.0702760 0.1849840 0.0350176 0.0221629

Orientation ('UB') matrix (Component 1.3 (3)): 0.0511716 0.0673395 0.0618221 0.0375258 0.1523325 - 0.0422504 - 0.1961485 0.0568526 0.0112710

Orientation ('UB') matrix (Component 1.4 (4)): 0.0770344 - 0.0673223 - 0.0617684 0.0485787 - 0.1521777 0.0422631 - 0.1850317 - 0.0568346 - 0.0112963

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
F1	0.4059 (8)	0.3817 (6)	0.8853 (2)	0.0346 (9)
F2	−0.0025 (8)	0.5432 (6)	0.8558 (3)	0.0348 (9)
F3	0.4761 (7)	0.2581 (6)	0.7018 (3)	0.0320 (8)
F4	0.0464 (7)	0.3487 (6)	0.6670 (2)	0.0333 (9)
F5	0.5090 (8)	0.7370 (6)	0.7351 (3)	0.0328 (8)
F6	0.0999 (7)	0.7996 (6)	0.6739 (2)	0.0304 (8)
O1	−0.0047 (9)	0.1011 (7)	0.9698 (3)	0.0310 (10)
H1A	0.1369	0.0484	1.0007	0.047*
O2	0.4994 (10)	0.9049 (7)	0.5273 (3)	0.0347 (10)
H2A	0.3564	0.9660	0.4995	0.052*
F7	0.5730 (8)	0.3695 (6)	0.3820 (3)	0.0354 (9)
F8	0.9676 (8)	0.5310 (6)	0.3562 (2)	0.0359 (9)
F9	0.5695 (7)	0.2604 (5)	0.1976 (2)	0.0307 (8)
F10	0.9979 (7)	0.3423 (6)	0.1650 (2)	0.0306 (8)
F11	0.4824 (7)	0.7441 (6)	0.2379 (2)	0.0310 (8)
F12	0.8956 (7)	0.7916 (6)	0.1720 (2)	0.0291 (8)
O3	0.9963 (9)	0.0837 (7)	0.4664 (3)	0.0311 (10)
H3A	0.8441	0.0523	0.4959	0.047*
O4	0.5023 (9)	0.9131 (7)	0.0305 (3)	0.0332 (10)
H4A	0.6488	0.9785	0.0115	0.050*
C1	0.0582 (14)	0.1288 (10)	0.8631 (4)	0.0270 (13)
H1C	−0.1113	0.1178	0.8260	0.032*
H1B	0.1930	0.0020	0.8459	0.032*
C2	0.1767 (12)	0.3656 (10)	0.8321 (4)	0.0235 (12)
C3	0.2586 (12)	0.4082 (10)	0.7184 (4)	0.0208 (10)
C4	0.3345 (12)	0.6552 (9)	0.6731 (4)	0.0207 (11)
C5	0.4570 (14)	0.6668 (10)	0.5657 (4)	0.0289 (13)
H5A	0.6347	0.5729	0.5652	0.035*
H5B	0.3303	0.6001	0.5223	0.035*
C6	0.9648 (13)	0.1191 (10)	0.3606 (4)	0.0258 (12)
H6A	0.8558	−0.0062	0.3404	0.031*
H6B	1.1480	0.1111	0.3251	0.031*
C7	0.8208 (13)	0.3554 (9)	0.3311 (4)	0.0243 (12)
C8	0.7657 (12)	0.4043 (10)	0.2170 (4)	0.0223 (11)
C9	0.6752 (12)	0.6559 (10)	0.1733 (4)	0.0237 (12)
C10	0.5647 (13)	0.6744 (10)	0.0673 (4)	0.0262 (12)
H10B	0.7043	0.6053	0.0213	0.031*
H10A	0.3965	0.5850	0.0691	0.031*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.040 (2)	0.044 (2)	0.0214 (16)	−0.0159 (18)	−0.0070 (15)	−0.0015 (15)
F2	0.049 (2)	0.0239 (18)	0.0297 (18)	0.0036 (17)	0.0077 (17)	−0.0031 (14)
F3	0.042 (2)	0.0209 (16)	0.0306 (16)	0.0067 (16)	0.0077 (15)	−0.0006 (13)
F4	0.044 (2)	0.038 (2)	0.0187 (16)	−0.0135 (18)	−0.0080 (15)	−0.0018 (14)
F5	0.043 (2)	0.0260 (17)	0.0305 (18)	−0.0124 (16)	−0.0071 (15)	−0.0016 (13)
F6	0.034 (2)	0.0251 (17)	0.0302 (18)	0.0023 (15)	0.0056 (15)	0.0020 (14)
O1	0.035 (2)	0.036 (2)	0.020 (2)	−0.009 (2)	−0.0002 (17)	0.0071 (18)
O2	0.032 (2)	0.033 (3)	0.035 (3)	−0.003 (2)	0.0000 (19)	0.0097 (19)
F7	0.036 (2)	0.039 (2)	0.0289 (18)	0.0031 (17)	0.0069 (15)	−0.0010 (15)
F8	0.059 (3)	0.0256 (19)	0.0253 (18)	−0.0107 (18)	−0.0128 (17)	−0.0016 (14)
F9	0.044 (2)	0.0182 (16)	0.0315 (17)	−0.0095 (16)	−0.0101 (16)	−0.0018 (13)
F10	0.0352 (19)	0.034 (2)	0.0205 (15)	0.0046 (16)	0.0050 (14)	−0.0022 (13)
F11	0.040 (2)	0.0272 (17)	0.0242 (16)	0.0049 (16)	0.0060 (15)	−0.0026 (13)
F12	0.0360 (19)	0.0243 (16)	0.0278 (17)	−0.0115 (15)	−0.0086 (14)	0.0013 (13)
O3	0.036 (2)	0.032 (2)	0.023 (2)	−0.002 (2)	−0.0036 (17)	0.0060 (18)
O4	0.030 (2)	0.030 (2)	0.037 (3)	−0.0068 (19)	−0.0035 (19)	0.0084 (19)
C1	0.038 (3)	0.026 (3)	0.016 (3)	−0.010 (3)	0.001 (2)	0.003 (2)
C2	0.026 (3)	0.025 (3)	0.019 (3)	−0.002 (2)	0.004 (2)	−0.001 (2)
C3	0.025 (3)	0.021 (3)	0.016 (2)	0.001 (2)	−0.004 (2)	−0.0018 (18)
C4	0.027 (3)	0.017 (2)	0.017 (2)	0.000 (2)	0.003 (2)	0.000 (2)
C5	0.043 (4)	0.026 (3)	0.016 (3)	0.003 (3)	0.005 (2)	−0.001 (2)
C6	0.033 (3)	0.022 (3)	0.020 (3)	0.004 (3)	−0.006 (2)	0.004 (2)
C7	0.037 (3)	0.020 (3)	0.017 (2)	−0.007 (2)	0.000 (2)	−0.002 (2)
C8	0.023 (3)	0.026 (3)	0.019 (2)	−0.009 (2)	0.001 (2)	−0.0042 (19)
C9	0.026 (3)	0.023 (3)	0.022 (3)	−0.006 (2)	0.006 (2)	−0.003 (2)
C10	0.033 (3)	0.028 (3)	0.017 (3)	−0.004 (3)	−0.001 (2)	0.002 (2)

Geometric parameters (Å, º)

F1—C2	1.364 (7)	O4—C10	1.415 (7)
F2—C2	1.357 (7)	O4—H4A	0.8400
F3—C3	1.350 (6)	C1—C2	1.511 (8)
F4—C3	1.350 (6)	C1—H1C	0.9900
F5—C4	1.355 (6)	C1—H1B	0.9900
F6—C4	1.368 (6)	C2—C3	1.541 (6)
O1—C1	1.431 (6)	C3—C4	1.529 (7)
O1—H1A	0.8400	C4—C5	1.519 (7)
O2—C5	1.421 (7)	C5—H5A	0.9900
O2—H2A	0.8400	C5—H5B	0.9900
F7—C7	1.358 (6)	C6—C7	1.503 (8)
F8—C7	1.354 (6)	C6—H6A	0.9900
F9—C8	1.354 (6)	C6—H6B	0.9900
F10—C8	1.348 (6)	C7—C8	1.545 (7)
F11—C9	1.360 (6)	C8—C9	1.533 (7)
F12—C9	1.362 (6)	C9—C10	1.525 (7)
O3—C6	1.414 (6)	C10—H10B	0.9900
O3—H3A	0.8400	C10—H10A	0.9900
C1—O1—H1A	109.5	C4—C5—H5B	109.8
C5—O2—H2A	109.5	H5A—C5—H5B	108.2
C6—O3—H3A	109.5	O3—C6—C7	109.7 (4)
C10—O4—H4A	109.5	O3—C6—H6A	109.7
O1—C1—C2	109.3 (4)	C7—C6—H6A	109.7
O1—C1—H1C	109.8	O3—C6—H6B	109.7
C2—C1—H1C	109.8	C7—C6—H6B	109.7
O1—C1—H1B	109.8	H6A—C6—H6B	108.2
C2—C1—H1B	109.8	F8—C7—F7	106.8 (4)
H1C—C1—H1B	108.3	F8—C7—C6	111.1 (5)
F2—C2—F1	105.9 (4)	F7—C7—C6	109.9 (4)
F2—C2—C1	111.2 (5)	F8—C7—C8	108.3 (4)
F1—C2—C1	109.5 (4)	F7—C7—C8	107.2 (5)
F2—C2—C3	108.9 (4)	C6—C7—C8	113.2 (4)
F1—C2—C3	108.0 (4)	F10—C8—F9	107.3 (4)
C1—C2—C3	113.0 (4)	F10—C8—C9	107.2 (4)
F3—C3—F4	107.7 (4)	F9—C8—C9	107.9 (5)
F3—C3—C4	107.8 (4)	F10—C8—C7	108.1 (5)
F4—C3—C4	107.7 (4)	F9—C8—C7	107.7 (4)
F3—C3—C2	107.2 (4)	C9—C8—C7	118.2 (4)
F4—C3—C2	107.5 (5)	F11—C9—F12	106.0 (4)
C4—C3—C2	118.5 (4)	F11—C9—C10	110.3 (5)
F5—C4—F6	106.3 (4)	F12—C9—C10	109.6 (4)
F5—C4—C5	110.9 (5)	F11—C9—C8	108.8 (4)
F6—C4—C5	109.2 (4)	F12—C9—C8	108.1 (5)
F5—C4—C3	108.8 (4)	C10—C9—C8	113.8 (5)
F6—C4—C3	107.7 (4)	O4—C10—C9	110.0 (5)
C5—C4—C3	113.6 (4)	O4—C10—H10B	109.7
O2—C5—C4	109.5 (4)	C9—C10—H10B	109.7
O2—C5—H5A	109.8	O4—C10—H10A	109.7
C4—C5—H5A	109.8	C9—C10—H10A	109.7
O2—C5—H5B	109.8	H10B—C10—H10A	108.2
O1—C1—C2—F2	−58.7 (6)	O3—C6—C7—F8	60.5 (6)
O1—C1—C2—F1	57.9 (6)	O3—C6—C7—F7	−57.5 (6)
O1—C1—C2—C3	178.4 (5)	O3—C6—C7—C8	−177.4 (5)
F2—C2—C3—F3	167.7 (4)	F8—C7—C8—F10	78.0 (5)
F1—C2—C3—F3	53.1 (5)	F7—C7—C8—F10	−167.1 (4)
C1—C2—C3—F3	−68.2 (6)	C6—C7—C8—F10	−45.7 (6)
F2—C2—C3—F4	−76.7 (5)	F8—C7—C8—F9	−166.4 (4)
F1—C2—C3—F4	168.7 (5)	F7—C7—C8—F9	−51.5 (5)
C1—C2—C3—F4	47.4 (6)	C6—C7—C8—F9	69.8 (6)
F2—C2—C3—C4	45.5 (7)	F8—C7—C8—C9	−43.9 (7)
F1—C2—C3—C4	−69.1 (6)	F7—C7—C8—C9	71.0 (6)
C1—C2—C3—C4	169.7 (5)	C6—C7—C8—C9	−167.6 (5)
F3—C3—C4—F5	−75.7 (5)	F10—C8—C9—F11	−166.0 (4)
F4—C3—C4—F5	168.3 (4)	F9—C8—C9—F11	78.8 (5)
C2—C3—C4—F5	46.2 (6)	C7—C8—C9—F11	−43.6 (7)
F3—C3—C4—F6	169.5 (4)	F10—C8—C9—F12	−51.2 (5)
F4—C3—C4—F6	53.5 (5)	F9—C8—C9—F12	−166.5 (4)
C2—C3—C4—F6	−68.6 (6)	C7—C8—C9—F12	71.1 (6)
F3—C3—C4—C5	48.4 (6)	F10—C8—C9—C10	70.7 (6)
F4—C3—C4—C5	−67.5 (6)	F9—C8—C9—C10	−44.6 (6)
C2—C3—C4—C5	170.3 (5)	C7—C8—C9—C10	−166.9 (5)
F5—C4—C5—O2	−61.8 (6)	F11—C9—C10—O4	61.1 (6)
F6—C4—C5—O2	54.9 (6)	F12—C9—C10—O4	−55.3 (6)
C3—C4—C5—O2	175.2 (5)	C8—C9—C10—O4	−176.4 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O4^i	0.84	1.93	2.746 (6)	163
O2—H2A···O3^ii	0.84	1.89	2.714 (6)	167
O3—H3A···O2^iii	0.84	1.93	2.733 (6)	160
O4—H4A···O1^iv	0.84	1.90	2.736 (6)	175

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

(Ic) 2,2,3,3,4,4-hexafluoropentane-1,5-diol

Crystal data

C5H6F6O2	Z = 2
Mr = 212.10	F(000) = 212
Triclinic, P1	Dx = 1.867 Mg m^−3
Hall symbol: P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.9215 (18) Å	Cell parameters from 2985 reflections
b = 6.871 (3) Å	θ = 3.1–27.3°
c = 11.314 (4) Å	µ = 0.23 mm^−1
α = 81.973 (5)°	T = 283 K
β = 85.839 (5)°	Block, colourless
γ = 86.562 (5)°	0.35 × 0.20 × 0.17 mm
V = 377.3 (2) Å^3

Data collection

Bruker SMART 1000 CCD Platform diffractometer	1729 independent reflections
Radiation source: normal-focus sealed tube	1200 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
ω and ϕ scans	θmax = 27.5°, θmin = 1.8°
Absorption correction: multi-scan (TWINABS, Version 2008/1; Sheldrick, 2008)	h = −6→6
Tmin = 0.924, Tmax = 0.962	k = −8→8
5825 measured reflections	l = 0→14

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.049	H-atom parameters constrained
wR(F^2) = 0.129	w = 1/[σ^2(Fo^2) + (0.0647P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max < 0.001
1729 reflections	Δρmax = 0.27 e Å^−3
242 parameters	Δρmin = −0.30 e Å^−3
3 restraints	Absolute structure: Flack (1983), with Friedel pairs merged
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.2 (14)

Special details

Experimental. Cell Refinement: Component Input RLV.Excl Used WorstRes BestRes Min.2 T h Max.2 T h 1.1 (1) 872 0 872 6.7949 0.7985 5.996 52.850 1.2 (2) 921 0 921 5.5897 0.7985 7.290 52.850 1.3 (3) 560 0 560 6.7949 0.9132 5.996 45.801 1.4 (4) 616 0 616 6.7949 0.8768 5.996 47.820 A l l 2969 0 2969 6.7949 0.7985 5.996 52.850 Rotated from first domain by 179.9 degrees about reciprocal axis 1.000 0.069 0.137 and real axis 1.000 0.002 0.004

Rotated from first domain by 179.2 degrees about reciprocal axis -0.003 - 0.790 1.000 and real axis 0.002 1.000 - 0.507

Rotated from first domain by 179.6 degrees about reciprocal axis -0.004 0.505 1.000 and real axis -0.174 1.000 0.792

Twin Laws, (SAINT V7.34 A) Transforms h1.1(1)->h1.2(2) 1.00002 - 0.00060 0.00028 0.16662 - 1.00021 0.00021 0.33540 - 0.00060 - 0.99945

Transforms h1.1(1)->h1.3(3) -0.99914 - 0.00285 0.00167 - 0.00216 0.22271 - 0.61154 0.00804 - 1.55587 - 0.22238

Transforms h1.2(2)->h1.3(3) -0.99904 0.00345 - 0.00195 - 0.17019 - 0.22293 0.61178 - 0.32586 1.55560 0.22274

Transforms h1.1(1)->h1.4(4) -0.99962 - 0.00354 0.00177 - 0.16330 - 0.22294 0.61172 - 0.34161 1.55406 0.22281

Transforms h1.2(2)->h1.4(4) -0.99960 0.00414 - 0.00205 0.00476 0.22326 - 0.61201 - 0.00787 - 1.55359 - 0.22327

Transforms h1.3(3)->h1.4(4) 1.00048 - 0.00030 0.00040 0.16560 - 0.99979 - 0.00013 0.33387 0.00000 - 0.99945

SAINT V7.34 A final UB matrices:

Orientation ('UB') matrix (Component 1.1 (1)): -0.0477110 - 0.1218109 - 0.0313513 - 0.0370147 0.0794615 - 0.0787042 0.1948454 - 0.0225065 - 0.0287094

Orientation ('UB') matrix (Component 1.2 (2)): -0.0784969 0.1218321 0.0313470 - 0.0501602 - 0.0794627 0.0786809 0.1814754 0.0223873 0.0287776

Orientation ('UB') matrix (Component 1.3 (3)): 0.0481961 0.0217619 0.0813463 0.0362060 0.1401732 - 0.0311011 - 0.1948779 0.0391977 0.0204199

Orientation ('UB') matrix (Component 1.4 (4)): 0.0790404 - 0.0218297 - 0.0813253 0.0491009 - 0.1401953 0.0311274 - 0.1815292 - 0.0390809 - 0.0204636

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
F1	0.3772 (8)	0.3503 (5)	0.9006 (3)	0.0554 (9)
F2	−0.0361 (8)	0.4585 (5)	0.8657 (3)	0.0578 (10)
F3	0.5158 (7)	0.3432 (4)	0.6736 (3)	0.0520 (9)
F4	0.0978 (7)	0.3959 (4)	0.6240 (2)	0.0493 (9)
F5	0.4547 (7)	0.7081 (4)	0.7663 (3)	0.0507 (9)
F6	0.0633 (7)	0.7519 (4)	0.6880 (3)	0.0499 (8)
O1	0.0258 (8)	0.0554 (6)	0.9525 (4)	0.0526 (11)
H1A	0.1633	0.0081	0.9847	0.079*
O2	0.4685 (8)	0.9323 (5)	0.5412 (4)	0.0524 (11)
H2A	0.3204	0.9856	0.5238	0.079*
C1	0.0969 (12)	0.1348 (7)	0.8327 (5)	0.0444 (14)
H1C	−0.0563	0.1301	0.7841	0.053*
H1B	0.2490	0.0572	0.8009	0.053*
C2	0.1741 (11)	0.3442 (7)	0.8279 (4)	0.0328 (11)
C3	0.2738 (11)	0.4366 (7)	0.7015 (5)	0.0349 (11)
C4	0.3107 (11)	0.6572 (7)	0.6778 (4)	0.0342 (12)
C5	0.4493 (13)	0.7253 (8)	0.5572 (5)	0.0451 (14)
H5A	0.6304	0.6621	0.5513	0.054*
H5B	0.3460	0.6879	0.4948	0.054*
F7	0.5767 (8)	0.3475 (5)	0.3947 (3)	0.0557 (9)
F8	0.9766 (8)	0.4687 (5)	0.3739 (3)	0.0591 (10)
F9	0.5658 (7)	0.3398 (4)	0.1642 (3)	0.0566 (10)
F10	0.9916 (7)	0.4074 (5)	0.1304 (3)	0.0535 (9)
F11	0.4964 (8)	0.7054 (5)	0.2624 (3)	0.0589 (10)
F12	0.9064 (7)	0.7594 (5)	0.1875 (3)	0.0574 (10)
O3	0.9746 (8)	0.0630 (6)	0.4575 (4)	0.0529 (11)
H3A	0.8235	0.0415	0.4907	0.079*
O4	0.5217 (8)	0.9288 (5)	0.0373 (4)	0.0522 (11)
H4A	0.6648	0.9859	0.0262	0.078*
C6	0.9462 (13)	0.1427 (8)	0.3366 (5)	0.0468 (14)
H6A	0.8334	0.0601	0.2998	0.056*
H6B	1.1240	0.1452	0.2936	0.056*
C7	0.8179 (11)	0.3482 (8)	0.3281 (4)	0.0384 (12)
C8	0.7648 (10)	0.4409 (7)	0.2002 (4)	0.0334 (11)
C9	0.6840 (11)	0.6597 (7)	0.1765 (4)	0.0350 (12)
C10	0.5802 (12)	0.7235 (8)	0.0538 (4)	0.0417 (13)
H10B	0.7169	0.6891	−0.0071	0.050*
H10A	0.4165	0.6557	0.0458	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.066 (2)	0.060 (2)	0.0419 (18)	−0.0187 (17)	−0.0239 (17)	0.0049 (14)
F2	0.071 (2)	0.048 (2)	0.0441 (18)	0.0170 (18)	0.0207 (18)	0.0066 (15)
F3	0.053 (2)	0.0411 (18)	0.056 (2)	0.0121 (16)	0.0149 (17)	0.0000 (15)
F4	0.070 (2)	0.0502 (19)	0.0310 (16)	−0.0183 (17)	−0.0144 (16)	−0.0047 (13)
F5	0.069 (2)	0.0411 (17)	0.0446 (18)	−0.0077 (17)	−0.0206 (18)	−0.0038 (13)
F6	0.0439 (18)	0.0386 (17)	0.061 (2)	0.0102 (15)	0.0048 (16)	0.0033 (14)
O1	0.047 (2)	0.048 (3)	0.056 (3)	−0.008 (2)	−0.006 (2)	0.0229 (19)
O2	0.050 (2)	0.041 (2)	0.060 (3)	−0.001 (2)	−0.005 (2)	0.013 (2)
C1	0.054 (4)	0.035 (3)	0.042 (3)	−0.005 (3)	−0.009 (3)	0.005 (2)
C2	0.036 (3)	0.034 (3)	0.028 (2)	−0.002 (2)	−0.002 (2)	0.000 (2)
C3	0.036 (3)	0.037 (3)	0.033 (3)	0.001 (2)	−0.006 (2)	−0.005 (2)
C4	0.036 (3)	0.033 (3)	0.034 (3)	0.004 (2)	−0.010 (2)	−0.001 (2)
C5	0.055 (4)	0.040 (3)	0.037 (3)	−0.003 (3)	−0.007 (3)	0.009 (2)
F7	0.056 (2)	0.055 (2)	0.0464 (19)	0.0101 (17)	0.0166 (17)	0.0084 (14)
F8	0.084 (3)	0.053 (2)	0.0439 (18)	−0.0129 (19)	−0.0309 (19)	−0.0022 (15)
F9	0.069 (2)	0.0412 (18)	0.063 (2)	−0.0131 (17)	−0.034 (2)	−0.0003 (16)
F10	0.057 (2)	0.059 (2)	0.0388 (18)	0.0153 (17)	0.0075 (16)	0.0006 (14)
F11	0.081 (3)	0.0460 (18)	0.0425 (18)	0.0188 (19)	0.0096 (19)	0.0025 (14)
F12	0.062 (2)	0.0465 (18)	0.065 (2)	−0.0193 (17)	−0.0247 (19)	0.0062 (16)
O3	0.047 (2)	0.056 (3)	0.050 (2)	−0.001 (2)	−0.011 (2)	0.017 (2)
O4	0.049 (2)	0.041 (2)	0.061 (3)	0.0033 (19)	−0.011 (2)	0.013 (2)
C6	0.049 (3)	0.045 (3)	0.043 (3)	−0.003 (3)	−0.006 (3)	0.006 (2)
C7	0.040 (3)	0.042 (3)	0.034 (3)	−0.007 (2)	−0.003 (2)	−0.004 (2)
C8	0.030 (2)	0.037 (3)	0.033 (3)	−0.003 (2)	−0.006 (2)	−0.002 (2)
C9	0.040 (3)	0.029 (3)	0.034 (3)	0.001 (2)	−0.003 (2)	0.001 (2)
C10	0.050 (3)	0.039 (3)	0.034 (3)	0.000 (3)	−0.008 (3)	0.005 (2)

Geometric parameters (Å, º)

F1—C2	1.346 (6)	F7—C7	1.359 (6)
F2—C2	1.342 (6)	F8—C7	1.349 (6)
F3—C3	1.357 (6)	F9—C8	1.352 (6)
F4—C3	1.343 (6)	F10—C8	1.347 (6)
F5—C4	1.363 (6)	F11—C9	1.348 (6)
F6—C4	1.351 (6)	F12—C9	1.348 (6)
O1—C1	1.416 (6)	O3—C6	1.415 (7)
O1—H1A	0.8200	O3—H3A	0.8200
O2—C5	1.417 (6)	O4—C10	1.412 (6)
O2—H2A	0.8200	O4—H4A	0.8200
C1—C2	1.502 (7)	C6—C7	1.505 (8)
C1—H1C	0.9700	C6—H6A	0.9700
C1—H1B	0.9700	C6—H6B	0.9700
C2—C3	1.540 (6)	C7—C8	1.531 (6)
C3—C4	1.521 (6)	C8—C9	1.523 (6)
C4—C5	1.507 (7)	C9—C10	1.513 (7)
C5—H5A	0.9700	C10—H10B	0.9700
C5—H5B	0.9700	C10—H10A	0.9700
C1—O1—H1A	109.5	C6—O3—H3A	109.5
C5—O2—H2A	109.5	C10—O4—H4A	109.5
O1—C1—C2	109.7 (4)	O3—C6—C7	110.5 (5)
O1—C1—H1C	109.7	O3—C6—H6A	109.5
C2—C1—H1C	109.7	C7—C6—H6A	109.5
O1—C1—H1B	109.7	O3—C6—H6B	109.5
C2—C1—H1B	109.7	C7—C6—H6B	109.5
H1C—C1—H1B	108.2	H6A—C6—H6B	108.1
F2—C2—F1	107.5 (4)	F8—C7—F7	106.3 (4)
F2—C2—C1	111.5 (4)	F8—C7—C6	110.9 (5)
F1—C2—C1	109.3 (4)	F7—C7—C6	109.8 (4)
F2—C2—C3	107.8 (4)	F8—C7—C8	107.6 (4)
F1—C2—C3	107.7 (4)	F7—C7—C8	108.2 (4)
C1—C2—C3	112.9 (4)	C6—C7—C8	113.8 (4)
F4—C3—F3	106.8 (4)	F10—C8—F9	107.0 (4)
F4—C3—C4	107.0 (4)	F10—C8—C9	107.8 (4)
F3—C3—C4	108.1 (4)	F9—C8—C9	108.3 (4)
F4—C3—C2	108.2 (4)	F10—C8—C7	107.6 (4)
F3—C3—C2	107.3 (4)	F9—C8—C7	106.6 (4)
C4—C3—C2	118.9 (3)	C9—C8—C7	119.0 (4)
F6—C4—F5	105.9 (4)	F11—C9—F12	106.8 (4)
F6—C4—C5	109.6 (4)	F11—C9—C10	110.6 (4)
F5—C4—C5	110.2 (4)	F12—C9—C10	109.0 (4)
F6—C4—C3	108.6 (4)	F11—C9—C8	109.0 (4)
F5—C4—C3	108.5 (4)	F12—C9—C8	107.6 (4)
C5—C4—C3	113.9 (4)	C10—C9—C8	113.5 (4)
O2—C5—C4	110.2 (5)	O4—C10—C9	109.8 (4)
O2—C5—H5A	109.6	O4—C10—H10B	109.7
C4—C5—H5A	109.6	C9—C10—H10B	109.7
O2—C5—H5B	109.6	O4—C10—H10A	109.7
C4—C5—H5B	109.6	C9—C10—H10A	109.7
H5A—C5—H5B	108.1	H10B—C10—H10A	108.2
O1—C1—C2—F2	−62.5 (5)	O3—C6—C7—F8	61.9 (6)
O1—C1—C2—F1	56.1 (6)	O3—C6—C7—F7	−55.2 (6)
O1—C1—C2—C3	176.0 (5)	O3—C6—C7—C8	−176.7 (4)
F2—C2—C3—F4	−76.6 (5)	F8—C7—C8—F10	77.0 (5)
F1—C2—C3—F4	167.7 (4)	F7—C7—C8—F10	−168.6 (4)
C1—C2—C3—F4	46.9 (5)	C6—C7—C8—F10	−46.2 (5)
F2—C2—C3—F3	168.4 (4)	F8—C7—C8—F9	−168.5 (5)
F1—C2—C3—F3	52.7 (5)	F7—C7—C8—F9	−54.1 (5)
C1—C2—C3—F3	−68.0 (5)	C6—C7—C8—F9	68.2 (6)
F2—C2—C3—C4	45.6 (6)	F8—C7—C8—C9	−45.8 (6)
F1—C2—C3—C4	−70.1 (5)	F7—C7—C8—C9	68.6 (6)
C1—C2—C3—C4	169.2 (4)	C6—C7—C8—C9	−169.1 (4)
F4—C3—C4—F6	56.3 (5)	F10—C8—C9—F11	−166.7 (4)
F3—C3—C4—F6	171.0 (4)	F9—C8—C9—F11	77.9 (5)
C2—C3—C4—F6	−66.6 (6)	C7—C8—C9—F11	−43.9 (6)
F4—C3—C4—F5	170.9 (4)	F10—C8—C9—F12	−51.2 (5)
F3—C3—C4—F5	−74.4 (5)	F9—C8—C9—F12	−166.6 (4)
C2—C3—C4—F5	48.0 (6)	C7—C8—C9—F12	71.5 (6)
F4—C3—C4—C5	−66.1 (5)	F10—C8—C9—C10	69.5 (5)
F3—C3—C4—C5	48.6 (5)	F9—C8—C9—C10	−45.9 (6)
C2—C3—C4—C5	171.1 (5)	C7—C8—C9—C10	−167.8 (4)
F6—C4—C5—O2	56.5 (6)	F11—C9—C10—O4	59.6 (6)
F5—C4—C5—O2	−59.6 (6)	F12—C9—C10—O4	−57.5 (6)
C3—C4—C5—O2	178.3 (4)	C8—C9—C10—O4	−177.4 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O4^i	0.82	1.93	2.736 (5)	169
O2—H2A···O3^ii	0.82	1.93	2.728 (6)	166
O3—H3A···O2^iii	0.82	1.96	2.756 (6)	164
O4—H4A···O1^iv	0.82	1.96	2.741 (6)	158

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