Buy article online - an online subscription or single-article purchase is required to access this article.
The high-pressure crystal structure of phenol (C6H5OH), including the positions of the H atoms, has been determined using a combination of single-crystal X-ray diffraction techniques and ab initio density-functional calculations. It is found that at a pressure of 0.16 GPa, which is just sufficient to cause crystallization of a sample held at a temperature just above its ambient-pressure melting point (313 K), a previously unobserved monoclinic structure with P21 symmetry is formed. The structure is characterized by the formation of hydrogen-bonded molecular chains, and the molecules within each chain adopt a coplanar arrangement so that they are ordered in an alternating 1-1-1 sequence. Although the crystal structure of the ambient-pressure P1121 phase is also characterized by the formation of molecular chains, the molecules adopt an approximate threefold arrangement. A series of ab initio calculations indicates that the rearrangement of the molecules from helical to coplanar results in an energy difference of only 0.162 eV molecule−1 (15.6 kJ mole−1) at 0.16 GPa. The calculations also indicate that there is a slight increase in the dipole moment of the molecules, but, as the high-pressure phase has longer hydrogen-bond distances, it is found that, on average, the hydrogen bonds in the ambient-pressure phase are stronger.
Supporting information
CCDC reference: 201623
Data collection: Bruker SMART; cell refinement: Bruker SMART; data reduction: Bruker SHELXTL; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Bruker SHELXTL; software used to prepare material for publication: Bruker SHELXTL.
Crystal data top
PhOH | F(000) = 300 |
Mr = 94.11 | Dx = 1.240 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
a = 11.610 (4) Å | Cell parameters from 331 reflections |
b = 5.4416 (11) Å | θ = 2.5–25.5° |
c = 12.217 (5) Å | µ = 0.08 mm−1 |
β = 101.47 (3)° | T = 293 K |
V = 756.4 (4) Å3 | × × mm |
Z = 6 | |
Data collection top
CCD area detector diffractometer | 455 independent reflections |
Radiation source: fine-focus sealed tube | 269 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.057 |
phi and ω scans | θmax = 24.9°, θmin = 2.7° |
Absorption correction: SADABS ? | h = −12→12 |
Tmin = 0.213, Tmax = 1.000 | k = −6→6 |
1129 measured reflections | l = −7→7 |
Refinement top
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)] = 0.086 | w = 1/[σ2(Fo2) + (0.1876P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.278 | (Δ/σ)max = 0.002 |
S = 0.98 | Δρmax = 0.32 e Å−3 |
455 reflections | Δρmin = −0.20 e Å−3 |
29 parameters | Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881 |
14 restraints | Absolute structure parameter: 0 (10) |
Crystal data top
PhOH | V = 756.4 (4) Å3 |
Mr = 94.11 | Z = 6 |
Monoclinic, P21 | Mo Kα radiation |
a = 11.610 (4) Å | µ = 0.08 mm−1 |
b = 5.4416 (11) Å | T = 293 K |
c = 12.217 (5) Å | × × mm |
β = 101.47 (3)° | |
Data collection top
CCD area detector diffractometer | 455 independent reflections |
Absorption correction: SADABS ? | 269 reflections with I > 2σ(I) |
Tmin = 0.213, Tmax = 1.000 | Rint = 0.057 |
1129 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.086 | 14 restraints |
wR(F2) = 0.278 | Δρmax = 0.32 e Å−3 |
S = 0.98 | Δρmin = −0.20 e Å−3 |
455 reflections | Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881 |
29 parameters | Absolute structure parameter: 0 (10) |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes. |
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 (Å2) top | x | y | z | Uiso*/Ueq | |
O1A | 0.7050 (10) | 0.4386 (19) | 0.3000 (15) | 0.0583 (15)* | |
H1A | 0.6716 | 0.3230 | 0.3235 | 0.087* | |
C2A | 0.6911 (8) | 0.4219 (16) | 0.1876 (15) | 0.0583 (15)* | |
C3A | 0.6275 (9) | 0.2301 (18) | 0.1293 (17) | 0.0583 (15)* | |
H3A | 0.5935 | 0.1113 | 0.1675 | 0.070* | |
C4A | 0.6146 (10) | 0.216 (2) | 0.0139 (17) | 0.0583 (15)* | |
H4A | 0.5721 | 0.0877 | −0.0251 | 0.070* | |
C5A | 0.6654 (11) | 0.394 (3) | −0.0432 (15) | 0.0583 (15)* | |
H5A | 0.6568 | 0.3842 | −0.1204 | 0.070* | |
C6A | 0.7290 (11) | 0.585 (3) | 0.0150 (15) | 0.0583 (15)* | |
H6A | 0.7629 | 0.7043 | −0.0232 | 0.070* | |
C7A | 0.7418 (9) | 0.5996 (18) | 0.1304 (15) | 0.0583 (15)* | |
H7A | 0.7844 | 0.7279 | 0.1694 | 0.070* | |
O1B | 0.6823 (10) | 0.937 (2) | 0.3864 (14) | 0.0583 (15)* | |
H1B | 0.7209 | 0.8193 | 0.3720 | 0.087* | |
C2B | 0.6694 (11) | 0.923 (2) | 0.4937 (14) | 0.0583 (15)* | |
C3B | 0.7169 (10) | 0.726 (2) | 0.5603 (15) | 0.0583 (15)* | |
H3B | 0.7597 | 0.6059 | 0.5317 | 0.070* | |
C4B | 0.7005 (9) | 0.709 (3) | 0.6697 (15) | 0.0583 (15)* | |
H4B | 0.7322 | 0.5776 | 0.7143 | 0.070* | |
C5B | 0.6366 (10) | 0.889 (3) | 0.7124 (14) | 0.0583 (15)* | |
H5B | 0.6256 | 0.8773 | 0.7856 | 0.070* | |
C6B | 0.5891 (9) | 1.085 (3) | 0.6458 (14) | 0.0583 (15)* | |
H6B | 0.5463 | 1.2053 | 0.6744 | 0.070* | |
C7B | 0.6055 (10) | 1.102 (2) | 0.5364 (14) | 0.0583 (15)* | |
H7B | 0.5737 | 1.2337 | 0.4918 | 0.070* | |
O1C | 1.0164 (12) | 0.860 (2) | 0.4541 (16) | 0.0583 (15)* | |
H1C | 0.9818 | 0.9714 | 0.4791 | 0.087* | |
C2C | 1.0088 (13) | 0.893 (2) | 0.3444 (13) | 0.0583 (15)* | |
C3C | 0.9567 (10) | 1.0874 (15) | 0.2791 (17) | 0.0583 (15)* | |
H3C | 0.9167 | 1.2084 | 0.3103 | 0.070* | |
C4C | 0.9644 (10) | 1.101 (2) | 0.1671 (16) | 0.0583 (15)* | |
H4C | 0.9295 | 1.2314 | 0.1235 | 0.070* | |
C5C | 1.0241 (12) | 0.920 (4) | 0.1205 (13) | 0.0583 (15)* | |
H5C | 1.0293 | 0.9295 | 0.0456 | 0.070* | |
C6C | 1.0762 (10) | 0.726 (3) | 0.1858 (17) | 0.0583 (15)* | |
H6C | 1.1162 | 0.6046 | 0.1546 | 0.070* | |
C7C | 1.0686 (11) | 0.7119 (15) | 0.2977 (16) | 0.0583 (15)* | |
H7C | 1.1034 | 0.5817 | 0.3414 | 0.070* | |
Geometric parameters (Å, º) top
O1A—C2A | 1.354 (15) | C4B—C5B | 1.3900 |
C2A—C3A | 1.3900 | C5B—C6B | 1.3900 |
C2A—C7A | 1.3900 | C6B—C7B | 1.3900 |
C3A—C4A | 1.3900 | O1C—C2C | 1.338 (17) |
C4A—C5A | 1.3900 | C2C—C3C | 1.3900 |
C5A—C6A | 1.3900 | C2C—C7C | 1.3900 |
C6A—C7A | 1.3900 | C3C—C4C | 1.3900 |
O1B—C2B | 1.351 (16) | C4C—C5C | 1.3900 |
C2B—C3B | 1.3900 | C5C—C6C | 1.3900 |
C2B—C7B | 1.3900 | C6C—C7C | 1.3900 |
C3B—C4B | 1.3900 | | |
| | | |
O1A—C2A—C3A | 120.9 (7) | C5B—C4B—C3B | 120.0 |
O1A—C2A—C7A | 119.1 (7) | C4B—C5B—C6B | 120.0 |
C3A—C2A—C7A | 120.0 | C7B—C6B—C5B | 120.0 |
C4A—C3A—C2A | 120.0 | C6B—C7B—C2B | 120.0 |
C3A—C4A—C5A | 120.0 | O1C—C2C—C3C | 127.7 (14) |
C6A—C5A—C4A | 120.0 | O1C—C2C—C7C | 112.1 (14) |
C7A—C6A—C5A | 120.0 | C3C—C2C—C7C | 120.0 |
C6A—C7A—C2A | 120.0 | C2C—C3C—C4C | 120.0 |
O1B—C2B—C3B | 120.3 (7) | C5C—C4C—C3C | 120.0 |
O1B—C2B—C7B | 119.6 (7) | C6C—C5C—C4C | 120.0 |
C3B—C2B—C7B | 120.0 | C5C—C6C—C7C | 120.0 |
C2B—C3B—C4B | 120.0 | C6C—C7C—C2C | 120.0 |
Experimental details
Crystal data |
Chemical formula | PhOH |
Mr | 94.11 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 293 |
a, b, c (Å) | 11.610 (4), 5.4416 (11), 12.217 (5) |
β (°) | 101.47 (3) |
V (Å3) | 756.4 (4) |
Z | 6 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | × × |
|
Data collection |
Diffractometer | CCD area detector diffractometer |
Absorption correction | SADABS |
Tmin, Tmax | 0.213, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1129, 455, 269 |
Rint | 0.057 |
(sin θ/λ)max (Å−1) | 0.592 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.086, 0.278, 0.98 |
No. of reflections | 455 |
No. of parameters | 29 |
No. of restraints | 14 |
Δρmax, Δρmin (e Å−3) | 0.32, −0.20 |
Absolute structure | Flack H D (1983), Acta Cryst. A39, 876-881 |
Absolute structure parameter | 0 (10) |
Subscribe to Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials
The full text of this article is available to subscribers to the journal.
If you have already registered and are using a computer listed in your registration details, please email
support@iucr.org for assistance.