X-ray and neutron diffraction study of benzoylacetone in the temperature range 8–300 K: comparison with other cis-enol molecules

Herbstein, F.H.; Iversen, B.B.; Kapon, M.; Larsen, F.K.; Madsen, G.K.H.; Reisner, G.M.

doi:10.1107/S0108768199004279

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X-ray and neutron diffraction study of benzoylacetone in the temperature range 8–300 K: comparison with other cis-enol molecules

F. H. Herbstein, B. B. Iversen, M. Kapon, F. K. Larsen, G. K. H. Madsen and G. M. Reisner

The crystal structure of benzoylacetone (1-phenyl-1,3-butanedione, C₁₀H₁₀O₂; P2₁/c, Z = 4) has been determined at 300, 160 (both Mo Kα X-ray diffraction, XRD), 20 (λ = 1.012 Å neutron diffraction, ND) and 8 K (Ag Kα XRD), to which should be added earlier structure determinations at 300 (Mo Kα XRD and ND, λ = 0.983 Å) and 143 K (Mo Kα XRD). Cell dimensions have been measured over the temperature range 8–300 K; a first- or second-order phase change does not occur within this range. The atomic displacement parameters have been analyzed using the thermal motion analysis program THMA11. The most marked change in the molecular structure is in the disposition of the methyl group, which has a librational amplitude of ∼20° at 20 K and is rotationally disordered at 300 K. The lengths of the two C—O bonds in the cis-enol ring do not differ significantly, nor do those of the two C—C bonds, nor do these lengths change between 8 and 300 K. An ND difference synthesis (20 K) shows a single enol hydrogen trough (rather than two half H atoms), approximately centered between the O atoms; analogous results were obtained by XRD (8 K). It is inferred that the enol hydrogen is in a broad, flat-bottomed single-minimum potential well between the O atoms, with a libration amplitude of ∼0.30 Å at 8 K. These results suggest that at 8 K the cis-enol ring in benzoylacetone has quasi-aromatic character, in agreement with the results of high-level ab initio calculations made for benzoylacetone [Schiøtt et al. (1998). J. Am. Chem. Soc. 120, 12117–12124]. Application [in a related paper by Madsen et al. (1998). J. Am. Chem. Soc. 120, 10040–10045] of multipolar analysis and topological methods to the charge density obtained from the combined lowest temperature X-ray and neutron data provides evidence for an intramolecular hydrogen bond with partly electrostatic and partly covalent character, and large p-delocalization in the cis-enol ring. This is in good agreement with what is expected from the observed bond lengths. Analysis of the total available (through the Cambridge Structural Database, CSD) population of cis-enol ring geometries confirms earlier reports of correlation between the degree of bond localization in the pairs of C—C and C—O bonds, but does not show the dependence of bond localization on d(O

O) that was reported earlier for a more restricted sample. It is suggested that the only reliable method of determining whether the enol hydrogen is found in a single or double potential well is by low-temperature X-ray or (preferably) neutron diffraction.

Keywords: Benzoylacetone; X-ray and neutron diffraction; Low-temperature diffraction; cis-Enols.

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Supporting information

	Crystallographic Information File (CIF) Contains datablocks global, xray, neutron
	Structure factor file (CIF format) Contains datablock benzoylacetone
	Structure factor file (CIF format) Contains datablock benzoylacetone
	Portable Document Format (PDF) file Supplementary material

CCDC references: 136457; 136458

Computing details top

Figures top

(xray) top

Crystal data top

C₁₀H₁₀O₂	D_x = 1.350 Mg m⁻³
M_r = 162.19	Ag Kα radiation, λ = 0.5616 Å
Monoclinic, P2₁/C	Cell parameters from 91 reflections
a = 8.006 (3) Å	θ = 13.6–22.8°
b = 5.482 (3) Å	µ = 0.06 mm⁻¹
c = 19.444 (8) Å	T = 20 K
β = 110.46 (3)°	Spherical, colourless
V = 799.5 (5) Å³	0.3 mm (radius)
Z = 4

Data collection top

Huber 512 diffractometer	R_int = 0.024
2θ/ω scans	θ_max = 25.0°, θ_min = 1.8°
Absorption correction: gaussian ?	h = −9→12
T_min = 0.972, T_max = 0.973	k = −8→8
10494 measured reflections	l = −29→26
2862 independent reflections	3 standard reflections every 50 reflections
2013 reflections with I > 2σ(I)	intensity decay: none

Refinement top

Refinement on F²	H-atom parameters not refined
Least-squares matrix: full	Calculated w = 1/[σ²]
R[F² > 2σ(F²)] = 0.026	(Δ/σ)_max = 0.06
wR(F²) = 0.0231	Δρ_max = 0.15 e Å⁻³
2013 reflections	Δρ_min = −0.13 e Å⁻³
307 parameters

Crystal data top

C₁₀H₁₀O₂	V = 799.5 (5) Å³
M_r = 162.19	Z = 4
Monoclinic, P2₁/C	Ag Kα radiation, λ = 0.5616 Å
a = 8.006 (3) Å	µ = 0.06 mm⁻¹
b = 5.482 (3) Å	T = 20 K
c = 19.444 (8) Å	0.3 mm (radius)
β = 110.46 (3)°

Data collection top

Huber 512 diffractometer	2013 reflections with I > 2σ(I)
Absorption correction: gaussian ?	R_int = 0.024
T_min = 0.972, T_max = 0.973	3 standard reflections every 50 reflections
10494 measured reflections	intensity decay: none
2862 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.026	H-atom parameters not refined
wR(F²) = 0.0231	Δρ_max = 0.15 e Å⁻³
2013 reflections	Δρ_min = −0.13 e Å⁻³
307 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O(1)	0.2432 (2)	0.3076 (3)	−0.04171 (8)	0.010
O(2)	0.4922 (2)	0.1317 (3)	0.06367 (8)	0.009
C(1)	0.1234 (2)	0.7008 (2)	−0.03634 (6)	0.010
C(2)	0.2507 (2)	0.4985 (2)	−0.00234 (6)	0.008
C(3)	0.3740 (2)	0.5199 (2)	0.06969 (6)	0.008
C(4)	0.4924 (1)	0.3281 (2)	0.10055 (6)	0.007
C(5)	0.6223 (1)	0.3358 (2)	0.17655 (6)	0.006
C(6)	0.6232 (1)	0.5266 (2)	0.22471 (5)	0.007
C(7)	0.7462 (1)	0.5262 (2)	0.29599 (5)	0.008
C(8)	0.8693 (2)	0.3368 (2)	0.32015 (6)	0.008
C(9)	0.8688 (1)	0.1466 (2)	0.27246 (5)	0.008
C(10)	0.7455 (1)	0.1444 (2)	0.20119 (5)	0.008
H(1A)	0.1043	0.8211	0.0030	0.052
H(1B)	−0.0030	0.6301	−0.0694	0.039
H(1C)	0.1719	0.8055	−0.0705	0.059
H(3)	0.3782	0.6871	0.0992	0.021
H(6)	0.5282	0.6738	0.2073	0.019
H(7)	0.7453	0.6751	0.3328	0.020
H(8)	0.9666	0.3372	0.3755	0.019
H(9)	0.9658	−0.0013	0.2906	0.020
H(10)	0.7436	−0.0034	0.1641	0.020
H(X1)	0.3765	0.1768	0.0028	0.048

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O(1)	0.0114 (4)	0.0086 (5)	0.0065 (4)	0.0007 (5)	0.0003 (4)	−0.0005 (3)
O(2)	0.0075 (5)	0.0107 (5)	0.0079 (5)	0.0013 (5)	0.0001 (4)	−0.0031 (5)
C(1)	0.0090 (5)	0.0101 (5)	0.0099 (4)	0.0016 (5)	0.0014 (4)	0.0019 (4)
C(2)	0.0070 (5)	0.0096 (5)	0.0069 (5)	0.0015 (5)	0.0018 (4)	0.0004 (5)
C(3)	0.0085 (5)	0.0075 (5)	0.0072 (5)	0.0024 (4)	0.0009 (4)	−0.0013 (4)
C(4)	0.0066 (5)	0.0072 (5)	0.0053 (4)	0.0000 (4)	0.0002 (4)	−0.0006 (4)
C(5)	0.0066 (4)	0.0055 (5)	0.0059 (4)	0.0010 (4)	0.0008 (4)	0.0001 (4)
C(6)	0.0080 (4)	0.0068 (4)	0.0058 (4)	0.0008 (3)	0.0006 (3)	−0.0012 (3)
C(7)	0.0084 (4)	0.0083 (4)	0.0069 (4)	0.0008 (4)	0.0013 (3)	−0.0013 (3)
C(8)	0.0079 (5)	0.0092 (5)	0.0060 (4)	0.0011 (4)	0.0010 (4)	0.0000 (4)
C(9)	0.0083 (4)	0.0064 (4)	0.0071 (4)	0.0020 (3)	0.0007 (3)	0.0005 (3)
C(10)	0.0085 (4)	0.0062 (4)	0.0063 (4)	0.0015 (4)	0.0010 (3)	0.0003 (3)

Geometric parameters (Å, º) top

O(1)—O(2)	2.499 (2)	C(4)—C(5)	1.481 (1)
C(2)—O(1)	1.286 (2)	C(5)—C(6)	1.402 (1)
C(4)—O(2)	1.293 (2)	C(5)—C(10)	1.405 (1)
O(1)—H(X1)	1.325	C(6)—C(7)	1.391 (1)
O(2)—H(X1)	1.247	C(7)—C(8)	1.395 (2)
C(1)—C(2)	1.495 (2)	C(8)—C(9)	1.395 (2)
C(1)—H(1A)	1.060	C(9)—C(10)	1.392 (1)
C(1)—H(1B)	1.064	C(6)—H(6)	1.079
C(1)—H(1C)	1.050	C(7)—H(7)	1.087
C(2)—C(3)	1.408 (2)	C(8)—H(8)	1.086
C(3)—C(4)	1.402 (2)	C(9)—H(9)	1.092
C(3)—H(3)	1.076	C(10)—H(10)	1.081

C(2)—O(1)—H(X1)	101.1	C(4)—C(5)—C(6)	121.7 (1)
C(4)—O(2)—H(X1)	102.6	C(4)—C(5)—C(10)	118.9 (1)
O(1)—H(X1)—O(2)	152.7	C(6)—C(5)—C(10)	119.4 (2)
C(2)—C(1)—H(1A)	113.0	C(5)—C(6)—C(7)	120.0 (1)
C(2)—C(1)—H(1B)	110.7	C(5)—C(6)—H(6)	120.6
C(2)—C(1)—H(1C)	109.8	C(7)—C(6)—H(6)	119.3
H(1A)—C(1)—H(1B)	108.4	C(6)—C(7)—C(8)	120.5 (1)
H(1A)—C(1)—H(1C)	107.2	C(6)—C(7)—H(7)	119.3
H(1B)—C(1)—H(1C)	107.5	C(8)—C(7)—H(7)	120.2
O(1)—C(2)—C(1)	117.3 (2)	C(7)—C(8)—C(9)	119.7 (2)
O(1)—C(2)—C(3)	122.0 (2)	C(7)—C(8)—H(8)	120.7
C(1)—C(2)—C(3)	120.7 (2)	C(9)—C(8)—H(8)	119.6
C(2)—C(3)—C(4)	119.8 (2)	C(8)—C(9)—C(10)	120.3 (1)
C(2)—C(3)—H(3)	118.8	C(8)—C(9)—H(9)	120.2 (1)
C(4)—C(3)—H(3)	121.3	C(10)—C(9)—H(9)	119.5
O(2)—C(4)—C(3)	121.2 (2)	C(5)—C(10)—C(9)	120.1 (1)
O(2)—C(4)—C(5)	116.2 (2)	C(5)—C(10)—H(10)	119.2
C(3)—C(4)—C(5)	122.7 (2)	C(9)—C(10)—H(10)	120.7

(neutron) top

Crystal data top

C₁₀H₁₀O₂	D_x = 1.350 Mg m⁻³
M_r = 162.19	Neutron radiation, λ = 1.012 Å
Monoclinic, P2₁/C	Cell parameters from 50 reflections
a = 8.027 (7) Å	θ = 8.1–43.8°
b = 5.483 (2) Å	µ = 0.20 mm⁻¹
c = 19.478 (13) Å	T = 20 K
β = 110.42 (5)°	Prism, colourless
V = 803.4 (6) Å³	6.0 × 2.8 × 1.2 mm
Z = 4

Data collection top

Huber 512 diffractometer	R_int = 0.023
Berylium monochromator	θ_max = 45.2°, θ_min = 3.2°
2θ/ω scans	h = −11→10
Absorption correction: gaussian ?	k = −1→7
T_min = 0.555, T_max = 0.737	l = −6→27
2722 measured reflections	3 standard reflections every 60 reflections
1597 independent reflections	intensity decay: none
1236 reflections with I > 2σ(I)

Refinement top

Refinement on F²	Calculated w = 1/[σ²]
Least-squares matrix: full	(Δ/σ)_max = 0.01
R[F² > 2σ(F²)] = 0.052	Δρ_max = 0.04 e Å⁻³
wR(F²) = 0.0500	Δρ_min = −0.04 e Å⁻³
1236 reflections	Extinction correction: XD
219 parameters	Extinction coefficient: 0.102 (4)
All H-atom parameters refined

Crystal data top

C₁₀H₁₀O₂	V = 803.4 (6) Å³
M_r = 162.19	Z = 4
Monoclinic, P2₁/C	Neutron radiation, λ = 1.012 Å
a = 8.027 (7) Å	µ = 0.20 mm⁻¹
b = 5.483 (2) Å	T = 20 K
c = 19.478 (13) Å	6.0 × 2.8 × 1.2 mm
β = 110.42 (5)°

Data collection top

Huber 512 diffractometer	1236 reflections with I > 2σ(I)
Absorption correction: gaussian ?	R_int = 0.023
T_min = 0.555, T_max = 0.737	3 standard reflections every 60 reflections
2722 measured reflections	intensity decay: none
1597 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.052	All H-atom parameters refined
wR(F²) = 0.0500	Δρ_max = 0.04 e Å⁻³
1236 reflections	Δρ_min = −0.04 e Å⁻³
219 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O(1)	0.2431 (4)	0.3084 (5)	−0.0416 (1)	0.013
O(2)	0.4920 (4)	0.1328 (5)	0.0635 (2)	0.013
C(1)	0.1230 (3)	0.7009 (4)	−0.0365 (1)	0.013
C(2)	0.2508 (3)	0.4990 (4)	−0.0023 (1)	0.010
C(3)	0.3743 (3)	0.5201 (4)	0.0698 (1)	0.010
C(4)	0.4923 (3)	0.3278 (4)	0.1007 (1)	0.009
C(5)	0.6226 (3)	0.3355 (4)	0.1765 (1)	0.009
C(6)	0.6231 (3)	0.5268 (4)	0.2245 (1)	0.010
C(7)	0.7466 (3)	0.5258 (4)	0.2962 (1)	0.011
C(8)	0.8688 (3)	0.3375 (4)	0.3200 (1)	0.010
C(9)	0.8690 (3)	0.1459 (4)	0.2724 (1)	0.011
C(10)	0.7455 (3)	0.1444 (4)	0.2012 (1)	0.010
H(1A)	0.1043 (11)	0.8211 (14)	0.0030 (4)	0.068
H(1B)	−0.0030 (9)	0.6301 (12)	−0.0694 (4)	0.052
H(1C)	0.1719 (9)	0.8054 (13)	−0.0705 (5)	0.078
H(3)	0.3782 (7)	0.6871 (10)	0.0992 (3)	0.028
H(6)	0.5282 (7)	0.6738 (9)	0.2073 (3)	0.025
H(7)	0.7453 (7)	0.6751 (9)	0.3328 (3)	0.026
H(8)	0.9666 (7)	0.3372 (10)	0.3755 (3)	0.024
H(9)	0.9658 (7)	−0.0013 (9)	0.2906 (3)	0.027
H(10)	0.7436 (7)	−0.0034 (10)	0.1641 (3)	0.027
H(X1)	0.3764 (19)	0.177 (3)	0.0027 (8)	0.063

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O(1)	0.012 (1)	0.013 (1)	0.010 (1)	0.002 (1)	−0.001 (1)	−0.002 (1)
O(2)	0.015 (1)	0.010 (1)	0.011 (2)	0.000 (1)	0.002 (1)	−0.003 (1)
C(1)	0.013 (1)	0.009 (1)	0.013 (1)	0.001 (1)	0.002 (1)	0.001 (1)
C(2)	0.011 (1)	0.009 (1)	0.009 (1)	0.002 (1)	0.002 (1)	0.001 (1)
C(3)	0.013 (1)	0.008 (1)	0.007 (1)	0.003 (1)	0.000 (1)	0.001 (1)
C(4)	0.011 (1)	0.006 (1)	0.009 (1)	0.000 (1)	0.001 (1)	0.000 (1)
C(5)	0.012 (1)	0.006 (1)	0.007 (1)	0.000 (1)	0.002 (1)	0.000 (1)
C(6)	0.012 (1)	0.007 (1)	0.010 (1)	0.001 (1)	0.001 (1)	−0.001 (1)
C(7)	0.012 (1)	0.010 (1)	0.008 (1)	0.003 (1)	0.002 (1)	0.001 (1)
C(8)	0.010 (1)	0.008 (1)	0.008 (1)	0.002 (1)	0.000 (1)	0.001 (1)
C(9)	0.012 (1)	0.009 (1)	0.010 (1)	0.002 (1)	0.002 (1)	0.000 (1)
C(10)	0.012 (1)	0.008 (1)	0.009 (1)	0.001 (1)	0.001 (1)	0.000 (1)
H(1A)	0.091 (6)	0.065 (5)	0.030 (3)	0.051 (5)	−0.001 (4)	−0.017 (4)
H(1B)	0.030 (3)	0.029 (4)	0.077 (5)	0.005 (3)	−0.015 (4)	−0.002 (4)
H(1C)	0.061 (4)	0.054 (4)	0.117 (7)	0.036 (4)	0.060 (5)	0.068 (5)
H(3)	0.037 (3)	0.016 (2)	0.023 (3)	0.006 (2)	−0.002 (3)	−0.006 (2)
H(6)	0.029 (3)	0.018 (2)	0.023 (3)	0.012 (2)	0.003 (2)	−0.001 (2)
H(7)	0.031 (3)	0.019 (2)	0.021 (3)	0.003 (2)	0.001 (2)	−0.008 (2)
H(8)	0.027 (3)	0.031 (3)	0.008 (3)	0.005 (2)	−0.006 (3)	−0.002 (2)
H(9)	0.028 (3)	0.023 (2)	0.022 (3)	0.013 (2)	0.000 (2)	0.008 (2)
H(10)	0.030 (3)	0.024 (3)	0.019 (3)	0.005 (2)	0.000 (3)	−0.006 (2)
H(X1)	0.066 (6)	0.047 (4)	0.077 (6)	−0.022 (4)	0.053 (6)	−0.025 (4)

Geometric parameters (Å, º) top

O(1)—O(2)	2.502 (4)	C(4)—C(5)	1.483 (4)
C(2)—O(1)	1.286 (4)	C(5)—C(6)	1.406 (3)
C(4)—O(2)	1.293 (4)	C(5)—C(10)	1.404 (3)
O(1)—H(X1)	1.329 (11)	C(6)—C(7)	1.402 (4)
O(2)—H(X1)	1.245 (11)	C(7)—C(8)	1.387 (4)
C(1)—C(2)	1.499 (4)	C(8)—C(9)	1.404 (4)
C(1)—H(1A)	1.064 (7)	C(9)—C(10)	1.394 (4)
C(1)—H(1B)	1.062 (8)	C(6)—H(6)	1.079 (6)
C(1)—H(1C)	1.051 (6)	C(7)—H(7)	1.090 (6)
C(2)—C(3)	1.414 (4)	C(8)—H(8)	1.091 (7)
C(3)—C(4)	1.405 (4)	C(9)—H(9)	1.090 (6)
C(3)—H(3)	1.076 (6)	C(10)—H(10)	1.085 (6)

C(2)—O(1)—H(X1)	101.2 (4)	C(4)—C(5)—C(6)	121.5 (2)
C(4)—O(2)—H(X1)	103.2 (4)	C(4)—C(5)—C(10)	119.0 (2)
O(1)—H(X1)—O(2)	152.3 (6)	C(6)—C(5)—C(10)	119.5 (3)
C(2)—C(1)—H(1A)	112.6 (5)	C(5)—C(6)—C(7)	119.8 (3)
C(2)—C(1)—H(1B)	110.8 (4)	C(5)—C(6)—H(6)	120.9 (4)
C(2)—C(1)—H(1C)	109.8 (4)	C(7)—C(6)—H(6)	119.2 (4)
H(1A)—C(1)—H(1B)	108.7 (7)	C(6)—C(7)—C(8)	120.4 (3)
H(1A)—C(1)—H(1C)	107.2 (7)	C(6)—C(7)—H(7)	119.0 (4)
H(1B)—C(1)—H(1C)	107.7 (7)	C(8)—C(7)—H(7)	120.6 (4)
O(1)—C(2)—C(1)	117.0 (3)	C(7)—C(8)—C(9)	120.1 (3)
O(1)—C(2)—C(3)	122.1 (3)	C(7)—C(8)—H(8)	120.7 (4)
C(1)—C(2)—C(3)	120.9 (2)	C(9)—C(8)—H(8)	119.2 (4)
C(2)—C(3)—C(4)	119.7 (2)	C(8)—C(9)—C(10)	119.9 (3)
C(2)—C(3)—H(3)	118.7 (4)	C(8)—C(9)—H(9)	120.4 (4)
C(4)—C(3)—H(3)	121.5 (4)	C(10)—C(9)—H(9)	119.7 (4)
O(2)—C(4)—C(3)	120.9 (3)	C(5)—C(10)—C(9)	120.3 (2)
O(2)—C(4)—C(5)	116.4 (3)	C(5)—C(10)—H(10)	119.1 (4)
C(3)—C(4)—C(5)	122.6 (2)	C(9)—C(10)—H(10)	120.6 (4)

Experimental details

	(xray)	(neutron)
Crystal data
Chemical formula	C₁₀H₁₀O₂	C₁₀H₁₀O₂
M_r	162.19	162.19
Crystal system, space group	Monoclinic, P2₁/C	Monoclinic, P2₁/C
Temperature (K)	20	20
a, b, c (Å)	8.006 (3), 5.482 (3), 19.444 (8)	8.027 (7), 5.483 (2), 19.478 (13)
β (°)	110.46 (3)	110.42 (5)
V (Å³)	799.5 (5)	803.4 (6)
Z	4	4
Radiation type	Ag Kα, λ = 0.5616 Å	Neutron, λ = 1.012 Å
µ (mm⁻¹)	0.06	0.20
Crystal size (mm)	0.3 (radius)	6.0 × 2.8 × 1.2

Data collection
Diffractometer	Huber 512 diffractometer	Huber 512 diffractometer
Absorption correction	Gaussian	Gaussian
T_min, T_max	0.972, 0.973	0.555, 0.737
No. of measured, independent and observed [I > 2σ(I)] reflections	10494, 2862, 2013	2722, 1597, 1236
R_int	0.024	0.023
(sin θ/λ)_max (Å⁻¹)	0.753	0.701

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.026, 0.0231, ?	0.052, 0.0500, ?
No. of reflections	2013	1236
No. of parameters	307	219
No. of restraints	?	?
H-atom treatment	H-atom parameters not refined	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.15, −0.13	0.04, −0.04

Table 10. Benzoylacetone - molecular dimensions, bonds (Å) and angles (°)). top

(a) Interatomic distances determined in the 20 K ND and the 8.4K XRD studies. The small differences between ND and XRD X-H distances are due to the use of fixed ND parameters for hydrogens in the X-ray refinement; thus s.u.'s are omitted for XRD distances involving hydrogen. (b) Bond angles determined in the 20K ND and the 8.4K XRD studies. As the hydrogen parameters were not refined in the X-ray study, s.u.'s are omitted for anglews involving hydrogen.

O(1)—O(2)	2.502 (4)	2.499 (2)
C(2)—O(1)	1.286 (4)	1.286 (2)
C(4)—O(2)	1.293 (4)	1.293 (2)
O(1)—H(X1)	1.329 (11)	1.325
O(2)—H(X1)	1.245 (11)	1.247
C(1)—C(2)	1.499 (4)	1.495 (2)
C(1)—H(1A)	1.064 (7)	1.060
C(1)—H(1B)	1.062 (8)	1.064
C(1)—H(1C)	1.051 (6)	1.050
C(2)—C(3)	1.414 (4)	1.408 (2)
C(3)—C(4)	1.405 (4)	1.402 (2)
C(3)—H(3)	1.076 (6)	1.076
C(4)—C(5)	1.483 (4)	1.481 (1)
C(5)—C(6)	1.406 (3)	1.402 (1)
C(5)—C(10)	1.404 (3)	1.405 (1)
C(6)—C(7)	1.402 (4)	1.391 (1)
C(7)—C(8)	1.387 (4)	1.395 (2)
C(8)—C(9)	1.404 (4)	1.395 (2)
C(9)—C(10)	1.394 (4)	1.392 (1)
C(6)—H(6)	1.079 (6)	1.079
C(7)—H(7)	1.090 (6)	1.087
C(8)—H(8)	1.091 (7)	1.086
C(9)—H(9)	1.090 (6)	1.092
C(10)—H(10)	1.085 (6)	1.081
C(2)—O(1)—H(X1)	101.2 (4)	101.1
C(4)—O(2)—H(X1)	103.2 (4)	102.6
O(1)—H(X1)—O(2)	152.3 (6)	152.7
C(2)—C(1)—H(1A)	112.6 (5)	113.0
C(2)—C(1)—H(1B)	110.8 (4)	110.7
C(2)—C(1)—H(1C)	109.8 (4)	109.8
H(1A)—C(1)—H(1B)	108.7 (7)	108.4
H(1A)—C(1)—H(1C)	107.2 (7)	107.2
H(1B)—C(1)—H(1C)	107.7 (7)	107.5
O(1)—C(2)—C(1)	117.0 (3)	117.3 (2)
O(1)—C(2)—C(3)	122.1 (3)	122.0 (2)
C(1)—C(2)—C(3)	120.9 (2)	120.7 (2)
C(2)—C(3)—C(4)	119.7 (2)	119.8 (2)
C(2)—C(3)—H(3)	118.7 (4)	118.8
C(4)—C(3)—H(3)	121.5 (4)	121.3
O(2)—C(4)—C(3)	120.9 (3)	121.2 (2)
O(2)—C(4)—C(5)	116.4 (3)	116.2 (2)
C(3)—C(4)—C(5)	122.6 (2)	122.7 (2)
C(4)—C(5)—C(6)	121.5 (2)	121.7 (1)
C(4)—C(5)—C(10)	119.0 (2)	118.9 (1)
C(6)—C(5)—C(10)	119.5 (3)	119.4 (2)
C(5)—C(6)—C(7)	119.8 (3)	120.0 (1)
C(5)—C(6)—H(6)	120.9 (4)	120.6
C(7)—C(6)—H(6)	119.2 (4)	119.3
C(6)—C(7)—C(8)	120.4 (3)	120.5 (1)
C(6)—C(7)—H(7)	119.0 (4)	119.3
C(8)—C(7)—H(7)	120.6 (4)	120.2
C(7)—C(8)—C(9)	120.1 (3)	119.7 (2)
C(7)—C(8)—H(8)	120.7 (4)	120.7
C(9)—C(8)—H(8)	119.2 (4)	119.6
C(8)—C(9)—C(10)	119.9 (3)	120.3 (1)
C(8)—C(9)—H(9)	120.4 (4)	120.2 (1)
C(10)—C(9)—H(9)	119.7 (4)	119.5
C(5)—C(10)—C(9)	120.3 (2)	120.1 (1)
C(5)—C(10)—H(10)	119.1 (4)	119.2
C(9)—C(10)—H(10)	120.6 (4)	120.7

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