trans-4-(Tosyl­oxymeth­yl)cyclo­hexane­carboxylic acid

Qi, Q.-R.; Huang, W.-C.; Zheng, H.

doi:10.1107/S1600536807068572

organic compounds

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ISSN: 2056-9890

Volume 64| Part 2| February 2008| Page o405

doi:10.1107/S1600536807068572

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trans-4-(Tosyloxymethyl)cyclohexanecarboxylic acid

Qing-Rong Qi,^a Wen-Cai Huang ^b and Hu Zheng ^a ^*

^aDepartment of Medicinal Chemistry, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China, and ^bDepartment of Pharmaceutical and Bioengineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China
^*Correspondence e-mail: wcums416@yahoo.com.cn

(Received 14 December 2007; accepted 28 December 2007; online 9 January 2008)

The title compound, C₁₅H₂₀O₅S, is an intermediate in the synthesis of a new type of poly(amidoamine) (PAMAM) dendrimer. The cyclohexane ring exhibits a chair conformation, with C—C bond lengths in the range 1.518 (3)–1.531 (3) Å and C—C—C angles in the range 110.45 (19)–112.09 (19)°; these agree well with the values in other cyclohexane derivatives described in the literature. In the crystal structure, adjacent molecules are linked by O—H⋯·O hydrogen bonds. The H atoms of the methyl group are disordered equally over two positions.

Related literature

For related literature, see: Ahmed et al. (2001 ); Bucourt & Hainaut (1965 ); Dunitz & Strickler (1966 ); Grabchev et al. (2003 ); Luger et al. (1972 ); Wang et al. (2004 ); van Koningsveld & Jansen (1984 ).

Experimental

Crystal data

C₁₅H₂₀O₅S
M_r = 312.37
Triclinic, $[P \overline 1]$
a = 5.9006 (5) Å
b = 7.0880 (9) Å
c = 20.2754 (18) Å
α = 90.371 (3)°
β = 97.479 (2)°
γ = 111.222 (2)°
V = 782.44 (14) Å³
Z = 2
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 293 (2) K
0.53 × 0.48 × 0.12 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ) T_min = 0.890, T_max = 0.974
7685 measured reflections
3562 independent reflections
2442 reflections with I > 2σ(I)
R_int = 0.024

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.179
S = 1.01
3562 reflections
195 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.48 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4O⋯O5ⁱ	0.89 (4)	1.76 (4)	2.654 (3)	178 (3)
Symmetry code: (i) -x, -y, -z+1.

Data collection: RAPID-AUTO (Rigaku, 2004 ); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 1997 ); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807068572/wn2233sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536807068572/wn2233Isup2.hkl

checkCIF report

Comment top

PAMAM (poly(amidoamine)) dendrimers have attracted much interest for their symmetry, high degree of branching and high density of terminal functional groups, which can participate in different reactions. The modification of the periphery of PAMAM dendrimers, aimed to change their physical or chemical properties, have been reported recently (Grabchev et al.,2003; Ahmed et al.,2001; Wang et al.,2004). To improve the lipophilicity of PAMAM dendrimers and provide a new type of linker with special stereostructure, a series of cyclohexane derivatives were synthesized. In our synthetic work on PAMAM dendrimers, we obtained the title compound, and report here its crystal structure.

The crystal structure shows that molecules are linked by O—H···.O hydrogen bonds and the cyclohexane ring exists in the chair conformation. The mean C—C bond length of the cyclohexane ring is 1.524 (3) Å, which is close to the value in trans-1,4-cyclohexane dicarboxylic acid (1.523 (3) Å; Luger et al., 1972). The mean endocyclic angle is 111.3 (2)°, which is close to the value for an ideal cyclohexane ring, (C—C—C 111.1°; Bucourt & Hainaut, 1965) and the mean value in trans-1,4-cyclohexanedicarboxylic acid (111.4 (4)°; Dunitz & Strickler, 1966; Luger et al., 1972).

Related literature top

For related literature, see: Ahmed et al. (2001); Bucourt & Hainaut (1965); Dunitz & Strickler (1966); Grabchev et al. (2003); Luger et al. (1972); Wang et al. (2004).

Experimental top

trans-4-(Methoxycarbonyl)cyclohexanemethanol (10 mmol), triethylamine (10 mmol) and a small amount of trimethylamine hydrochloride were suspended in dichloromethane (20 ml), and p-toluenesulfonyl chloride (11 mmol) was added dropwise with vigorous stirring at room temperature; after 1 h the reaction was quenched by addition of water. The organic layer which separated was evaporated to give an oil and the oil was hydrolyzed in a methanol and aqueous NaOH (11 mmol) solution for 5 h at 323 K. The title compound was then obtained by acidification with hydrochloric acid and recrystallized from acetone. Colorless crystals suitable for X-ray analysis were obtained by slow evaporation of a cyclohexane and acetone solution at room temperature.

Computing details top

Data collection: RAPID-AUTO (Rigaku, 2004); cell refinement: RAPID-AUTO (Rigaku, 2004); data reduction: RAPID-AUTO (Rigaku, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL (Sheldrick, 1997b).

Figures top

	Fig. 1. The molecular structure of the title compound, with displacement ellipsoids drawn at the 20% probability level.
	Fig. 2. A packing diagram of the title compound. Intermolecular hydrogen bonds are shown as dashed lines.

trans-4-(Tosyloxymethyl)cyclohexanecarboxylic acid top

Crystal data top

C₁₅H₂₀O₅S	Z = 2
M_r = 312.37	F(000) = 332
Triclinic, P1	D_x = 1.326 Mg m⁻³
a = 5.9006 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.0880 (9) Å	Cell parameters from 5250 reflections
c = 20.2754 (18) Å	θ = 3.1–27.5°
α = 90.371 (3)°	µ = 0.23 mm⁻¹
β = 97.479 (2)°	T = 293 K
γ = 111.222 (2)°	Block, colourless
V = 782.44 (14) Å³	0.53 × 0.48 × 0.12 mm

Data collection top

Rigaku R-AXIS RAPID diffractometer	3562 independent reflections
Radiation source: Rotating Anode	2442 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.024
ω scans	θ_max = 27.5°, θ_min = 3.1°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −6→7
T_min = 0.890, T_max = 0.974	k = −9→9
7685 measured reflections	l = −26→26

Refinement top

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)] = 0.044	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.179	w = 1/[σ²(F_o²) + (0.1018P)² + 0.285P] where P = (F_o² + 2F_c²)/3
S = 1.01	(Δ/σ)_max < 0.001
3562 reflections	Δρ_max = 0.30 e Å⁻³
195 parameters	Δρ_min = −0.48 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997a), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.047 (7)

Crystal data top

C₁₅H₂₀O₅S	γ = 111.222 (2)°
M_r = 312.37	V = 782.44 (14) Å³
Triclinic, P1	Z = 2
a = 5.9006 (5) Å	Mo Kα radiation
b = 7.0880 (9) Å	µ = 0.23 mm⁻¹
c = 20.2754 (18) Å	T = 293 K
α = 90.371 (3)°	0.53 × 0.48 × 0.12 mm
β = 97.479 (2)°

Data collection top

Rigaku R-AXIS RAPID diffractometer	3562 independent reflections
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	2442 reflections with I > 2σ(I)
T_min = 0.890, T_max = 0.974	R_int = 0.024
7685 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.179	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	Δρ_max = 0.30 e Å⁻³
3562 reflections	Δρ_min = −0.48 e Å⁻³
195 parameters

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	U_iso*/U_eq	Occ. (<1)
S1	0.95047 (11)	0.96589 (9)	0.20554 (3)	0.0486 (2)
O1	0.8978 (3)	0.9010 (3)	0.27746 (8)	0.0470 (4)
O2	0.8958 (4)	1.1432 (3)	0.19236 (10)	0.0610 (5)
O3	1.1925 (3)	0.9708 (3)	0.20334 (10)	0.0655 (5)
O4	−0.1018 (4)	0.1728 (3)	0.44904 (11)	0.0642 (6)
O5	0.2394 (4)	0.1042 (3)	0.46193 (10)	0.0624 (5)
C1	0.5304 (5)	0.5148 (3)	0.31242 (13)	0.0497 (6)
H1A	0.4091	0.4897	0.2729	0.060*
H1B	0.6801	0.5106	0.2988	0.060*
C2	0.4366 (5)	0.3497 (4)	0.36070 (13)	0.0518 (6)
H2A	0.3981	0.2181	0.3383	0.062*
H2B	0.5646	0.3666	0.3980	0.062*
C3	0.2093 (4)	0.3565 (3)	0.38646 (11)	0.0431 (5)
H3	0.0790	0.3290	0.3484	0.052*
C4	0.2559 (5)	0.5666 (3)	0.41785 (12)	0.0486 (6)
H4A	0.1041	0.5699	0.4303	0.058*
H4B	0.3742	0.5924	0.4580	0.058*
C5	0.3526 (5)	0.7314 (4)	0.36991 (13)	0.0514 (6)
H5A	0.3915	0.8629	0.3924	0.062*
H5B	0.2255	0.7154	0.3325	0.062*
C6	0.5811 (4)	0.7245 (3)	0.34417 (11)	0.0408 (5)
H6	0.7122	0.7516	0.3820	0.049*
C7	0.1191 (4)	0.1984 (3)	0.43585 (11)	0.0425 (5)
C8	0.6621 (4)	0.8906 (3)	0.29618 (12)	0.0436 (5)
H8A	0.5399	0.8620	0.2568	0.052*
H8B	0.6794	1.0195	0.3171	0.052*
C9	0.7391 (4)	0.7608 (4)	0.15427 (12)	0.0478 (6)
C10	0.7786 (5)	0.5806 (4)	0.15077 (14)	0.0583 (7)
H10	0.9218	0.5712	0.1731	0.070*
C11	0.6055 (6)	0.4147 (5)	0.11411 (15)	0.0655 (8)
H11	0.6334	0.2940	0.1116	0.079*
C12	0.3903 (6)	0.4259 (5)	0.08091 (14)	0.0629 (7)
C13	0.3540 (5)	0.6067 (5)	0.08475 (15)	0.0657 (8)
H13	0.2106	0.6158	0.0624	0.079*
C14	0.5257 (5)	0.7752 (4)	0.12102 (14)	0.0581 (7)
H14	0.4985	0.8963	0.1231	0.070*
C15	0.1990 (7)	0.2410 (6)	0.04226 (17)	0.0855 (11)
H15A	0.2558	0.1300	0.0451	0.103*	0.50
H15B	0.1716	0.2706	−0.0036	0.103*	0.50
H15C	0.0481	0.2051	0.0608	0.103*	0.50
H15D	0.0612	0.2738	0.0231	0.103*	0.50
H15E	0.1454	0.1332	0.0717	0.103*	0.50
H15F	0.2689	0.1987	0.0074	0.103*	0.50
H4O	−0.145 (6)	0.081 (5)	0.4795 (18)	0.085 (11)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0436 (4)	0.0492 (4)	0.0561 (4)	0.0181 (3)	0.0138 (3)	0.0168 (3)
O1	0.0410 (8)	0.0506 (9)	0.0490 (9)	0.0158 (7)	0.0070 (7)	0.0125 (7)
O2	0.0630 (12)	0.0484 (10)	0.0761 (12)	0.0226 (9)	0.0186 (10)	0.0222 (9)
O3	0.0395 (9)	0.0834 (14)	0.0793 (13)	0.0239 (9)	0.0234 (9)	0.0198 (10)
O4	0.0575 (11)	0.0653 (12)	0.0795 (13)	0.0268 (10)	0.0295 (10)	0.0342 (10)
O5	0.0615 (11)	0.0614 (11)	0.0751 (12)	0.0295 (9)	0.0257 (10)	0.0298 (9)
C1	0.0605 (15)	0.0417 (12)	0.0521 (13)	0.0198 (11)	0.0224 (11)	0.0060 (10)
C2	0.0639 (15)	0.0373 (12)	0.0632 (15)	0.0235 (11)	0.0254 (12)	0.0101 (10)
C3	0.0470 (12)	0.0366 (11)	0.0454 (12)	0.0136 (9)	0.0107 (10)	0.0065 (9)
C4	0.0595 (14)	0.0382 (12)	0.0528 (13)	0.0191 (11)	0.0206 (11)	0.0057 (10)
C5	0.0641 (15)	0.0374 (12)	0.0616 (14)	0.0237 (11)	0.0246 (12)	0.0111 (10)
C6	0.0454 (12)	0.0363 (11)	0.0419 (11)	0.0149 (9)	0.0104 (9)	0.0093 (8)
C7	0.0440 (12)	0.0367 (11)	0.0474 (12)	0.0138 (9)	0.0117 (10)	0.0049 (9)
C8	0.0446 (12)	0.0401 (11)	0.0502 (12)	0.0178 (10)	0.0143 (10)	0.0119 (9)
C9	0.0486 (13)	0.0572 (14)	0.0464 (12)	0.0277 (11)	0.0131 (10)	0.0120 (10)
C10	0.0613 (16)	0.0627 (16)	0.0602 (15)	0.0345 (13)	0.0065 (13)	0.0108 (12)
C11	0.085 (2)	0.0545 (16)	0.0618 (16)	0.0309 (15)	0.0104 (15)	0.0065 (12)
C12	0.0669 (18)	0.0685 (18)	0.0484 (14)	0.0174 (14)	0.0123 (13)	0.0065 (12)
C13	0.0554 (16)	0.085 (2)	0.0592 (16)	0.0309 (15)	−0.0002 (13)	0.0036 (14)
C14	0.0601 (16)	0.0658 (17)	0.0585 (15)	0.0349 (13)	0.0078 (12)	0.0094 (12)
C15	0.087 (2)	0.082 (2)	0.0660 (19)	0.0063 (18)	0.0072 (17)	−0.0036 (16)

Geometric parameters (Å, º) top

S1—O3	1.4226 (18)	C5—H5B	0.9700
S1—O2	1.4250 (19)	C6—C8	1.513 (3)
S1—O1	1.5678 (17)	C6—H6	0.9800
S1—C9	1.755 (3)	C8—H8A	0.9700
O1—C8	1.465 (3)	C8—H8B	0.9700
O4—C7	1.313 (3)	C9—C10	1.382 (4)
O4—H4O	0.89 (4)	C9—C14	1.387 (4)
O5—C7	1.216 (3)	C10—C11	1.378 (4)
C1—C2	1.524 (3)	C10—H10	0.9300
C1—C6	1.525 (3)	C11—C12	1.387 (4)
C1—H1A	0.9700	C11—H11	0.9300
C1—H1B	0.9700	C12—C13	1.377 (4)
C2—C3	1.518 (3)	C12—C15	1.514 (4)
C2—H2A	0.9700	C13—C14	1.383 (4)
C2—H2B	0.9700	C13—H13	0.9300
C3—C7	1.505 (3)	C14—H14	0.9300
C3—C4	1.531 (3)	C15—H15A	0.9600
C3—H3	0.9800	C15—H15B	0.9600
C4—C5	1.520 (3)	C15—H15C	0.9600
C4—H4A	0.9700	C15—H15D	0.9600
C4—H4B	0.9700	C15—H15E	0.9600
C5—C6	1.525 (3)	C15—H15F	0.9600
C5—H5A	0.9700

O3—S1—O2	119.63 (12)	O4—C7—C3	113.7 (2)
O3—S1—O1	104.45 (11)	O1—C8—C6	108.88 (18)
O2—S1—O1	109.39 (11)	O1—C8—H8A	109.9
O3—S1—C9	109.50 (12)	C6—C8—H8A	109.9
O2—S1—C9	109.39 (12)	O1—C8—H8B	109.9
O1—S1—C9	103.13 (10)	C6—C8—H8B	109.9
C8—O1—S1	117.51 (13)	H8A—C8—H8B	108.3
C7—O4—H4O	110 (2)	C10—C9—C14	120.2 (3)
C2—C1—C6	111.4 (2)	C10—C9—S1	119.55 (19)
C2—C1—H1A	109.4	C14—C9—S1	120.1 (2)
C6—C1—H1A	109.4	C11—C10—C9	119.9 (2)
C2—C1—H1B	109.4	C11—C10—H10	120.1
C6—C1—H1B	109.4	C9—C10—H10	120.1
H1A—C1—H1B	108.0	C10—C11—C12	120.7 (3)
C3—C2—C1	111.5 (2)	C10—C11—H11	119.6
C3—C2—H2A	109.3	C12—C11—H11	119.6
C1—C2—H2A	109.3	C13—C12—C11	118.7 (3)
C3—C2—H2B	109.3	C13—C12—C15	121.2 (3)
C1—C2—H2B	109.3	C11—C12—C15	120.1 (3)
H2A—C2—H2B	108.0	C12—C13—C14	121.6 (3)
C7—C3—C2	112.18 (19)	C12—C13—H13	119.2
C7—C3—C4	109.70 (19)	C14—C13—H13	119.2
C2—C3—C4	111.24 (19)	C13—C14—C9	118.9 (3)
C7—C3—H3	107.8	C13—C14—H14	120.5
C2—C3—H3	107.8	C9—C14—H14	120.5
C4—C3—H3	107.8	C12—C15—H15A	109.5
C5—C4—C3	111.32 (19)	C12—C15—H15B	109.5
C5—C4—H4A	109.4	H15A—C15—H15B	109.5
C3—C4—H4A	109.4	C12—C15—H15C	109.5
C5—C4—H4B	109.4	H15A—C15—H15C	109.5
C3—C4—H4B	109.4	H15B—C15—H15C	109.5
H4A—C4—H4B	108.0	C12—C15—H15D	109.5
C4—C5—C6	112.09 (19)	H15A—C15—H15D	141.1
C4—C5—H5A	109.2	H15B—C15—H15D	56.3
C6—C5—H5A	109.2	H15C—C15—H15D	56.3
C4—C5—H5B	109.2	C12—C15—H15E	109.5
C6—C5—H5B	109.2	H15A—C15—H15E	56.3
H5A—C5—H5B	107.9	H15B—C15—H15E	141.1
C8—C6—C5	108.55 (18)	H15C—C15—H15E	56.3
C8—C6—C1	112.53 (19)	H15D—C15—H15E	109.5
C5—C6—C1	110.45 (19)	C12—C15—H15F	109.5
C8—C6—H6	108.4	H15A—C15—H15F	56.3
C5—C6—H6	108.4	H15B—C15—H15F	56.3
C1—C6—H6	108.4	H15C—C15—H15F	141.1
O5—C7—O4	122.8 (2)	H15D—C15—H15F	109.5
O5—C7—C3	123.5 (2)	H15E—C15—H15F	109.5

O3—S1—O1—C8	177.44 (16)	C5—C6—C8—O1	173.23 (17)
O2—S1—O1—C8	48.24 (18)	C1—C6—C8—O1	−64.2 (3)
C9—S1—O1—C8	−68.10 (17)	O3—S1—C9—C10	37.0 (2)
C6—C1—C2—C3	56.1 (3)	O2—S1—C9—C10	169.9 (2)
C1—C2—C3—C7	−178.2 (2)	O1—S1—C9—C10	−73.7 (2)
C1—C2—C3—C4	−54.9 (3)	O3—S1—C9—C14	−147.2 (2)
C7—C3—C4—C5	178.8 (2)	O2—S1—C9—C14	−14.3 (3)
C2—C3—C4—C5	54.1 (3)	O1—S1—C9—C14	102.0 (2)
C3—C4—C5—C6	−54.7 (3)	C14—C9—C10—C11	0.0 (4)
C4—C5—C6—C8	179.1 (2)	S1—C9—C10—C11	175.7 (2)
C4—C5—C6—C1	55.3 (3)	C9—C10—C11—C12	−0.5 (4)
C2—C1—C6—C8	−177.1 (2)	C10—C11—C12—C13	0.7 (5)
C2—C1—C6—C5	−55.6 (3)	C10—C11—C12—C15	−178.4 (3)
C2—C3—C7—O5	13.6 (3)	C11—C12—C13—C14	−0.4 (5)
C4—C3—C7—O5	−110.5 (3)	C15—C12—C13—C14	178.7 (3)
C2—C3—C7—O4	−167.2 (2)	C12—C13—C14—C9	−0.1 (4)
C4—C3—C7—O4	68.6 (3)	C10—C9—C14—C13	0.2 (4)
S1—O1—C8—C6	147.88 (16)	S1—C9—C14—C13	−175.4 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4O···O5ⁱ	0.89 (4)	1.76 (4)	2.654 (3)	178 (3)

Symmetry code: (i) −x, −y, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₅H₂₀O₅S
M_r	312.37
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	5.9006 (5), 7.0880 (9), 20.2754 (18)
α, β, γ (°)	90.371 (3), 97.479 (2), 111.222 (2)
V (Å³)	782.44 (14)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.23
Crystal size (mm)	0.53 × 0.48 × 0.12

Data collection
Diffractometer	Rigaku R-AXIS RAPID diffractometer
Absorption correction	Multi-scan (ABSCOR; Higashi, 1995)
T_min, T_max	0.890, 0.974
No. of measured, independent and observed [I > 2σ(I)] reflections	7685, 3562, 2442
R_int	0.024
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.179, 1.01
No. of reflections	3562
No. of parameters	195
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.30, −0.48

Computer programs: RAPID-AUTO (Rigaku, 2004), SHELXS97 (Sheldrick, 1997a), SHELXL97 (Sheldrick, 1997a), SHELXTL (Sheldrick, 1997b).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4O···O5ⁱ	0.89 (4)	1.76 (4)	2.654 (3)	178 (3)

Symmetry code: (i) −x, −y, −z+1.

Acknowledgements

The authors thank Mr Kai-Bei Yu of the Chengdu Branch of the Chinese Academy of Science for the X-ray measurements.

References

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