1-Phenyl-5-{[2-(trimethyl­sil­yl)eth­yl]sulfon­yl}-1H-tetra­zole

Tymann, D.; Nelson, B.; Strohmann, C.; Preut, H.; Hiersemann, M.

doi:10.1107/S1600536811030492

organic compounds

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ISSN: 2056-9890

Volume 67| Part 9| September 2011| Page o2369

doi:10.1107/S1600536811030492

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1-Phenyl-5-{[2-(trimethylsilyl)ethyl]sulfonyl}-1H-tetrazole

David Tymann,^a Björn Nelson,^a Carsten Strohmann,^a Hans Preut ^a ^* and Martin Hiersemann ^a

^aFakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany
^*Correspondence e-mail: hans.preut@tu-dortmund.de

(Received 19 July 2011; accepted 28 July 2011; online 17 August 2011)

The title compound, C₁₂H₁₈N₄O₂SSi, was synthesized to be employed in a Julia–Kocieński olefination. In the molecule, the dihedral angle between the phenyl ring and the tetrazole ring is 41.50 (5)°. The significantly longer Si—C(methylene) bond [1.8786 (13) Å] and the shortened adjacent C—C bond [1.5172 (18) Å], as well as the significant deviation of the corresponding Si—C—C angle [114.16 (9)°] from the ideal tetrahedral angle, can be attributed to the β-effect of silicon. In the crystal, molecules are held together by van der Waals interactions.

Related literature

For Julia–Kocieński olefination, see: Blakemore et al. (1998 ). For the use of unsaturated α-keto esters in intramolecular carbonyl-ene reactions in natural product synthesis, see: Helmboldt & Hiersemann (2009 ); Helmboldt et al. (2006 ); Schnabel & Hiersemann (2009 ); Schnabel et al. (2011 ) The title compound was synthesized using a reduction of ethyl 2-(trimethylsilyl)acetate (Gerlach, 1977 ) followed by a Mitsunobu reaction (Mitsunobu & Yamada, 1967 ; Mitsunobu et al., 1967 ) and a subsequent Mo-(VI)-catalyzed oxidation of the thioether (Schultz et al., 1963 ).

Experimental

Crystal data

C₁₂H₁₈N₄O₂SSi
M_r = 310.45
Monoclinic, P 2₁ /c
a = 11.3126 (4) Å
b = 13.2707 (4) Å
c = 10.8277 (4) Å
β = 106.902 (4)°
V = 1555.31 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 173 K
0.50 × 0.50 × 0.20 mm

Data collection

Oxford Diffraction Xcalibur S CCD diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 $[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]$ ) T_min = 0.868, T_max = 0.944
22841 measured reflections
3384 independent reflections
2961 reflections with I > 2σ(I)
R_int = 0.024

Refinement

R[F² > 2σ(F²)] = 0.027
wR(F²) = 0.079
S = 1.10
3384 reflections
184 parameters
H-atom parameters constrained
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.37 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 $[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]$ ); cell refinement: CrysAlis CCD; data reduction: CrysAlis CCD; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811030492/hg5066sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811030492/hg5066Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811030492/hg5066Isup3.cml

checkCIF report

Comment top

On the search for an alternative synthetic route for the preparation of unsaturated α-keto esters we envisioned the Julia–Kocieński olefination (Blakemore et al., 1998) as a key connecting step for the construction of the C=C-double bond. Unsaturated α-keto esters have been successfully employed in intramolecular carbonyl-ene reactions in natural product synthesis (Helmboldt et al., 2006; Helmboldt & Hiersemann, 2009; Schnabel & Hiersemann, 2009; Schnabel et al., 2011). For the preparation of the title compound I, 1-phenyl-5-((2-(trimethylsilyl)ethyl)thio)-1H-tetrazole was synthesized using a reduction of ethyl 2-(trimethylsilyl)acetate (Gerlach, 1977) followed by a Mitsunobu reaction (Mitsunobu & Yamada, 1967; Mitsunobu et al., 1967). A subsequent Mo-(VI)-catalyzed oxidation of the thioether II (Schultz et al., 1963) gave the title compound (I).

Related literature top

For Julia–Kocieński olefination, see: Blakemore et al. (1998). For the use of unsaturated α-keto esters in intramolecular carbonyl-ene reactions in natural product synthesis, see: Helmboldt & Hiersemann (2009); Helmboldt et al. (2006); Schnabel & Hiersemann (2009); Schnabel et al. (2011) The title compound was synthesized using a reduction of ethyl 2-(trimethylsilyl)acetate (Gerlach, 1977) followed by a Mitsunobu reaction (Mitsunobu & Yamada, 1967; Mitsunobu et al., 1967) and a subsequent Mo-(VI)-catalyzed oxidation of the thioether (Schultz et al., 1963)

Experimental top

To a solution of II (6.07 g, 21.8 mmol, 1.0 eq) in ethanol (220 ml, 10 ml/mmol II) was added a solution of (NH₄)Mo₇O₂₄.2H₂O (2.70 g, 0.22 mmol, 0.1 eq) in 35% aqueous H₂O₂ (18.75 ml, 0.22 mol, 10.0 eq). After stirring at room temperature for 22 h the reaction mixture was diluted with aqueous NH₄Cl solution and methylene chloride. The layers were separated and the aqueous phase was extracted with methylene chloride (3x). The combined organic phases were washed with water (3x), dried over anhydrous MgSO₄, filtered, and concentrated under reduced pressure (323 K, 0.05 mbar) to afford I (6.72 g, 21.7 mmol, 99%) as crystals. Single crystals of I were obtained by recrystallization from n-pentane to give colorless cuboids: R_f 0.63 (cyclohexane/ethyl acetate 5/1); ¹H NMR (CDCl₃, 400 MHz, δ): 0.11 (s, 9H), 1.10–1.16 (m, 2H), 3.64–3.70 (m, 2H), 7.61–7.70 (m, 5H); ¹³C NMR (CDCl₃, 101 MHz, δ): -1.8 (3xCH₃), 8.4 (CH₂), 53.3 (CH₂), 125.3 (2xCH), 129.9 (2xCH), 131.7 (CH), 133.3 (C), 153.5 (C); IR (cm^-1): 2955 (w) (ν_as,s C—H, CH₃, CH₂), 1496 (m) (ν C=C, Ar), 1426 (w), 1347 (s) (ν R₂SO₂), 1251 (m), 1172 (m), 1152 (s), 1111 (w), 1014 (w), 834 (m); Anal. Calcd. for C₁₂H₁₈N₄O₂SSi: C, 46.4; H, 5.8; N, 18.1; Found: C, 46.4; H, 5.8; N, 17.9; M = 310.45 g/mol.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis CCD (Oxford Diffraction, 2008); data reduction: CrysAlis CCD (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

Fig. 1. : The molecular structure of the title compound, showing the labelling of all non-H atoms. Displacement ellipsoids are shown at the 30% probability level.

1-Phenyl-5-{[2-(trimethylsilyl)ethyl]sulfonyl}-1H-tetrazole top

Crystal data top

C₁₂H₁₈N₄O₂SSi	F(000) = 656
M_r = 310.45	D_x = 1.326 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 16653 reflections
a = 11.3126 (4) Å	θ = 2.4–29.2°
b = 13.2707 (4) Å	µ = 0.29 mm⁻¹
c = 10.8277 (4) Å	T = 173 K
β = 106.902 (4)°	Block, colourless
V = 1555.31 (9) Å³	0.50 × 0.50 × 0.20 mm
Z = 4

Data collection top

Oxford Diffraction Xcalibur S CCD diffractometer	3384 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2961 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.024
Detector resolution: 16.0560 pixels mm^-1	θ_max = 27.0°, θ_min = 2.4°
ω scans	h = −14→14
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008)	k = −16→16
T_min = 0.868, T_max = 0.944	l = −13→13
22841 measured reflections

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)] = 0.027	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.079	H-atom parameters constrained
S = 1.10	w = 1/[σ²(F_o²) + (0.0465P)² + 0.3668P] where P = (F_o² + 2F_c²)/3
3384 reflections	(Δ/σ)_max = 0.001
184 parameters	Δρ_max = 0.37 e Å⁻³
0 restraints	Δρ_min = −0.37 e Å⁻³

Crystal data top

C₁₂H₁₈N₄O₂SSi	V = 1555.31 (9) Å³
M_r = 310.45	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 11.3126 (4) Å	µ = 0.29 mm⁻¹
b = 13.2707 (4) Å	T = 173 K
c = 10.8277 (4) Å	0.50 × 0.50 × 0.20 mm
β = 106.902 (4)°

Data collection top

Oxford Diffraction Xcalibur S CCD diffractometer	3384 independent reflections
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008)	2961 reflections with I > 2σ(I)
T_min = 0.868, T_max = 0.944	R_int = 0.024
22841 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.027	0 restraints
wR(F²) = 0.079	H-atom parameters constrained
S = 1.10	Δρ_max = 0.37 e Å⁻³
3384 reflections	Δρ_min = −0.37 e Å⁻³
184 parameters

Special details top

Experimental. CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.32.37 (release 24-10-2008) Empirical absorption correction using sperical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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
Si	0.47993 (3)	0.79710 (3)	1.25192 (3)	0.01949 (10)
C1	0.47042 (15)	0.87175 (12)	1.39384 (14)	0.0341 (3)
H1A	0.3933	0.8557	1.4135	0.051*
H1B	0.4722	0.9438	1.3744	0.051*
H1C	0.5408	0.8552	1.4684	0.051*
C2	0.61720 (14)	0.83876 (13)	1.20403 (15)	0.0346 (3)
H2A	0.6923	0.8247	1.2743	0.052*
H2B	0.6114	0.9113	1.1862	0.052*
H2C	0.6203	0.8022	1.1263	0.052*
C3	0.48654 (13)	0.66005 (11)	1.28620 (15)	0.0310 (3)
H3A	0.4895	0.6228	1.2090	0.046*
H3B	0.4130	0.6399	1.3105	0.046*
H3C	0.5607	0.6450	1.3573	0.046*
C4	0.33521 (12)	0.81809 (10)	1.11572 (13)	0.0255 (3)
H4A	0.3418	0.7802	1.0393	0.031*
H4B	0.2643	0.7903	1.1407	0.031*
C5	0.30914 (11)	0.92782 (10)	1.07831 (12)	0.0206 (3)
H5A	0.3797	0.9573	1.0541	0.025*
H5B	0.2977	0.9664	1.1523	0.025*
S	0.17351 (3)	0.93484 (2)	0.94605 (3)	0.01563 (9)
O1	0.19901 (9)	0.90232 (7)	0.83074 (9)	0.0253 (2)
O2	0.07296 (8)	0.89053 (7)	0.98167 (9)	0.0222 (2)
C6	0.14770 (11)	1.06672 (9)	0.93227 (12)	0.0162 (2)
N1	0.20780 (10)	1.12950 (8)	1.02188 (10)	0.0209 (2)
N2	0.16789 (11)	1.22251 (8)	0.97617 (11)	0.0253 (3)
N3	0.08670 (11)	1.21661 (8)	0.86430 (11)	0.0233 (2)
N4	0.07262 (9)	1.11767 (8)	0.83393 (10)	0.0172 (2)
C10	−0.01458 (11)	1.08607 (10)	0.71540 (12)	0.0187 (3)
C11	−0.02014 (13)	1.14131 (11)	0.60586 (13)	0.0254 (3)
H11	0.0318	1.1982	0.6096	0.030*
C12	−0.10312 (14)	1.11189 (12)	0.49061 (13)	0.0320 (3)
H12	−0.1085	1.1485	0.4138	0.038*
C13	−0.17799 (14)	1.02960 (12)	0.48703 (14)	0.0331 (3)
H13	−0.2349	1.0098	0.4075	0.040*
C14	−0.17131 (13)	0.97537 (11)	0.59818 (14)	0.0295 (3)
H14	−0.2235	0.9187	0.5945	0.035*
C15	−0.08875 (12)	1.00359 (10)	0.71465 (13)	0.0223 (3)
H15	−0.0834	0.9672	0.7916	0.027*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Si	0.01680 (18)	0.01994 (18)	0.02019 (18)	0.00148 (13)	0.00294 (13)	0.00318 (13)
C1	0.0433 (9)	0.0335 (8)	0.0261 (7)	0.0030 (7)	0.0110 (6)	0.0011 (6)
C2	0.0267 (7)	0.0423 (9)	0.0372 (8)	−0.0053 (7)	0.0130 (6)	−0.0001 (7)
C3	0.0248 (7)	0.0253 (7)	0.0384 (8)	0.0043 (6)	0.0022 (6)	0.0080 (6)
C4	0.0224 (6)	0.0195 (6)	0.0288 (7)	0.0011 (5)	−0.0019 (5)	0.0030 (5)
C5	0.0172 (6)	0.0206 (6)	0.0198 (6)	0.0009 (5)	−0.0012 (5)	0.0015 (5)
S	0.01427 (15)	0.01592 (15)	0.01611 (15)	0.00142 (11)	0.00350 (11)	0.00039 (10)
O1	0.0287 (5)	0.0278 (5)	0.0199 (5)	0.0066 (4)	0.0081 (4)	−0.0022 (4)
O2	0.0181 (4)	0.0204 (5)	0.0283 (5)	−0.0012 (4)	0.0069 (4)	0.0039 (4)
C6	0.0142 (5)	0.0170 (6)	0.0184 (6)	0.0009 (4)	0.0064 (4)	0.0012 (4)
N1	0.0185 (5)	0.0195 (5)	0.0242 (5)	−0.0010 (4)	0.0055 (4)	−0.0021 (4)
N2	0.0255 (6)	0.0192 (6)	0.0300 (6)	−0.0004 (4)	0.0064 (5)	−0.0022 (5)
N3	0.0266 (6)	0.0157 (5)	0.0278 (6)	−0.0007 (4)	0.0081 (5)	−0.0010 (4)
N4	0.0188 (5)	0.0152 (5)	0.0182 (5)	0.0011 (4)	0.0064 (4)	0.0017 (4)
C10	0.0176 (6)	0.0202 (6)	0.0174 (6)	0.0052 (5)	0.0039 (5)	−0.0006 (5)
C11	0.0289 (7)	0.0250 (7)	0.0233 (6)	0.0073 (6)	0.0092 (5)	0.0056 (5)
C12	0.0391 (8)	0.0355 (8)	0.0196 (7)	0.0160 (7)	0.0058 (6)	0.0050 (6)
C13	0.0326 (8)	0.0369 (8)	0.0223 (7)	0.0143 (7)	−0.0040 (6)	−0.0076 (6)
C14	0.0250 (7)	0.0250 (7)	0.0331 (8)	0.0032 (6)	−0.0004 (6)	−0.0061 (6)
C15	0.0218 (6)	0.0212 (6)	0.0224 (6)	0.0034 (5)	0.0039 (5)	0.0008 (5)

Geometric parameters (Å, º) top

Si—C3	1.8534 (15)	S—O2	1.4295 (9)
Si—C1	1.8575 (15)	S—C6	1.7734 (13)
Si—C2	1.8586 (15)	C6—N1	1.3093 (16)
Si—C4	1.8786 (13)	C6—N4	1.3366 (15)
C1—H1A	0.9800	N1—N2	1.3573 (16)
C1—H1B	0.9800	N2—N3	1.2924 (16)
C1—H1C	0.9800	N3—N4	1.3517 (15)
C2—H2A	0.9800	N4—C10	1.4353 (15)
C2—H2B	0.9800	C10—C15	1.3778 (19)
C2—H2C	0.9800	C10—C11	1.3802 (18)
C3—H3A	0.9800	C11—C12	1.382 (2)
C3—H3B	0.9800	C11—H11	0.9500
C3—H3C	0.9800	C12—C13	1.376 (2)
C4—C5	1.5172 (18)	C12—H12	0.9500
C4—H4A	0.9900	C13—C14	1.385 (2)
C4—H4B	0.9900	C13—H13	0.9500
C5—S	1.7710 (12)	C14—C15	1.3850 (18)
C5—H5A	0.9900	C14—H14	0.9500
C5—H5B	0.9900	C15—H15	0.9500
S—O1	1.4275 (9)

C3—Si—C1	111.49 (7)	H5A—C5—H5B	108.3
C3—Si—C2	111.06 (7)	O1—S—O2	119.38 (6)
C1—Si—C2	109.04 (8)	O1—S—C5	110.09 (6)
C3—Si—C4	106.14 (6)	O2—S—C5	109.30 (6)
C1—Si—C4	108.88 (7)	O1—S—C6	107.15 (6)
C2—Si—C4	110.18 (7)	O2—S—C6	107.71 (6)
Si—C1—H1A	109.5	C5—S—C6	101.69 (6)
Si—C1—H1B	109.5	N1—C6—N4	109.95 (11)
H1A—C1—H1B	109.5	N1—C6—S	121.89 (9)
Si—C1—H1C	109.5	N4—C6—S	128.11 (9)
H1A—C1—H1C	109.5	C6—N1—N2	105.22 (10)
H1B—C1—H1C	109.5	N3—N2—N1	110.92 (10)
Si—C2—H2A	109.5	N2—N3—N4	106.75 (10)
Si—C2—H2B	109.5	C6—N4—N3	107.16 (10)
H2A—C2—H2B	109.5	C6—N4—C10	132.60 (11)
Si—C2—H2C	109.5	N3—N4—C10	120.20 (10)
H2A—C2—H2C	109.5	C15—C10—C11	122.78 (12)
H2B—C2—H2C	109.5	C15—C10—N4	119.77 (11)
Si—C3—H3A	109.5	C11—C10—N4	117.45 (12)
Si—C3—H3B	109.5	C10—C11—C12	118.37 (14)
H3A—C3—H3B	109.5	C10—C11—H11	120.8
Si—C3—H3C	109.5	C12—C11—H11	120.8
H3A—C3—H3C	109.5	C13—C12—C11	120.05 (13)
H3B—C3—H3C	109.5	C13—C12—H12	120.0
C5—C4—Si	114.16 (9)	C11—C12—H12	120.0
C5—C4—H4A	108.7	C12—C13—C14	120.69 (13)
Si—C4—H4A	108.7	C12—C13—H13	119.7
C5—C4—H4B	108.7	C14—C13—H13	119.7
Si—C4—H4B	108.7	C15—C14—C13	120.17 (14)
H4A—C4—H4B	107.6	C15—C14—H14	119.9
C4—C5—S	108.77 (9)	C13—C14—H14	119.9
C4—C5—H5A	109.9	C10—C15—C14	117.94 (13)
S—C5—H5A	109.9	C10—C15—H15	121.0
C4—C5—H5B	109.9	C14—C15—H15	121.0
S—C5—H5B	109.9

C3—Si—C4—C5	176.60 (11)	S—C6—N4—N3	−177.75 (9)
C1—Si—C4—C5	56.46 (12)	N1—C6—N4—C10	−177.91 (11)
C2—Si—C4—C5	−63.07 (13)	S—C6—N4—C10	4.50 (19)
Si—C4—C5—S	178.07 (7)	N2—N3—N4—C6	0.40 (14)
C4—C5—S—O1	−74.32 (11)	N2—N3—N4—C10	178.48 (10)
C4—C5—S—O2	58.65 (11)	C6—N4—C10—C15	40.14 (19)
C4—C5—S—C6	172.32 (9)	N3—N4—C10—C15	−137.36 (12)
O1—S—C6—N1	−127.27 (10)	C6—N4—C10—C11	−140.07 (13)
O2—S—C6—N1	103.12 (11)	N3—N4—C10—C11	42.42 (16)
C5—S—C6—N1	−11.74 (12)	C15—C10—C11—C12	−0.5 (2)
O1—S—C6—N4	50.06 (12)	N4—C10—C11—C12	179.73 (12)
O2—S—C6—N4	−79.55 (12)	C10—C11—C12—C13	0.3 (2)
C5—S—C6—N4	165.59 (11)	C11—C12—C13—C14	0.0 (2)
N4—C6—N1—N2	−0.12 (13)	C12—C13—C14—C15	0.0 (2)
S—C6—N1—N2	177.64 (9)	C11—C10—C15—C14	0.5 (2)
C6—N1—N2—N3	0.38 (14)	N4—C10—C15—C14	−179.75 (11)
N1—N2—N3—N4	−0.49 (14)	C13—C14—C15—C10	−0.2 (2)
N1—C6—N4—N3	−0.17 (14)

Experimental details

Crystal data
Chemical formula	C₁₂H₁₈N₄O₂SSi
M_r	310.45
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	173
a, b, c (Å)	11.3126 (4), 13.2707 (4), 10.8277 (4)
β (°)	106.902 (4)
V (Å³)	1555.31 (9)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.29
Crystal size (mm)	0.50 × 0.50 × 0.20

Data collection
Diffractometer	Oxford Diffraction Xcalibur S CCD diffractometer
Absorption correction	Multi-scan (CrysAlis RED; Oxford Diffraction, 2008)
T_min, T_max	0.868, 0.944
No. of measured, independent and observed [I > 2σ(I)] reflections	22841, 3384, 2961
R_int	0.024
(sin θ/λ)_max (Å⁻¹)	0.639

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.027, 0.079, 1.10
No. of reflections	3384
No. of parameters	184
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.37, −0.37

Computer programs: CrysAlis CCD (Oxford Diffraction, 2008), SHELXS97 (Sheldrick, 2008), SHELXTL-Plus (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

References

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