3′-Methyl­acetanilide and N-benzyl­thio­acetamide at low temperature

Mol­ecules of the title compounds, 3′-methyl­acetanilide [or N-(m-tolyl)­acetamide], C₉H₁₁NO, (I), and N-benzyl­thio­acet­amide, C₉H₁₁NS, (II), are connected by a framework of inter­molecular N—H...O and N—H...S hydrogen bonds, respectively, forming chains with the graph-set description C(4), which run along the b axis. Analyses of the crystal structures of (I) and (II) are helpful in the elucidation of a generation mechanism of the IR spectra of hydrogen-bonded mol­ecular crystals. The correlation between the IR spectra of studied compounds and structural data is also discussed.

S1. Comment

3'-Methylacetanilide, (I), and the sulfur analogue N-(m-tolyl)thioacetamide, as well as N-benzylthioacetamide, (II), and the oxygen analogue N-benzylacetamide, have been the subject of our studies for a generation mechanism of the IR spectra of hydrogen-bonded molecular crystals [please clarify]. The theoretical analysis of (I) and (II) and of their analogues N-(m-tolyl)thioacetamide and N-benzylacetamide, respectively, preceded by measurement of the IR spectra of polycrystalline and monocrystalline samples, concerned characteristic isotopic and spectroscopic effects, e.g. linear dichroic effects, self-organization and temperature effects. These effects were observed in the solid-state IR spectra of hydrogen and deuterium bonds at the frequency ranges of the ν_N—H and ν_N—D bands, respectively. Some spectacular effects are especially visible for those systems where the proton acceptor is sulfur or oxygen (Flakus et al., 2003, 2004, 2005, 2006, 2007). Accordingly, for a reliable interpretation of the isotopic and spectroscopic effects, determination of the crystal structure (I) and (II) is indispensable. In the case of N-(m-tolyl)thioacetamide (Śmiszek-Lindert et al., 2007a) and N-benzylacetamide (Śmiszek-Lindert et al., 2007b), crystallographic studies have been reported previously.

Compound (I) crystallizes with one molecule in the asymmetric unit cell (Fig. 1). In each molecule, the six-membered ring (C1–C6) form a planar skeleton, with r.m.s. deviations from the mean plane of 0.0023Å; atoms O1, C8, C9 are significantly out of the benzene ring plane by 0.5411 (13), 0.2385 (13) and 0.1325 (16)Å, respectively. The benzene ring is not coplanar with the CO–NH plane [torsion angles: C8—N1—C1—C2 = -165.66 (9)° and C8—N1—C1—C6 = 15.95 (16)°]. The dihedral angle between the plane of the benzene ring and the plane of the –CO–NH– group is 14.89 (10)°. Moreover, in the molecule of (I), the –CO–NH– group adopts a trans conformation. By comparison, in the molecule N-(m-tolyl)thioacetamide, the –CS–NH– group also adopts a trans conformation. However, different from (I), the –CS–NH– group is twisted out of the benzene ring plane [torsion angles: C8—N1—C1—C2 = 135.02 (15)° and C8—N1—C1—C6 = -47.40 (2)°]. The dihedral angle between the plane of the benzene ring and the plane of the –CS–NH– group is 48.35(0.12)° (Śmiszek-Lindert et al., 2007a). This is very surprising because in the literature the trans acetanilides and thioacetanilides have planar main skeletons with the amide and thioamide groups lying in the plane of the aromatic ring. The deviations from planarity are smaller than 3° (Galabov et al., 2003). The length of the C8═O1 bond [1.2312 (13)Å] is very similar to that of the corresponding bond [1.230 (9)Å] in the analogous compound 4'-methylacetanilide (Haisa et al., 1977) and these values are both different for bonds of this type [average value 1.224 (1)Å; Allen et al., 1997]. The elongation of the C═O bond lengths is connected with electron shift accompanying formation of an intermolecular N—H···O hydrogen bond. The length of the C8—N1 single bond [1.3568 (13)Å] is typical for bonds of this type [average value 1.351 (1)Å; Allen et al., 1997]. The C—N bond length differs slightly from the values found in similar structures, for example, p-aminoacetanilide [1.344 (4)Å; Haisa et al., 1977], 4'-methylacetanilide [1.349 (3)Å; Haisa et al., 1977], p-hydroxyacetanilide [1.341 (6)Å; Haisa et al., 1974], and other amide derivatives, such as acetanilide (1.330Å; Brown & Corbridge, 1954) or trans-N-phenylformamide [1.3359 (18)Å; Omondi et al., 2008]. The C1—N1 single bond is shortened [Table 1; average value 1.4260Å; Allen et al. (1987)], but this shortening always occurs when an N atom is attached to a benzene ring; a summary of corresponding lengths in other compounds has already been reported (Brown, 1949). The sum of the angles around the amide N atom is 360°, which indicates that the geometry around this atom is trigonal planar (sp²-hybridization). An almost identical angle sum [359.87°] around the thioamide N atom is observed in the case of N-(m-tolyl)thioacetamide (Śmiszek-Lindert et al., 2007a).

The crystal structure of (I) is stabilized by intermolecular N—H···O hydrogen bonds (Fig. 2). Atom N1 of the NH group in the molecule at (x, y, z) acts as a hydrogen-bond donor via atom H1 to carbonyl atom O1 of the molecule at (-x, y+1/2, 1/2-z) (Fig. 3). These interactions form a zigzag chain running parallel to the [010] direction with graph-set motif C₁¹(4) (Bernstein et al., 1995; Etter et al., 1990). The same graph-set motif is found in N-(m-tolyl)thioacetamide (Śmiszek-Lindert et al., 2007a).

The IR spectrum of a polycrystalline sample of (I) is shown in Fig. 4. The values of the H···O and N···O distances, as well the N—H···O angle (Table 2), characterize this as a medium-strength hydrogen bond (Desiraju & Steiner, 1999; Steiner, 2002). The strength of the hydrogen bond in (I) is supported by spectroscopic measurements. Analysis of the IR spectrum of (I) shows that the band of the isolated N—H stretching vibration, ν_N—H, is located in the frequency range 3380–2900 cm^-1, with the centre of gravity at ca 3198 cm^-1. In not associated compounds [please clarify], this band lies at 3400 cm^-1, e.g. the ν_N—H band in 3'-methylacetanilide is shifted towards the lower frequencies by about ca 202 cm^-1, or 6%. This relative shift is larger than 5% and is characteristic of a medium-strength hydrogen bond (Desiraju & Steiner, 1999). The N—H···O hydrogen bond has an N···O distance of 2.8882 (12)Å, shorter than the values of 2.935 (3), 3.088 (4) and 2.904 (8)Å found in acetanilide (Johnson et al., 1995), p-aminoacetanilide (Haisa et al., 1977) and 4'-methylacetanilide (Haisa et al., 1977), respectively. The N—H···O angle of (I) is almost linear, as is also the case in acetanilide [172.3 (4)°; Johnson et al., 1995].

The molecule of (II) with the atom-labelling scheme is shown in Fig. 5. As revealed by X-ray structure analysis, the molecule of (II) is not planar. The –CS—NH– group is twisted out of the benzene ring plane [torsion angles: C2—C1—C7—N1 = -143.30 (12)° and C6—C1—C7—N1 = 39.01 (17)°]. The dihedral angle between the plane of the benzene ring and the plane of the –CS—NH– group is 86.30 (7)°. Nevertheless, the –CH₂– group directly attached to the benzene ring is almost coplanar with it, as shown by the relevant torsion angles [C7–C1–C2–C3 = -177.31 (12)° and C7–C1–C6–C5 = 177.66 (12)°]. The C8═S1 bond (Table 3) is approximately 0.04Å longer than the average C═S double-bond length of 1.654 (2)Å (Allen et al., 1997) and also longer than in thioamide compounds studied previously by us, for example N-(m-tolyl)thioacetamide [1.6565 (15)Å; Śmiszek-Lindert et al., 2007a], N-(p-tolyl)thioacetamide [1.6723 (12)Å; Śmiszek-Lindert et al., 2007c], N-benzylthioformamide [1.6652 (11)Å; Śmiszek-Lindert et al., 2007d], N-methylthiobenzamide [1.6630 (2)Å; Śmiszek-Lindert et al., 2007e]. The lengthening of the C═S double bond is probably connected withan electron shift accompanying the formation of the N—H···S hydrogen bond. The C8—N1 single-bond length in N-benzylthioacetamide is consistent with the average value found in the fragment X₂C═S (X = C, N, O or S) of 1.322 (2)Å (Allen et al.,1997). The average value is very close to the values found in similar structures, i.e. thioacetanilide (Michta et al., 2008), N-methylthioacetamide (Flakus et al., 2007), N-(2-hydroxyethyl)-2-thiofuramide (Galešić et al., 1987) or N-(m-tolyl)thioacetamide (Śmiszek-Lindertet et al., 2007a). The value of the C═S bond distance of 1.61Å is cited in the literature as representing 100% double-bond character, e.g. thioformaldehyde, in the gas phase (Johnson et al., 1971). Moreover, C═S bond lengths of ca 1.74Å are cited as representing ca 50% double-bond character, as in the case of dithiolate anions (Johnson et al., 1971; Fausto et al., 1989).

In the crystal structure, molecules of (II) are linked by a single N—H···S hydrogen bond into infinite zigzag chains which run parallel to the [010] direction. An intermolecular N—H···S hydrogen bond between donor atom N1 and acceptor atom S1 can be described by the graph-set motif C₁¹(4) (Bernstein et al., 1995; Etter et al., 1990) (Fig. 6). Atom N1 in the molecule at (x, y, z) acts as an intermolecular hydrogen-bond donor via atom H1 to atom S1 at (2-x, y-1/2, 1/2-z). The values of the H···S, N···S distances and the N—H···S angle (Table 4) characterize this as a weak hydrogen bond (Desiraju & Steiner, 1999; Steiner, 2002). The strength of the hydrogen bonds in this compound was also investigated by IR spectroscopy. The ν_N—H proton-stretching band covers the range 3300–2990 cm^-1 (Fig. 7), with the centre of gravity at ca 3140 cm^-1. This band is shifted towards the lower frequencies by ca 260 cm^-1, or 8%. This relative shift is larger than 5% and is characteristic for a medium-strength hydrogen bond (Desiraju & Steiner, 1999).

Knowledge of the hydrogen-bond geometry in the molecular crystals of amides and thioamides enables us to interpret and understand isotopic and spectroscopic effects in IR spectra. Further studies on the polarized IR spectra of the title compounds and their isotopic derivatives will be carried out in the future.

Related literature

For related literature, see: Allen et al. (1987, 1997); Bernstein et al. (1995); Brown (1949); Brown & Corbridge (1954); Desiraju & Steiner (1999); Etter et al. (1990); Fausto et al. (1989); Flakus & Michta (2004, 2005); Flakus & Pyzik (2006); Flakus et al. (2003, 2007); Galabov et al. (2003); Haisa et al. (1974, 1977); Johnson et al. (1971); Michta et al. (2008); Omondi et al. (2008); Schlatter (1942); Steiner (2002); Śmiszek-Lindert, Nowak & Kusz (2007a, 2007b, 2007c, 2007d, 2007e).

S2. Experimental

3'-Methylacetanilide, (I), was purchased from Sigma–Aldrich (98% pure). White plate-shaped crystals suitable for diffraction analysis were obtained by slow evaporation of an ethanol–acetone solution at 281 K. N-Benzylthioacetamide, (II), was obtained by the reaction of N-benzylacetamide with phosphorus pentasulfide. Phosphorus pentasulfide (0.61 g, 0.1 mol) was added in small portions to a solution of N-benzylacetamide (2.06 g, 0.5 mol) in toluene (5.50 ml) at 343–353 K with stirring. The reaction mixture was then brought to reflux for 2 h. After heating, the hot reaction mixture was decanted and the solution concentrated to give a yellow precipitate. The precipitate was dissolved in petroleum ether and the solution left for crystallization at room temperature. Single crystals of (II) suitable for X-ray diffraction analysis were obtained by a slow evaporation of a diethyl ether–acetone solution [yield: 1.55 g, 67.83%; m.p. 338–339 K, literature m.p. 338 K (Schlatter, 1942)]. The IR spectra of polycrystalline samples of (I) and (II) dispersed in KBr were measured by the transmission method at room temperature using an FT–IR Nicolet Magna 560 spectrometer with a resolution of 2 cm^-1.

S3. Refinement

For (I), some of the H atoms were located in a difference Fourier map and were refined freely; other H atoms were introduced in geometrically idealized positions and refined with an appropriate riding model, with C—H = 0.95 (aromatic C) or 0.98Å (methyl C). The isotropic displacement parameters were constrained with U_iso(H) values of 1.2U_eq(C) for H atoms in CH groups and 1.5U_eq(C) for the methyl H atoms. For (II), some of the H atoms were located in a difference Fourier map and were refined freely; other H atoms were introduced in geometrically idealized positions and refined with an appropriate riding model, with C—H = 0.95 (aromatic), 0.99 (methylene) or 0.98Å (methyl). The isotropic displacement parameters were constrained with U_iso(H) values of 1.2U_eq(C) for H atoms in CH and CH₂ groups and 1.5U_eq(C) for the methyl H atoms.

Computing details

For both compounds, data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: publCIF (Westrip, 2008).

Figures

	Fig. 1. The molecule of compound (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. The arrangement of molecules of (I) in the unit cell. Intermolecular N—H···O interactions are represented by dashed lines.
	Fig. 3. Part of the crystal structure of (I), showing the formation of a hydrogen-bonded C1^1(4) chain along the b axis. Molecules labelled with an asterisk (*) or a hash (#) are at the symmetry positions (-x, y+1/2, 1/2–z) and (-x, y-1/2, 1/2-z), respectively.
	Fig. 4. The IR spectrum of a polycrystalline sample of (I) measured at 293 K by the KBr pellet technique in the νN—H band frequency range.
	Fig. 5. The molecule of compound (II), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 6. Part of the crystal structure of (II), viewed along the b axis. Hydrogen bonds are shown as dashed lines. [Symmetry codes: (i) 2-x, y-1/2, 1/2-z].
	Fig. 7. The IR spectrum of a polycrystalline sample of (II) measured at 293 K by the KBr pellet technique in the νN—H band frequency range.

(I) 3'-Methylacetanilide

Crystal data

C9H11NO	F(000) = 320
Mr = 149.19	Dx = 1.188 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4166 reflections
a = 12.280 (3) Å	θ = 3.4–32.7°
b = 9.4471 (19) Å	µ = 0.08 mm^−1
c = 7.3028 (15) Å	T = 100 K
β = 99.97 (3)°	Plate, colourless
V = 834.4 (3) Å^3	0.4 × 0.4 × 0.07 mm
Z = 4

Data collection

Oxford Diffraction KM-4-CCD Sapphire3 diffractometer	1965 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.029
Graphite monochromator	θmax = 32.8°, θmin = 3.4°
Detector resolution: 16.0328 pixels mm^-1	h = −18→18
ω scans	k = −10→14
7872 measured reflections	l = −9→10
2807 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.135	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0879P)^2 + 0.0298P] where P = (Fo^2 + 2Fc^2)/3
2807 reflections	(Δ/σ)max = 0.001
105 parameters	Δρmax = 0.34 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Special details

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
O1	−0.02585 (6)	0.73920 (8)	0.14590 (10)	0.02283 (19)
N1	0.05229 (7)	0.95381 (9)	0.22691 (12)	0.01784 (19)
H1	0.0399 (10)	1.0377 (14)	0.2722 (18)	0.021*
C1	0.15971 (8)	0.93353 (10)	0.18758 (13)	0.0171 (2)
C2	0.23887 (9)	1.03419 (11)	0.26142 (14)	0.0198 (2)
H2	0.2186	1.1085	0.3366	0.024*
C3	0.34665 (9)	1.02751 (11)	0.22684 (15)	0.0218 (2)
C4	0.37505 (9)	0.91664 (12)	0.11781 (15)	0.0223 (2)
H4	0.4484	0.9100	0.0933	0.027*
C5	0.29710 (9)	0.81616 (11)	0.04498 (14)	0.0216 (2)
H5	0.3179	0.7413	−0.0287	0.026*
C6	0.18906 (9)	0.82308 (11)	0.07795 (14)	0.0194 (2)
H6	0.1361	0.7541	0.0270	0.023*
C7	0.42999 (10)	1.13762 (14)	0.30661 (19)	0.0320 (3)
H7A	0.3971	1.2320	0.2850	0.048*
H7B	0.4951	1.1307	0.2463	0.048*
H7C	0.4520	1.1219	0.4406	0.048*
C8	−0.03272 (8)	0.86013 (11)	0.20571 (13)	0.0176 (2)
C9	−0.13768 (9)	0.91364 (12)	0.26136 (14)	0.0216 (2)
H9A	−0.1970	0.9140	0.1526	0.032*
H9B	−0.1261	1.0101	0.3103	0.032*
H9C	−0.1584	0.8517	0.3574	0.032*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0271 (4)	0.0175 (4)	0.0245 (4)	−0.0038 (3)	0.0063 (3)	−0.0021 (3)
N1	0.0199 (4)	0.0150 (4)	0.0191 (4)	−0.0002 (3)	0.0049 (3)	−0.0019 (3)
C1	0.0195 (5)	0.0167 (4)	0.0152 (4)	0.0003 (3)	0.0036 (3)	0.0024 (3)
C2	0.0235 (5)	0.0179 (5)	0.0181 (5)	−0.0013 (4)	0.0044 (4)	−0.0015 (4)
C3	0.0220 (5)	0.0208 (5)	0.0224 (5)	−0.0028 (4)	0.0031 (4)	0.0021 (4)
C4	0.0206 (5)	0.0246 (5)	0.0227 (5)	0.0018 (4)	0.0060 (4)	0.0026 (4)
C5	0.0242 (5)	0.0210 (5)	0.0202 (5)	0.0039 (4)	0.0056 (4)	0.0001 (4)
C6	0.0224 (5)	0.0172 (5)	0.0183 (4)	−0.0002 (4)	0.0027 (4)	−0.0006 (3)
C7	0.0256 (6)	0.0312 (6)	0.0389 (7)	−0.0088 (5)	0.0045 (5)	−0.0052 (5)
C8	0.0211 (5)	0.0178 (5)	0.0137 (4)	0.0000 (4)	0.0024 (3)	0.0027 (3)
C9	0.0217 (5)	0.0219 (5)	0.0213 (5)	−0.0006 (4)	0.0039 (4)	0.0025 (4)

Geometric parameters (Å, º)

O1—C8	1.2312 (13)	C4—H4	0.9500
N1—C8	1.3568 (13)	C5—C6	1.3904 (15)
N1—C1	1.4109 (14)	C5—H5	0.9500
N1—H1	0.882 (13)	C6—H6	0.9500
C1—C2	1.3995 (14)	C7—H7A	0.9800
C1—C6	1.3999 (14)	C7—H7B	0.9800
C2—C3	1.3912 (15)	C7—H7C	0.9800
C2—H2	0.9500	C8—C9	1.5046 (15)
C3—C4	1.3960 (15)	C9—H9A	0.9800
C3—C7	1.5041 (16)	C9—H9B	0.9800
C4—C5	1.3870 (16)	C9—H9C	0.9800
C8—N1—C1	128.04 (9)	C5—C6—C1	118.82 (9)
C8—N1—H1	116.8 (8)	C5—C6—H6	120.6
C1—N1—H1	115.2 (8)	C1—C6—H6	120.6
C2—C1—C6	119.76 (9)	C3—C7—H7A	109.5
C2—C1—N1	116.16 (9)	C3—C7—H7B	109.5
C6—C1—N1	124.06 (9)	H7A—C7—H7B	109.5
C3—C2—C1	121.23 (9)	C3—C7—H7C	109.5
C3—C2—H2	119.4	H7A—C7—H7C	109.5
C1—C2—H2	119.4	H7B—C7—H7C	109.5
C2—C3—C4	118.50 (10)	O1—C8—N1	123.17 (9)
C2—C3—C7	120.21 (10)	O1—C8—C9	121.48 (9)
C4—C3—C7	121.29 (10)	N1—C8—C9	115.35 (9)
C5—C4—C3	120.54 (10)	C8—C9—H9A	109.5
C5—C4—H4	119.7	C8—C9—H9B	109.5
C3—C4—H4	119.7	H9A—C9—H9B	109.5
C4—C5—C6	121.15 (10)	C8—C9—H9C	109.5
C4—C5—H5	119.4	H9A—C9—H9C	109.5
C6—C5—H5	119.4	H9B—C9—H9C	109.5
C8—N1—C1—C2	−165.66 (9)	C7—C3—C4—C5	−179.86 (10)
C8—N1—C1—C6	15.95 (16)	C3—C4—C5—C6	0.13 (16)
C6—C1—C2—C3	0.51 (15)	C4—C5—C6—C1	−0.33 (15)
N1—C1—C2—C3	−177.95 (9)	C2—C1—C6—C5	0.02 (15)
C1—C2—C3—C4	−0.71 (15)	N1—C1—C6—C5	178.35 (9)
C1—C2—C3—C7	179.54 (10)	C1—N1—C8—O1	−0.09 (16)
C2—C3—C4—C5	0.39 (15)	C1—N1—C8—C9	179.68 (9)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^i	0.882 (13)	2.011 (14)	2.8882 (12)	172.3 (12)

Symmetry code: (i) −x, y+1/2, −z+1/2.

(II) N-benzylthioacetamide

Crystal data

C9H11NS	F(000) = 352
Mr = 165.25	Dx = 1.238 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 6508 reflections
a = 5.5957 (11) Å	θ = 3.3–25.0°
b = 8.2201 (16) Å	µ = 0.30 mm^−1
c = 19.278 (4) Å	T = 95 K
V = 886.7 (3) Å^3	Needle, colourless
Z = 4	0.6 × 0.15 × 0.14 mm

Data collection

Oxford Diffraction KM-4-CCD Sapphire3 diffractometer	1557 independent reflections
Radiation source: fine-focus sealed tube	1496 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.061
Detector resolution: 16.0328 pixels mm^-1	θmax = 25.0°, θmin = 3.3°
ω scans	h = −6→3
Absorption correction: analytical [CrysAlis RED (Oxford Diffraction, 2006); nalytical numeric absorption correction using a multifaceted crystal model based on expressions derived by Clark & Reid (1995)]	k = −9→9
Tmin = 0.974, Tmax = 0.990	l = −22→22
5596 measured reflections

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)] = 0.021	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.066	w = 1/[σ^2(Fo^2) + (0.0483P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max = 0.001
1557 reflections	Δρmax = 0.13 e Å^−3
104 parameters	Δρmin = −0.19 e Å^−3
0 restraints	Absolute structure: Flack (1983), 618 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.01 (6)

Special details

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
S1	0.63434 (6)	0.96207 (4)	0.223279 (17)	0.02212 (13)
N1	1.0166 (2)	0.76854 (14)	0.21454 (5)	0.0180 (3)
H1	1.109 (3)	0.698 (2)	0.2337 (8)	0.022*
C1	0.9766 (2)	0.66430 (16)	0.09427 (7)	0.0165 (3)
C2	1.1098 (2)	0.62576 (16)	0.03507 (7)	0.0190 (3)
H2	1.2537	0.6829	0.0256	0.023*
C3	1.0327 (2)	0.50387 (17)	−0.01021 (7)	0.0217 (3)
H3	1.1237	0.4790	−0.0504	0.026*
C4	0.8234 (2)	0.41908 (17)	0.00346 (7)	0.0221 (3)
H4	0.7706	0.3363	−0.0273	0.027*
C5	0.6914 (2)	0.45616 (17)	0.06246 (7)	0.0216 (3)
H5	0.5488	0.3977	0.0721	0.026*
C6	0.7667 (2)	0.57863 (16)	0.10773 (7)	0.0193 (3)
H6	0.6747	0.6035	0.1478	0.023*
C7	1.0591 (2)	0.80248 (17)	0.14085 (6)	0.0196 (3)
H7A	1.2320	0.8212	0.1334	0.024*
H7B	0.9733	0.9033	0.1278	0.024*
C8	0.8409 (2)	0.82857 (15)	0.25267 (7)	0.0182 (3)
C9	0.8330 (3)	0.76823 (17)	0.32645 (7)	0.0229 (3)
H9A	0.9716	0.6983	0.3353	0.034*
H9B	0.6859	0.7059	0.3338	0.034*
H9C	0.8363	0.8612	0.3583	0.034*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.01793 (19)	0.0210 (2)	0.0274 (2)	0.00247 (13)	−0.00427 (14)	−0.00280 (14)
N1	0.0183 (6)	0.0178 (6)	0.0180 (6)	0.0019 (5)	−0.0041 (5)	0.0012 (4)
C1	0.0158 (6)	0.0165 (7)	0.0171 (7)	0.0031 (5)	−0.0020 (6)	0.0040 (5)
C2	0.0165 (6)	0.0198 (6)	0.0208 (7)	0.0021 (6)	0.0033 (6)	0.0056 (5)
C3	0.0252 (6)	0.0227 (7)	0.0171 (7)	0.0053 (6)	0.0043 (5)	0.0011 (5)
C4	0.0251 (7)	0.0205 (7)	0.0208 (7)	0.0023 (5)	−0.0032 (6)	−0.0039 (5)
C5	0.0171 (7)	0.0234 (7)	0.0245 (7)	−0.0019 (6)	0.0007 (5)	−0.0012 (6)
C6	0.0154 (6)	0.0228 (7)	0.0198 (7)	0.0021 (5)	0.0036 (5)	0.0003 (6)
C7	0.0181 (6)	0.0229 (7)	0.0178 (7)	−0.0021 (6)	0.0015 (5)	0.0010 (6)
C8	0.0191 (6)	0.0136 (6)	0.0219 (7)	−0.0051 (6)	−0.0037 (6)	−0.0040 (5)
C9	0.0292 (8)	0.0207 (7)	0.0189 (7)	−0.0021 (6)	0.0007 (6)	−0.0017 (5)

Geometric parameters (Å, º)

S1—C8	1.6917 (14)	C4—C5	1.390 (2)
N1—C8	1.3230 (17)	C4—H4	0.9500
N1—C7	1.4669 (17)	C5—C6	1.3974 (19)
N1—H1	0.858 (16)	C5—H5	0.9500
C1—C6	1.3938 (19)	C6—H6	0.9500
C1—C2	1.3994 (19)	C7—H7A	0.9900
C1—C7	1.5197 (19)	C7—H7B	0.9900
C2—C3	1.397 (2)	C8—C9	1.507 (2)
C2—H2	0.9500	C9—H9A	0.9800
C3—C4	1.3883 (19)	C9—H9B	0.9800
C3—H3	0.9500	C9—H9C	0.9800
C8—N1—C7	125.98 (12)	C1—C6—C5	120.12 (12)
C8—N1—H1	117.4 (10)	C1—C6—H6	119.9
C7—N1—H1	116.5 (11)	C5—C6—H6	119.9
C6—C1—C2	119.09 (13)	N1—C7—C1	112.39 (11)
C6—C1—C7	121.56 (12)	N1—C7—H7A	109.1
C2—C1—C7	119.30 (12)	C1—C7—H7A	109.1
C3—C2—C1	120.49 (13)	N1—C7—H7B	109.1
C3—C2—H2	119.8	C1—C7—H7B	109.1
C1—C2—H2	119.8	H7A—C7—H7B	107.9
C4—C3—C2	120.14 (13)	N1—C8—C9	115.07 (12)
C4—C3—H3	119.9	N1—C8—S1	124.30 (11)
C2—C3—H3	119.9	C9—C8—S1	120.63 (10)
C3—C4—C5	119.56 (13)	C8—C9—H9A	109.5
C3—C4—H4	120.2	C8—C9—H9B	109.5
C5—C4—H4	120.2	H9A—C9—H9B	109.5
C4—C5—C6	120.59 (12)	C8—C9—H9C	109.5
C4—C5—H5	119.7	H9A—C9—H9C	109.5
C6—C5—H5	119.7	H9B—C9—H9C	109.5
C6—C1—C2—C3	0.45 (19)	C4—C5—C6—C1	−0.4 (2)
C7—C1—C2—C3	−177.31 (12)	C8—N1—C7—C1	−102.17 (15)
C1—C2—C3—C4	−0.4 (2)	C6—C1—C7—N1	39.01 (17)
C2—C3—C4—C5	−0.1 (2)	C2—C1—C7—N1	−143.30 (12)
C3—C4—C5—C6	0.5 (2)	C7—N1—C8—C9	177.61 (11)
C2—C1—C6—C5	−0.04 (19)	C7—N1—C8—S1	−1.87 (19)
C7—C1—C6—C5	177.66 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···S1^i	0.858 (16)	2.554 (17)	3.4056 (13)	171.8 (15)

Symmetry code: (i) −x+2, y−1/2, −z+1/2.