Download citation
Download citation
link to html
The title compound, C6H6N2S, consists of a thio­phene ring carrying three substitutent groups. Two N—H...N intermolec­ular hydrogen bonds link neighboring mol­ecules into a three-dimensional network.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803017549/wn6180sup1.cif
Contains datablocks global, II

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536803017549/wn6180IIsup2.hkl
Contains datablock II

CCDC reference: 222887

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.005 Å
  • R factor = 0.052
  • wR factor = 0.154
  • Data-to-parameter ratio = 13.8

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 5
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 1 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion

Comment top

Highly substituted thiophenes form an important part of numerous natural products (Koike et al., 1997) and pharmaceuticals (World Drug Index, 2000). They are often used as novel conducting polymers and isostatic replacements for phenyl groups in medicinal chemistry (Jarvest et al., 1999). The electronic and optical properties of polythiophene and its derivatives have been the subject of many investigations (Roncali, 1997; Ekinci et al., 2002).

The title compound, (II) (Fig. 1), consists of a thiophene ring carrying three subtituents, viz. an amino group, a methyl group and a cyano group. The S—C bond lengths, 1.728 (4) and 1.725 (4) Å, are in good agreement with those in the literature, e.g. 1.734 (2) and 1.721 (3) Å (Han & Choi, 2000), 1.727 (1) and 1.729 (2) Å (Elerman & Elmalı, 1998), and 1.723 (2) and 1.735 (3) Å (Wouters et al., 1997). The C1N1 bond distance is 1.153 (4) Å, typical of such a triple bond. This value agrees well with similar bonds reported in the literature, e.g. 1.132 (2) Å (Elerman et al., 1998), 1.130 (5) and 1.142 (5) Å (Çoruh et al., 2002), and 1.148 (2) Å (Boitsov et al., 2002). The molecule of (II) is planar, the maximum deviation from the least-squares plane being 0.0074 (33) Å for atom C4.

A packing diagram of (II) is shown Fig.2. The molecules are stacked such that there are no ring–ring or X—H···π interactions between molecules in the stacks; the distance between planes of molecules in the stacks is 5.671 (7) Å. The crystal structure of (II) is stabilized by two N—H···N intermolecular hydrogen bonds (Table 3 and Fig. 2).

Experimental top

2-(2-Bromo-1-methylethylidene)malononitrile (0.94 g, 5 mmol) was dissolved in a solution of dioxane (5 ml) and absolute ethanol (20 ml). The stirred solution was cooled to 273 K in an ice-salt bath, and a suspension of NaSH (0.3 g) in 10 ml of absolute ethanol was then added dropwise over a period of 30 min. The resulting reaction mixture was stirred for a further 1 h at room temperature. After removal of the solvent, the residue was filtered on a short Al2O3 column, eluting with hexane-ethyl acetate (7:3). The solvent was removed and the residue crystallized from chloroform to yield (556 mg, 81%) 2-amino-4-methylthiophene-3-carbonitrile (light pink crystals, mp 391–392 K). 1H NMR (200 MHz, CDCl3): δ 5.59 (s, 1H, H5), 4.81 (bs, 2H, NH2), 2.11 (s, 3H, CH3); 13C NMR (50 MHz, CDCl3) δ 162.44, 135.91, 115.52, 105.32, 91.03, 15.53. IR (CHCl3) 3417, 3212, 3097, 2977, 2202, 1627, 1558, 1446, 1300, 1191, 1068, 836.

Refinement top

All H atoms were positioned geometrically and refined in riding mode, with methyl C—H = 0.96 Å, other C—H = 0.93 Å, and N—H = 0.86 Å. For methyl H, Uiso values were set equal to 1.5Ueq of the carrier C atom. For other C—H and N—H, Uiso(H) values were set equal to 1.2Ueq of the carrier atom.

Structure description top

Highly substituted thiophenes form an important part of numerous natural products (Koike et al., 1997) and pharmaceuticals (World Drug Index, 2000). They are often used as novel conducting polymers and isostatic replacements for phenyl groups in medicinal chemistry (Jarvest et al., 1999). The electronic and optical properties of polythiophene and its derivatives have been the subject of many investigations (Roncali, 1997; Ekinci et al., 2002).

The title compound, (II) (Fig. 1), consists of a thiophene ring carrying three subtituents, viz. an amino group, a methyl group and a cyano group. The S—C bond lengths, 1.728 (4) and 1.725 (4) Å, are in good agreement with those in the literature, e.g. 1.734 (2) and 1.721 (3) Å (Han & Choi, 2000), 1.727 (1) and 1.729 (2) Å (Elerman & Elmalı, 1998), and 1.723 (2) and 1.735 (3) Å (Wouters et al., 1997). The C1N1 bond distance is 1.153 (4) Å, typical of such a triple bond. This value agrees well with similar bonds reported in the literature, e.g. 1.132 (2) Å (Elerman et al., 1998), 1.130 (5) and 1.142 (5) Å (Çoruh et al., 2002), and 1.148 (2) Å (Boitsov et al., 2002). The molecule of (II) is planar, the maximum deviation from the least-squares plane being 0.0074 (33) Å for atom C4.

A packing diagram of (II) is shown Fig.2. The molecules are stacked such that there are no ring–ring or X—H···π interactions between molecules in the stacks; the distance between planes of molecules in the stacks is 5.671 (7) Å. The crystal structure of (II) is stabilized by two N—H···N intermolecular hydrogen bonds (Table 3 and Fig. 2).

Computing details top

Data collection: COLLECT (Nonius BV, 1997-2000); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 1997); software used to prepare material for publication: SHELXL97 and WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. View of the title compound, with the atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level.
[Figure 2] Fig. 2. The hydrogen-bond network in (II), viewed approximately along the [010] direction. Hydrogen bonds are indicated by dashed lines.
2-Amino-4-methyl-thiophene-3-carbonitrile top
Crystal data top
C6H6N2SF(000) = 288
Mr = 138.20Dx = 1.376 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2ybcCell parameters from 1153 reflections
a = 11.900 (5) Åθ = 1.8–25.2°
b = 4.130 (5) ŵ = 0.39 mm1
c = 14.085 (5) ÅT = 293 K
β = 105.562 (5)°Block, pink
V = 666.9 (9) Å30.20 × 0.15 × 0.10 mm
Z = 4
Data collection top
Nonius KappaCCD
diffractometer
789 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.060
Graphite monochromatorθmax = 25.2°, θmin = 1.8°
Detector resolution: 9.0 pixels mm-1h = 1313
φ and ω scansk = 44
1849 measured reflectionsl = 1616
1135 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.052Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.154H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.087P)2]
where P = (Fo2 + 2Fc2)/3
1135 reflections(Δ/σ)max < 0.001
82 parametersΔρmax = 0.33 e Å3
0 restraintsΔρmin = 0.31 e Å3
Crystal data top
C6H6N2SV = 666.9 (9) Å3
Mr = 138.20Z = 4
Monoclinic, P21/cMo Kα radiation
a = 11.900 (5) ŵ = 0.39 mm1
b = 4.130 (5) ÅT = 293 K
c = 14.085 (5) Å0.20 × 0.15 × 0.10 mm
β = 105.562 (5)°
Data collection top
Nonius KappaCCD
diffractometer
789 reflections with I > 2σ(I)
1849 measured reflectionsRint = 0.060
1135 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0520 restraints
wR(F2) = 0.154H-atom parameters constrained
S = 1.00Δρmax = 0.33 e Å3
1135 reflectionsΔρmin = 0.31 e Å3
82 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
xyzUiso*/Ueq
S10.22387 (8)0.4859 (2)0.19442 (6)0.0548 (4)
N10.4040 (3)0.2476 (9)0.5560 (2)0.0705 (13)
N20.4211 (2)0.1820 (7)0.29110 (19)0.0569 (10)
C10.3527 (3)0.3217 (9)0.4774 (2)0.0492 (11)
C40.3236 (3)0.3380 (8)0.2982 (2)0.0443 (11)
C50.2886 (3)0.4118 (8)0.3817 (2)0.0438 (10)
C60.1794 (3)0.5838 (8)0.3609 (2)0.0476 (11)
C70.1362 (3)0.6384 (9)0.2635 (2)0.0569 (12)
C90.1231 (3)0.6872 (10)0.4390 (3)0.0666 (14)
H2A0.471070.114440.343430.0682*
H2B0.433020.150430.234240.0682*
H70.066490.746890.236380.0682*
H9A0.170890.621500.502430.0995*
H9B0.047660.587980.427260.0995*
H9C0.114670.918460.437610.0995*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0595 (7)0.0625 (7)0.0379 (5)0.0033 (4)0.0054 (4)0.0032 (4)
N10.067 (2)0.096 (3)0.0456 (18)0.0009 (19)0.0099 (15)0.0109 (17)
N20.0566 (18)0.069 (2)0.0454 (15)0.0089 (17)0.0140 (13)0.0038 (14)
C10.0479 (19)0.056 (2)0.0443 (19)0.0050 (17)0.0132 (15)0.0022 (16)
C40.0470 (19)0.0425 (19)0.0425 (17)0.0048 (16)0.0105 (14)0.0021 (14)
C50.0454 (18)0.0456 (19)0.0388 (17)0.0067 (15)0.0084 (14)0.0013 (14)
C60.0461 (19)0.049 (2)0.0462 (19)0.0053 (16)0.0096 (15)0.0031 (15)
C70.051 (2)0.059 (2)0.055 (2)0.0052 (18)0.0042 (16)0.0027 (18)
C90.063 (2)0.076 (3)0.064 (2)0.005 (2)0.0226 (18)0.006 (2)
Geometric parameters (Å, º) top
S1—C41.728 (4)C5—C61.440 (5)
S1—C71.725 (4)C6—C91.496 (5)
N1—C11.153 (4)C6—C71.349 (4)
N2—C41.354 (5)C7—H70.9299
N2—H2B0.8599C9—H9A0.9605
N2—H2A0.8600C9—H9B0.9600
C1—C51.409 (4)C9—H9C0.9600
C4—C51.383 (5)
S1···N1i3.401 (5)C1···H2A2.7756
S1···H9Aii3.0699C1···H9A2.5976
N1···N2iii3.117 (6)C7···H7vii2.9042
N1···S1iv3.401 (5)H2A···C12.7756
N1···N2iv3.276 (5)H2A···N1iii2.3070
N2···N1i3.276 (5)H2B···N2v2.6863
N2···N2v3.209 (5)H2B···N2vi2.8798
N2···N2vi3.209 (5)H2B···H2Bv2.5735
N2···N1iii3.117 (6)H2B···H2Bvi2.5735
N1···H2Aiii2.3071H2B···N1i2.4767
N1···H2Biv2.4767H7···C7viii2.9042
N2···H2Bvi2.6863H9A···C12.5976
N2···H2Bv2.8798H9A···S1ix3.0699
C4—S1—C791.95 (15)C5—C6—C9123.3 (3)
H2A—N2—H2B120.01C7—C6—C9125.2 (3)
C4—N2—H2A120.02S1—C7—C6112.9 (3)
C4—N2—H2B119.98S1—C7—H7123.50
N1—C1—C5179.2 (4)C6—C7—H7123.57
S1—C4—N2120.9 (2)C6—C9—H9A109.46
S1—C4—C5110.3 (3)C6—C9—H9B109.52
N2—C4—C5128.8 (3)C6—C9—H9C109.52
C4—C5—C6113.4 (3)H9A—C9—H9B109.43
C1—C5—C4123.1 (3)H9A—C9—H9C109.42
C1—C5—C6123.5 (3)H9B—C9—H9C109.48
C5—C6—C7111.5 (3)
C7—S1—C4—N2179.3 (3)C1—C5—C6—C7179.7 (3)
C7—S1—C4—C50.8 (3)C1—C5—C6—C90.5 (5)
C4—S1—C7—C60.3 (3)C4—C5—C6—C9179.4 (3)
S1—C4—C5—C61.1 (4)C4—C5—C6—C70.8 (4)
N2—C4—C5—C11.7 (6)C9—C6—C7—S1180.0 (3)
S1—C4—C5—C1179.9 (3)C5—C6—C7—S10.2 (4)
N2—C4—C5—C6179.4 (3)
Symmetry codes: (i) x, y+1/2, z1/2; (ii) x, y+3/2, z1/2; (iii) x+1, y, z+1; (iv) x, y+1/2, z+1/2; (v) x+1, y1/2, z+1/2; (vi) x+1, y+1/2, z+1/2; (vii) x, y1/2, z+1/2; (viii) x, y+1/2, z+1/2; (ix) x, y+3/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2B···N1i0.862.483.276 (5)155
N2—H2A···N1iii0.862.313.117 (6)157
Symmetry codes: (i) x, y+1/2, z1/2; (iii) x+1, y, z+1.

Experimental details

Crystal data
Chemical formulaC6H6N2S
Mr138.20
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)11.900 (5), 4.130 (5), 14.085 (5)
β (°) 105.562 (5)
V3)666.9 (9)
Z4
Radiation typeMo Kα
µ (mm1)0.39
Crystal size (mm)0.20 × 0.15 × 0.10
Data collection
DiffractometerNonius KappaCCD
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
1849, 1135, 789
Rint0.060
(sin θ/λ)max1)0.599
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.052, 0.154, 1.00
No. of reflections1135
No. of parameters82
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.33, 0.31

Computer programs: COLLECT (Nonius BV, 1997-2000), HKL SCALEPACK (Otwinowski & Minor 1997), HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 1997), SHELXL97 and WinGX (Farrugia, 1999).

Selected geometric parameters (Å, º) top
S1—C41.728 (4)N1—C11.153 (4)
S1—C71.725 (4)N2—C41.354 (5)
S1···N1i3.401 (5)N1···S1iii3.401 (5)
N1···N2ii3.117 (6)
C4—S1—C791.95 (15)S1—C4—C5110.3 (3)
N1—C1—C5179.2 (4)N2—C4—C5128.8 (3)
S1—C4—N2120.9 (2)S1—C7—C6112.9 (3)
Symmetry codes: (i) x, y+1/2, z1/2; (ii) x+1, y, z+1; (iii) x, y+1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2B···N1i0.862.483.276 (5)155
N2—H2A···N1ii0.862.313.117 (6)157
Symmetry codes: (i) x, y+1/2, z1/2; (ii) x+1, y, z+1.
 

Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds