5-(4-Meth­ylphenyl)-1,3,4-thia­diazol-2-amine

The title compound, C₉H₉N₃S, was synthesized by the reaction of 4-methyl-benzoic acid and thio­semicarbazide. The thia­diazol ring adopts a planar conformation and makes a dihedral angle of 31.19 (18)° with the phenyl ring. In the crystal, mol­ecules are linked by N—H...N hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.059
• wR factor = 0.181
• Data-to-parameter ratio = 15.9

checkCIF/PLATON results

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Alert level C
            Value of measurement temperature given =   293.000
            Value of melting point given =     0.000
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          6
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety         C1

Alert level G
PLAT066_ALERT_1_G Predicted and Reported Transmissions Identical .          ?
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   4 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
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

1,3,4-Thiadiazole derivatives represent an interesting class of compounds possessing broad spectrum biological activities (Nakagawa et al., 1996; Wang et al., 1999). These compounds are known to exhibit diverse biological effects, such as insecticidal, fungicidal activities (Wang et al., 1999). We are focusing our synthetic and structural studies on thiadiazole derivatives and we have recently published the structure of 5-m-tolyl-[1,3,4]thiadiazol-2-ylamine (Han et al., 2007). We report here the crystal structure of the title compound, (I).

In (I) (Fig. 1), the bond lengths and angles are within normal ranges (Allen et al., 1987). The thiadiazole and the phenyl ring make a dihedral angle of 31.19 (18)°. The molecules link by N—H···N hydrogen bonds to stabilize the crystal structure (Fig. 2).

Related literature

For applications of thiadiazole ligands, see: Nakagawa et al. (1996); Wang et al. (1999); Han et al. (2007). For bond-length data, see: Allen et al. (1987).

S2. Experimental

4-Methyl-benzoic acid (5 mmol) and thiosemicarbazide (5 mmol) were added in toluene (50 ml), which is heated under reflux for 4 h. The reaction mixture was left to cool to room temperature, poured into ice water, filtered, and the filter cake was crystallized from acetone to give pure compound (I). Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of an acetone solution.

S3. Refinement

All H atoms were placed geometrically with C—H = 0.93–0.96 Å and N—H = 0.86 Å, and included in the refinement in riding motion approximation with U_iso(H) = 1.2 or 1.5U_eq of the carrier atom.

Computing details

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1989); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo,1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. A view of the molecular structure of (I). Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. View of the N—H···N hydrogen bonds (dashed lines) in the unit cell. Dashed lines indicate hydrogen bonds.

5-(4-methylphenyl)-1,3,4-thiadiazol-2-amine

Crystal data

C9H9N3S	F(000) = 400
Mr = 191.25	Dx = 1.318 Mg m^−3
Monoclinic, P21/c	Melting point = 476–478 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 12.284 (3) Å	Cell parameters from 25 reflections
b = 7.3730 (15) Å	θ = 9–13°
c = 11.263 (2) Å	µ = 0.29 mm^−1
β = 109.09 (3)°	T = 293 K
V = 964.0 (3) Å^3	Block, colourless
Z = 4	0.30 × 0.10 × 0.10 mm

Data collection

Nonius CAD4 diffractometer	1351 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.067
Graphite monochromator	θmax = 26.0°, θmin = 1.8°
ω/2θ scans	h = −15→0
Absorption correction: ψ scan (North et al., 1968)	k = 0→9
Tmin = 0.918, Tmax = 0.972	l = −13→13
1963 measured reflections	3 standard reflections every 200 reflections
1875 independent reflections	intensity decay: 1%

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)] = 0.059	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.181	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.1P)^2 + 0.5P] where P = (Fo^2 + 2Fc^2)/3
1875 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.26 e Å^−3
0 restraints	Δρmin = −0.43 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
S	0.34151 (8)	0.08993 (12)	0.57346 (7)	0.0494 (3)
N1	0.3802 (2)	0.1397 (4)	0.3670 (2)	0.0477 (7)
N2	0.4336 (3)	0.2834 (4)	0.4424 (2)	0.0504 (8)
N3	0.4638 (3)	0.3988 (5)	0.6437 (3)	0.0662 (10)
H3A	0.5027	0.4894	0.6309	0.079*
H3B	0.4527	0.3872	0.7149	0.079*
C1	0.0739 (4)	−0.6083 (7)	0.1831 (5)	0.0932 (17)
H1B	0.0401	−0.5868	0.0945	0.140*
H1C	0.0143	−0.6328	0.2186	0.140*
H1D	0.1250	−0.7105	0.1966	0.140*
C2	0.1409 (3)	−0.4424 (6)	0.2453 (4)	0.0623 (11)
C3	0.1475 (3)	−0.2912 (6)	0.1764 (4)	0.0673 (11)
H3C	0.1101	−0.2917	0.0900	0.081*
C4	0.2085 (3)	−0.1380 (6)	0.2323 (3)	0.0583 (10)
H4A	0.2112	−0.0376	0.1834	0.070*
C5	0.2653 (3)	−0.1341 (5)	0.3606 (3)	0.0449 (8)
C6	0.2590 (3)	−0.2873 (5)	0.4300 (4)	0.0568 (9)
H6A	0.2967	−0.2886	0.5164	0.068*
C7	0.1975 (4)	−0.4375 (5)	0.3720 (4)	0.0640 (11)
H7A	0.1943	−0.5384	0.4203	0.077*
C8	0.3296 (3)	0.0279 (4)	0.4202 (3)	0.0414 (7)
C9	0.4208 (3)	0.2763 (5)	0.5533 (3)	0.0451 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S	0.0640 (6)	0.0540 (6)	0.0378 (5)	−0.0091 (4)	0.0267 (4)	0.0006 (4)
N1	0.0611 (17)	0.0532 (17)	0.0353 (14)	−0.0070 (14)	0.0249 (13)	−0.0057 (12)
N2	0.0683 (18)	0.0538 (18)	0.0387 (15)	−0.0117 (15)	0.0305 (14)	−0.0064 (13)
N3	0.097 (3)	0.070 (2)	0.0441 (17)	−0.0336 (19)	0.0401 (17)	−0.0159 (15)
C1	0.095 (3)	0.086 (4)	0.108 (4)	−0.041 (3)	0.046 (3)	−0.035 (3)
C2	0.063 (2)	0.058 (2)	0.076 (3)	−0.0128 (19)	0.037 (2)	−0.019 (2)
C3	0.072 (3)	0.080 (3)	0.053 (2)	−0.016 (2)	0.024 (2)	−0.015 (2)
C4	0.072 (2)	0.059 (2)	0.046 (2)	−0.011 (2)	0.0240 (18)	−0.0032 (17)
C5	0.0524 (19)	0.0435 (18)	0.0451 (18)	0.0001 (15)	0.0247 (16)	−0.0016 (14)
C6	0.064 (2)	0.051 (2)	0.055 (2)	−0.0024 (18)	0.0193 (18)	0.0026 (18)
C7	0.070 (2)	0.045 (2)	0.084 (3)	−0.0041 (19)	0.034 (2)	0.005 (2)
C8	0.0544 (19)	0.0384 (17)	0.0370 (16)	0.0016 (15)	0.0224 (15)	−0.0011 (13)
C9	0.0540 (19)	0.0482 (19)	0.0380 (17)	−0.0039 (16)	0.0218 (15)	0.0008 (14)

Geometric parameters (Å, º)

S—C9	1.742 (3)	C2—C7	1.368 (6)
S—C8	1.745 (3)	C2—C3	1.376 (6)
N1—C8	1.292 (4)	C3—C4	1.387 (6)
N1—N2	1.382 (4)	C3—H3C	0.9300
N2—C9	1.309 (4)	C4—C5	1.385 (5)
N3—C9	1.335 (4)	C4—H4A	0.9300
N3—H3A	0.8600	C5—C6	1.390 (5)
N3—H3B	0.8600	C5—C8	1.468 (5)
C1—C2	1.512 (6)	C6—C7	1.380 (5)
C1—H1B	0.9600	C6—H6A	0.9300
C1—H1C	0.9600	C7—H7A	0.9300
C1—H1D	0.9600
C9—S—C8	86.96 (15)	C5—C4—C3	120.3 (4)
C8—N1—N2	114.0 (3)	C5—C4—H4A	119.9
C9—N2—N1	112.0 (3)	C3—C4—H4A	119.9
C9—N3—H3A	120.0	C4—C5—C6	117.9 (3)
C9—N3—H3B	120.0	C4—C5—C8	120.4 (3)
H3A—N3—H3B	120.0	C6—C5—C8	121.6 (3)
C2—C1—H1B	109.5	C7—C6—C5	120.6 (4)
C2—C1—H1C	109.5	C7—C6—H6A	119.7
H1B—C1—H1C	109.5	C5—C6—H6A	119.7
C2—C1—H1D	109.5	C2—C7—C6	121.9 (4)
H1B—C1—H1D	109.5	C2—C7—H7A	119.1
H1C—C1—H1D	109.5	C6—C7—H7A	119.1
C7—C2—C3	117.6 (4)	N1—C8—C5	125.2 (3)
C7—C2—C1	121.2 (4)	N1—C8—S	113.2 (2)
C3—C2—C1	121.2 (4)	C5—C8—S	121.6 (2)
C2—C3—C4	121.8 (4)	N2—C9—N3	124.1 (3)
C2—C3—H3C	119.1	N2—C9—S	113.8 (3)
C4—C3—H3C	119.1	N3—C9—S	122.2 (2)
C8—N1—N2—C9	−0.4 (4)	N2—N1—C8—S	0.5 (4)
C7—C2—C3—C4	−0.4 (6)	C4—C5—C8—N1	−30.4 (5)
C1—C2—C3—C4	179.9 (4)	C6—C5—C8—N1	149.7 (4)
C2—C3—C4—C5	0.3 (6)	C4—C5—C8—S	148.1 (3)
C3—C4—C5—C6	0.1 (6)	C6—C5—C8—S	−31.8 (4)
C3—C4—C5—C8	−179.8 (3)	C9—S—C8—N1	−0.3 (3)
C4—C5—C6—C7	−0.3 (5)	C9—S—C8—C5	−179.0 (3)
C8—C5—C6—C7	179.6 (3)	N1—N2—C9—N3	−179.9 (3)
C3—C2—C7—C6	0.2 (6)	N1—N2—C9—S	0.1 (4)
C1—C2—C7—C6	179.9 (4)	C8—S—C9—N2	0.1 (3)
C5—C6—C7—C2	0.2 (6)	C8—S—C9—N3	−179.9 (3)
N2—N1—C8—C5	179.1 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3A···N2^i	0.86	2.13	2.970 (5)	166
N3—H3B···N1^ii	0.86	2.18	3.025 (4)	166

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, −y+1/2, z+1/2.