3-Phenyl-1H-1,2,4-triazol-5-amine-5-phenyl-1H-1,2,4-triazol-3-amine (1/1).

In the title compound, C(8)H(8)N(4)·C(8)H(8)N(4), two tautomers, viz. 3-phenyl-1,2,4-triazol-5-amine and 5-phenyl-1,2,4-triazol-3-amine, are crystallized together in equal amounts. The 3-phenyl-1,2,4-triazol-5-amine mol-ecule is essentially planar; the phenyl ring makes a dihedral angle of 2.3 (2)° with the mean plane of the 1,2,4-triazole ring. In the 5-phenyl-1,2,4-triazol-3-amine tautomer, the mean planes of the phenyl and 1,2,4-triazole rings form a dihedral angle of 30.8 (2)°. The π-electron delocalization of the amino group with the 1,2,4-triazole nucleus in the 3-phenyl-1,2,4-triazol-5-amine mol-ecule is more extensive than that in the 5-phenyl-1,2,4-triazol-3-amine tautomer. The mol-ecules are linked into a two-dimensional network parallel to (100) by N-H⋯N hydrogen bonds.

Related literature

For a summary of structural data for 1,2,4-triazoles, see: Buzykin et al. (2006 ▶). For the crystal structure of 3-pyridin-2-yl-1,2,4-triazol-5-amine, see: Dolzhenko et al. (2009 ▶). For the use of 1,2,4-triazol-5-amines as building blocks in the synthesis of fused heterocyclic systems, see: Dolzhenko et al. (2006 ▶, 2007a ▶,b ▶); Fischer (2007 ▶).

Experimental

Crystal data

C8H8N4·C8H8N4

M = 320.36

Monoclinic,

a = 17.817 (2) Å

b = 5.0398 (6) Å

c = 18.637 (2) Å

β = 113.573 (4)°

V = 1533.9 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 223 (2) K

0.60 × 0.10 × 0.06 mm

Data collection

Bruker SMART APEX CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ▶) T min = 0.947, T max = 0.995

10288 measured reflections

3523 independent reflections

2394 reflections with I > 2σ(I)

R int = 0.063

Refinement

R[F 2 > 2σ(F 2)] = 0.067

wR(F 2) = 0.168

S = 0.99

3523 reflections

241 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.43 e Å−3

Δρmin = −0.24 e Å−3

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808042165/ci2720sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808042165/ci2720Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C8H8N4·C8H8N4	F(000) = 672
Mr = 320.36	Dx = 1.387 Mg m−3
Monoclinic, P21/c	Melting point: 460 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 17.817 (2) Å	Cell parameters from 1028 reflections
b = 5.0398 (6) Å	θ = 2.4–22.6°
c = 18.637 (2) Å	µ = 0.09 mm−1
β = 113.573 (4)°	T = 223 K
V = 1533.9 (3) Å3	Rod, colourless
Z = 4	0.60 × 0.10 × 0.06 mm

Bruker SMART APEX CCD diffractometer	3523 independent reflections
Radiation source: fine-focus sealed tube	2394 reflections with I > 2σ(I)
graphite	Rint = 0.063
φ and ω scans	θmax = 27.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −17→23
Tmin = 0.947, Tmax = 0.995	k = −6→6
10288 measured reflections	l = −24→20

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)] = 0.067	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.168	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	w = 1/[σ2(Fo2) + (0.0813P)2 + 0.5041P] where P = (Fo2 + 2Fc2)/3
3523 reflections	(Δ/σ)max = 0.001
241 parameters	Δρmax = 0.43 e Å−3
0 restraints	Δρmin = −0.24 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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.

	x	y	z	Uiso*/Ueq
N1	0.45958 (12)	0.2679 (4)	0.41243 (11)	0.0227 (5)
N2	0.44655 (12)	0.1498 (4)	0.29112 (11)	0.0228 (5)
N3	0.50228 (12)	0.3557 (4)	0.31965 (12)	0.0232 (5)
H3N	0.5206 (17)	0.441 (6)	0.2883 (17)	0.034 (8)*
N4	0.55437 (15)	0.6210 (5)	0.43462 (14)	0.0306 (5)
H4A	0.5543 (18)	0.650 (6)	0.483 (2)	0.047 (9)*
H4B	0.5900 (18)	0.694 (6)	0.4217 (17)	0.038 (8)*
C1	0.36387 (14)	−0.0976 (5)	0.34673 (13)	0.0221 (5)
C2	0.32601 (15)	−0.2542 (5)	0.28099 (14)	0.0275 (6)
H2	0.3384	−0.2297	0.2369	0.033*
C3	0.26999 (16)	−0.4464 (5)	0.27973 (16)	0.0326 (6)
H3	0.2450	−0.5525	0.2349	0.039*
C4	0.25056 (16)	−0.4837 (5)	0.34337 (16)	0.0317 (6)
H4	0.2119	−0.6128	0.3420	0.038*
C5	0.28814 (18)	−0.3303 (6)	0.40898 (17)	0.0405 (7)
H5	0.2754	−0.3557	0.4528	0.049*
C6	0.34456 (17)	−0.1385 (6)	0.41101 (16)	0.0352 (7)
H6	0.3700	−0.0352	0.4563	0.042*
C7	0.42378 (14)	0.1068 (5)	0.34941 (13)	0.0205 (5)
C8	0.50768 (14)	0.4241 (5)	0.39146 (13)	0.0223 (5)
N5	0.18197 (12)	0.2602 (4)	0.01779 (11)	0.0225 (5)
N6	0.17613 (13)	−0.1706 (4)	0.02735 (12)	0.0241 (5)
H6N	0.165 (2)	−0.339 (7)	0.0188 (19)	0.057 (10)*
N7	0.25003 (12)	−0.1005 (4)	0.08543 (11)	0.0247 (5)
N8	0.31434 (13)	0.3193 (5)	0.12197 (13)	0.0257 (5)
H8A	0.3424 (19)	0.261 (6)	0.1652 (19)	0.042 (9)*
H8B	0.302 (2)	0.500 (7)	0.1168 (19)	0.055 (10)*
C9	0.05728 (14)	0.0322 (5)	−0.07822 (14)	0.0237 (5)
C10	0.03648 (17)	0.2181 (5)	−0.13815 (16)	0.0341 (7)
H10	0.0741	0.3502	−0.1371	0.041*
C11	−0.04013 (18)	0.2079 (6)	−0.19945 (17)	0.0444 (8)
H11	−0.0542	0.3339	−0.2399	0.053*
C12	−0.09593 (17)	0.0147 (6)	−0.20168 (17)	0.0423 (8)
H12	−0.1477	0.0092	−0.2435	0.051*
C13	−0.07527 (17)	−0.1708 (6)	−0.14209 (18)	0.0417 (8)
H13	−0.1131	−0.3025	−0.1432	0.050*
C14	0.00090 (17)	−0.1621 (6)	−0.08100 (16)	0.0345 (6)
H14A	0.0148	−0.2891	−0.0408	0.041*
C15	0.13744 (15)	0.0420 (5)	−0.01207 (13)	0.0219 (5)
C16	0.24976 (14)	0.1614 (5)	0.07732 (13)	0.0198 (5)

	U11	U22	U33	U12	U13	U23
N1	0.0273 (11)	0.0216 (10)	0.0205 (10)	−0.0031 (9)	0.0108 (9)	−0.0002 (8)
N2	0.0274 (11)	0.0216 (10)	0.0200 (10)	−0.0022 (9)	0.0099 (8)	−0.0016 (8)
N3	0.0306 (11)	0.0236 (11)	0.0193 (10)	−0.0060 (9)	0.0143 (9)	−0.0013 (9)
N4	0.0378 (13)	0.0325 (13)	0.0266 (12)	−0.0140 (11)	0.0182 (10)	−0.0090 (10)
C1	0.0229 (12)	0.0212 (12)	0.0217 (12)	0.0036 (10)	0.0082 (10)	−0.0010 (10)
C2	0.0293 (13)	0.0302 (14)	0.0244 (13)	−0.0007 (11)	0.0122 (11)	−0.0013 (11)
C3	0.0286 (14)	0.0343 (15)	0.0310 (14)	−0.0080 (12)	0.0079 (11)	−0.0104 (12)
C4	0.0268 (14)	0.0275 (14)	0.0419 (15)	−0.0067 (11)	0.0150 (12)	0.0017 (12)
C5	0.0476 (18)	0.0449 (17)	0.0391 (16)	−0.0131 (15)	0.0279 (14)	−0.0024 (14)
C6	0.0448 (16)	0.0356 (15)	0.0298 (14)	−0.0133 (13)	0.0197 (13)	−0.0075 (12)
C7	0.0249 (12)	0.0190 (12)	0.0176 (11)	0.0031 (10)	0.0085 (9)	0.0007 (9)
C8	0.0237 (12)	0.0228 (13)	0.0208 (12)	0.0009 (10)	0.0093 (10)	0.0011 (10)
N5	0.0246 (10)	0.0196 (10)	0.0214 (10)	0.0019 (8)	0.0072 (8)	−0.0015 (8)
N6	0.0264 (11)	0.0176 (11)	0.0250 (11)	0.0004 (9)	0.0067 (9)	0.0018 (9)
N7	0.0276 (11)	0.0219 (11)	0.0211 (10)	0.0015 (9)	0.0061 (9)	0.0004 (8)
N8	0.0267 (12)	0.0222 (12)	0.0223 (11)	0.0028 (9)	0.0037 (9)	−0.0001 (9)
C9	0.0223 (12)	0.0203 (12)	0.0277 (13)	0.0023 (10)	0.0091 (10)	−0.0052 (10)
C10	0.0383 (15)	0.0234 (13)	0.0338 (14)	0.0007 (12)	0.0073 (12)	0.0002 (11)
C11	0.0453 (18)	0.0347 (17)	0.0357 (16)	0.0085 (14)	−0.0022 (14)	0.0022 (13)
C12	0.0278 (15)	0.0420 (18)	0.0431 (17)	0.0073 (13)	−0.0008 (13)	−0.0139 (14)
C13	0.0285 (15)	0.0431 (17)	0.0506 (18)	−0.0101 (13)	0.0126 (13)	−0.0157 (15)
C14	0.0357 (15)	0.0313 (15)	0.0349 (15)	−0.0016 (12)	0.0123 (12)	−0.0024 (12)
C15	0.0261 (12)	0.0193 (12)	0.0218 (12)	0.0001 (10)	0.0113 (10)	−0.0022 (10)
C16	0.0241 (12)	0.0196 (12)	0.0166 (11)	0.0031 (10)	0.0092 (9)	−0.0009 (9)

N1—C8	1.332 (3)	N5—C15	1.340 (3)
N1—C7	1.359 (3)	N5—C16	1.366 (3)
N2—C7	1.321 (3)	N6—C15	1.326 (3)
N2—N3	1.387 (3)	N6—N7	1.375 (3)
N3—C8	1.348 (3)	N6—H6N	0.87 (4)
N3—H3N	0.89 (3)	N7—C16	1.328 (3)
N4—C8	1.337 (3)	N8—C16	1.372 (3)
N4—H4A	0.92 (3)	N8—H8A	0.81 (3)
N4—H4B	0.85 (3)	N8—H8B	0.94 (4)
C1—C2	1.385 (3)	C9—C14	1.389 (4)
C1—C6	1.388 (3)	C9—C10	1.390 (4)
C1—C7	1.470 (3)	C9—C15	1.468 (3)
C2—C3	1.385 (4)	C10—C11	1.387 (4)
C2—H2	0.94	C10—H10	0.94
C3—C4	1.375 (4)	C11—C12	1.380 (4)
C3—H3	0.94	C11—H11	0.94
C4—C5	1.373 (4)	C12—C13	1.384 (4)
C4—H4	0.94	C12—H12	0.94
C5—C6	1.384 (4)	C13—C14	1.380 (4)
C5—H5	0.94	C13—H13	0.94
C6—H6	0.94	C14—H14A	0.94
C8—N1—C7	103.55 (19)	C15—N5—C16	102.86 (19)
C7—N2—N3	102.47 (18)	C15—N6—N7	110.6 (2)
C8—N3—N2	109.15 (19)	C15—N6—H6N	131 (2)
C8—N3—H3N	129.2 (18)	N7—N6—H6N	118 (2)
N2—N3—H3N	120.4 (18)	C16—N7—N6	101.93 (18)
C8—N4—H4A	118 (2)	C16—N8—H8A	115 (2)
C8—N4—H4B	121 (2)	C16—N8—H8B	113 (2)
H4A—N4—H4B	120 (3)	H8A—N8—H8B	119 (3)
C2—C1—C6	118.5 (2)	C14—C9—C10	119.3 (2)
C2—C1—C7	121.3 (2)	C14—C9—C15	120.1 (2)
C6—C1—C7	120.2 (2)	C10—C9—C15	120.7 (2)
C3—C2—C1	120.4 (2)	C11—C10—C9	119.7 (3)
C3—C2—H2	119.8	C11—C10—H10	120.2
C1—C2—H2	119.8	C9—C10—H10	120.2
C4—C3—C2	120.6 (2)	C12—C11—C10	120.7 (3)
C4—C3—H3	119.7	C12—C11—H11	119.6
C2—C3—H3	119.7	C10—C11—H11	119.6
C5—C4—C3	119.3 (2)	C11—C12—C13	119.7 (3)
C5—C4—H4	120.3	C11—C12—H12	120.2
C3—C4—H4	120.3	C13—C12—H12	120.2
C4—C5—C6	120.5 (3)	C14—C13—C12	119.9 (3)
C4—C5—H5	119.7	C14—C13—H13	120.0
C6—C5—H5	119.7	C12—C13—H13	120.0
C5—C6—C1	120.5 (3)	C13—C14—C9	120.7 (3)
C5—C6—H6	119.7	C13—C14—H14A	119.6
C1—C6—H6	119.7	C9—C14—H14A	119.6
N2—C7—N1	114.8 (2)	N6—C15—N5	110.0 (2)
N2—C7—C1	123.0 (2)	N6—C15—C9	123.7 (2)
N1—C7—C1	122.1 (2)	N5—C15—C9	126.3 (2)
N1—C8—N4	125.5 (2)	N7—C16—N5	114.6 (2)
N1—C8—N3	110.0 (2)	N7—C16—N8	122.9 (2)
N4—C8—N3	124.6 (2)	N5—C16—N8	122.4 (2)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3N···N2i	0.89 (3)	2.08 (3)	2.966 (3)	175 (3)
N4—H4A···N1ii	0.92 (3)	2.09 (3)	3.011 (3)	173 (3)
N4—H4B···N8i	0.85 (3)	2.25 (3)	3.091 (3)	170 (3)
N6—H6N···N5iii	0.87 (4)	2.04 (4)	2.879 (3)	159 (3)
N8—H8A···N2	0.81 (3)	2.41 (3)	3.206 (3)	168 (3)
N8—H8B···N7iv	0.94 (4)	2.19 (4)	3.115 (3)	169 (3)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3N⋯N2i	0.89 (3)	2.08 (3)	2.966 (3)	175 (3)
N4—H4A⋯N1ii	0.92 (3)	2.09 (3)	3.011 (3)	173 (3)
N4—H4B⋯N8i	0.85 (3)	2.25 (3)	3.091 (3)	170 (3)
N6—H6N⋯N5iii	0.87 (4)	2.04 (4)	2.879 (3)	159 (3)
N8—H8A⋯N2	0.81 (3)	2.41 (3)	3.206 (3)	168 (3)
N8—H8B⋯N7iv	0.94 (4)	2.19 (4)	3.115 (3)	169 (3)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .