4-Amino-3,5-dimethyl-4H-1,2,4-triazole

Abstract

In the title compound, C₄H₈N₄, inter­molecular N—H⋯N hydrogen bonds involving the amino groups and triazole N atoms form a two-dimensional sheet.

Related literature

For background, see: Desenko (1995 ▶); For further synthetic details, see: Van Albada et al. (1984 ▶). For related literature, see: Allen et al. (1987 ▶); Ding et al. (2004 ▶); Steel (2005 ▶); Van Diemen et al. (1991 ▶); Yi et al. (2004 ▶).

Experimental

Crystal data

• C₄H₈N₄

• M _r = 112.14

• Monoclinic,

• a = 5.8423 (12) Å

• b = 7.7540 (16) Å

• c = 12.846 (3) Å

• β = 96.91 (3)°

• V = 577.7 (2) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 293 (2) K

• 0.30 × 0.30 × 0.20 mm

Data collection

• Rigaku R-AXIS RAPID-S diffractometer

• Absorption correction: none

• 5941 measured reflections

• 1333 independent reflections

• 1101 reflections with I > 2σ(I)

• R _int = 0.031

Refinement

• R[F ² > 2σ(F ²)] = 0.051

• wR(F ²) = 0.142

• S = 1.12

• 1333 reflections

• 81 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.20 e Å⁻³

• Δρ_min = −0.19 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ▶); 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 and PLATON (Spek, 2003 ▶).

Supplementary Material

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4D⋯N1i	0.91 (2)	2.25 (2)	3.145 (2)	170 (2)
N)—H4E⋯N2ii	0.96 (2)	2.20 (2)	3.086 (2)	154 (2)

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

N-containing heterocyclic aromatic compounds are extensively used as bridging ligands in coordination and metallosupramolecular chemistry (Steel, 2005). For its strong σ-donor and weak π-acceptor properties, 1,2,4-triazole and its derivatives possess several coordination modes through three N donor atoms coordinating to metal ions (Van Diemen et al., 1991;Yi et al.,2004; Ding et al., 2004). We herein report the crystal structure of the title compound (I). In the molecule of (I), (Fig. 1), the bond lengths and angles are generally within normal ranges (Allen et al., 1987). The H atoms of the amino group form hydrogen bonds with the N atoms of neighbouring triazole rings. The geometric parameters of the N—H···N (Spek, 2003) hydrogen-bonding interactions are given in Table 1, and a two dimensional sheet is formed by these intermolecular hydrogen bonds (Fig. 2).

Experimental

A 80% aqueous solution of 2.6 mol of hydrazine hydrate was added slowly to 2.0 mol of acetic acid. The mixture was heated slowly and kept at 493 K for about 3 h. When the mixture was cooled, colourless block shape crystals 4-amino-3,5-dimethyl-4H-1,2,4-triazole were isolated.

Refinement

Methyl H atoms were included in calculated positions and treated in the subsequent refinement as riding atoms, with C—H = 0.96Å and U_iso(H) = 1.5U_eq(C). Atoms H4D and H4E, which are involved in hydrogen-bonding interactions, were located in a difference Fourier map and refined freely with isotropic displacement parameters.

Figures

Fig. 1.

The structure of the title compound with ellipsoids drawn with 30% displacement probability.

Fig. 2.

Two dimensional sheet formed by intermolecular hydrogen bonds in the title compound, with the hydrogen bonds shown as dashed lines.

Crystal data

C4H8N4	F000 = 240
Mr = 112.14	Dx = 1.289 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5363 reflections
a = 5.8423 (12) Å	θ = 3.1–27.5º
b = 7.7540 (16) Å	µ = 0.09 mm−1
c = 12.846 (3) Å	T = 293 (2) K
β = 96.91 (3)º	Block, colourless
V = 577.7 (2) Å3	0.30 × 0.30 × 0.20 mm
Z = 4

Data collection

Rigaku R-AXIS RAPID-S diffractometer	1101 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.031
Monochromator: graphite	θmax = 27.5º
T = 293(2) K	θmin = 3.1º
ω scans	h = −7→7
Absorption correction: none	k = −10→10
5941 measured reflections	l = −16→16
1333 independent reflections

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.051	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.142	w = 1/[σ2(Fo2) + (0.068P)2 + 0.1583P] where P = (Fo2 + 2Fc2)/3
S = 1.12	(Δ/σ)max < 0.001
1333 reflections	Δρmax = 0.20 e Å−3
81 parameters	Δρmin = −0.19 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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
N3	1.0528 (2)	0.17414 (16)	0.13102 (10)	0.0297 (3)
N4	1.2366 (2)	0.2703 (2)	0.09833 (12)	0.0396 (4)
N2	0.8357 (3)	0.02909 (19)	0.22608 (11)	0.0408 (4)
N1	0.7072 (2)	0.06903 (19)	0.13019 (12)	0.0406 (4)
C2	0.8418 (3)	0.1557 (2)	0.07503 (12)	0.0322 (4)
C1	1.0418 (3)	0.0933 (2)	0.22443 (13)	0.0323 (4)
C3	1.2408 (3)	0.0804 (3)	0.30796 (15)	0.0481 (5)
H3A	1.1950	0.0182	0.3667	0.072*
H3B	1.2906	0.1941	0.3299	0.072*
H3C	1.3651	0.0206	0.2812	0.072*
C4	0.7788 (3)	0.2255 (3)	−0.03203 (14)	0.0467 (5)
H4A	0.6213	0.1969	−0.0559	0.070*
H4B	0.8775	0.1762	−0.0787	0.070*
H4C	0.7968	0.3486	−0.0308	0.070*
H4D	1.362 (4)	0.200 (3)	0.1041 (18)	0.060 (6)*
H4E	1.263 (4)	0.361 (3)	0.1488 (19)	0.064 (7)*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N3	0.0243 (7)	0.0317 (7)	0.0332 (7)	−0.0002 (5)	0.0036 (5)	−0.0007 (5)
N4	0.0288 (8)	0.0462 (9)	0.0446 (9)	−0.0059 (7)	0.0082 (6)	0.0035 (7)
N2	0.0359 (8)	0.0444 (8)	0.0421 (9)	−0.0032 (6)	0.0042 (6)	0.0060 (6)
N1	0.0296 (7)	0.0453 (8)	0.0458 (9)	−0.0045 (6)	0.0003 (6)	0.0014 (7)
C2	0.0272 (8)	0.0332 (8)	0.0353 (8)	0.0019 (6)	0.0006 (6)	−0.0042 (6)
C1	0.0301 (8)	0.0323 (8)	0.0342 (9)	0.0017 (6)	0.0029 (6)	0.0009 (6)
C3	0.0413 (10)	0.0579 (11)	0.0426 (10)	0.0024 (9)	−0.0060 (8)	0.0093 (9)
C4	0.0457 (11)	0.0541 (11)	0.0378 (10)	0.0022 (9)	−0.0050 (8)	0.0020 (8)

Geometric parameters (Å, °)

N3—C2	1.358 (2)	C2—C4	1.482 (2)
N3—C1	1.362 (2)	C1—C3	1.487 (2)
N3—N4	1.4123 (18)	C3—H3A	0.9600
N4—H4D	0.91 (2)	C3—H3B	0.9600
N4—H4E	0.95 (2)	C3—H3C	0.9600
N2—C1	1.305 (2)	C4—H4A	0.9600
N2—N1	1.398 (2)	C4—H4B	0.9600
N1—C2	1.306 (2)	C4—H4C	0.9600
C2—N3—C1	106.40 (13)	N3—C1—C3	123.42 (15)
C2—N3—N4	124.91 (14)	C1—C3—H3A	109.5
C1—N3—N4	128.54 (13)	C1—C3—H3B	109.5
N3—N4—H4D	106.9 (14)	H3A—C3—H3B	109.5
N3—N4—H4E	104.6 (13)	C1—C3—H3C	109.5
H4D—N4—H4E	109 (2)	H3A—C3—H3C	109.5
C1—N2—N1	107.45 (14)	H3B—C3—H3C	109.5
C2—N1—N2	107.31 (13)	C2—C4—H4A	109.5
N1—C2—N3	109.51 (14)	C2—C4—H4B	109.5
N1—C2—C4	126.35 (15)	H4A—C4—H4B	109.5
N3—C2—C4	124.14 (15)	C2—C4—H4C	109.5
N2—C1—N3	109.34 (14)	H4A—C4—H4C	109.5
N2—C1—C3	127.23 (16)	H4B—C4—H4C	109.5
C1—N2—N1—C2	−0.04 (18)	N1—N2—C1—N3	0.12 (18)
N2—N1—C2—N3	−0.05 (18)	N1—N2—C1—C3	−178.51 (17)
N2—N1—C2—C4	−179.82 (16)	C2—N3—C1—N2	−0.15 (18)
C1—N3—C2—N1	0.12 (18)	N4—N3—C1—N2	175.53 (15)
N4—N3—C2—N1	−175.76 (14)	C2—N3—C1—C3	178.54 (16)
C1—N3—C2—C4	179.90 (15)	N4—N3—C1—C3	−5.8 (3)
N4—N3—C2—C4	4.0 (2)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4D···N1i	0.91 (2)	2.25 (2)	3.145 (2)	170 (2)
N)—H4E···N2ii	0.96 (2)	2.20 (2)	3.086 (2)	154 (2)

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