1,4-Bis(5-methyl-1H-1,2,4-triazol-3-yl)benzene tetra­hydrate

In the title compound, C₁₂H₁₂N₆·4H₂O, the two triazole rings adopt a cis configuration with a crystallographic twofold axis passing through the central benzene group. The benzene and triazole rings are almost coplanar with a dihedral angle of 5.5 (1)°. In the crystal, water mol­ecules are joined together by OW—H⋯OW hydrogen bonds to form a one-dimensional zigzag chain. These water chains are further connected to the organic mol­ecule, forming a three-dimensional network by inter­molecular OW—H⋯N and N—H⋯OW hydrogen bonds. Moreover, π–π stacking inter­actions between triazole rings [centroid–centroid distances = 3.667 (1)–3.731 (1) Å] are observed. One of the water mol­ecules shows one of the H atoms to be disordered over two positions.

Related literature

For applications of 1,2,4-triazole and its derivatives in coordination chemistry, see: Zhang et al. (2005); Ouellette et al. (2006); Zhu et al. (2009). For the structures of ruthenium complexes with pyridine-2-yl-1,2,4-triazole-based ligands, see: Passaniti et al. (2002). For the previous synthesis of the title compound, see: Bahçeci et al. (2005).

Experimental

Crystal data

• C₁₂H₁₂N₆·4H₂O

• M_r = 312.34

• Monoclinic, C 2/c

• a = 12.7343 (19) Å

• b = 13.937 (2) Å

• c = 9.0648 (14) Å

• β = 100.893 (3)°

• V = 1579.8 (4) ų

• Z = 4

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 293 K

• 0.35 × 0.28 × 0.08 mm

Data collection

• Bruker APEX CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T_min = 0.966, T_max = 0.992

• 4670 measured reflections

• 1542 independent reflections

• 1286 reflections with I > 2σ(I)

• R_int = 0.021

Refinement

• R[F² > 2σ(F²)] = 0.052

• wR(F²) = 0.148

• S = 1.04

• 1542 reflections

• 102 parameters

• H-atom parameters constrained

• Δρ_max = 0.27 e Å⁻³

• Δρ_min = −0.25 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1D⋯O1W	0.86	1.88	2.736 (2)	173
O1W—H1WA⋯N2^i	0.85	2.08	2.926 (2)	172
O1W—H1WB⋯O2W^ii	0.85	1.96	2.801 (2)	170
O2W—H2WA⋯N3^iii	0.85	1.95	2.800 (2)	173
O2W—H2WB⋯O2W^iii	0.85	1.93	2.754 (3)	164
O2W—H2WC⋯O2W^iv	0.85	1.92	2.774 (3)	178
Symmetry codes: (i) ; (ii) ; (iii) -x+1, -y, -z; (iv) .

Data collection: SMART (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Supporting information

S1. Comment

In the past few years, 1,2,4-triazole and its derivatives have attracted increasing attention as N-heterocyclic aromatic ligands, since they are effective bridging ligands combining the coordination modes of both imidazoles and pyrazoles. In addition, metal-triazolate frameworks have demonstrated high thermal and chemical stabilities, and interesting luminescent, magnetic and gas-adsorption properties (Zhang et al. 2005; Ouellette et al. 2006; Zhu et al. 2009). However, there are rare crystal structure reports of 1,2,4-triazole derivatives attached to aromatic groups (Passaniti et al. 2002). Although the synthesis of the title compound 1,4-bis(5-methyl-1H-1,2,4-triazol-3-yl)benzene has been reported by Bahçeci et al. (2005), no crystallographic study has been reported on this ligand and related metal coordination compounds. We reported herein another synthetic method and the crystal structure of the title compound.

The asymmetric unit of the title compound contains one-half organic molecule, which adopts a cis-configuration with a crystallographic mirror plane passing through the central benzene group, and two water molecules (Fig. 1). The bond lengths and angles are within normal ranges in accordance with the corresponding values reported (Passaniti et al. 2002). The benzene and the triazole rings are almost coplanar, with a dihedral angle of 5.4 (1)°. In the crystal structure, water molecules are joined together by OW—H···OW hydrogen bonds to form a one-dimensional zig-zag water chain (Fig. 2, Table 1). These water chains are further connected to the organic molecule producing a three-dimensional network (Fig. 2) by intermolecular OW—H···N and N—H···OW hydrogen bonds (Table 1). Moreover, π-π stacking interactions between triazole rings (centroid-centroid distance = 3.665 (1)–3.732 (1) Å) are observed (Fig. 3).

Related literature

For applications of 1,2,4-triazole and its derivatives in coordination chemistry, see: Zhang et al. (2005); Ouellette et al. (2006); Zhu et al. (2009). For the structures of ruthenium complexes with pyridine-2-yl-1,2,4-triazole-based ligands, see: Passaniti et al. (2002). For the previous synthesis of the title compound, see: Bahçeci et al. (2005).

S2. Experimental

The ligand 1,4-bis(5-methyl-1H-1,2,4-triazol-3-yl)benzene was synthesized according to a literature method (Bahçeci et al. 2005). Yellow, plate-like single crystals of the title compound are obtained from a solution of 1,4-bis(5-methyl-1H-1,2,4-triazol-3-yl)benzene (24 mg, 0.1 mmol) in methanol (1 ml) and water (5 ml) if the solution is placed in a Teflon-lined stainless steel vessel (15 ml), heated at 453 K for 24 h and then cooled to room temperature at a rate of 5 K h^-1.

S3. Refinement

All H atoms were placed in idealized positions (O—H = 0.85 Å, N—H = 0.86 Å and C—H = 0.95 Å) and refined as riding atoms with U_iso(H) = 1.2U_eq(C, N) and U_iso(H) = 1.5U_eq(O). One hydrogen atom from O2W is disordered over two positions in a 0.52 (3):0.48 (3) ratio, which is freely refined with the command 'PART'.

Computing details

Data collection: SMART (Bruker, 2004); cell refinement: SMART [SAINT?] (Bruker, 2004); data reduction: SMART [SAINT?] (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. Molecular structure of the title compound, non-H atoms are depicted as 30% probability displacement ellipsoids.
	Fig. 2. Packing diagram of the title compound showing the hydrogen bonding interactions as dashed lines. H atoms not involved in hydrogen bondings have been omitted.
	Fig. 3. π-π Stacking interactions between triazole rings, H and O atoms are omitted for clarity.

5-methyl-3-[4-(5-methyl-1H-1,2,4-triazol-3-yl)phenyl]-1H- 1,2,4-triazole tetrahydrate

Crystal data

C12H12N6·4H2O	Z = 4
Mr = 312.34	F(000) = 664
Monoclinic, C2/c	Dx = 1.313 Mg m^−3
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 12.7343 (19) Å	µ = 0.10 mm^−1
b = 13.937 (2) Å	T = 293 K
c = 9.0648 (14) Å	Plate, yellow
β = 100.893 (3)°	0.35 × 0.28 × 0.08 mm
V = 1579.8 (4) Å^3

Data collection

Bruker APEX CCD diffractometer	1542 independent reflections
Radiation source: fine-focus sealed tube	1286 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
ω scans	θmax = 26.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −15→15
Tmin = 0.966, Tmax = 0.992	k = −15→17
4670 measured reflections	l = −11→11

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)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.148	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0816P)^2 + 0.7602P] where P = (Fo^2 + 2Fc^2)/3
1542 reflections	(Δ/σ)max < 0.001
102 parameters	Δρmax = 0.27 e Å^−3
0 restraints	Δρmin = −0.25 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. One hydrogen atom from O2W is disordered over two positions in a 0.52 (3):0.48 (3) ratio, which is freely refined with command 'PART'.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
N1	0.66106 (13)	0.34969 (11)	−0.19565 (17)	0.0531 (5)
H1D	0.6874	0.3847	−0.2578	0.064*
N2	0.62354 (14)	0.38395 (11)	−0.07499 (17)	0.0522 (5)
N3	0.60877 (12)	0.22386 (10)	−0.09140 (16)	0.0454 (4)
C1	0.68428 (18)	0.19667 (15)	−0.3248 (2)	0.0590 (6)
H1A	0.7292	0.1449	−0.2805	0.088*
H1B	0.7230	0.2361	−0.3830	0.088*
H1C	0.6218	0.1711	−0.3887	0.088*
C2	0.65166 (14)	0.25529 (13)	−0.20444 (18)	0.0448 (4)
C3	0.59264 (14)	0.30486 (12)	−0.01538 (19)	0.0425 (4)
C4	0.54472 (14)	0.30544 (12)	0.12072 (19)	0.0421 (4)
C5	0.52248 (17)	0.22014 (13)	0.1863 (2)	0.0510 (5)
H5A	0.5379	0.1622	0.1443	0.061*
C6	0.52170 (16)	0.39108 (13)	0.1860 (2)	0.0510 (5)
H6A	0.5358	0.4491	0.1429	0.061*
O1W	0.73472 (14)	0.45314 (11)	−0.41166 (19)	0.0757 (5)
H1WA	0.6969	0.4969	−0.4609	0.091*
H1WB	0.8001	0.4691	−0.4017	0.091*
O2W	0.44076 (12)	−0.02791 (9)	0.10493 (16)	0.0602 (4)
H2WA	0.4240	−0.0868	0.0928	0.072*
H2WB	0.4790	−0.0006	0.0500	0.072*	0.52 (3)
H2WC	0.4784	−0.0277	0.1930	0.072*	0.48 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0657 (11)	0.0516 (10)	0.0484 (8)	−0.0032 (8)	0.0274 (8)	0.0074 (7)
N2	0.0662 (11)	0.0437 (9)	0.0523 (9)	−0.0025 (7)	0.0257 (8)	0.0035 (7)
N3	0.0540 (9)	0.0428 (8)	0.0425 (8)	−0.0035 (7)	0.0166 (7)	−0.0015 (6)
C1	0.0649 (13)	0.0672 (13)	0.0495 (10)	−0.0045 (10)	0.0232 (9)	−0.0060 (9)
C2	0.0467 (10)	0.0488 (10)	0.0401 (9)	−0.0022 (8)	0.0115 (7)	0.0016 (7)
C3	0.0452 (10)	0.0437 (9)	0.0397 (9)	−0.0003 (7)	0.0108 (7)	0.0012 (7)
C4	0.0448 (10)	0.0431 (10)	0.0396 (9)	−0.0001 (7)	0.0109 (7)	0.0010 (7)
C5	0.0774 (14)	0.0368 (9)	0.0429 (9)	0.0004 (9)	0.0218 (9)	−0.0027 (7)
C6	0.0603 (12)	0.0380 (10)	0.0604 (11)	−0.0004 (8)	0.0260 (9)	0.0049 (8)
O1W	0.0804 (11)	0.0679 (10)	0.0871 (11)	0.0058 (8)	0.0373 (9)	0.0277 (8)
O2W	0.0809 (11)	0.0447 (7)	0.0611 (9)	−0.0064 (7)	0.0289 (8)	−0.0014 (6)

Geometric parameters (Å, º)

N1—C2	1.322 (3)	C4—C5	1.382 (2)
N1—N2	1.360 (2)	C4—C6	1.388 (2)
N1—H1D	0.8600	C5—C5^i	1.383 (4)
N2—C3	1.320 (2)	C5—H5A	0.9300
N3—C2	1.324 (2)	C6—C6^i	1.376 (4)
N3—C3	1.358 (2)	C6—H6A	0.9300
C1—C2	1.484 (3)	O1W—H1WA	0.8500
C1—H1A	0.9600	O1W—H1WB	0.8500
C1—H1B	0.9600	O2W—H2WA	0.8500
C1—H1C	0.9600	O2W—H2WB	0.8501
C3—C4	1.476 (2)	O2W—H2WC	0.8499
C2—N1—N2	110.87 (14)	N2—C3—C4	122.67 (15)
C2—N1—H1D	124.6	N3—C3—C4	123.69 (15)
N2—N1—H1D	124.6	C5—C4—C6	118.63 (17)
C3—N2—N1	102.31 (15)	C5—C4—C3	120.35 (15)
C2—N3—C3	104.00 (15)	C6—C4—C3	121.01 (15)
C2—C1—H1A	109.5	C4—C5—C5^i	120.67 (10)
C2—C1—H1B	109.5	C4—C5—H5A	119.7
H1A—C1—H1B	109.5	C5^i—C5—H5A	119.7
C2—C1—H1C	109.5	C6^i—C6—C4	120.69 (10)
H1A—C1—H1C	109.5	C6^i—C6—H6A	119.7
H1B—C1—H1C	109.5	C4—C6—H6A	119.7
N1—C2—N3	109.18 (15)	H1WA—O1W—H1WB	108.3
N1—C2—C1	123.88 (16)	H2WA—O2W—H2WB	121.0
N3—C2—C1	126.93 (17)	H2WA—O2W—H2WC	102.0
N2—C3—N3	113.64 (16)	H2WB—O2W—H2WC	105.4

Symmetry code: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1D···O1W	0.86	1.88	2.736 (2)	173
O1W—H1WA···N2^ii	0.85	2.08	2.926 (2)	172
O1W—H1WB···O2W^iii	0.85	1.96	2.801 (2)	170
O2W—H2WA···N3^iv	0.85	1.95	2.800 (2)	173
O2W—H2WB···O2W^iv	0.85	1.93	2.754 (3)	164
O2W—H2WC···O2W^i	0.85	1.92	2.774 (3)	178

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