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In the title compound, C8H8N4OS, the planar triazole ring is effectively coplanar with the benzene ring, which facilitates the formation of three intra­molecular inter­actions N—H...S (leading to a thione tautomer in the solid state), O—H...N and C—H...N. Inter­molecular N—H...S inter­actions lead to the formation of dimers, which are, in turn, linked to each other by N—H...O hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536805027972/tk6257sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536805027972/tk6257Isup2.hkl
Contains datablock I

CCDC reference: 287735

Key indicators

  • Single-crystal X-ray study
  • T = 296 K
  • Mean [sigma](C-C) = 0.003 Å
  • R factor = 0.038
  • wR factor = 0.110
  • Data-to-parameter ratio = 12.4

checkCIF/PLATON results

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Alert level C PLAT063_ALERT_3_C Crystal Probably too Large for Beam Size ....... 0.68 mm PLAT128_ALERT_4_C Non-standard setting of Space group P21/c .... P21/a
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 2 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 1 ALERT type 4 Improvement, methodology, query or suggestion

Comment top

1,2,4-Triazole ring systems are typical planar six-π-electron partially aromatic systems, and are used, along with their derivatives, as starting materials for the synthesis of many heterocycles (Desenko, 1995). Substituted 1,2,4-triazoles have also been actively studied as bridging ligands coordinating through their vicinal N atoms and some have special structures with interesting magnetic properties (Vos et al., 1983; Albada et al., 1984; Vreugdenhil et al., 1987; Kahn & Martinez, 1998). Studies also indicate that the 1,2,4-triazole moiety is associated with anticorrosion (Al-Kharafi et al., 1986) and anti-inflammatory action (Gupta & Bhargava, 1978), and other pharmacological activities, by exhibiting antiviral, anti-asthmatic, diuretic, analgesic, antimicrobial, antidepressant and antifungal effects (Jones et al., 1965; Bennur et al., 1976; Webb & Parsons, 1977; Sughen & Yoloye, 1978; Heubach et al., 1980; Kane et al., 1988; Massa et al., 1992; Mohamed et al., 1993; Cansiz et al., 2001). Furthermore, nitro derivatives of 1,2,4-triazole are of interest as highly energetic compounds (Pevzner, 1997). In addition, there are some studies on electronic structures and thiol–thione tautomeric equilibrium of heterocyclic thione derivatives (Koparır et al., 2005). As part of our on-going study of the relationship between the molecular and crystal structures of triazole derivatives, the crystal structure determination of the title compound, (II), has been undertaken and the results are presented here. Previously, we have reported the structure of the closely related compound 4-ethyl-5-(2-hydroxyphenyl)-2H-1,2,4-triazole-3(4H)-thione, (III) (Dege et al., 2005). The main aim of the present investigation was to study the differences between the structures of (II) and (III).

In the present study, (II) was synthesized by the reaction of 2-hydroxybenzohydrazide, (I), and a solution of KOH in absolute ethanol solution. The resulting 2-(2-hydroxyphenyl)dithiocarbazate was cyclized with hydrazine to give the triazole in good yield.

The conformation of (II), together with the atom-numbering scheme and the intramolecular hydrogen bonding, is shown in Fig. 1. The crystallographic analysis demonstrates that compound (II) exists as the thione illustrated on the lower right-hand side of the scheme rather than the thiol shown above. The molecule comprises a triazole ring with a hydroxyphenyl group substituted on the C-2 atom, an –NH2 group at the N-4 atom and an S atom at the C-3 position. The 1,2,4-triazole ring is planar, with a maximum deviation of 0.0074 (9) Å for atom N4. The dihedral angle between this plane and that through the phenyl ring is 10.95 (12)°. This value indicates that the whole molecule is almost flat. When the bond lengths and angles of the triazole ring in (II) (Table 1) are compared with those in (III) (Dege et al., 2005), it is noted that there are no significant differences.

The observed conformation allows for three intramolecular N—H···S, O—H···N and C—H···N interactions, as detailed in Fig. 1 and Table 2. Each of these interactions leads to the formation of a closed ring, the first being five-membered and the others being six-membered.

In the crystal structure, two intermolecular hydrogen-bonding interactions are also observed (Table 2). In a fashion similiar to that found in the structure of (III) (Dege et al., 2005), centrosymmetric dimers are formed via N—H···S hydrogen bonds, generating an R22(8) ring highlighted in Fig. 2. The dimers are connected to each other via intermolecular N—H···O hydrogen bonds.

Experimental top

To a solution of KOH (0.015 mol, 8.40 g) and 2-hydroxybenzohydrazide (0.01 mol, 1.52 g) in absolute ethanol (100 ml) was added CS2 (0.015 mol, 0.91 ml). This mixture was diluted with absolute ethanol (50 ml) and agiated for 14 h. It was then diluted with dry ether (200 ml) and vacuum dried at 343 K. A suspension of potassium salts, 98% hydrazine hydrate (0.03 mol, 15 ml) and water (2 ml) was refluxed with stirring for 1 h. The color of the reaction mixture turned green, H2S was evolved and a homogeneous solution resulted. Dilution with cold water (100 ml) and acidification with concentrated HCl precipitated a white solid. The product was filtered, washed with 3 × 10 ml portions of cold water and recrystallized from ethanol solution to analytical purity. Yield 80%; m.p. 489–491 K.

Refinement top

The H atoms were located in a difference map and refined isotropically [C—H = 0.91 (2)–0.97 (2) Å].

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); 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); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of (II), showing the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. The intramolecular N—H···S, O—H···N and C—H···N hydrogen bonds are represented by dashed lines.
[Figure 2] Fig. 2. A projection of the crystal structure of (II) along the b axis. Dashed lines show the N—H···S and N—H···O interactions.
4-Amino-5-(2-hydroxyphenyl)-2H-1,2,4-triazole-3(4H)-thione top
Crystal data top
C8H8N4OSF(000) = 432
Mr = 208.24Dx = 1.517 Mg m3
Monoclinic, P21/aMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yabCell parameters from 5921 reflections
a = 12.0231 (19) Åθ = 1.6–27.2°
b = 5.7685 (8) ŵ = 0.33 mm1
c = 14.434 (2) ÅT = 296 K
β = 114.393 (11)°Prism, pale yellow
V = 911.7 (2) Å30.68 × 0.48 × 0.37 mm
Z = 4
Data collection top
Stoe IPDS-II
diffractometer
1620 reflections with I > 2σ(I)
Radiation source: sealed X-ray tubeRint = 0.053
Plane graphite monochromatorθmax = 27.1°, θmin = 1.6°
Detector resolution: 6.67 pixels mm-1h = 1515
ω scansk = 67
5061 measured reflectionsl = 1818
1979 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)] = 0.038Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.110All H-atom parameters refined
S = 1.02 w = 1/[σ2(Fo2) + (0.0684P)2 + 0.0697P]
where P = (Fo2 + 2Fc2)/3
1979 reflections(Δ/σ)max = 0.001
159 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = 0.19 e Å3
Crystal data top
C8H8N4OSV = 911.7 (2) Å3
Mr = 208.24Z = 4
Monoclinic, P21/aMo Kα radiation
a = 12.0231 (19) ŵ = 0.33 mm1
b = 5.7685 (8) ÅT = 296 K
c = 14.434 (2) Å0.68 × 0.48 × 0.37 mm
β = 114.393 (11)°
Data collection top
Stoe IPDS-II
diffractometer
1620 reflections with I > 2σ(I)
5061 measured reflectionsRint = 0.053
1979 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.110All H-atom parameters refined
S = 1.02Δρmax = 0.21 e Å3
1979 reflectionsΔρmin = 0.19 e Å3
159 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
S10.79119 (4)0.43992 (8)0.44540 (4)0.05258 (18)
O10.97514 (12)1.3337 (3)0.28049 (12)0.0646 (4)
H10.996 (2)1.225 (5)0.325 (2)0.077 (8)*
N10.93585 (13)0.9429 (3)0.35329 (12)0.0508 (4)
N20.93974 (13)0.7646 (3)0.41683 (12)0.0510 (4)
H21.014 (2)0.713 (4)0.4591 (18)0.070 (7)*
N30.62881 (14)0.7548 (4)0.26278 (15)0.0607 (4)
H3A0.613 (3)0.602 (6)0.269 (3)0.118 (12)*
H3B0.595 (3)0.830 (7)0.298 (3)0.142 (15)*
N40.75416 (11)0.7978 (2)0.31375 (10)0.0424 (3)
C10.83099 (15)0.6692 (3)0.39431 (13)0.0445 (4)
C20.82097 (14)0.9617 (3)0.28973 (12)0.0423 (3)
C30.77851 (15)1.1365 (3)0.20970 (13)0.0432 (4)
C40.66078 (16)1.1332 (3)0.13197 (15)0.0515 (4)
H40.606 (2)1.006 (4)0.1276 (18)0.064 (6)*
C50.62337 (19)1.3002 (4)0.05669 (17)0.0586 (5)
H50.546 (2)1.296 (4)0.0077 (19)0.070 (7)*
C60.7027 (2)1.4748 (4)0.05846 (16)0.0588 (5)
H60.676 (2)1.586 (4)0.009 (2)0.073 (7)*
C70.81927 (19)1.4813 (4)0.13422 (16)0.0561 (5)
H70.873 (2)1.598 (4)0.1347 (19)0.072 (7)*
C80.85850 (15)1.3138 (3)0.20962 (13)0.0469 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0469 (3)0.0540 (3)0.0592 (3)0.00644 (18)0.0244 (2)0.0125 (2)
O10.0504 (8)0.0706 (9)0.0624 (9)0.0153 (7)0.0130 (7)0.0082 (7)
N10.0387 (7)0.0500 (8)0.0575 (9)0.0017 (6)0.0135 (6)0.0081 (7)
N20.0392 (7)0.0515 (8)0.0548 (9)0.0037 (6)0.0118 (7)0.0101 (7)
N30.0344 (7)0.0698 (11)0.0728 (11)0.0008 (7)0.0172 (7)0.0174 (9)
N40.0347 (6)0.0455 (7)0.0472 (7)0.0046 (5)0.0170 (6)0.0030 (6)
C10.0418 (8)0.0457 (8)0.0473 (8)0.0084 (7)0.0196 (7)0.0023 (7)
C20.0391 (7)0.0413 (8)0.0472 (8)0.0022 (6)0.0186 (7)0.0010 (7)
C30.0416 (8)0.0418 (8)0.0482 (8)0.0039 (6)0.0206 (7)0.0006 (7)
C40.0429 (9)0.0486 (9)0.0582 (10)0.0023 (7)0.0161 (8)0.0063 (8)
C50.0484 (10)0.0602 (11)0.0597 (11)0.0080 (8)0.0149 (9)0.0088 (9)
C60.0659 (12)0.0525 (10)0.0596 (11)0.0103 (9)0.0275 (10)0.0131 (9)
C70.0603 (11)0.0502 (10)0.0604 (11)0.0031 (8)0.0274 (9)0.0046 (8)
C80.0456 (8)0.0473 (9)0.0488 (9)0.0021 (7)0.0205 (7)0.0026 (7)
Geometric parameters (Å, º) top
S1—C11.6773 (18)C2—C31.457 (2)
O1—C81.357 (2)C3—C41.397 (3)
O1—H10.86 (3)C3—C81.405 (2)
N1—N21.366 (2)C4—C51.381 (3)
N1—C21.309 (2)C4—H40.97 (2)
N2—C11.329 (2)C5—C61.380 (3)
N2—H20.90 (2)C5—H50.91 (2)
N3—N41.399 (2)C6—C71.377 (3)
N3—H3A0.91 (3)C6—H60.92 (3)
N3—H3B0.88 (4)C7—C81.384 (3)
N4—C11.367 (2)C7—H70.93 (3)
N4—C21.375 (2)
C8—O1—H1113.2 (18)C4—C3—C2122.30 (15)
N2—N1—C2105.47 (14)C8—C3—C2119.25 (15)
N1—N2—C1112.96 (14)C5—C4—C3121.01 (18)
C1—N2—H2129.1 (15)C5—C4—H4118.8 (14)
N1—N2—H2117.0 (15)C3—C4—H4120.0 (14)
N4—N3—H3A110 (2)C6—C5—C4119.8 (2)
N4—N3—H3B105 (3)C6—C5—H5120.9 (15)
H3A—N3—H3B105 (3)C4—C5—H5119.3 (16)
N3—N4—C1123.64 (14)C7—C6—C5120.23 (19)
N3—N4—C2127.14 (14)C7—C6—H6120.8 (15)
C1—N4—C2109.14 (13)C5—C6—H6118.9 (16)
S1—C1—N2130.49 (13)C6—C7—C8120.67 (18)
S1—C1—N4125.91 (13)C6—C7—H7120.3 (16)
N2—C1—N4103.55 (14)C8—C7—H7119.1 (16)
N1—C2—N4108.86 (14)O1—C8—C3123.75 (16)
N1—C2—C3122.39 (15)O1—C8—C7116.39 (16)
N4—C2—C3128.74 (15)C7—C8—C3119.86 (17)
C4—C3—C8118.44 (16)
C2—N1—N2—C10.7 (2)N4—C2—C3—C411.9 (3)
N1—N2—C1—N41.40 (19)N1—C2—C3—C810.2 (2)
N1—N2—C1—S1176.24 (13)N4—C2—C3—C8168.64 (15)
C2—N4—C1—N21.51 (17)C8—C3—C4—C50.1 (3)
N3—N4—C1—N2178.42 (17)C2—C3—C4—C5179.51 (17)
C2—N4—C1—S1176.28 (12)C3—C4—C5—C60.7 (3)
N3—N4—C1—S10.6 (2)C4—C5—C6—C70.8 (3)
N2—N1—C2—N40.26 (18)C5—C6—C7—C80.2 (3)
N2—N1—C2—C3179.28 (15)C6—C7—C8—O1179.49 (18)
C1—N4—C2—N11.14 (18)C6—C7—C8—C30.6 (3)
N3—N4—C2—N1177.92 (17)C4—C3—C8—O1179.37 (17)
C1—N4—C2—C3179.92 (15)C2—C3—C8—O10.1 (2)
N3—N4—C2—C33.1 (3)C4—C3—C8—C70.7 (3)
N1—C2—C3—C4169.24 (16)C2—C3—C8—C7179.83 (16)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N10.86 (3)1.89 (3)2.611 (2)140 (2)
C4—H4···N30.97 (2)2.35 (2)3.013 (3)124.5 (18)
N3—H3A···S10.91 (3)2.73 (4)3.1319 (18)108 (3)
N2—H2···S1i0.90 (2)2.34 (2)3.2400 (16)174 (2)
N3—H3B···O1ii0.88 (4)2.37 (4)3.083 (2)138 (3)
Symmetry codes: (i) x+2, y+1, z+1; (ii) x1/2, y+5/2, z.

Experimental details

Crystal data
Chemical formulaC8H8N4OS
Mr208.24
Crystal system, space groupMonoclinic, P21/a
Temperature (K)296
a, b, c (Å)12.0231 (19), 5.7685 (8), 14.434 (2)
β (°) 114.393 (11)
V3)911.7 (2)
Z4
Radiation typeMo Kα
µ (mm1)0.33
Crystal size (mm)0.68 × 0.48 × 0.37
Data collection
DiffractometerStoe IPDS-II
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
5061, 1979, 1620
Rint0.053
(sin θ/λ)max1)0.641
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.110, 1.02
No. of reflections1979
No. of parameters159
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.21, 0.19

Computer programs: X-AREA (Stoe & Cie, 2002), X-AREA, X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999) and PLATON (Spek, 2003).

Selected geometric parameters (Å, º) top
S1—C11.6773 (18)N3—N41.399 (2)
O1—C81.357 (2)N4—C11.367 (2)
N1—N21.366 (2)N4—C21.375 (2)
N1—C21.309 (2)C2—C31.457 (2)
N2—C11.329 (2)
N2—N1—C2105.47 (14)N2—C1—N4103.55 (14)
N1—N2—C1112.96 (14)N1—C2—N4108.86 (14)
N3—N4—C1123.64 (14)N1—C2—C3122.39 (15)
N3—N4—C2127.14 (14)N4—C2—C3128.74 (15)
C1—N4—C2109.14 (13)O1—C8—C3123.75 (16)
S1—C1—N2130.49 (13)O1—C8—C7116.39 (16)
S1—C1—N4125.91 (13)
N1—C2—C3—C4169.24 (16)N4—C2—C3—C8168.64 (15)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N10.86 (3)1.89 (3)2.611 (2)140 (2)
C4—H4···N30.97 (2)2.35 (2)3.013 (3)124.5 (18)
N3—H3A···S10.91 (3)2.73 (4)3.1319 (18)108 (3)
N2—H2···S1i0.90 (2)2.34 (2)3.2400 (16)174 (2)
N3—H3B···O1ii0.88 (4)2.37 (4)3.083 (2)138 (3)
Symmetry codes: (i) x+2, y+1, z+1; (ii) x1/2, y+5/2, z.
 

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