Crystal structure of a monoclinic polymorph of 5-amino-1,3,4-thia­diazol-2(3H)-one

Namhun Kim; Sung Kwon Kang

doi:10.1107/S1600536814016055

. 2014 Aug 1;70(Pt 9):o922. doi: 10.1107/S1600536814016055

Crystal structure of a monoclinic polymorph of 5-amino-1,3,4-thiadiazol-2(3H)-one

Namhun Kim ^a, Sung Kwon Kang ^a,^*

PMCID: PMC4186073 PMID: 25309254

Abstract

The title compound, C₂H₃N₃OS, is a monoclinic (P2₁/c) polymorph of the previously reported triclinic structure [Kang et al. (2012 ▶). Acta Cryst. E68, o1198]. The asymmetric unit contains two independent molecules which are essentially planar, with r.m.s. deviations of 0.001 and 0.032 Å from the mean plane defined by the seven non-H atoms. In the crystal, N—H⋯N and N—H⋯O hydrogen bonds link the molecules into a sheet parallel to (111).

Keywords: crystal structure, polymorph, thiadiazolone, hydrogen bonds

Related literature

For structures and reactivity of thiadiazole derivatives, see: Parkanyi et al. (1989 ▶); Cho et al. (1996 ▶). For the triclinic polymorph, see; Kang et al. (2012 ▶). graphic file with name e-70-0o922-scheme1.jpg

Experimental

Crystal data

C₂H₃N₃OS
M _r = 117.13
Monoclinic,
a = 3.8182 (3) Å
b = 10.8166 (7) Å
c = 21.8043 (15) Å
β = 91.015 (4)°
V = 900.37 (11) Å³
Z = 8
Mo Kα radiation
μ = 0.58 mm⁻¹
T = 296 K
0.21 × 0.1 × 0.09 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2002 ▶) T _min = 0.911, T _max = 0.931
5812 measured reflections
1709 independent reflections
1376 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.099
S = 1.08
1709 reflections
151 parameters
All H-atom parameters refined
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: SMART (Bruker, 2002 ▶); cell refinement: SAINT (Bruker, 2002 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536814016055/tk5326sup1.cif

e-70-0o922-sup1.cif^{(186.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814016055/tk5326Isup2.hkl

e-70-0o922-Isup2.hkl^{(94.2KB, hkl)}

Click here for additional data file.^{(2KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814016055/tk5326Isup3.cml

Click here for additional data file.^{(979.4KB, tif)}

. DOI: 10.1107/S1600536814016055/tk5326fig1.tif

Molecular structure of the title compound, showing the atom-numbering scheme and 30% probability ellipsoids. Intermolecular N—H⋯N and N—H⋯O hydrogen bonds are indicated by dashed lines.

Click here for additional data file.^{(1.5MB, tif)}

. DOI: 10.1107/S1600536814016055/tk5326fig2.tif

Part of the crystal structure of the title compound, showing molecules linked by intermolecular N—H⋯N and N—H⋯O hydrogen bonds (dashed lines).

CCDC reference: 1013072

Additional supporting information: crystallographic information; 3D view; checkCIF report

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3⋯N11	0.77 (3)	2.12 (3)	2.891 (4)	174 (3)
N7—H7A⋯O13ⁱ	0.86 (3)	2.07 (4)	2.913 (4)	167 (3)
N7—H7B⋯N4ⁱⁱ	0.85 (4)	2.21 (4)	3.048 (4)	171 (3)
N10—H10⋯O13ⁱⁱⁱ	0.84 (3)	2.09 (3)	2.910 (3)	165 (3)
N14—H14A⋯O6^iv	0.91 (4)	2.14 (4)	3.005 (4)	159 (4)
N14—H14B⋯O6	0.73 (4)	2.58 (4)	3.306 (5)	173 (4)

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

Acknowledgments

This work was supported by the research fund of Chungnam National University.

supplementary crystallographic information

S1. Chemical context

S2. Structural commentary

5-Amino-2H-1,2,4-thiadiazolin-3-one heterocycle is an analog of cytosine (Parkanyi et al., 1989). Derivatives of this heterocyclic compound are interesting in the antibacterial activity, potential carcinogenicity, and kinase inhibitor activity (Cho et al., 1996). The title compound, 5-amino-1,3,4-thiadiazol-2(3H)-one (I) is an isomer of 5-amino-2H-1,2,4-thiadiazolin-3-one, which has become an attractive moiety due to potential biological activities. These heterocyclic compounds are potentially good ligands because of N, O, and S atoms which are good donor atoms to both transition metals (Cu, Zn, Cd) and lanthanide metals (Tb and Eu). In our interest to metal complexes with these heterocyclic compounds, the title compound was isolated accidently.

In (I), Fig. 1, two independent molecules comprise the asymmetric unit, which are linked by the intermolecular N—H···N and N—H···O hydrogen bonds. The 1,3,4-thiadiazol-2-one units are almost planar, with r.m.s. deviations of 0.001 – 0.032 Å from the corresponding least-squares plane defined by the seven constituent atoms. The crystal structure is stabilized by the intermolecular N—H···N and N—H···O hydrogen bonds, which link the molecules into a two-dimensional sheet parallel to 111 plane (Table 1 and Fig. 2).

S3. Supramolecular features

S4. Database survey

S5. Synthesis and crystallization

The title compound (I) was synthesized by the process of the previous report (Kang et al. 2012). Copper(II) chloride (1.36 g, 8 mmol) dissolved in ethanol, was added drop wise to a stirred ethanolic solution containing 5-amino-1,3,4-thiadiazol-2(3H-one (1.87 g, 16 mmol). The mixture was stirred for 10 h at room temperature. The resulting solution was filtered and allowed to stand at room temperature. Colourless crystals of (I) were obtained at room temperature over a period of a few weeks.

S6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms of the NH and NH₂ groups were located in a difference Fourier map and refined freely [refined distances = 0.73 (4)–0.91 (4) Å].