Synthesis and crystal structure studies of 5-(tri-fluoro-meth-yl)-1,3,4-thia-diazol-2(3H)-one at 180†K.

The synthesis and crystal structure of C3HF3N2OS, systematic name 5-(tri-fluoro-meth-yl)-1,3,4-thia-diazol-2(3H)-one (5-TMD-2-one), a compound containing the pharmacologically important heterocycle 1,3,4-thia-diazole, is presented. The asymmetric unit comprises six independent mol-ecules (Z' = 6), all of which are planar. The r.m.s. deviations from each mean plane range from 0.0063 to 0.0381 Å, not including the CF3 fluorine atoms. Within the crystal, two of the mol-ecules form hydrogen-bonded dimers that in turn combine with inversion-related copies to form tetra-meric constructs. Similar tetra-mers, but lacking inversion symmetry, are formed by the remaining four mol-ecules. The tetra-mers are linked into tape-like motifs by S⋯O and O⋯O close contacts. The environments of each symmetry-independent mol-ecule were compared via a Hirshfeld surface analysis. The most abundant atom-atom contacts are between fluorine atoms, while the strongest result from N-H⋯O hydrogen bonds.

Crystal structure of the insecticide ethiprole (C13H9Cl2F3N4OS): a case study of whole-mol-ecule configurational disorder.

The crystal structure of ethiprole {systematic name: 5-amino-1-[2,6-di-chloro-4-(tri-fluoro-meth-yl)phen-yl]-4-ethane-sulfinyl-1H-imidazole-3-carbo-nitrile}, C13H9Cl2F3N4OS, a phenyl-pyrazole-based insecticide, is presented. The pyrazole ring carries four substituents: an N-bound 2,6-di-chloro-4-tri-fluoro-methyl-phenyl ring and C-bound amine, ethane-sulfinyl, and cyano groups. The sulfur atom of the ethane-sulfinyl group is trigonal-pyramidal and stereogenic. The structure exhibits whole-mol-ecule configurational disorder due to superposition of enanti-omers. The crystal packing is dominated by strong N-H⋯O and N-H⋯N hydrogen bonds, which form R 4 4(18) and R 2 2(12) ring motifs. Since the ethiprole mol-ecule is quite small, and structure solution and refinement were straightforward, the structure presents a convenient instructional example for modelling whole-body disorder of a non-rigid mol-ecule. To this end, a step-by-step overview of the model-building and refinement process is also given. The structure could form the basis of a useful classroom, practical, or workshop-style example.

Synthesis, spectroscopic and crystal structure studies of N-{3-cyano-1-[2,6-di-chloro-4-(tri-fluoro-meth-yl)phen-yl]-4-(ethyl-sulfan-yl)-1H-pyrazol-5-yl}-2,2,2-tri-fluoro-acetamide.

The structure of the title compound, C15H8N4Cl2F6OS, a phenyl-pyrazole-based insecticide related to ethiprole, fipronil, and derivatives thereof is presented. The pyrazole ring has four chemically diverse substituents, namely a nitro-gen-bound 2,6-di-chloro-4-tri-fluoro-methyl-phenyl and carbon-bound cyano, ethyl-sulfanyl, and 2,2,2-tri-fluoro-acetamide groups. The pyrazole and phenyl rings are perpendicular, subtending a dihedral angle of 89.80 (5)°. In the crystal, strong N-H⋯O hydrogen bonds link the mol-ecules into chains that extend parallel to the a-axis.