Crystal structure of fipronil

Area of Science:

• Crystallography and Molecular Structure
• Agrochemical Science
• Organic Chemistry

Background:

• Phenylpyrazole compounds are a significant class of acaricides and insecticides.
• Understanding the precise molecular structure of these compounds is crucial for their development and application.
• The title compound, C12H4Cl2F6N4OS, belongs to this important chemical family.

Purpose of the Study:

• To elucidate the detailed crystal structure of the title phenylpyrazole compound.
• To investigate the intermolecular interactions governing its crystal packing.
• To provide a structural basis for understanding the activity of this acaricide/insecticide.

Main Methods:

• Single crystal X-ray diffraction analysis was employed to determine the molecular and crystal structure.
• Analysis of bond lengths, bond angles, dihedral angles, and intermolecular interactions (hydrogen bonds, π-π stacking, F⋯F contacts).
• Identification of disordered atomic sites and their occupancy ratios.

Main Results:

• The dihedral angle between the pyrazole and benzene rings is 89.03(9)°.
• Fluorine atoms of the trifluoromethyl group on the benzene ring exhibit positional disorder.
• Crystal structure is stabilized by a combination of C-N⋯π, N-H⋯N, C-H⋯F, and N-H⋯O hydrogen bonds, along with C-Cl⋯π interactions, forming a 3D network.

Conclusions:

• The study provides a comprehensive structural characterization of a novel phenylpyrazole acaricide/insecticide.
• Specific intermolecular interactions, including hydrogen bonding and π-interactions, are key to the compound's crystal packing.
• The observed structural features, such as ring planarity and substituent disorder, may influence the compound's biological activity.