Hydrogen-bonding patterns in two aroylthiocarbamates and two aroylimidothiocarbonates

Area of Science:

• Solid-state chemistry
• Supramolecular chemistry
• Crystallography

Background:

• Understanding intermolecular interactions is crucial for predicting and controlling crystal packing.
• Hydrogen bonds and pi-pi stacking are key non-covalent forces driving molecular self-assembly.
• Thiocarbamate and imidothiocarbonate derivatives offer diverse functionalities for exploring supramolecular architectures.

Purpose of the Study:

• To elucidate the role of specific hydrogen bonds (N-H...O, C-H...S, C-H...O) and pi-pi stacking in the crystal engineering of selected organic molecules.
• To characterize the supramolecular structures formed by O-ethyl N-benzoylthiocarbamate, O-ethyl N-(4-methylbenzoyl)thiocarbamate, O,S-diethyl N-(4-methylbenzoyl)imidothiocarbonate, and O,S-diethyl N-(4-chlorobenzoyl)imidothiocarbonate.
• To investigate the influence of different substituents and heteroatoms (S, O) on the hydrogen bonding patterns and resulting solid-state architectures.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to determine the three-dimensional crystal structures.
• Identification and analysis of intermolecular interactions, including hydrogen bonds (two-centre, three-centre) and pi-pi stacking.
• Topological analysis of the resulting supramolecular assemblies (sheets, chains, dimers, ladder-type structures).

Main Results:

• O-ethyl N-benzoylthiocarbamate molecules form sheets through N-H...O, C-H...S, and C-H...(O,S) hydrogen bonds.
• O-ethyl N-(4-methylbenzoyl)thiocarbamate forms ring chains via N-H...O and C-H...O hydrogen bonds, further organized into sheets by pi-pi stacking.
• O,S-diethyl N-(4-methylbenzoyl)imidothiocarbonate forms dimers via C-H...pi(arene) interactions, while O,S-diethyl N-(4-chlorobenzoyl)imidothiocarbonate forms chains linked into ladders by pi-pi stacking.

Conclusions:

• The specific types and combinations of hydrogen bonds and pi-pi stacking interactions are critical determinants of the observed crystal structures.
• Substituent variations (e.g., methyl, chloro groups) and the presence of sulfur atoms influence the nature and extent of intermolecular interactions.
• This study provides insights into the rational design of organic materials with tailored solid-state properties based on predictable supramolecular assembly.