Two isomorphous benzenesulfonamide crystal structures determined by intermolecular C-H...O, C-H...pi and C-H...Cl...

Area of Science:

• Crystallography
• Organic Chemistry
• Materials Science

Background:

• Sulfonamides are a versatile class of organic compounds with diverse applications.
• Chlorophenyl and furan moieties are common structural features in biologically active molecules.
• Understanding crystal packing is crucial for predicting material properties.

Purpose of the Study:

• To investigate and compare the crystal structures of two related sulfonamide compounds.
• To elucidate the role of intermolecular interactions in their crystal packing.
• To analyze the influence of chlorine atom positioning on crystal structure.

Main Methods:

• Single-crystal X-ray diffraction analysis.
• Comparative structural analysis of isomorphous compounds.
• Identification and quantification of intermolecular interactions (C-H...O, C-H...pi, C-H...Cl).

Main Results:

• Both title compounds, N-[5-(4-chlorophenyl)furan-2-ylmethyl]-4-methyl-N-(prop-2-ynyl)benzenesulfonamide (Ia) and N-[5-(2-chlorophenyl)furan-2-ylmethyl]-4-methyl-N-(prop-2-ynyl)benzenesulfonamide (Ib), possess isomorphous crystal structures.
• Crystal packing is predominantly governed by similar intermolecular C-H...O and C-H...pi interactions in both compounds.
• Intermolecular C-H...Cl interactions are less significant and differ between (Ia) and (Ib) due to the varied positions of the chlorine atoms, leading to subtle variations in crystal packing.

Conclusions:

• The crystal structures of the two sulfonamide derivatives are largely dictated by common weak intermolecular forces.
• The precise positioning of the chlorine substituent has a minor but discernible effect on the overall crystal packing.
• This study provides insights into structure-property relationships for substituted sulfonamides.