Synthesis, Molecular Structure and Crystal Packing Peculiarities of Some 5-Arylidene-3-Phenylrhodanine Derivatives

We report the synthesis and single-crystal X ray structures of three novel (Z)-5 arylidene-3-phenylrhodanine derivatives, differing in the substituents on the ben-zylidene fragment (two methoxy groups (compound I), a dioxine ring (compound II), or a dioxole ring (compound III)). Despite the overall similarity of the molecules, their su-pramolecular architectures were found out to be strikingly different. In both compounds I and II, short S···S chalcogen bonds together with forced C–H···O hydrogen bonds generate dimeric motifs, whereas III lacks S···S interactions and instead features an n→π* contact from the rhodanine carbonyl oxygen to the benzodioxole ring, as well as C-H···S bifurcate hydrogen bond. The results of intermolecular interactions in those structures are checked via Hirshfield surface analysis. The fine modulation of the arylidene substituent can switch the primary intermolecular synthon from chalcogen bonding to n→π* interactions, offering new possibilities for crystal engineering of rhodanine-based materials.