To gain insights into the stereochemistry and properties of PTMs, we synthesized methine-bridged trithiophene 1S and its furan analog 1O as model compounds. Through detailed structural analyses, including NMR spectroscopy and X-ray crystallography combined with theoretical calculations, we investigated the role of chalcogen bonding in determining the conformational preferences and stereochemistry of these systems. A comparison between 1S and 1O provides valuable insights into the chalcogen-specific effects on the molecular structure and isomer distribution.