To elucidate the nature of the interactions between adjacent chalcogen atoms in syn,syn-ZZ-1S, a non-covalent interaction (NCI) analysis was performed (Figure ). The analysis revealed attractive interactions between adjacent sulfur atoms, which are considered to be weak interactions, similar to van der Waals forces. These S•••S interactions provide additional support for the observed conformational preferences in these systems. The intramolecular chalcogen bonding was further investigated using natural bond orbital (NBO) calculations. Figure shows the orbital interactions and their corresponding energies for syn,syn-ZZ-1S. Two distinct donor-acceptor interactions were identified for each S•••S pair in the syn conformation. In the first interaction, the lone pair (LP) of the sulfur atom in the terminal thiophene acted as a donor to the σ*(S-C) orbital of the sulfur in the central quinoid moiety (stabilization energy E(2) = 1.69 kcal/mol). The second interaction exhibited a reversed donor-acceptor relationship with E(2) = 1.36 kcal/mol. This asymmetry in the stabilization energies can be attributed to the electronic nature of the respective rings, that is, electron-rich thiophenes versus the electron-deficient quinoid core. While the individual interaction energies are lower than those typically observed for chalcogen bonds involving thiophene units (approximately 2-8 kcal/mol), their combined effect approaches the magnitude of a conventional chalcogen bond.