To understand the solution-phase E/Z isomer distributions of 1S and 1O and determine the most stable structures, we performed quantum chemical calculations. As per the NMR and X-ray crystallography results, these molecules are expected to have multiple conformers for each geometric isomer owing to the rotation of the terminal thiophene and aryl substituents. This conformational complexity renders manual stable conformer searches impractical. Therefore, we developed our own modifications to the conformer search and Gibbs energy calculation protocols originally reported by Grimme et al. In the original protocol, CREST was used for the initial conformer search, followed by energy refinement using the command line energetic sorting (CENSO) program. In our approach, we employed the global optimizer algorithm (GOAT) implemented in ORCA 6.0.1 for the initial conformer search because it does not distinguish between single and double bonds by default, allowing us to consider both conformations and configurations in a single calculation. The GOAT was executed to simultaneously explore all geometric isomer/conformer ensembles within a 12 kcal/mol threshold of Gibbs free energy (at 55 °C) at the semi-empirical GFN1-xTB calculation level. The resulting ensemble was subsequently refined to the r 2 SCAN-3c level using the CENSO program. The relative Gibbs free energies at 55 °C of the conformer ensembles of 1S and 1O are shown in Figure , while selected conformers of 1S and 1O are shown in Figures and, respectively.