The ESCA molecule-Historical remarks and new results

► Highly resolved new C1s core photoelectron spectrum of ethyl trifluoroacetate. ► Perhaps the most well known core electron spectroscopy result from a historical perspective. ► New measurement using the most advanced synchrotron radiation facility PLEIADES at SOLEIL. ► Detection of two conformers. ► The role of the dynamics upon core photoionization is both experimentally and theoretically described. ► Both stretch and torsion modes active. ► Dissociation involving charge transfer observed.