Résumé : In order to search for a proposed α : 2n : α : 2n : α molecular structure in 16C its break-up into 10Be + 6He, 12Be + α, 8He + 2α and 6He + 6He + α has been studied using a 560 MeV 16C beam inelastically excited on a 12C target. States in 16C appear to be only weakly populated in this reaction.