[en] A yield of alpha particles emitted at rest is clearly observed in ¹⁶O+¹²C at several incident energies. These alpha particles are detected by two methods: i) the alpha particle is considered as a missing mass in the detection of two ¹²C nuclei in coincidence; ii) the alpha particle is detected at zero degree with a velocity due to centre of mass motion. Such a yield is assigned to a linear chain formation of the type ¹²C-α-¹²C and an excitation function between 40 and 65 MeV is given. The emission due to Coulomb effects is emphasized in the discussion to give the chief explanation of the coincidence results