We study the ground state structure of nuclei in the vicinity of the one-neutron drip line within the latest version of the quark–meson coupling (QMC) model with a particular emphasis on 23 O. For this nucleus the model predicts a O22(0+)⊗n2s1/2 configuration for its ground state, with a one-neutron separation energy in close agreement with the corresponding experimental value. The wave function describing the valence neutron-core relative motion was then used to calculate the Coulomb dissociation of 23 O on a lead target at a beam energy of 422 MeV/nucleon. The experimental neutron-core relative energy spectrum and the total one-neutron removal cross sections are well described by the calculations. The widths of the longitudinal momentum distributions of the 22 O fragment are found to be broad, which do not support the formation of a neutron halo in this nucleus.