2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/19918The excitonic luminescence of an isolated polydiacetylene polymer chain in its monomer matrix is studied by micro-photoluminescence. These chains behave as perfect 1D excitonic systems with the expected 1/sqrt{E} density of states between 5 and 50 K. The temperature dependence of the homogeneous width is quantitatively explained by interaction with longitudinal acoustic phonons of the crystal in the range of temperature explored.7 pages, 3 figures (TeX format)Materials Sciencetext