The ligand L11 was designed such a way that it should have a tetradentate binding cavity with the naphthyl luminophore. The PL spectra at room temperature and 77 K were measured for the ligand L11 and the complex 17, and the emission spectra of the complex are close to the emission of the naphthalene from the ligand. To investigate the thermal dependency of the of the emission intensity, a series of time-dependent measurements was carried out on complex 17. The intensity of the fluorescence gradually decreases with time (with temperature therefore), although not following a steady nature. The normalized emission intensity decreases sharply between 10 min and 20 min, again decreasing progressively until reaching a plateau of about 60 min, around 10% intensity. From the time evolution of the emission spectra, an interplay between SCO and luminescence is indicated until 20 min, after which thermal quenching takes over.