The steady state photophysical properties analysis of compounds 4a-d and 6a-d were performed in protic and aprotic solvents covering a broad polarity range going from toluene to methanol. Despite its relevance for biological applications, water was excluded due to the limited solubility of the compounds. Indeed, solubility in water remained too low for accurate spectroscopic analysis even after the addition of about 1% of DMSO and the ultrasonication of the solutions.