A new supramolecular polyhedral oligomeric silsesquioxanes (POSS)-porphyrin nanohybrid: synthesis and spectroscopic characterization

An organic/inorganic nanohybrid, based on tetra-anionic mesotetrakis-(4-sulfonatophenyl)porphyrin (TPPS) and a positively charged polyhedral oligomeric silsesquioxane (POSS), has been synthesized and fully characterized. Differential scanning calorimetry and thermogravimetric analyses have allowed classification of this compound as a room temperature ionic liquid (RT-IL). The POSS bulky cation is responsible for the observed amorphous waxy solid appearance and for the high solubility in halogenated solvents. The formation of emissive nanosized porphyrin J-aggregates has been detected both in solution and on a quartz cuvette surface upon light irradiation on a dichloromethane porphyrin-POSS solution.