Synthesis, characterization and aggregation behavior of room temperature ionic liquid based on porphyrin-trihexyl(tetradecyl)phosphonium adduct

A room temperature ionic liquid (RT-IL) made by the negatively charged water soluble meso-tetrakis(4 sulfonatophenyl)porphyrin (TPPS4) and the positively charged trihexyl(tetradecyl)phosphonium (CYPHOS (R) IL 101) has been synthesized and fully characterized by NMR, MALDI-TOF, differential scanning calorimetry and thermogravimetric analyses. Moreover, the growth of nanosized porphyrin J-aggregates has been induced in solution through the "in situ" photogeneration of HCI acid in chlorinated solvent as well as the addition in solution of a strong chiral acid. In this latter case supramolecular chiral induction has been observed on the resulting emissive nanosized aggregates. The data reported clearly evidence the central role of trihexyl(tetradecyl)phosphonium (THTDP) counter-cation in i) determining the monomeric nature of the adduct in chlorinate solution, and ii) in limiting the size of the aggregates on a nanometric scale. (C) 2016 Elsevier B.V. All rights reserved.