Abstract
Amphiphilic aluminum(III) porphyrin (AlC7P) has been designed, and its aggregation-induced photophysics has been reported. The meso-positions of the aluminum(III) porphyrin are functionalized with a heptyl chain (C7), while the central porphyrin features an axial OH group on the Al center. The hydrophilic (OH) and hydrophobic (C7) properties combined with the Lewis acid (Al center) and Lewis base (OH group) functionality to facilitate the formation of aggregation through self-assembly. Spectroscopic studies indicate that aggregation can be modulated by solvent and temperature; it is more pronounced in long-chain hydrocarbon solvents, such as hexanes and n-heptane, and is favored at lower temperatures. At low temperature conditions, the aggregated molecules manifest low fluorescence yields, whereas at higher temperatures, the self-assembly breaks down to exhibit high fluorescence yields. This temperature-dependent aggregation-induced photophysical behavior observed in hexanes makes this porphyrin ideal for a luminescent molecular thermometer.