The influence of ultrasound on porphyrin-based metallogel formation: efficient control of H- and J-type aggregations

Efficient control of aggregation modes of the porphyrin-Pd2+ complexes by ultrasonication and heating is reported. A porphyrin-based metallogel is formed in the presence of Pd2+, which displays H-type aggregation. Heating the porphyrin derivative in the presence of Pd2+, however, results in J-type aggregation that does not produce a gel. Conclusive evidence was found that the crystal structure of the related porphyrin-Pd2+ complex obtained by heating shows J-type aggregation.