The observed loss of activity is accompanied by a gradual decrease in crystallinity, as evident from a drop in X-ray peak intensity (Figure ). No changes in the solution UV-vis spectrum (Figure ) were observed after 110 hours photolysis; also, the photoluminescence spectrum (Figure ) and the solution 1 H NMR spectrum (SI, Figure ) remain unchanged. This suggests that the loss of catalytic activity is connected to changes in the TBAP packing, rather than any chemical degradation.