Consequentially, we irradiated aggregated samples with NIR and SWIR LEDs, which were not effective for photoisomerizing fully dissolved PATs. To our delight irradiation with 880 nm, 970 nm and 1020 nm did indeed lead to effective photoisomerization and conversion to the metastable Z isomer for all aggregated PAT derivatives 1-3 (Figure ). The conversion is almost complete in case of PAT 1 and 2 leaving only traces of the aggregated absorption (Figure and). For the less soluble PAT 3 a bit more aggregated E isomer remained after irradiation as can be seen in the corresponding absorption spectra (Figure ). In all cases, the Z isomer is much less prone to aggregation and thus appears fully dissolved. Therefore, photoisomerization leads to a dissolution of the E isomer aggregates accompanied by the appearance of a deep blue color owed to fully dissolved Z isomer. This process apparently requires much longer irradiation times (several hours) at the very long wavelengths as the restricted environment of the aggregate is likely hindering efficient photoisomerization. We suspect that in fact photoisomerization and dissolving happen from the surface of the aggregates, which would explain the slow pacing of the process. We then set out to establish a solvent system allowing us to photoswitch between aggregated E isomer and dissolved Z isomer in a fully reversible manner. This required a more extensive screening of conditions (see details in the Supporting Information), which ultimately uncovered benzene/CH3CN or toluene/CH3CN mixtures as most suited for the task. For PAT 1 a 1/1 benzene/CH3CN mixture was effective (Figure ), while the increasing solubility of PAT 3 and 2 required higher relative amounts of CH3CN (Figure and). In this way reversible aggregation and deaggregation via photoisomerization with 1020 nm NIR and 590 nm orange light, respectively could be demonstrated for the three PAT derivatives 1-3 (Figure ). We thus established AIB as highly effective mechanism to push light-responsiveness of photoswitches beyond the 1000 nm mark and at the same time fully control aggregation behavior in a reversible all-photonic fashion. It also became evident that the particular choice of solubilizing group allows for modulation of solvent conditions for this elevated photochemical control and that the 10/10' position of PAT is ideally suited to tune solubility without interfering with photophysical and photochemical properties.