Biexcitonic states govern singlet fission and triplet–triplet and exciton–exciton annihilation, yet a unified understanding of how these processes compete within a shared electronic manifold remains e...

N-Alkyl imines are prevalent in dynamic-covalent chemistry and self-assembled structures, yet their E/Z photochromism is often overlooked due to the high-energy light required for isomerization. Here, we present a simple strategy to enhance their photoswitching properties, achieving switching wavelengths and photostationary state distributions comparable to azobenzene. Moreover, we demonstrate that these N-alkyl imines undergo photoisomerization in the condensed phase and exhibit isomer-dependent fluorescence. We anticipate that this study will inspire the design of photoresponsive architectures that operate directly at the dynamic-covalent bond, eliminating the need for dedicated photoswitchable motifs.