Light-driven transcription and replication are always subordinate to a delicate chirality transfer. Enabling light work in construction of the helical self-assembly with reversible chiral transformation becomes attractive. Herein we demonstrate that a helical hydrogen-bonded self-assembly is reversibly photoswitched between photochromic open and closed forms upon irradiation with alternative UV and visible light, in which molecular chirality is amplified with the formation of helixes at supramolecular level. The characteristics in these superhelixes such as left-handed or right-handed twist and helical length, height, and pitch are revealed by SEM and AFM. The helical photoswitchable nanostructure provides an easily accessible route to an unprecedented photoreversible modulation in morphology, fluorescence, and helicity, with precise assembly/disassembly architectures similar to biological systems such as protein and DNA.

An unprecedented light-driven chiral switching supramolecular system exhibits reversible and enantiospecific transformation along with a unique concerted photoconversion process. It is guidable for the development of light-driven supramolecular architectures, especially for stimuli-responsive chiral functional materials.

Multifunctional switches, as well as gated photochromism, are particularly challenging. Here, a ferrocene (Fc)‐modified photochromic diarylethene (DAE) with sterically hindered ethene bridge, in which the photo‐inactive parallel conformer and photoactive antiparallel conformer are individually investigated, is reported. The photoswitchable triad system (parallel conformer p‐Fc and anti‐parallel ap‐Fc) contains three functional parts: photochromic DAE unit, naphthalimide chromophore, and redox‐active ferrocene. Upon incorporation of ferrocene unit, the photochromic efficiency in the anti‐parallel triad conformer ap‐Fc is blocked to a great extent in the ferrocene state but distinctly enhanced in the ferrocenium state via chemical or electrochemical stimuli, thereby constructing redox‐gated photochromism. Meanwhile, the reversible redox between ferrocene and ferrocenium states can also switch “OFF/ON” the fluorescence of naphthalimide chromophore via photoinduced electron transfer pathway (PET). The fluorescence and photoisomerization in the triad system are well modulated with chemical‐ or electrochemical redox and light stimuli, which enables the specific gated photochromism and fluorescence switches work in multi‐addressable states.

Based on benzobis(thiadiazole)-bridged diarylethenes, the exchanging rate between the main conformers in the ring-open form gradually slows down, offering the opportunity for isolating photoactive anti-parallel conformers. In the ring-closed state, the excess steric hindrance can disrupt the thermal bistability.

In this study, photoswitchable fluorescent supramolecular metallacycles with high fatigue‐resistance have been constructed by coordination‐driven self‐assembly by using bithienylethene with dipyridyl units (BTE) as a coordination donor and a fluorescent di‐platinum(II) (Pt‐F) as a coordination acceptor. The photo‐triggered reversible transformation between the ring‐open and ring‐closed form of the metallacycles was confirmed by 1H NMR, 31P NMR, and UV/Vis spectroscopy. This unique property enabled a reversible noninvasive “off–on” switching of fluorescence through efficient Förster resonance energy transfer (FRET). Importantly, the metallacycles remained structurally intact after up to 10 photoswitching cycles. The photoresponsive property and exceptional photostability of the metallacycles posit their potential promising application in optical switching, image storage, and super‐resolution microscopy.