The ability of molecular photoswitches to convert on/off responses into large macroscale property change is fundamental to light-responsive materials. However, moving beyond simple binary responses necessitates the introduction of new elements that control the chemistry of the photoswitching process at the molecular scale. To achieve this goal, we designed, synthesized and developed a single photochrome, based on a modified donor–acceptor Stenhouse adduct (DASA), capable of independently addressing multiple molecular states. The multi-stage photoswitch enables complex switching phenomena. To demonstrate this, we show spatial control of the transformation of a three-stage photoswitch by tuning the population of intermediates along the multi-step reaction pathway of the DASAs without interfering with either the first or final stage. This allows for a photonic three-stage logic gate where the secondary wavelength solely negates the input of the primary wavelength. These results provide a new strategy to move beyond traditional on/off binary photochromic systems and enable the design of future molecular logic systems.

分子光开关将开/关响应转换为大的宏观性质变化的能力是光响应材料的基础。然而，超越简单的二元响应需要引入新元素，以在分子尺度上控制光开关过程的化学性质。为了实现这一目标，我们设计、合成和开发了一种基于修饰的供体-受体 Stenhouse 加合物 (DASA) 的单一光致变色材料，能够独立处理多个分子状态。多级光电开关可实现复杂的开关现象。为了证明这一点，我们通过沿 DASA 的多步反应途径调整中间体的数量而不干扰第一阶段或最后阶段，展示了对三阶段光开关转换的空间控制。这允许光子三级逻辑门，其中次级波长完全否定初级波长的输入。这些结果提供了一种新的策略，可以超越传统的开/关二元光致变色系统，并能够设计未来的分子逻辑系统。