A simple strategy for constructing fused diarylmaleimides (FAMs) under mild condition is presented through a cascade reaction involving a selective bromination with NBS and a visible-light-driven cyclization under 18 W of LED. Compared with traditional oxidation method, the cascade reaction does not use any oxidant, metal-based catalyst, and ultraviolet rays. According to the strategy, a series of symmetrical and asymmetrical FAMs with different aromatic rings are obtained in high yield up to 96%. Most of FAMs exhibit blue-shifted emission and higher luminescent efficiency (Φ_f up to 84%) in solution than their open-ring counterparts for the large π-conjugated systems weakening intramolecular charge transfer. Unexpectedly, the fused rings with nearly coplanar do not quench the solid-state fluorescence of FAMs, due to the heteroatoms and peripheral substituents inhibiting molecules forming H-aggregation-like tight packing, resulting in decent quantum yield in solid. Particularly, FAM with indolo [2,3-a] pyrrolo [3,4-c] carbazoles (B3IM-BHc) has unique pores in the crystal structure, which imposes it huge potential as smart florescent material and switch.

通过级联反应，提出了一种在温和条件下构建稠合二芳基马来酰亚胺（FAM）的简单策略，该级联反应包括用NBS选择性溴化和在18 W LED下的可见光驱动环化。与传统的氧化方法相比，级联反应不使用任何氧化剂，金属基催化剂和紫外线。根据该策略，可以以高达96％的高收率获得一系列具有不同芳环的对称和不对称FAM。最FAMS表现出蓝移发射和更高的发光效率（Φ _˚F对于较大的π共轭体系，其在溶液中的浓度要比其开环对应物高84％），从而削弱了分子内的电荷转移。出乎意料的是，由于杂原子和外围取代基抑制了分子​​形成类似H聚集的紧密堆积，导致固体中的量子产率很高，几乎共面的稠合环不会猝灭FAM的固态荧光。特别是，带有吲哚[2,3-a]吡咯并[3,4-c]咔唑（B3IM-BHc）的FAM在晶体结构中具有独特的孔，这使其具有作为智能荧光材料和开关的巨大潜力。