Comprehensive Summary The development of photoresists that combine high‐sensitivity with environmental benignity is essential for advancing next‐generation nanofabrication technologies. Herein, we present a molecular engineering strategy wherein selenite ligands are employed to assemble a series of dinuclear phenylantimony(oxo)‐selenite clusters (designated as α , β , γ ) with precisely tunable phenyl group densities, ranging from four to eight per cluster. A synergistic sensitivity mechanism is elucidated: the high‐atomic‐number ( Z ) inorganic core, comprising Sb and Se, functions as an efficient energy absorption antenna, while the surrounding shell of labile Sb–C bonds gives a high density of reactive initiation sites. Among the series, cluster γ exhibits optimal lithographic performance, achieving complete solubility switching at 26 μC·cm –2 , while maintaining sub‐nanometer film smoothness. Notably, all resists are fully developable in pure water, underscoring their compatibility with environmentally sustainable processing. This work establishes a synergistic core‐shell design principle for the development of high‐performance, eco‐friendly photoresists.
Xiong et al. (Mon,) studied this question.