Cocrystallization of 4-stilbazole with 4,6-diX resorcinol (X = Cl or Br) yields a pair of photoreactive isostructural solids. Small variations in the spatial arrangement within each cocrystal leads to either the head-to-head (hh) or the unexpected head-to-tail (ht) photoproduct after undergoing a solid-state [2 + 2] cycloaddition reaction.

中文翻译：

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变含有4-芪唑等结构的氢键键合的共晶体内的[2 + 2]环加成反应的区域化学†

4-stilbazole与4,6-diX间苯二酚（X = Cl或Br）共结晶会产生一对光反应性同构固体。在经历固态[2 + 2]环加成反应后，每个共晶体内空间排列的细微变化都会导致头对头（hh）或意外的头对尾（ht）光产物。