Abstract:
Aryl-maleimides undergo a novel [2+4]-photodimerization instead of the expected [2+2]-photodimerization under both direct irradiation with visible light and under sensitized energy transfer conditions. This new excited state reactivity in aryl-maleimides is deciphered through photochemical, photophysical, and spectroscopic studies. The stereochemistry of the photodimer depends on the type of non-bonding interactions prevalent during photodimerization which is in turn dictated by the substituents on the maleimide ring. More importantly, the stereochemistry of the photodimer formed is complementary to the product observed under thermal conditions.
摘要:
芳基-马来酰亚胺在可见光直接照射和敏化能量转移条件下都经历了新型的[24]-光二聚化,而不是预期的[22]-光二聚化。芳基-马来酰亚胺中的这种新激发态反应性通过光化学破译,光物理,和光谱学研究。光二聚体的立体化学取决于光二聚过程中普遍存在的非键合相互作用的类型,其又由马来酰亚胺环上的取代基决定。更重要的是,形成的光二聚体的立体化学与在热条件下观察到的产物互补。