Facile Incorporation of Pd(PPh3)2Hal Substituents into Polymethines, Merocyanines, and Perylene Diimides as a Means of Suppressing Intermolecular Interactions

Compounds with polarizable
π systems that are susceptible
to attack with nucleophiles at C–Hal (Hal = Cl, Br) bonds react
with Pd­(PPh3)4 to yield net oxidative addition.
X-ray structures show that the resulting Pd­(PPh3)2Hal groups greatly reduce intermolecular π–π interactions.
The Pd-functionalized dyes generally exhibit solution-like absorption
spectra in films, whereas their Hal analogues exhibit features attributable
to aggregation.

具有可极化π系统的化合物，在C-卤（卤 = Cl, Br）键处易受亲核试剂攻击，与Pd(PPh3)4反应，产生净氧化加成反应。X射线晶体学结构显示，生成的Pd(PPh3)2Hal基团显著降低了分子间π-π相互作用。Pd官能化的染料在薄膜中通常表现出类似于溶液的吸收光谱，而它们的卤素类似物则展现出与聚集相关的特征。