How Structure-Directing Cations Tune the Fluorescence of Metal–Organic Frameworks

A series of metal-organic frameworks (MOFs), {Zn-BTC}­{cations}, which contain anionic Zn-BTC coordination polymers, is reported here. It was observed that cations with different hydrogen-bond forming abilities could significantly affect the coordination of Zn-BTC structures in the frameworks. The 13 Zn-BTC MOFs reported herein showed solid-state fluorescent emission in the visible spectrum, and the fluorescence of the frameworks was tunable by adjusting the interactions of the cations with the anionic Zn-BTC structure in the MOFs

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