Two cyclometalated Pt(II) complexes showing reversible phosphorescence switching due to grinding-induced destruction and crystallization-induced formation of supramolecular dimer structure

Complexes [Pt(dfppy)(pbdtmi)]PF6 (1) and [Pt(ppy)(pbdtmi)]PF6 (2) have been constructed based on dithienylethene-based N boolean AND N ligand pbdtmi, showing supramolecular dimer structure in which two coordination cations connect each other through pi center dot center dot center dot pi stacking interaction. The crystalline state samples of both 1 and 2 reveal strong phosphorescence (emission peak: around 579 nm for 1, and 551 nm for 2). Interestingly, a grinding treatment for either 1 or 2 Leads to phosphorescence switching from on-state to off-state. The subsequent crystallization with toluene recovers the initial on-state. This work discusses the relationship between the supramolecular dimer structures and the related phosphorescence switching behaviors in 1 and 2, and also explores the photochromism of pbdtmi, 1 and 2.

Automated summary

Two platinum complexes based on the pbdtmi ligand were constructed, showing supramolecular dimer structure with strong phosphorescence. The phosphorescence switching from on-state to off-state could be achieved through grinding treatment and subsequent recrystallization, demonstrating good controllability.