Singlet oxygen ( 1 O 2 ), as an important active reagent, has found wide applications in photodynamic therapy (PDT), synthetic chemistry and materials science. Organic conjugated aromatics serving as hosts to capture and release singlet oxygen have been systematically investigated over the last decades. Herein, we present a [6+6] organoplatinum(II) metallacycle by using ~180° dipyridylanthracene donor and ~120° Pt(II) acceptor as the building blocks, which enables the capture and release of singlet oxygen with relatively high photooxygenation and thermolysis rate constants. The photooxygenation of the metallacycle to the corresponding endoperoxide was performed by sensitized irradiation, and the resulting endoperoxide is stable at room temperature and can be stored under ambient condition over months. Upon simple heating the neat endoperoxide under inert atmosphere at 120 °C for 4 h, the resulting endoperoxide can be reconverted to the corresponding parent form and singlet oxygen. The photooxygenation and thermolysis products were characterized by NMR spectroscopy and ESI-TOF-MS analysis. Density functional theory calculations were conducted in order to reveal the frontier molecular orbital interactions and reactivity. This work provides a new material-platform for singlet oxygen related promising applications.

In this work, we present the formation of two open-ended hexagonal-prism tubular macrocycles by the [6 + 12] self-assembly of the symmetric ∼120° organic ligand donor with ∼90° Pt­(II) acceptor in a 1:2 ratio. The assembled structures were characterized by multinuclear NMR (1H NMR, 31P­{1H} NMR, and 1H–1H COSY NMR), electrospray ionization mass spectrometry (ESI-TOF-MS), traveling wave ion mobility–mass spectrometry (TWIM-MS), and transmission electron microscopy. Molecular modeling was further conducted to get insight into their structured characteristics. We also examined their photophysical properties.

Through Ru(II)-catalyzed C-H bond activation, a methodology for the synthesis of 2- or 2,7-functionalized pyrene derivatives has been developed using the substrate 1-(pyrid-2-yl)pyrene or 1,6-di(pyrid-2-yl)pyrene.

A new class of high-quality ionic organic microcrystals with bright deep-blue luminescence (with up to 60% quantum yield) have been prepared in situ by the protonation of 2,2′-di­(pyrid-2-yl)­biphenyl (1) with different proton acids (HCl, HClO4, CH3SO3H, or CF3SO3H). The obtained rod-shaped microcrystals are characterized by SEM and PXRD analyses. As a result of the deprotonation and reprotonation of the pyridine groups, the microcrystals of 1(HCl)2 show reversible blue luminescence switching in response to NEt3/HCl vapor. In addition, single crystals of the ionic salts of 1(HCl)2, 1(HClO4)2, 1(CH3SO3H)2, and 1(CF3SO3H)2 have been obtained. X-ray analyses show that the counteranions are connected to the pyridinium protons by hydrogen bonding.