The structural and electronic properties of Cu3O3- and Cu3O4- were investigated using mass-selected anion photoelectron spectroscopy in combination with density functional theoretical calculations. The vertical detachment energies of Cu3O3- and Cu3O4- were measured to be 3.48 ± 0.08 and 3.54 ± 0.08 eV, respectively. Their geometrical structures were determined by comparison of the theoretical calculations with the experimental results. The most stable structure of Cu3O3- can be characterized as a C3v symmetric six-membered ring structure with alternating Cu-O bonds, in which the plane of the three O atoms is slightly above that of the three Cu atoms. The most stable structure of Cu3O4- can be viewed as a Cs symmetric seven-membered ring with a peroxo unit. The bond order and molecular orbital analyses indicate that the Cu-Cu interactions in Cu3O3- and Cu3O4- are weak. The calculated NICS(0) and NICS(1) values of Cu3O3- are -25.0 ppm and -19.2 ppm, respectively, and those of Cu3O4- are -18.6 ppm and -10.5 ppm, respectively, indicating that they both are significantly aromatic.

Thermally activated delayed-fluorescent (TADF) materials are anticipated to overcome triplet-related losses towards electrically driven organic lasers.T hus far,c ontributions from triplets to lasing have not yet been experimentally demonstrated owing to the limited knowledge about the excited-state processes.H erein, we experimentally achieve reverse intersystem crossing (RISC)-boosted lasing in organic microspheres with uniformly dispersed TADF emitters.I n these materials,triplets are continuously converted to radiative singlets through RISC,g iving rise to reduced losses in stimulated emission. The involvement of regenerated singlets in population inversion results in athermally activated lasing; that is,t he lasing intensity increases with increasing temperature,a ccompanied by accelerated depletion of the excitedstate population. Benefiting from the suppression of triplet accumulations by RISC processes,ahigh-repetition-rate microlaser was achieved.