An Unexpected Dual-Emissive Luminogen: Tunable Aggregation-Induced Emission with Cyan-White-Red Colors, Stable Inherent Chirality, and Enhanced Chiroptical Property

Herein we report a novel chiral bismacrocycle with unexpected dual emission and tunable aggregation-induced emission colors. A facile four-step synthesis strategy is developed to construct this rigid bismacrocycle, (1,4)[8]cycloparaphenylenophane (SCPP[8]), which possesses a 1,2,4,5-tetraphenylbenzene core locked by two intersecting polyphenylene-based macrocycles. The luminescent behavior of SCPP[8] shows the unique characteristics of both aggregation-caused quenching effect and aggrega-tion-induced emission (AIE) effect, inducing remarkable redshift emission including near white-light emission. SCPP[8] is configurationally stable and possesses a novel shape-persistent bismacrocycle scaffold with a high strain energy (up to 127.83 kcal/mol). In addition, SCPP[8] displays enhanced circularly polarized luminescence properties due to AIE effect.

A Novel 1D Organic Lead Halide Hybrid for Blue and White Dual Emission

In recent years, photoelectric performances of many low-dimensional metal halide hybrid materials have been researched and utilized in the domain of phosphors, light emitting diodes (LEDs) and photoelectric detection etc. Nevertheless, unlike two-dimensional (2D) ones, one-dimensional (1D) hybrids received less attention to study their structures and optical properties. Herein, we deal with luminous performance and photoluminescence mechanism for an original 1D organic-inorganic lead chloride hybrid C5H14N3PbCl3 which is abbreviated as TMGPbCl3 (TMG+ = 1, 1, 3, 3-tetramethyguanidine cation). According to photoluminescence spectra, its broadband white-light luminescence are dual emissions from organic component TMG+ peaked at 429 nm and self-trapped excitons (STEs) of inorganic metal halide octahedra peaked at 510 nm, respectively and this property make it to be a promising white-light phosphor.

Cyclometalated Iridium-Coumarin Ratiometric Oxygen Sensors: Improved Signal Resolution and Tunable Dynamic Ranges

In this work we introduce a new series of ratiometric oxygen sensors for hypoxic environments based on phosphorescent cyclometalated iridium centers partnered with organic coumarin fluorophores. Three different cyclometalating ligands and two different pyridyl-containing coumarin types were used to prepare six target complexes with tunable excited-state energies. Some of the complexes exhibit only phosphorescence originating from the cyclometalated Ir moiety, as a result of excited-state energy transfer from the coumarin to the Ir-centered excited states. Three of the complexes display dual emission, with fluorescence arising from the coumarin ligands and phosphorescence from the cyclometalated iridium synthons, and hence function as ratiometric oxygen sensors. Oxygen quenching experiments with these complexes demonstrate that the iridium centered phosphorescence is quenched under O₂ while fluorescence is unaffected. These sensors have good signal resolution, and the sensitivity and dynamic range, measured with Stern-Volmer analysis, span two orders of magnitude. This work demonstrates that this simple, modular approach for conjoining fluorescent and phosphorescent molecules can produce effective oxygen sensors with a wide range of attributes.