The sunlight-driven reduction of CO 2 into carbonaceous fuels can lower the atmospheric CO 2 concentration and provide renewable energy simultaneously, attracting scientists to design photocatalytic systems for facilitating this process. Significant progress has been made in designing high-performance photosensitizers and catalysts in this regard, and further improvement can be realized by installing additional interactions between the abovementioned two components, however, the design strategies and mechanistic investigations on such interactions remain challenging. Here, we present the construction of molecular models for intermolecular π–π interactions between the photosensitizer and the catalyst, via the introduction of pyrene groups into both molecular components. The presence, types, and strengths of diverse π–π interactions, as well as their roles in the photocatalytic mechanism, have been examined by 1 H NMR titration, fluorescence quenching measurements, transient absorption spectroscopy, and quantum chemical simulations. We have also explored the rare dual emission behavior of the pyrene-appended iridium photosensitizer, of which the excited state can deliver the photo-excited electron to the pyrene-decorated cobalt catalyst at a fast rate of 2.60 × 10 6 s –1 via co-facial π–π interaction, enabling a remarkable apparent quantum efficiency of 14.3 ± 0.8% at 425 nm and a high selectivity of 98% for the photocatalytic CO 2 -to-CO conversion. This research demonstrates non-covalent interaction construction as an effective strategy to achieve rapid CO 2 photoreduction besides a conventional photosensitizer/catalyst design.

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Histoplasmosis is an endemic disease mainly occurring in North America and is rare in China. Confirmation of histoplasmosis should be based on a compatible clinical scenario and a positive culture or histopathology. However, there are still many cases that are misdiagnosed or missed, especially in individuals from non-endemic areas. In recent years, metagenomic next-generation sequencing (mNGS) has led to the accurate and timely diagnosis of some rare and complicated infectious diseases. We describe the case of a 27-year-old Chinese man who had chronic progressive pulmonary lesions without any symptoms for more than 1 year, until the lesions reached the epiglottis and led to progressive pharyngeal pain. There were no positive results from bronchoalveolar lavage fluid (BALF) and epiglottis tissue cultures, or from epiglottis and lung pathological examinations, but mNGS was able to identify Histoplasma capsulatum in the epiglottis tissues and BALF as the cause of the lesions. The patient was treated successfully with itraconazole.

The design of a highly efficient system for CO 2 photoreduction fully based on earth-abundant elements presents a challenge, which may be overcome by installing suitable interactions between photosensitizer and catalyst to expedite the intermolecular electron transfer. Herein, we have designed a pyrene-decorated Cu(I) complex with a rare dual emission behavior, aiming at additional π-interaction with a pyrene-appended Co(II) catalyst for visible light–driven CO 2 -to-CO conversion. The results of 1 H NMR titration, time-resolved fluorescence/absorption spectroscopies, quantum chemical simulations, and photocatalytic experiments clearly demonstrate that the dynamic π–π interaction between sensitizer and catalyst is highly advantageous in photocatalysis by accelerating the intermolecular electron transfer rate up to 6.9 × 10 5 s −1 , thus achieving a notable apparent quantum yield of 19% at 425 nm with near-unity selectivity. While comparable to most earth-abundant molecular systems, this value is over three times of the pyrene-free system (6.0%) and far surpassing the benchmarking Ru(II) tris(bipyridine) (0.3%) and Ir(III) tris(2-phenylpyridine) (1.4%) photosensitizers under parallel conditions.

Improving the photocatalytic efficiency of a fully noble-metal-free system for CO2 reduction remains a fundamental challenge, which can be accomplished by facilitating electron delivery as a consequence of exploiting intermolecular interactions. Herein, we have designed two Cu­(I) photosensitizers with different pyridyl pendants at the phenanthroline moiety to enable dynamic coordinative interactions between the sensitizers and a cobalt macrocyclic catalyst. Compared to the parent Cu­(I) photosensitizer, one of the pyridine-tethered derivatives boosts the apparent quantum yield up to 76 ± 6% at 425 nm for selective (near 99%) CO2-to-CO conversion. This value is nearly twice that of the parent system with no pyridyl pendants (40 ± 5%) and substantially surpasses the record (57%) of the noble-metal-free systems reported so far. This system also realizes a maximum turnover number of 11 800 ± 1400. In contrast, another Cu­(I) photosensitizer, in which the pyridine substituents are directly linked to the phenanthroline moiety, is inactive. The above behavior and photocatalytic mechanism are systematically elucidated by transient fluorescence, transient absorption, transient X-ray absorption spectroscopies, and quantum chemical calculations. This work highlights the advantage of constructing coordinative interactions to fine-tune the electron transfer processes within noble-metal-free systems for CO2 photoreduction.