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Indium–salen complexes with electron‐donating 9,9‐dimethyl‐9,10‐dihydroacridine (DMAC) groups at positions 4 (DMACIn1) and 4 and 6 (DMACIn2) were synthesized and characterized to investigate the effect of the substituents number and structural rigidity on photophysical properties. The single crystal structure of DMACIn1 revealed highly twisted arrays (83–89°) between the DMAC groups and salen moieties and a nearly square‐pyramidal geometry around the indium center. Both complexes exhibited green fluorescence in toluene at 298 K and in rigid states (in toluene at 77 K and in a film), which originates from intramolecular charge transfer (ICT) transitions. The absolute photoluminescence quantum yields (PLQYs) of DMACIn1 and DMACIn2 were low in solution but high in the rigid states. The film‐state PLQY of DMACIn2 (59.5%) was more than five‐fold higher than that of DMACIn1 (11.1%). A similar result was observed in toluene at 77 K. These findings were rationalized in terms of the beneficial effects of structural rigidity and higher number of DMAC donors on ICT‐based radiative decay. The experimental results agreed with those of computational studies. [ABSTRACT FROM AUTHOR]

We used stable and nontoxic [(dimethylamino)methyl]ferrocene (Fc‐N), (hydroxymethyl)ferrocene (Fc‐O), 1,2‐bis[(dimethylamino)methyl]ferrocene (Fc‐N2), and 1‐[(dimethylamino)methyl]‐2‐(hydroxymethyl)ferrocene (Fc‐NO) as halide‐free, neutral, and bifunctional one‐component catalysts for the synthesis of cyclic carbonates. They do not need halide‐based additives or tethered salts attached to ligands when used for this coupling reaction. Among them, Fc‐N2 exhibited the best catalytic activity under the same reaction conditions. Catalytic activity decreased rapidly in the order Fc‐N2 > Fc‐NO > Fc‐N > Fc‐O, and interestingly, the more amino groups introduced into the Cp groups, the higher the activity. Various terminal and internal epoxides were easily converted into the corresponding cyclic carbonates. Calculations based on the density functional theory were also carried out to elucidate the mechanism of the coupling reaction. [ABSTRACT FROM AUTHOR]

2–(1H–1,2,4–Triazol–3–yl)phenol (CAT–1) was used as an organocatalyst for the coupling reaction of CO2 and epoxides at an ambient temperature and atmospheric CO2 pressure (1 bar). This compound has a structure in which a hydrogen bond donor, a hydrogen bond acceptor, and another hydrogen bond donor are adjacent in sequence in a molecule. The binary catalytic system of CAT–1/nBu4NI showed TON = 19.2 and TOF = 1.60 h−1 under 1 bar CO2 at room temperature within 12 h using 2–butyloxirane. Surprisingly, the activity of CAT–1, in which phenol and 1H–1,2,4–triazole are chemically linked, showed a much greater synergistic effect than when simply mixing the same amount of phenol and 1H–1,2,4–triazole under the same reaction conditions. In addition, our system showed a broad terminal and internal epoxide substrate scope. [ABSTRACT FROM AUTHOR]

Herein, we report our findings on 4-carbazole (CBZ)-appended salen-based indium complexes, CBZIn1 and CBZIn2, which feature diimine bridges exhibiting different electron-accepting properties. Notably, CBZIn2 exhibited a significantly higher photoluminescence quantum efficiency (PLQY, ΦPL) in toluene than CBZIn1, with a value over 15 times greater (ΦPL = 57.7% for CBZIn2; ΦPL = 3.7% for CBZIn1). In particular, in the rigid state of THF at 77 K, CBZIn2 exhibited a near-unity PLQY of 98.2%. Even in the PMMA film, CBZIn2 maintained a high level of PLQY (ΦPL = 70.2%). These results can be attributed to the highly efficient radiative decay process based on intramolecular charge-transfer (ICT) transition between the moderately twisted CBZ, characterized by its conformational rigidity and the 1,2-dicyanoethylene-bridged salen, which exhibits a strong electron-accepting ability. Furthermore, these findings are supported by theoretical calculations. [ABSTRACT FROM AUTHOR]

Introduction: Parathyroid glands may be compromised during thyroid surgery which can lead to hypoparathyroidism and hypocalcemia. Identifying the parathyroid glands relies on the surgeon's experience and the only way to confirm their presence was through tissue biopsy. Near infrared autofluorescence technology offers an opportunity for real-time, non-invasive identification of the parathyroid glands. Methods: We used a new research prototype (hANDY-I) developed by Optosurgical, LLC. It offers coaxial excitation light and a dual-Red Green Blue/Near Infrared sensor that guides anatomical landmarks and can aid in identification of parathyroid glands by showing a combined autofluorescence and colored image simultaneously. Results: We tested the imager during 23 thyroid surgery cases, where initial clinical feasibility data showed that out of 75 parathyroid glands inspected, 71 showed strong autofluorescence signal and were correctly identified (95% accuracy) by the imager. Conclusions: The hANDY-I prototype demonstrated promising results in this feasibility study by aiding in real-time visualization of the parathyroid glands. However, further testing by conducting randomized clinical trials with a bigger sample size is required to study the effect on levels of hypoparathyroidism and hypocalcemia. [ABSTRACT FROM AUTHOR]

A series of dimeric aluminum compounds [Al(OCMe2CH2N(R)CH2X)]2 [X=pyridin‐2‐yl, R=H (PyrH); X= pyridin‐2‐yl, R=Me (PyrMe); X=furan‐2‐yl, R=H (FurH); X= furan‐2‐yl, R=Me (FurMe); X=thiophen‐2‐yl, R=H (ThioH); X= thiophen‐2‐yl, R=Me (ThioMe)] containing heterocyclic pendant group attached to the nitrogen catalyze the coupling of CO2 with epoxides under ambient conditions. In a comparison of their catalytic activities with those of aluminum complexes without pendant groups at N [X=H, R=H (HH); X=H, R=Me (HMe)] or with non‐heterocyclic pendant groups [X=CH2CH2OMe, R=H (OMeH); X=CH2CH2NMe2, R=H (NMe2H); X=CH2CH2NMe2, R=Me (NMe2Me)], complexes containing heterocycles, in conjunction with (nBu)4NBr as a cocatalyst, show higher catalytic activities for the synthesis of cyclic carbonates under the same ambient conditions. The best catalyst system for this reaction is PyrH/(nBu)4NBr system, which gives a turnover number of 99 and a turnover frequency of 4.1 h−1, making it 14‐ and 20‐times more effective than HH/(nBu)4NBr and HMe/(nBu)4NBr, respectively. Although there are no direct interactions between the aluminum and the heteroatoms in the heterocyclic pendants, electronic effects combined with the increased local concentration of CO2 around the active centers influences the catalytic activity in the coupling of CO2 with epoxides. In addition, PyrH/(nBu)4NBr shows broad epoxide substrate scope and seven terminal epoxides and two internal epoxides undergo the designed reaction. [ABSTRACT FROM AUTHOR]

Plants synthesize numerous ecologically specialized, lineage-specific metabolites through biosynthetic gene duplication and functional specialization. However, it remains unclear how duplicated genes are wired into existing regulatory networks. We show that the duplicated gene CYP82C2 has been recruited into the WRKY33 regulon and indole-3-carbonylnitrile (ICN) biosynthetic pathway through exaptation of a retroduplicated LINE retrotransposon (EPCOT3) into an enhancer. The stepwise development of a chromatin-accessible WRKY33-binding site on EPCOT3 has potentiated the regulatory neofunctionalization of CYP82C2 and the evolution of inducible defense metabolite 4-hydroxy-ICN in Arabidopsis thaliana. Although transposable elements (TEs) have long been recognized to have the potential to rewire regulatory networks, these results establish a more complete understanding of how duplicated genes and TEs contribute in concert to chemical diversity and pathogen defense. Arabidopsis plants can produce 4-hydroxyindole-3-carbonitrile (4OH-ICN) upon pathogen infection. Here, the authors show that EPCOT3, a retrotransposonderived enhancer, mediates WRKY33-binding, pathogen-responsive transcription of CYP82C2, and synthesis of 4OH-ICN. [ABSTRACT FROM AUTHOR]

Intraoperative localization and preservation of parathyroid glands (PTGs) are challenging during thyroid surgery. Using a technique of combined near-infrared PTG autofluorescence detection and dye-free imaging angiography, this study developed a portable device for localization of PTGs and assessment of viability by confirming tissue perfusion. The imager's performance was evaluated through a pilot clinical study (N=10).

Novel scorpionate-type organocatalysts capable of effectively coupling carbon dioxide and epoxides under mild conditions to afford cyclic propylene carbonates were developed. On the basis of a combined experimental and computational study, a precise mechanistic proposal was developed and rational optimization strategies were identified. The epoxide ring-opening, which requires an iodide as a nucleophile, was enhanced by utilizing an immonium functionality that can form an ion pair with iodide, making the ring-opening process intramolecular. The CO 2 activation and cyclic carbonate formation were catalyzed by the concerted action of two hydrogen bonds originating from two phenolic groups placed at the claw positions of the scorpionate scaffold. Electronic tuning of the hydrogen bond donors allowed to identify a new catalyst that can deliver >90% yield for a variety of epoxide substrates within 7 h at room temperature under a CO 2 pressure of only 10 bar, and is highly recyclable.