Modifying redox potential of substrates and intermediates to balance pairs of redox steps are important stages for multistep photosynthesis but faced marked challenges. Through co‐clathration of ...iridium photosensitizer and imine substrate within one packet of a metal‐organic capsule to shift the redox potentials of substrate, herein, we reported a multiphoton enzymatic strategy for the generation of heterocycles by intramolecular C−X hydrogen evolution cross‐couplings. The cage facilitated a pre‐equilibrium substrate‐involving clathrate that cathodic shifts the oxidation potential of the substrate‐dye‐host ternary complex and configuration inversion of substrate via spatial constraints in the confined space. The new two photon excitation strategy enabled the precise control of the multistep electron transfer between each pair (photosensitizer, substrate and the capsule), endowing the catalytic system proceeding smoothly with an enzymatic fashion. Three kinds of 2‐subsituted (−OH, −NH2, and −SH) imines and N‐aryl enamines all give the corresponding cyclization products efficiently under visible light irradiation, demonstrating the promising of the microenvironment driven thermodynamic activation in the host‐dye‐substrate ternary for synergistic combination of multistep photocatalytic transformations.
Through the confinement effect of the host‐dye photocatalytic system to shift the redox potentials of substrate, the isomerization and thermodynamic activation of substrate were achieved, which were followed by a multiphoton excitation enzymatic strategy for the generation of heterocycles by intramolecular C−X hydrogen evolution cross‐couplings.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
By incorporating tetrakis(4-carboxyphenyl)porphyrin and bis(3,5-dicarboxyphenyl)pyridine into one single metal-organic framework (MOF), a multifunctional mixed-ligand Zn-
MIX
with large pores was ...obtained. Under visible-light irradiation, Zn-
MIX
exhibits high photocatalytic activity for the oxidation of amines and sulfides.
Mixed-ligand Zn-
MIX
was obtained for the photooxidation of amines and sulfides, which presents a promising strategy for the design of multi-component MOFs with considerable photocatalytic activity.
Two dye-loaded metal–organic capsules constructed with different spatial sizes and functional groups simulated the enzymatic substrate activation for hydrogenation of nitroarenes with the kinetics ...obeying the Michaelis–Menten mechanism.
In this research, we synthesized CdS nanoparticle-doped metal-organic frameworks (CdS@DUT-52) with different contents using a solvothermal method. CdS@DUT-52 possesses strong light absorption ability ...and effective electron-hole separation properties, which was proved by performing UV-vis spectroscopy and photoelectrochemical testing. It was used to trigger the photooxidation of amines, sulfides, and alcohols to produce the corresponding imines, sulfoxides, and aldehydes in the presence of air or oxygen, exhibiting considerable yields of products under visible light irradiation compared with a single component.
A CdS-
x
(
x
= 1-4)@DUT-52 heterogeneous photocatalyst was constructed, which exhibits high catalytic efficiency in the photocatalytic oxidative coupling of benzylamine, oxidation of methylphenyl sulfide, and oxidation of benzyl alcohol.
Direct functionalization of C(sp
3
)-H bonds in a predictable, selective and recyclable manner has become a central challenge in modern organic chemistry. Through incorporating different ...triarylamine-containing ligands into one coordination polymer, we present herein a heterogeneous approach to the combination of hydrogen atom transfer (HAT) and photoredox catalysis for regioselective C-H arylation of benzylamines. The different molecular sizes and coordination modes of the ligands, tricarboxytriphenylamine (H
3
TCA
) and tris(4-(pyridinyl)phenyl)amine (
NPy
3
), in one coordination polymer consolidate the triarylamine (Ar
3
N) moiety into a special structural intermediate, which enhances the chemical and thermal stability of the polymers and diminishes structural relaxation during the catalytic process. The inherent redox potentials of Ar
3
N moieties prohibit the
in situ
formed Ar
3
N&z.rad;
+
to earn an electron from C(sp
3
)-H nucleophiles, but allow the abstraction of a hydrogen atom from C(sp
3
)-H nucleophiles, enabling the formation of the C(sp
3
)&z.rad; radical and the cross-coupling reaction to proceed at the most electron-rich sites with excellent regioselectivity. The new heterogeneous photoredox HAT approach skips several interactions between transient species during the typical synergistic SET/HAT cycles, demonstrating a promising redox-economical and reagent-economical heterogeneous platform that has not been reported for α-amino C-H arylation to form benzylamine derivatives. Control experiments based on monoligand coordination polymers suggested that the mixed-ligand approach improved the photochemical and photophysical properties, providing important insight into rational design and optimization of recyclable photocatalysts for rapid access to complex bioactive molecules and late-stage functionalized pharmaceuticals.
The efficiency of photosensitization and hydrogen atom transfer (HAT) catalysis is balanced in a recyclable heterogeneous manner by the modification of the N-central conformation in Cd-
MIX
.
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IJS, KILJ, NUK, UL, UM, UPUK
The prevailing informal contracts of farmland transfer in China are facing frequent disputes and defaults, which call for effective self-enforcement mechanisms operating through transactors’ ...reputations and social networks. However, the effects of reputation on contract choice and self-enforcement have not been thoroughly considered and examined by existing research in the case of farmland transfer. This study explores the reputation’s ex-ante signaling effect on farmers’ contract choices and the ex-post penalty effect on farmers’ performance in informal contracts. Based on 403 transfer contracts obtained from a field survey conducted in the Hebei province of China, we apply the multinomial logit model and Heckman probit model to perform empirical analysis. The results show that, affected by the penalty effect, farmers with good reputations are more likely to fulfill informal contracts to avoid reputation damage and the resulting loss of future trading opportunities. However, in the ex-ante stage of contract choice, a farmer’s reputation has no significant signaling effect on the formation of informal contracts. The informal contracts are chosen due to farmers’ trust in the close social network and the demand for reduced transaction costs. These findings highlight the importance of personal reputation serving as a form of relational governance in the self-enforcement of informal contracts, which provides a means of enhancing the informal contract’s effectiveness in terms of farmland transfer in the rural acquaintance society. It also provides insights into the necessity of creating a supportive environment for informal rules. Policies should encourage the building of personal reputation and establishment of good social norms to form a long-term, stable and reasonable contractual relationship for farmland transfer.
Abstract
in an effort to solve the large fluctuation of renewable energy power generation output, which brings many challenges to power system operation, Battery Energy Storage Systems (BESS) are ...more and more widespread in power systems. This paper proposes an energy management strategy for shared energy storage power plants. First, the shared energy storage power plants are divided into different PCS unit groups, which trade according to different electricity prices. Secondly, the charging and discharging priorities of PCS unit groups are ranked according to the electricity price to maximize the benefits. At the same time, considering the consistency of system SOC (state of charge), the system has higher stability, and more average battery SOC is conducive to better scheduling of BESS. The trade model of a 100MW shared energy storage power station is built in this paper to verify the effectiveness of this method.
Sodium intake from pre-packaged foods is increasing in China and is well above the WHO recommendation of 5 g per day. The purpose of this study is to analyze the sodium content of pre-packaged foods ...collected by the National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention (NINH, China CDC) in 20 provinces of China from 2017 to 2022. The proportion of pre-packaged foods that meet or exceed the low-sodium, medium-sodium, and high-sodium classifications were analyzed. The proportion of pre-packaged foods that meet and do not meet the WHO global sodium benchmarks and the difference in sodium content between these foods was also calculated. High-sodium foods include sauces, dips, and dressings (3896 mg/100 g), convenience foods (1578 mg/100 g), processed fish products (1470 mg/100 g), processed meat products (1323 mg/100 g), processed poultry products (1240 mg/100 g), snack foods (750 mg/100 g), processed egg products (741 mg/100 g), and fine dried noodles (602 mg/100 g). A large number of pre-packaged foods currently collected in China have a sodium content above sodium benchmarks. This study provided data to support the assessment of sodium intake from pre-packaged foods in the Chinese population and the implementation of comprehensive salt reduction strategies.
Pregnant women infected with pathogenic respiratory viruses, such as influenza A viruses (IAV) and coronaviruses, are at higher risk for mortality, hospitalization, preterm birth, and stillbirth. ...Several factors are likely to contribute to the susceptibility of pregnant individuals to severe lung disease including changes in pulmonary physiology, immune defenses, and effector functions of some immune cells. Pregnancy is also a physiologic state characterized by higher levels of multiple hormones that may impact the effector functions of immune cells, such as progesterone, estrogen, human chorionic gonadotropin, prolactin, and relaxin. Each of these hormones acts to support a tolerogenic immune state of pregnancy, which helps prevent fetal rejection, but may also contribute to an impaired antiviral response. In this review, we address the unique role of adaptive and innate immune cells in the control of pathogenic respiratory viruses and how pregnancy and specific hormones can impact their effector actions. We highlight viruses with sex‐specific differences in infection outcomes and why pregnancy hormones may contribute to fetal protection but aid the virus at the expense of the mother's health.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Dye-based metal-organic frameworks (MOFs) have received great attention due to their excellent photochemical stability in photocatalysis. However, the control of photoinduced electron transfer (PET) ...from dye to substrates rather than to metal nodes is still a challenging task for modern chemistry and organic synthesis, limiting the application of dye-based MOFs in photocatalytic transformations. Herein, we report a new method by introducing a carbonyl group into triphenylamine to form a planar conjugate acridone to compulsively generate a greater degree of conjugation torsion between the dye-based ligands and the metal-carboxylate nodes for controlling the direction of electron flow in the MOF. A new heterogeneous three-dimensional (3D) acridone-based Co-MOF was fabricated by the solvothermal reaction. In comparison with the similar triphenylamine-based Co-MOF, extensive control experiments in combination with density functional theory (DFT) calculations demonstrated that the acridone-based Co-MOF successfully inhibits the intramolecular PET process between the acridone-based ligands and the metal nodes for efficient photocatalytic organic transformations. This new heterogeneous platform exhibits a promising approach to modulating the direction of PET in MOFs by fine modifications of the ligands, thus providing a new avenue to develop multipurpose and flexible catalytic systems.
By judiciously controlling the twisted conjugation between ligands and coordinated carboxylates to inhibit intramolecular photoinduced electron transfer process, an acridone-based metal-organic framework was obtained for efficient photocatalysis.
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