The use of earth-abundant metal complexes in photoredox catalysis offers a complementary mode of activation for organic substrates through visible-light-induced homolysis (VLIH) of metal–substrate bonds. This Minireview describes different electronic transitions that occur in photoexcited metal–substrate complexes as well as recent advancements and future prospects in this area.

This Review summarizes advances in photoredox-mediated Giese reactions since 2013, with a focus on the breadth of methods that provide access to crucial carbon-centered radical intermediates that can engage in radical conjugate addition processes.

The photoredox-catalyzed win–win coupling strategy, in which CO₂ valorization is integrated with organic synthesis in one reaction system, provides a promising approach that enables sufficient utilization of excited electrons and holes to achieve feasible and sustainable light-mediated artificial photosynthesis.

The final puzzle piece fits in! Beryllium is the last of the non-radioactive s-block metals to be coordinated to indenyl ligands. Milling K[C₉H₇] with BeBr₂ produces the indenyl complex [Be(C₉H₇)₂]. Its crystal structure reveals mixed η⁵/η¹ ring coordination. The monomeric “half-sandwich” complex [Be{1,3-(SiMe₃)₂C₉H₅}Br] is available via the same method.

Conductive Dy³⁺ phthalocyaninato complex single-molecule magnets, which exhibit slow magnetic relaxation, can be arranged in a 1D array by using electro-oxidation and chemical oxidation. Hysteresis of the magnetoresistance of the 1D array derived from the π-f interactions was observed at 2.2 K.

NO and H₂S serve as signaling molecules in biology with intertwined reactivity through formation of HSNO and HSSNO. Zinc complexes of their conjugate bases ^Ph,MeTpZn(SNO) and ^Ph,MeTpZn(SSNO) result in stabilization of these anions at a biologically relevant metal site yet reveal disparate signaling output upon reaction with thiols.

A rhodium-catalyzed asymmetric addition/aldol/spirocyclization domino cascade to generate spiro-oxiranes is reported. sp²- and sp-hybridized carbon nucleophiles are used to initiate the cascade to give arylated and alkynylated products.

Fluorosulfuryl isocyanate (FSI, FSO₂-NCO) is established as a reliable bis-electrophilic linker for stepwise attachment of alcohol and amine bearing modules. In step-1, FSI's isocyanate fuses directly and quickly with alcohols and phenols, and aliphatic amines are attached through the sulfuryl carbamate transfer strategy, both with remarkable selectivity. In step-2, best yields of S−N linked products arise with a unique on water process. The scope of SuFEx ligation is greatly expanded in directions which would be especially interesting for drug discovery and chemical biology.

A hypoxia-responsive nanocomposite composed of CRISPR-Cas9 attached to gold nanorods delivers Cas9-sgHSP90α to tumors. Gene editing reduces the thermal tolerance of the tumor cells and then mild photothermal therapy (PTT) is possible with near-IR light.

A strong influence of electronic circular dichroism on the measurement of resonance Raman optical activity of colorful chiral compounds is reported for a series of vitamin B₁₂ derivatives. Neglecting this effect can lead to misinterpretation of recorded spectra, and seriously erroneous conclusions about molecular structure and chirality.

Rapid diagnostics are essential for early detection of COVID-19 and reduced disease spread. In this study, we discovered the DNA aptamer SNAP1 (SARS-CoV-2 spike protein N-terminal domain binding aptamer 1), which binds with high affinity and specificity to SARS-CoV-2 spike protein as well as UV-inactivated SARS-CoV-2 virus.

A new strategy for the coordination of cationic moieties offers a new possibility for the rational design and property modification of functional ionic materials, particularly NLO materials. As demonstrated by [Ag(NH₃)₂]₂SO₄ and Ag₂SO₄, the exceptional enhancements of the linear birefringence and nonlinear SHG properties are attributed to the unique [Ag(NH₃)₂]⁺ cation moiety.

A novel iron(II) metal–organic framework containing accessible coordination sites on adjacent metal centers facilitates the direct reduction of NO to N₂O.

Cyanine groups introduced into DNA could increase the noncovalent interaction between Cys-DNA and multiple drug molecules. More drug molecules were incorporated into Cys-DNA, tending to spontaneously form Cys-DNA/drug nanospheres. Therefore, cyanine-mediated self-assembly system provides an adaptable approach to prepare a two-in-one nanodrug.

A new family of carbon-bound boron enolates, in cooperation with a Pd complex supported by an 1,4-azaborine-derived phosphine ligand, transforms enynes into highly substituted dienyl boronates in exquisite site-, regio-, and cis-diastereoselectivity.

A p-block atomically dispersed antimony with Sb−N₄ configuration has been developed and used as highly efficient oxygen reduction reaction (ORR) electrocatalyst. The excellent ORR activity is credited to the p orbital interaction between Sb cation and O₂, which facilitates the charge transfer and generates appropriate adsorption strength for oxygen intermediates, lowering the energy barrier and modulating the rate-determining step.

The new class of microporous carbon nitride with rich nitrogen moieties templated from zeolite shows periodic porosity with a unique CN framework and enhanced active sites that triggered highly selective sensing owing to the high amount of hydrophilic nitrogen species.

A new approach to improve luminescence performance of covalent organic frameworks (COFs) is demonstrated by introducing an isotope effect, which is achieved through substitution of hydrogen in high-frequency oscillators X-H (X=O, N, C) by the heavier isotope deuterium. The first deuterated COF exhibits a 19-fold enhancement in quantum yield over the non-deuterated counterpart.

Organocatalytic Michael–Henry cascade reactions that occur through dynamic kinetic asymmetric transformations of racemic diastereomers having central and axial chiralities have been developed for the synthesis of spirooxindoles bearing furan-fused ring systems. The products, with four new chiral carbon centers, were obtained as single diastereomers in high yields with high enantioselectivities.

Engineered nitrogen vacancies serve as electron trap sites, thus directing photoelectrons to accumulate at Fe single sites under light illumination. The formation of a highly concentrated electron density at the Fe sites significantly improves the H₂O₂ conversion efficiency.

The first asymmetric total synthesis of (+)-mannolide C, a highly strained bowl-shaped cephalotane-type diterpenoid is reported. The synthetic strategy features efficient double ring-closing metathesis reactions for the formation of the highly strained bowl-shaped 7/6/6/5 tetracyclic system.

A new intermolecular approach for the expedient access to cyclopropane-incorporated tricyclic skeleton from the readily available isobenzopyryliums and vinyl boronic acids has been achieved. This protocol does not involve the highly active carbenoid intermediates or strong conditions as compared to traditional approaches.

Need for speed: An efficient and fast photocatalytic procedure that enables the acylation/arylation of unfunctionalized alkyl derivatives in flow has been realized by combining decatungstate photocatalysis and nickel catalysis. The methodology shows great functional group tolerance and high regioselectivity, and can be used for the late-stage functionalization of various biologically-relevant molecules.

A Wittig reaction within a dearomatized pyridine ring system results in 4-alkylated pyridines, a valuable motif in the pharmaceutical and agrochemical sciences. N-Triazinyl salts are key to this strategy, and a range of substituted pyridines and aldehydes are amenable. Late-stage methylation is also feasible using a formaldehyde surrogate.

B₃N₆-[4]triangulene, which is isoelectronic to the trianion of [4]triangulene, represents a key structural unit of a new hypothetical boron carbon nitride. The tert-butylated derivative of B₃N₆-[4]triangulene is synthesized by threefold nitrogen-directed borylation. Its fluorescence in solution is responsive to binding p-nitrobenzoate anion through H-bonds, and it forms DD-AA H-bond arrays with di(tert-butyl)-pyrenetetraone in the co-crystal.

A heteroarchitecture of MoS₂-CNTs was developed in which CNTs are vertically anchored within MoS₂ by a C−Mo covalent bond. Due to the high-speed interlaminar conductivity, unimpeded ion-diffusion channels, and sufficient pseudocapacitive reactivity, the all-unified solid-state flexible ECs show high energy density and large capacitance, which can power wearable health-monitoring devices efficiently.

Four coordination polymers with good flowability at low vitrification temperature were developed and fabricated into high-performance gas separation membranes by hot-casting or hot-pressing methods. The obtained membranes show excellent H₂ sieving ability, rivaling against the best-reported gas separation membranes. The cracks and functions of the broken membranes can be easily healed upon heating.

Well-separated physical capacitance, pseudo-capacitance, and diffusive capacity are achieved from the CV curves of typical electrode materials for metal-ion batteries after three successive treatments including de-polarization, de-residual and de-background as well as non-linear fitting calculation, offering a more rational and reliable method to calculate the pseudo-capacitance contribution.

A singlet biradical based on [5]cumulene end-capped with phenalenyl moieties was synthesized. The strong π–π stacking tendency of phenalenyl units led to controlled self-assembly, with the formation of one-dimensional chain assemblies. Variable-temperature structural and Raman spectroscopic studies demonstrated that intramolecular spin pairs forming cumulene bonds coupled intermolecularly to form a continuum spin system at low temperatures (see picture).

Four types of novel and complicated spiropyrazolones from pyrazolidinones and diazopyrazolones were constructed via a precise chemical bond activation/[n+1] annulation route, especially a selective N−N bond activation/[n+1] annulation cascade and a novel tandem C(sp²)−H/C(sp³)−H bond activation/[4+1] annulation strategy, and diazopyrazolones acted as unexpected 1C synthons.

An unprecedented kinetic resolution of 2-amido tertiary allyl alcohols through chiral phosphoric acid-catalyzed enamide–imine tautomerism is reported. Both dialkyl- and aryl-alkyl-disubstituted allyl alcohols were compatible with this protocol, generating α-hydroxy imines and enamides with high enantioselectivities.

The ligand-desorption process during calcination was elucidated for metal-oxide-supported thiolate-protected gold (Au) 25-atom metal nanoculusters (NCs) using five experimental techniques. Furthermore, based on obtained knowledge, a method was established to form a metal-oxide layer on the surface of Au NCs while preventing their aggregation, thereby succeeding in creating a water-splitting photocatalyst with high activity and stability.

A novel SERS sensor was created for biosensing extracellular concentrations of Cu⁺ and Cu²⁺ simultaneously in the live brain. Using our powerful tool, three routes were discovered for understanding the mechanisms of the increased concentrations of Cu⁺ and Cu²⁺ during ischemia: Cu⁺ and Cu²⁺ were transported from neurons; Cu⁺ and Cu²⁺ were released from the destroyed copper-containing proteins; and Cu⁺ was converted into Cu²⁺.

A nickel-catalysed radical relay strategy combines radical rearrangement and cross-coupling via a C(sp³)-centred radical, to produce valuable phenylalanine derivatives that are otherwise challenging to access. An N-benzyl amino acid ester functions as a molecular scaffold for the aryl migration reaction. The synthetic method offers mild reaction conditions, high diastereoselectivity, and broad substrate scope.

Energy levels of perovskite nanocrystallites depend on their size owing to quantum confinement and the concurrent yet distinct phenomenon of size-dependent structural changes where surface perturbations template the core. This effect can aid in the design of perovskite opto-electronic devices utilizing mesoporous layers to tailor the size of infiltrated nanocrystallites.

Gel-assisted precipitation (GAP) avoids synthesis challenges caused by the divergent properties of targeted metal and provides a simple and scalable method to build a large variety of hollow objects as demonstrated by more than 20 different kinds of HMMs as well as hollow structures of metal phosphate. The hollow and mesoporous Nb₂O₅ microspheres have favorable charge transport kinetics in a Li-ion intercalation pseudocapacitor.

The combination of the conceptually complementary formal ring distortion- and pseudo-natural product strategies yields novel natural product-inspired bioactive pseudo-sesquiterpenoid alkaloids.

An approach to directly examine the oxidation state and surface composition of nanosized Ir electrodes after oxygen evolution reaction (OER) was developed. Atom probe tomography reveals compositional changes in the topmost surface and subsurface on various Ir planes during OER. This approach provides atomic-scale insights into surface changes during electrochemical reactions.

The cross-linked polymers containing the biomimetic macrocyclic hosts, amide naphthotubes, are able to effectively and rapidly adsorb polar organic micropollutants from water by employing host–guest binding. The polymers can be readily regenerated through washing with MeOH or EtOH at room temperature.

Ketone-derived enolates can serve as nucleophiles for tryptophan synthase β-subunit (TrpB) catalysed reactions. The transient nucleophilic enolate species is intercepted by TrpB, which facilitates selective C−C bond formation, resulting in the asymmetric alkylation of ketones such as propiophenone and 2-fluoroacetophenone. The products spontaneously cyclize to form highly substituted nitrogen heterocycles that can be reduced to form proline analogs.

Electrochemical activation of conventional photocatalysts induces potent photoreductant activity. These studies resulted in the discovery of an electron-primed photoredox catalyst capable of cleaving strong aryl C−N and C−O bonds to aryl radical intermediates. Mechanistic experiments revealed that enhanced activity relative to previously developed electron-primed photoredox systems was a result of improved catalyst stability.

Heterometallic frameworks constructed from aluminum molecular rings of varying size, flexible copper ions, and conjugated carboxylate ligands act as adsorbents for the sequential confinement of iodine molecules. This work not only sets up a bridge between molecular rings and infinite porous networks but also reveals molecular details for the underlying host–guest binding interactions at crystallographic resolution.

Through the incorporation of Cl-substituted chiral organic cations, the chiroptical properties of 2D chiral perovskites can be significantly enhanced. The observed circular dichroism and circular polarized luminescence intensities are found to be associated with the d-spacing of hybrid organic–inorganic perovskites and the strength of the halogen–halogen interaction within the system.

A color-shifting, near-infrared (NIR) fluorescent aptamer–fluorophore module based on benzopyrylium-coumarin (BC) fluorophores for ratiometric RNA imaging is reported. Free BC is cyan fluorescent, however its fluorescence emission shifts to NIR upon complexation with the BC-binding aptamer (BeCA). This system enabled the visualization of mRNAs in the NIR region and the ratiometric analysis of target RNAs expressed at different levels in single cells.

We successfully synthesized {BiW₈}, a 10-nuclear heteroatom cluster modified {BiW₈O₃₀}. {BiW₈} suppressed the proliferation, migration, and invasion of MG63 cells. We identified POM-induced pyroptosis for the first time. Decreased GSH content and increased ROS levels were observed in {BiW₈}-treated cells. {BiW₈} executed multiple antitumor mechanisms, such as activation of pyroptosis, regulation of oxidative stress, and inhibition of DNA repair.

The synthetic iron(IV)-oxo complex [Fe^IV(O)(Py₅Me₂H)]²⁺ serves as a biomimetic model for TET by oxidizing the nucleobase 5-methyl cytosine (5mC) to its natural metabolites. In this work, we demonstrate that nucleosides and short oligonucleotide strands serve as substrates. The 5-position of 5mC is oxidized preferably and highly selectively by the complex.

This work reports a strategy of using a low-cost acidic aqueous solution of alcohols for efficient hydrogen/chemical co-production. The as-prepared non-precious metal MnO₂/carbon paper electrocatalyst in combination with alcohol oxidation demonstrates a significantly decreased total energy input for hydrogen production and ultra-high durability in acidic electrolytes.

The dielectric constants of solutions at different temperatures and compositions are comprehensively probed by considering the significant role in regulating solute–solvent interactions and solvation structures of working liquid electrolytes.

Metal-free Se,S,N-tri-doped carbon nanosheets (Se,S,N-CNs-1000) show high activity and selectivity for oxidative cyanation of various aldehydes to synthesize organic nitriles using ammonia as the nitrogen resource. Other oxidizable groups were tolerated, and no further reaction of the product was observed over Se,S,N-CNs-1000.

An organocatalytic enantioselective method for the preparation of polychiral molecules via vinylidene ortho-quinone methide (VQM)-mediated intramolecular electrophilic aromatic substitution was developed. With this methodology, four types of stereogenic elements including chiral nitrogen center, C−N axial chirality, C−C axial chirality and conformational behavior of the seven-membered ring were stereoselectively constructed.

Large-scale atomistic modeling studied the interfaces between lithium metal and solid electrolytes with a wide range of lattice mismatch, and discovered an interfacial disordered Li defect layer at the interfaces and their roles in leading to the interfacial failure during lithium cycling.

In the current study, with the aid of state-of-the-art spectroscopic techniques, transient kinetic analysis, and implementation of robust experimental methodologies, we resolve the nature of catalytic active sites and reaction mechanism for oxidative coupling of methane over supported Na₂WO₄/SiO₂ catalysts.

Mo₂C/C hierarchical double-shelled hollow spheres with mesoporous thick inner shell and microporous thin outer shell are proposed as an ideal sulfur host for Li-S batteries. The double-shelled spheres demonstrate superior structural and compositional advantages when employed as cathode material in Li-S batteries.

A tetra-diazirine based cross-linker (4CNN) is developed for the universal patterning of p-type, n-type, and ambipolar conjugated polymers by photo-induced carbene insertion. The interchain packing orders, the thin film morphologies and the charge carrier mobilities of four conjugated polymers are retained after patterning.

Sono-Fenton chemistry is used to generate polyphenols from small molecules and biological macromolecules containing phenolic groups, enabling the subsequent coordination of the polyphenols with metal ions to engineer coatings on a variety of substrates.

A stereoretentive C−N coupling of optically active amines and amino acid esters with aryl bromides is achieved by nickel catalysis under light irradiation, without the use of any external photosensitizers.

Catechol-functionalized self-immolative poly(disulfides) are synthesized and fashioned into dual-responsive gels through formation of catecholato–Al³⁺ cross-links. Two distinct pathways to cargo release are engineered, namely the depolymerization in a self-immolative fashion, or breaking catecholato–Al³⁺ cross-links at low pH. Both gel degradation pathways lead to release of bound dye molecules on demand.

A scalable low-temperature molten-salt-assisted method was developed for synthesis of WS₂ nanosheets with high-quality and high-yield. The WS₂ nanosheets show high electrocatalytic activity towards the alkaline sulfion (S²⁻) oxidation reaction and the acidic hydrogen evolution reaction. A proof-of-concept hybrid alkali-acid electrochemical device was set up for electrolytic H₂ generation and environmentally friendly recycling of sulfion.

We demonstrate the first example of a nonheme, mononuclear {FeNO}⁷ complex that mediates the conversion of NO to N₂O in the absence of an external reductant. A new mononuclear, 5-coordinate Fe^II complex is synthesized, which binds nitric oxide to form the {FeNO}⁷ complex. This complex exhibits a highly activated NO ligand as seen by RR spectroscopy, and generates N₂O in THF upon addition of H₂O.

We propose a nanomediator–effector cascade system that can convert the subtle events of kinase-regulated phosphorylation to augmented fluorescence recovery and cargo release via the DNA amplification machinery. This kinase-specific sensing and treating modality allows kinase activity imaging and cellular signaling-responsive drug release in vivo.

When an electrocatalyst for the alkaline hydrogen evolution reaction (HER) based on cubic CoSe₂ was doped with the light element nitrogen, the electronic structure was modulated while the highly symmetric crystal structure phase was maintained. This nitrogen-doped CoSe₂ shows enhanced alkaline HER electrocatalytic activity, while no structural reconstruction occurs during the HER process.

Fluoride chemistry in tin halide perovskites improves the crystallization process. Fluoride anions selectively coordinate and remove Sn^IV and affect the colloidal properties in solution. This study describes the working mechanism of SnF₂ and highlights the importance of solution chemistry for controlling crystallization and Sn^II oxidation in tin halide perovskites.