Leaving graphitic flatland: The atomically precise synthesis of graphitic nanocones was achieved by bottom-up synthetic methods. This advancement provides access to a new class of discrete nanocarbons and, with that, unlocks opportunities in the field of three-dimensional graphitic architectures amenable to molecular design.

To prepare high-quality, defect-free graphene nanoribbons (GNRs), cycloaromatization reactions need to be very efficient, proceed without side reaction and mild enough to accommodate various functional groups. In this Minireview, the latest approaches for the synthesis of GNRs and related structures, including alkyne benzannulation, photochemical cyclodehydrohalogenation, Mallory and Pd- and Ni-catalyzed reactions are presented.

Despite the rapid developments in the past decade, many great challenges remain for the practical use of metal–organic frameworks (MOFs) based electrocatalysts. This Minireview summaries some major recent research efforts and advances on MOF-based electrocatalysts for the oxygen reduction reaction. Some promising directions and strategies are also discussed.

A switch in time: Although dynamic and flexible metal–organic frameworks (MOFs) have been closely assessed in recent literature, analysis into the subcategory of switchable MOFs has been comparably lacking. By virtue of their steady rise in popularity, MOFs with intriguing, switchable responses to light, temperature, pressure, redox species and guests are surveyed.

Deconstructive arene cycloisomerization is reported as unprecedented strategy for the de novo synthesis of hydroxylated benzofuran, using kojic acid- or maltol-derived alkynes as precursors. Several types of free hydroxyl groups are introduced into the benezofurans with different substitution patterns. A collective total synthesis of hydroxylated benzofuran-containing natural products (11 examples) is realized.

A covalently linked paclitaxel–methylene blue conjugate (PTX-MB) is used for real-time monitoring of drug release from nanocarriers via photoacoustic imaging. The PTX-MB remained in acoustically silent form when encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles. After release, PTX-MB instantly oxidized to the photoacoustically active form to report quantity and biodistribution.

Alkalis passivate iodine interstitial defects in lead perovskites, eliminate the mid-gap states, and suppress the nonradiative recombination. Theoretical guidelines are developed for defect inactivation in perovskite solar cells and other devices.

Guanine perovskites: Stabilization of the α-FAPbI₃ phase (FA=formamidinium) is realized by using guaninium (G) based G₂PbI₄ low-dimensional perovskites, forming heterostructures that lead to improved performances and stabilities of the corresponding solar cells. The structural properties are investigated to unravel the mode of action and set the path for using this approach in perovskite solar cell research.

An ultra-high increase in the work function (WF) of silver, from 4.26 to 7.42 eV, by 3D dual-entrapment of the WF modifying components l-cysteine and Zn(OH)₂ within the metal is reported. The WF enhancement mechanism is based on directly affecting the charge transfer ability of the metal, separately by cysteine and hydrolyzed zinc(II), and synergistically by the combination of the two, through the known Zn-cysteine finger redox trap effect.

Mixing cellulose nanocrystal suspensions (CNC-Na⁺) with the polyionic macrocycle cyclobis(paraquat-p-phenylene) (CBPQT⁴⁺) yields gels with embedded active hosts. These materials reversibly absorb and recognize guests from solution to produce colorful host–guest complexes. This behavior has enabled CNC-CBPQT⁴⁺ gels to function as substrates for chromatography and encryption.

Stand and deliver: A coordinative dendrimer was rationally designed for cytosolic protein delivery. The synthesized polymer shows unprecedented efficiency in the cytosolic delivery of proteins and peptides with different isoelectric points. The bioactivities of the proteins are maintained after intracellular release.

A simple nanoprecipitation approach is used to produce drug-core polymer-shell nanoparticles with exceptionally high drug loading (up to 58.5 %) from a wide range of polymers and drugs. This technology is based on tuning the precipitation time of drugs and polymers using a mixed-solvent system.

Fluoropolymers that are water-soluble and low-fouling and have a high fluorine content demonstrate outstanding ¹⁹F magnetic resonance imaging sensitivity. They were used as self-trackable polymers for bioconjugation and in vivo tracking.

MgCo₂O₄, CoCr₂O₄, and Co₂TiO₄ were selected, where only Co³⁺ in the center of octahedron (Oh), Co²⁺ in the center of tetrahedron (Td), and Co²⁺ in the center of Oh can be active sites as model electrocatalysts for the oxygen evolution reaction. Co³⁺(Oh) sites are the best geometrical configuration; Co²⁺(Oh) sites exhibit better electrochemical activity than Co²⁺(Td).

Branch manager: Addition of AlCl₃ to a Pd-mediated chain-walking polymerization results in rapid isomerization of 1-alkenes to internal alkenes which polymerize with high branching. Block copolymers can be prepared by adding AlCl₃ midway through the reaction.

Bacteria are able to synthesise complex macromolecules from a variety of natural building blocks. It is now shown that they can also be utilized to produce entirely abiotic polymers from readily available synthetic precursors.

Circularly polarized organic ultralong room temperature phosphorescence (CP-OURTP) of small molecules is realized by direct bonding of achiral carbazole to a chiral ester chain for efficient chirality transfer and molecular packing arrangement upon photo-activation. The photo-activated CP-OURTP can be facilely deactivated by thermal treatment for stimuli-responsive reversible CP-OURTP with high photo/thermal stabilities.

Benefits of instability: MOFs are used as metal ion precursors for the synthesis of nanocomposites by exploiting the instability of MOFs. The reaction occurs simply by mixing the MOFs, substrates, and other reactants (such as TAA and nickel nitrate). Through a heterogeneous growth process, nanomaterials with uniform structures can be formed on different substrates.

Remote control: A nitrile-directed meta-C−H functionalization of biphenyl derivatives was realized by using 2-pyridone as a ligand. DFT calculations revealed that a new ligand-containing Pd–Ag dimeric transition state is responsible for the meta-selectivity.

The old switcheroo: Soft actuators with switchable thermal reprogrammability have been developed. By flexibly switching on/off network dynamics, easy reprogramming and excellent actuation stability can be achieved, as well as efficient recycling and seamless integration of different motions in a very common siloxane liquid crystalline elastomer.

On the bright side: The photophysical behavior of donor-acceptor (D-A) molecules can be improved through installation of a polar, solvent-shielding auxiliary to an amino-donating group. This β-carbonyl substituent generally enhances the fluorescence quantum yield of D-A fluorophores, enabling brighter labeling probes for live-cell imaging.

Powering the frozen world: The first flexible zinc–air battery with excellent low-temperature adaptability was achieved through the development of an innovative air-cathodic electrocatalyst and hydrogel electrolyte. The battery delivers a capacity of 691 mAh g⁻¹ and an energy density of 798 Wh kg⁻¹ at −20 °C, along with excellent flexibility and state-of-the-art low-temperature performance.

An aptamer-induced thermophoresis quantitation of exosomal programmed death-ligand 1 (PD-L1, a transmembrane protein) was developed, which integrates effective recognition of aptamer and homogeneous thermophoresis. The facile technique is more sensitive and efficient than the current enzyme-linked immunosorbent assay (ELISA)-based methods. Translation of the method into standard clinical practice for immunotherapy prediction and monitoring is anticipated.

The right channels: A novel class of foldamer-based pore-forming helically folded polyhydrazides, having hydrophobic cavities of about a 6.5 Å diameter, promote transport of anions, rather than cations, across membranes, with iodide as the preferred transport species. The best channel, having a helical height of 3.6 nm, exhibits the highest recorded iodide transport activity (EC₅₀=0.042 μm or 0.028 mol % relative to lipid) and high I⁻/Cl⁻ selectivity of 11, in terms of EC₅₀ values, or 42 based on initial rate constants.

A Sn/SnO_x interface reconstructed in situ facilitates formic acid production by optimizing the binding of the reaction intermediate HCOO* while promotes Faradaic efficiency of C₁ products by suppressing the competitive hydrogen evolution reaction. This results in high Faradaic efficiency, current density, and stability of electrochemical CO₂ reduction reaction at low overpotentials.

Highs and lows: Intrinsically low lattice thermal conductivity (κ_lat) and high carrier mobility (μ) occurs in BiTe, which is facilitated by its unique dual topological quantum phases. It is a weak topological insulator (WTI) as a result of its layered hetero-structure, and thus it exhibits low thermal conductivity; but simultaneously BiTe is also a topological crystalline insulator (TCI) and thus it has high carrier mobility.

Biomimetic strain-stiffening hydrogels have been prepared through the self-assembly of molecular gelators. On the basis of orthogonal self-assembly of the molecular gelators and lipids, hydrogel networks embedded with liposomes are formed and show strain-stiffening behavior as well, resembling both the structures and mechanical responsiveness of biological tissue.

An activating-group-assisted oxidative cross-coupling strategy for the assembly of biaryl-bridged cyclic peptides from natural amino acids was developed for the synthesis of arylomycin/G0775 and RP 66453 cyclic cores.

Sub-nm sieving: A flexible supramolecular membrane for the sub-nanometer sieving of nanoparticles is developed. This membrane comprises a highly oriented, honeycomb-like, two-dimensional supramolecular polymer with uniform nanocavities. Owing to this unique structural feature, a precise cutoff size of about 4 nm has been realized.

Crossing over: A highly efficient asymmetric radical-polar crossover reaction of indanonecarboxamides/esters and various electron-rich alkenes was realized by combining a chiral N,N′-dioxide/Ni^II complex catalyst with Ag₂O. Five types of products could be obtained with good to excellent yields and ee values.

A highly regioselective sequential activation of cage B−I and B−H bonds in o-carborane has been achieved in a one-pot manner. The thermodynamically favorable migration of Pd from exo-alkenyl sp² carbon to cage B(4) serves as a key step in this new process, which represents a new route for regioselective bifunctionalization of o-carborane with different substituents.

The salt-inclusion chalcogenide Li[LiCs₂Cl][Ga₃S₆] is presented, which features a 3D framework composed of [Ga₃S₆] nanosized tunnels. Introduction of an ionic guest to the covalent chalcogenide host produces a material with a moderate nonlinear optical (NLO) coefficient and an ultrawide band gap (E_g). These characteristics are promising for the development of infrared (IR) NLO materials.

The ribosome tolerates aromatic oligoamide foldamer–peptide hybrids not only when the foldamer belongs to the initiation unit, but also when it is appended as a sidechain within the peptide or at the C-terminus of the peptide. This expands the range of substrates known to be accepted by the ribosome to include significantly larger and more structurally defined substrates.

Live LICs: The balance of active sites and charge transport allow Nb₂O₅ with a hollow multi-shelled structure to deliver excellent energy density, an ultrahigh power density, and good cycle stability for high-performance Li-ion capacitors (LICs).

Triple action: The flavoprotein alcohol oxidase (AOX*) facilitates the double and triple oxidations of diols. Interestingly, depending on the diol substrate, these reactions result in formation of either lactones or hydroxy acids. Such biocatalytic route towards hydroxy acids has potential for the preparation of polyester building blocks.

Formaldehyde (HCHO) was unambiguously detected and quantified for the first time during methanol-to-hydrocarbon catalysis over HSAPO-34 and HZSM-5 by in situ synchrotron radiation photoionization mass spectrometry. The time-resolved profiles of products show that HCHO is mainly derived from the disproportionation of methanol at acidic sites, HCHO affects the hydrogen-transfer processes of olefins into aromatics and aromatics into coke, and HCHO controls the contribution of the aromatic-based cycle.

The enantio- and diastereoselective, copper-catalyzed three-component coupling of imines, 1,3-enynes, and diborons delivers complex, chiral homopropargyl amines; useful building blocks on the way to biologically- and medicinally-relevant compounds. In particular, functionalized homopropargyl amines bearing up to three contiguous stereocenters can be prepared in a single step.

The force awakens: Mechanical-force-induced cycloaddition of intact aziridine groups in a macromolecule with dipolarophiles does not follow the reaction pathways that occur under traditional thermal and photochemical conditions. The aziridines do not undergo cis–trans isomerization, thus suggesting retention of the ring structure under force. This demonstrates that nonvulnerable chemical structures can be attractive mechanophores.

Acetylene gas behaves as a dicarbene equivalent in the presence of gold(I). This concept has been applied to the one step total synthesis of the natural product waitziacuminone from acetylene and geranyl acetone.

Spherical nucleic acids (SNAs) are used to precisely position carbon nanotubes (CNTs) on DNA origami. The DNA hybridization occurring at the interface of the SNA and DNA-coated CNTs leads to an approximately five-fold improvement in the positioning efficiency in comparison to the positioning of DNA-coated CNTs directly on the DNA origami.

C−C coupling: An isolable molecular aluminium imide with a highly polarized Al−N bond has been found to react with CO via C≡O bond cleavage and C−C coupling. Key proposed intermediates in this transformation feature an aluminium-bound isocyanate fragment.

ORR inspiring: Incorporating cobalt porphyrins into a porous supramolecular cage structure isolates molecular active sites for selective electrochemical oxygen reduction, leading to direct electrosynthesis of hydrogen peroxide in neutral pH water.

Stack a nanoribbon: A facile method for atomically precise graphdiyne nanoribbons has been developed. The method featured inter- and intramolecular stepwise Glaser–Hay coupling strategy to reduce random intermolecular polymerization of the ethynyl groups.

Nitrogen-doped carbon catalysts are presented for application in the electrochemical CO₂ reduction reaction (CO₂RR). Molecular probes were designed to clarify the genuine catalytically active sites. CO₂RR takes place preferentially on pyridinic rather than pyrrolic nitrogen, and metallic cobalt nanoparticles enhance the CO₂RR on pyridinic nitrogen significantly.

Proton insertion chemistry based on organic aqueous zinc-ion batteries (ZIBs) was developed in a mild electrolyte. The H⁺ insertion/extraction endows the battery system with enhanced electrochemical performance. Moreover, the proton insertion chemistry will broaden horizons of aqueous ZIBs.

Liquid crystalline dynamic networks can be shaped into 3D objects at room temperature while being stabilized by slowly formed Diels–Alder-bonded (DA) cross-links. The actuators demonstrate thermally or optically induced reversible shape change for the purpose of performing mechanical work or locomotion.

Boron fit to a T: Pincer ligands distort boron cations toward a T-shaped geometry, enabling new reactivity patterns including a photochemical C−C formation/C−N cleavage yielding a Hofmann–Martius-type intermediate.

Selective [4+2] cycloaddition: A mechanistically unusual approach for a highly enantioselective [4+2] cycloaddition between rhodium-stabilized vinylcarbenes and siloxydienes was developed. The reaction is initiated by attack of the diene at the vinylogous position of the vinylcarbene and the outcome is dependent of the reacting conformation of the vinylcarbene intermediate.

The design and development of a manganese(I) mimic of [Fe]-hydrogenase is reported. This complex exhibits the highest activity and broadest scope in catalytic hydrogenation among known mimics. Thanks to its biomimetic nature, the complex exhibits unique activity in the hydrogenation of compounds analogous to methenyl-H₄MPT⁺, the natural substrate of [Fe]-hydrogenase.

1,2-Selective coordination polymerization of allenes was achieved using rare-earth-metal precursors. The resultant polyallenes can be easily transformed into the poly(allyl alcohol) derivatives through hydroboration/oxidation. The copolymerization of propylene and allene monomers also proceeds to afford unprecedented hydroxy-functionalized polypropylene after post-functionalization. DFT simulations suggests kinetic rather than thermodynamic control.

The host–guest interaction between the chiral void of γCD-MOF and achiral luminophores with different charges and sizes are presented. Numerous achiral luminophores could be integrated into γCD-MOF and emitted significantly boosted positive or negative circularly polarized luminescence (CPL). When the size of the guest luminophores was close to the cube size, strong negative CPL was observed.

Enantioselective construction of axially chiral compounds by the electrophilic carbothiolation of alkynes is disclosed. This transformation is enabled by the use of a tosyl-protected bifunctional sulfide catalyst and mesyl-protected ortho-alkynylaryl amines. The obtained products can easily be converted into biaryl amino sulfides, biaryl amino sulfoxides, biaryl amines, vinyl–aryl amines, and other valuable difunctionalized compounds.

Regio- and diastereoselective synthesis of unprotected δ-lactams has been realized starting from readily accessible acrylamides and unactivated alkenes. The reaction provides an efficient means of synthesizing a diverse set of δ-lactams in good yield and stereoselectivity, which serve as useful building blocks for substituted piperidines.