The "sweet spot" in length for contorted conjugated ladders in ultrafast-charging Li and Mg batteries.

Here, we explore a conjugated, contorted polymer framework tailored for ultrafast-rate charging/discharging, leveraging a tunable synthetic strategy to control its molecular length. We systematically explore the helical perylene diimide (hPDI) ladder polymers across three length regimes, short, medium, and long, to determine the optimal electrochemical stability and performance. The intermediate-length polymer strikes a critical balance between electrode integrity, solubility, and rate capability.

RNA adapts its flexibility to efficiently fold and resist unfolding.

Recent studies have demonstrated that the mechanisms through which biopolymers like RNA interconvert between multiple folded structures are critical for their cellular functions. A major obstacle to elucidating these mechanisms is the lack of experimental approaches that can resolve these interconversions between functionally relevant biomolecular structures. Here, we dissect the complete set of structural rearrangements executed by an ultra-stable RNA, the UUCG stem-loop, at the single-molecule level using a nano-electronic device with microsecond time resolution.

Chirality Unbound in Graphene Nanoribbons.

In this manuscript, we report the first demonstration of controlled helicity in extended graphene nanoribbons (GNRs). We present a wealth of new graphene nanoribbons that are a direct consequence of the high-yielding and robust synthetic method revealed in this study. We created a series of defect-free, ultralong, chiral cove-edged graphene nanoribbons where helical twisting of the graphene nanoribbon backbone is tuned through functionalization with chiral side chains.

Reversible excited state electron transfer in an acceptor-acceptor hetero dyad.

In this manuscript, we create a new hetero dyad consisting of two electron acceptors with nearly isoenergetic HOMO and LUMO levels, namely perylene diimide (PDI) and aza dioxa triangulenium (ADOTA). This dyad system displays an unusual and reversible excited state electron transfer process. Upon excitation, the dyad shows complete energy transfer from the locally excited PDI to the ADOTA moiety in ∼1 ps, followed by photoinduced electron transfer (PET), forming oxidized PDI and reduced ADOTA.

Charge Density Wave and Ferromagnetism in Intercalated CrSBr.

In materials with 1D electronic bands, electron-electron interactions can produce intriguing quantum phenomena, including spin-charge separation and charge density waves (CDW). Most of these systems, however, are non-magnetic, motivating a search for anisotropic materials where the coupling of charge and spin may affect emergent quantum states. Here, chemical intercalation of the van der Waals magnetic semiconductor CrSBr yields Li(tetrahydrofuran)CrSBr, which possesses an electronically driven quasi-1D CDW with an onset temperature above room temperature.

Spin Filtering with Surface-Active Helicene- and Twistacene-Based Perylene Diimides.

Creating new chiral molecular and macromolecular systems that can polarize the spin of electrons has the dual promise of both applications in spintronics and a fundamental understanding of their origins. Here, we put forward two optically active helical ladder dimers from perylene diimide-based twistacenes and helicenes. We detail a scalable method to separate the helices for each of these systems and methods to functionalize them with thiol groups that allow for self-assembled monolayer formation on metal surfaces.

Contorted acene ribbons for stable and ultrasensitive neural probes.

Organic materials that conduct both electrons and ions are integral to implantable bioelectronics because of their conformable nature. There is a dearth of these materials that are highly sensitive to cations, which are the majority ions on the surface of neurons. This manuscript offers a solution using an extended ribbon structure that is defect-free, providing high electronic mobility along its fused backbone, while the edge structure of these ribbons promotes high ionic conductivity.

Cannabis Access by Retailer Type in New York.

Objective: Increasing state-level cannabis legalization in the United States aims to reduce risks to consumers through regulation but may also lead to more unlicensed retailers and youth access. This study examines how age verification and business practices (eg, pricing, signage, and youth-appealing products) differ by licensing status.

Methods: The Cannabis Access and Safety in New York (CASNY) secret shopper study observed 37 dispensaries and smoke shops (5 licensed medical, 7 licensed recreational, 10 unlicensed dispensaries, and 15 smoke shops), randomly selected from 840 outlets across New York City (NYC) in November to December 2023 to audit age verification and other business practices.

Molten Metal Synthesis of Nanographenes.

This manuscript describes a simple and effective method to cyclodehydrogenate arenes using liquid alkali metals. Direct reaction between molten potassium and arenes forms 6-membered rings and zigzag edged structures within polyarenes. The approach is extended to integration of pyridinic nitrogen and 5-membered rings to arene structures and synthesis of larger, open-shell nanographenes.

Evaluating the Ability of External Electric Fields to Accelerate Reactions in Solution.

This study investigates the catalytic effects of external electric fields (EEFs) on two reactions in solution: the Menshutkin reaction and the Chapman rearrangement. Utilizing a scanning tunneling microscope-based break-junction (STM-BJ) setup and monitoring reaction rates through high-performance liquid chromatography connected to a UV detector (HPLC-UV) and ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-q-ToF-MS), we observed no rate enhancement for either reaction under ambient conditions. Density functional theory (DFT) calculations indicate that electric field-induced changes in reactant orientation and the minimization of activation energy are crucial factors in determining the efficacy of EEF-driven catalysis.

Electrochemical Doping of Two-Dimensional Superatomic Materials.

We report an electrochemical method for doping two-dimensional (2D) superatomic semiconductor ReSeCl that significantly improves the material's electrical transport while retaining the in-plane and stacking structures. The electrochemical reduction induces the complete dissociation of chloride anions from the surface of each superatomic nanosheet. After the material is dehalogenated, we observe the electrical conductivity () increases by two orders of magnitude while the 3D electron carrier density () increases by three orders of magnitude.

RNA adapts its flexibility to efficiently fold and resist unfolding.

Recent studies have demonstrated that the mechanisms through which biopolymers like RNA interconvert between multiple folded structures are critical for their cellular functions. A major obstacle to elucidating these mechanisms is the lack of experimental approaches that can resolve these interconversions between functionally relevant biomolecular structures. Here, we dissect the complete set of structural rearrangements executed by an ultra-stable RNA, the UUCG stem-loop, at the single-molecule level using a nano-electronic device with microsecond time resolution.

Long-Range Gating in Single-Molecule One-Dimensional Topological Insulators.

Single-molecule one-dimensional topological insulator (1D TI) is a class of molecular wires that exhibit increasing conductance with wire length. This unique trend is due to the coupling between the two low-lying topological edge states of 1D TIs described by the Su-Schrieffer-Heeger model. In principle, this quantum phenomenon within 1D TIs can be utilized to achieve long-range gating in molecular conductors.

Spin-Polarized Charge Separation at Two-Dimensional Semiconductor/Molecule Interfaces.

Spin-polarized electrons can improve the efficiency and selectivity of photo- and electro-catalytic reactions, as demonstrated in the past with magnetic or magnetized catalysts. Here, we present a scheme in which spin-polarized charge separation occurs at the interfaces of nonmagnetic semiconductors and molecular films in the absence of a magnetic field. We take advantage of the spin-valley-locked band structure and valley-dependent optical selection rule in group VI transition metal dichalcogenide (TMDC) monolayers to generate spin-polarized electron-hole pairs.

Air-Stable Perylene Diimide Trimer Material for N-Type Organic Electrochemical Transistors.

A new method is reported to make air-stable n-type organic mixed ionic-electronic conductor (OMIEC) films for organic electrochemical transistors (OECTs) using a solution-processable small molecule helical perylene diimide trimer, hPDI[3]-C. Alkyl side chains are attached to the conjugated core for processability and film making, which are then cleaved via thermal annealing. After the sidechains are removed, the hPDI[3] film becomes less hydrophobic, more ordered, and has a deeper lowest unoccupied molecular orbital (LUMO).

Effective Gating in Single-Molecule Junctions through Fano Resonances.

The successful incorporation of molecules as active circuit elements relies on the ability to tune their electronic properties through chemical design. A synthetic strategy that has been used to manipulate and gate circuit conductance involves attaching a pendant substituent along the molecular conduction pathway. However, such a chemical gate has not yet been shown to significantly modify conductance.

Near-Infrared, Organic Chiroptic Switch with High Dissymmetry Factors.

Here we unveil a chiral molecular redox switch derived from PDI-based twistacenes─ that has the remarkable attributes of high-intensity and a broadband chiral response. This material exhibits facile, stable, and reversible multistate chiroptical switching behavior over a broad active wavelength range close to 700 nm, encompassing ultraviolet, visible, and near-infrared regions. Upon reduction, exhibits a substantial increase in the amplitude of its circular dichroic response, with an outstanding |ΔΔε| > 300 M cm and a high dissymmetry factor of 3 × 10 at 960 nm.

Electron and Spin Delocalization in [Co Se (PEt ) ] Superatoms.

Molecular clusters can function as nanoscale atoms/superatoms, assembling into superatomic solids, a new class of solid-state materials with designable properties through modifications on superatoms. To explore possibilities on diversifying building blocks, here we thoroughly studied one representative superatom, Co Se (PEt ) . We probed its structural, electronic, and magnetic properties and revealed its detailed electronic structure as valence electrons delocalize over inorganic [Co Se ] core while ligands function as an insulated shell.

Interplay between Local Moment and Itinerant Magnetism in the Layered Metallic Antiferromagnet TaFeTe.

Two-dimensional antiferromagnets have garnered considerable interest for the next generation of functional spintronics. However, many bulk materials from which two-dimensional antiferromagnets are isolated are limited by their air sensitivity, low ordering temperatures, and insulating transport properties. TaFeTe aims to address these challenges with increased air stability, metallic transport, and robust antiferromagnetism.

Radical Single-Molecule Junctions.

Radicals are unique molecular systems for applications in electronic devices due to their open-shell electronic structures. Radicals can function as good electrical conductors and switches in molecular circuits while also holding great promise in the field of molecular spintronics. However, it is both challenging to create stable, persistent radicals and to understand their properties in molecular junctions.

Designing Long and Highly Conducting Molecular Wires with Multiple Nontrivial Topological States.

Molecular one-dimensional topological insulators (1D TIs), described by the Su-Schrieffer-Heeger (SSH) model, are a new class of molecular electronic wires whose low-energy topological edge states endow them with high electrical conductivity. However, when these 1D TIs become long, the high conductance is not sustained because the coupling between the edge states decreases with increasing length. Here, we present a new design where we connect multiple short 1D SSH TI units linearly or in a cycle to create molecular wires with a continuous topological state density.

Functional Monolayers on a Superatomic Pegboard.

We advance the chemistry of apical chlorine substitution in the 2D superatomic semiconductor ReSeCl to build functional and atomically precise monolayers on the surface of the 2D superatomic ReSe substrate. We create a functional monolayer by installing surface (2,2'-bipyridine)-4-sulfide (Sbpy) groups that chelate to catalytically active metal complexes. Through this reaction chemistry, we can create monolayers where we can control the distribution of catalytic sites.

Fusing perylene diimide with helicenes.

Incorporating perylene diimide (PDI) units into helicene structures has become a useful strategy for giving access to non-planar electron acceptors as well as a method of creating molecules with unique and intriguing chiroptical properties. This minireview describes this fusion of PDIs with helicenes.

Coaxially Conductive Organic Wires Through Self-Assembly.

Here, we describe the synthesis of the hexameric macrocyclic aniline (MA[]), which spontaneously assembles into coaxially conductive organic wires in its oxidized and acidified emeraldine salt (ES) form. Electrical measurements reveal that ES-MA[] exhibits high electrical conductivity (7.5 × 10 S·cm) and that this conductivity is acid-base responsive.

Electric fields drive bond homolysis.

Electric fields have been used to control and direct chemical reactions in biochemistry and enzymatic catalysis, yet directly applying external electric fields to activate reactions in bulk solution and to characterize them remains a challenge. Here we utilize the scanning tunneling microscope-based break-junction technique to investigate the electric field driven homolytic cleavage of the radical initiator 4-(methylthio)benzoic peroxyanhydride at ambient temperatures in bulk solution, without the use of co-initiators or photochemical activators. Through time-dependent quantification by high performance liquid chromatography using a UV-vis detector, we find that the electric field catalyzes the reaction.