Silver Surface-Assisted Dehydrobrominative Cross-Coupling between Identical Aryl Bromides.

Cross-coupling reactions represent an indispensable tool in chemical synthesis. An intriguing challenge in this field is to achieve selective cross-coupling between two precursors with similar reactivity or, to the limit, the identical molecules. Here we report an unexpected dehydrobrominative cross-coupling between 1,3,5-tris(2-bromophenyl)benzene molecules on silver surfaces.

Enhanced Ultrasound Transmission through Skull Using Flexible Matching Layer with Gradual Acoustic Impedance.

Transcranial ultrasound imaging and therapy have gained significant attention due to their noninvasive nature, absence of ionizing radiation, and portability. However, the presence of the skull, which has a high acoustic impedance, presents a challenge for the penetration of ultrasound into intracranial tissue. This leads to a low transmission of ultrasound through the skull, hindering energy focusing and imaging quality.

Unraveling the Dynamic Processes of Methanol Electrooxidation at Isolated Rhodium Sites by In Situ Electrochemical Scanning Tunneling Microscopy.

Materials with isolated single-atom Rh-N sites are emerging as promising and compelling catalysts for methanol electrooxidation. Herein, we carried out an in situ electrochemical scanning tunneling microscopy (ECSTM) investigation of the dynamic processes of methanol absorption and catalytic conversion in the rhodium octaethylporphyrin (RhOEP)-catalyzed methanol oxidation reaction at the molecular scale. The high-contrast RhOEP-CHOH complex formed by methanol adsorption was visualized distinctly in the STM images.

Probing the Synergistic Effects of Mg on CO Reduction Reaction on CoPc by Electrochemical Scanning Tunneling Microscopy.

We report herein the electrochemical scanning tunneling microscopy (ECSTM) study on the synergistic effect of Mg in CO reduction reaction (CORR) catalyzed by cobalt phthalocyanine (CoPc). ECSTM measurement molecularly resolves the self-assembled CoPc monolayer on the Au(111) substrate. In the CO environment, high-contrast species are observed in the adlayer and assigned to the CO adsorption on CoPc.

Evolution of Br⋯Br contacts in enantioselective molecular recognition during chiral 2D crystallization.

Halogen-mediated interactions play an important role in molecular recognition and crystallization in many chemical and biological systems, whereas their effect on homochiral versus heterochiral recognition and crystallization has rarely been explored. Here we demonstrate the evolution of Br⋯Br contacts in chiral recognition during 2D crystallization. On Ag(100), type I contacts prevail at low coverage and lead to homochiral recognition and the formation of 2D conglomerates; whereas type II contacts mediating heterochiral recognition are suppressed at medium coverage and appear in the racemates induced by structural transitions at high coverage.

Aromatic Ring Fusion to Benzoporphyrin γ- Cyclodehydrogenation on a Ag(111) Surface.

Aromatic ring fusion to porphyrins and their derivatives represents an attractive route to tune the molecular conjugation and thus expand their functionalities. Here, we report the expansion of the aromatic π-system of palladium tetraphenyltetrabenzoporphyrins (Pd-TPTBP) surface-assisted γ- cyclodehydrogenation on Ag(111). The chemical transformation of Pd-TPTBP into different products at an elevated temperature of 600 K was revealed at the single-molecule level using bond-resolved scanning tunneling microscopy with a CO-functionalized tip.

Construction of 2D extended cocrystals on the Au(111) surface via IO halogen bonds.

2D extended organic cocrystals were constructed using 1,4-diiodotetrafluorobenzene and aromatic aldehydes via IOaldehyde halogen bonds on an Au(111) surface. The competition and synergy of halogen bonds and hydrogen bonds in 2D co-crystallization were revealed by scanning tunneling microscopy.

Oxygen Defects in β-MnO Enabling High-Performance Rechargeable Aqueous Zinc/Manganese Dioxide Battery.

Rechargeable aqueous Zn/manganese dioxide (Zn/MnO) batteries are attractive energy storage technology owing to their merits of low cost, high safety, and environmental friendliness. However, the β-MnO cathode is still plagued by the sluggish ion insertion kinetics due to the relatively narrow tunneled pathway. Furthermore, the energy storage mechanism is under debate as well.

Radical Borylative Cyclization of 1,6-Dienes: Synthesis of Boron-Substituted Six-Membered Heterocycles and Carbocycles.

A radical borylative cyclization reaction of 1,6-dienes was developed to assemble boron-handled six-membered heterocycles and carbocycles. This reaction was initiated by the chemo- and regio-controlled addition of an N-heterocyclic carbene-boryl radical to one of the alkene tethers, followed by an intramolecular 6- exo cyclization to afford a six-membered ring framework. The utility of this method was demonstrated in the synthesis of diverse paroxetine analogues through late-stage derivatization of the boryl functional unit.