Hydrogen-Bonded Fibrous Nanotubes Assembled from Trigonal Prismatic Building Blocks.

In reticular chemistry, molecular building blocks are designed to create crystalline open frameworks. A key principle of reticular chemistry is that the most symmetrical networks are the likely outcomes of reactions, particularly when highly symmetrical building blocks are involved. The strategy of synthesizing low-dimensional networks aims to reduce explicitly the symmetry of the molecular building blocks.

Precise tracking of tip-induced structural variation at the single-chemical-bond limit.

Sub-nanometer-resolved TERS provides a systematic way for investigating tip-molecule interaction and molecular motions, enabling a promising approach to examine on-surface reaction mechanisms and catalysis at the microscopic level.

Chemically identifying single adatoms with single-bond sensitivity during oxidation reactions of borophene.

The chemical interrogation of individual atomic adsorbates on a surface significantly contributes to understanding the atomic-scale processes behind on-surface reactions. However, it remains highly challenging for current imaging or spectroscopic methods to achieve such a high chemical spatial resolution. Here we show that single oxygen adatoms on a boron monolayer (i.

Chemically imaging nanostructures formed by the covalent assembly of molecular building blocks on a surface with ultrahigh vacuum tip-enhanced Raman spectroscopy.

Surface-bound reactions have become a viable method to develop nanoarchitectures through bottom-up assembly with near atomic precision. However, the bottom-up fabrication of nanostructures on surfaces requires careful consideration of the intrinsic properties of the precursors and substrate as well as the complex interplay of any interactions that arise in the heterogeneous two-dimensional (2D) system. Therefore, it becomes necessary to consider these systems with characterization methods sensitive to such properties with suitable spatial resolution.

Reconfigurable perovskite nickelate electronics for artificial intelligence.

Reconfigurable devices offer the ability to program electronic circuits on demand. In this work, we demonstrated on-demand creation of artificial neurons, synapses, and memory capacitors in post-fabricated perovskite NdNiO devices that can be simply reconfigured for a specific purpose by single-shot electric pulses. The sensitivity of electronic properties of perovskite nickelates to the local distribution of hydrogen ions enabled these results.

Controlling Localized Plasmons via an Atomistic Approach: Attainment of Site-Selective Activation inside a Single Molecule.

Chemical reactions such as bond dissociation and formation assisted by localized surface plasmons (LSPs) of noble metal nanostructures hold promise in solar-to-chemical energy conversion. However, the precise control of localized plasmons to activate a specific moiety of a molecule, in the presence of multiple chemically equivalent parts within a single molecule, is scarce due to the relatively large lateral distribution of the plasmonic field. Herein, we report the plasmon-assisted dissociation of a specific molecular site (C-Si bond) within a polyfunctional molecule adsorbed on a Cu(100) surface in the scanning tunneling microscope (STM) junction.

Angstrom-Scale Spectroscopic Visualization of Interfacial Interactions in an Organic/Borophene Vertical Heterostructure.

Two-dimensional boron monolayers (i.e., borophene) hold promise for a variety of energy, catalytic, and nanoelectronic device technologies due to the unique nature of boron-boron bonds.

On-Surface Synthesis and Molecular Engineering of Carbon-Based Nanoarchitectures.

On-surface synthesis covalent coupling of adsorbed precursor molecules on metal surfaces has emerged as a promising strategy for the design and fabrication of novel organic nanoarchitectures with unique properties and potential applications in nanoelectronics, optoelectronics, spintronics, catalysis, . Surface-chemistry-driven molecular engineering (., bond cleavage, linkage, and rearrangement) by means of thermal activation, light irradiation, and tip manipulation plays critical roles in various on-surface synthetic processes, as exemplified by the work from the Ernst group in a prior issue of .

An Integrated and Multibiomarker approach to delineate oxidative stress status of Bellamya bengalensis under the interactions of elevated temperature and chlorpyrifos contamination.

Synergistic effects of warming on bioconcentration and receptiveness of pollutants are still poorly unravelled in conjunction with cellular and molecular responses. The present study addressed the impact of an environmental relevant dose of chlorpyrifos (organophosphate pesticide), under control (25 °C) and elevated levels of temperature (30 °C, 35 °C) in Bellamya bengalensis, a freshwater gastropod for 60 days across various endpoints. Multiple levels of biomarkers were measured: growth conditions (organ to flesh weight ratio, condition index), oxidative stress status (SOD, CAT, GST, LPO) and DNA damage (Comet assay-3, 30 and 60 days only) after acute (24, 48 and 72 h) and long-term exposures (10, 20, 30, 40, 50 and 60 days).

Tip-enhanced Raman spectroscopy: Chemical analysis with nanoscale to angstrom scale resolution.

Tip-enhanced Raman spectroscopy (TERS), a cutting-edge near-field spectroscopic tool, provides invaluable chemical insight with impressive spatial resolution in chemistry-related fields such as molecular and catalytic systems, surface science, two-dimensional materials, and biochemistry. High-resolution TERS, in particular, which has advanced exceptionally in the last five years, provides a unique opportunity to scrutinize single molecules individually. Here, this perspective places emphasis on the basic concepts and recent experimental findings of this state-of-the-art research and concludes with a glimpse of future prospects.

The Expanding Frontiers of Tip-Enhanced Raman Spectroscopy.

Fundamental understanding of chemistry and physical properties at the nanoscale enables the rational design of interface-based systems. Surface interactions underlie numerous technologies ranging from catalysis to organic thin films to biological systems. Since surface environments are especially prone to heterogeneity, it becomes crucial to characterize these systems with spatial resolution sufficient to localize individual active sites or defects.

Angstrom Scale Chemical Analysis of Metal Supported Trans- and Cis-Regioisomers by Ultrahigh Vacuum Tip-Enhanced Raman Mapping.

Real space chemical analysis of two structurally very similar components, that is, regioisomers lies at the heart of heterogeneous catalysis reactions, modern-age electronic devices, and various other surface related problems in surface science and nanotechnology. One of the big challenges in surface chemistry is to identify different surface adsorbed molecules and analyze their chemical properties individually. Herein, we report a topological and chemical analysis of two regioisomers, trans- and cis-tetrakispentafluorophenylporphodilactone ( trans- and cis-HFTPPDL) molecules by high-resolution scanning tunneling microscopy, and ultrahigh vacuum tip-enhanced Raman spectroscopy (UHV-TERS).

Low-Threshold Reversible Electron-Induced and Selective Photoinduced Switching of Azobenzene Derivatives under Ambient Conditions.

Mono-carboxyl-functionalized azobenzene and arylazopyrazole have been employed for electron-induced and photoinduced switching under ambient conditions. The microscopic structure and the switching behavior is understood using scanning tunneling microscopy. The carboxyl functional group in these molecules offers low threshold energy for the electron-induced reversible switching compared with nonfunctionalized azobenzene.