On-surface synthesis is a promising approach for constructing covalently bound nanostructures. However, the number of reliable chemical reactions suitable on-surface chemistry very limited. Arylalkynes can be coupled at various surfaces in novel 2D Glaser coupling (see picture). This used conjugated materials directly on surfaces.

On-surface synthesis is the bottom-up construction of covalent bonds between molecular building blocks, which has been greatly developed during past decade. Dozens reactions have successfully realized and scrutinized on various surfaces with help surface science techniques combined theoretical calculations. Functional nanoarchitectures such as one-dimensional nanowires, nanoribbons two-dimensional nanonetworks constructed explored in several potential applications. In fact, generation...

To investigate systemic and ocular risk factors for angle closure (AC) in older Singaporeans to determine if these are different men vs women Chinese non-Chinese persons.A cross-sectional study of 2042 subjects with phakia 50 years or recruited from a primary care clinic Singapore. Subjects completed detailed questionnaire underwent refraction, biometry, gonioscopy. Univariate multivariate analyses were performed AC.The prevalence AC among this population was 19.3% (n = 395); 89.4% 1826) the...

Metal-catalyzed polymerization of 2,6-naphthalenedicarboxylic acid (NDCA) to form poly-2,6-naphthalenes at various surfaces is reported. Polymerizations occur via initial formal dehydrogenation self-assembled diacids with subsequent decarboxylation give polymeric bisnaphthyl-Cu species elevated temperature as intermediate structures (<160 °C). Further increase eventually leads poly-naphthalenes reductive elimination. It demonstrated that the Cu(111) surface works most efficiently conduct...

Tuning the binding mode of N-heterocyclic carbenes on metal surfaces is crucial for development new functional materials. To understand impact alkyl side groups formation NHC species at Au(111) surface, we combined scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density theory calculations. We reveal two significantly different modes depending chain length. In case a short substituent, an up-standing configuration with one Au adatom preferred, whereas longer result...

The homocoupling of alkynes at metal surfaces, which was disclosed recently, is a promising reaction for efficient construction conjugated nanostructures surfaces. However, the role substrate as well mechanistic course this process have not been investigated. surface could act cooperatively (a) two-dimensional confinement to properly orient organic reactant and (b) also an active mediator in C–C bond-forming reaction. Herein we report covalent coupling dimers 1,4-diethynylbenzene various...

On-surface synthesis is a powerful cutting-edge technology to build up covalently bound nanostructures directly at surfaces which enables the preparation of highly advanced one- or two-dimensional materials. In these processes, bond formation generally occurs by thermal activation precursor building blocks. this Article we report light-induced homocoupling aryl-alkynes (Glaser coupling) metal surfaces. Such photochemical approaches are particular importance as potentially orthogonal...

Scanning-tunneling-microscope-induced light emission serves as a powerful approach in revealing and manipulating the optical properties of molecular species, intermolecular energy transfer, plasmon-molecule coupling. Earlier studies have established existence up-conversion electroluminescence diverse situations, but underlying microscopic mechanisms are still under active debate, dominated by triplet-triplet annihilation plasmonic pumping. Here we report on experimental realization from...

Abstract Herein we report the on‐surface oxidative homocoupling of 6,6′‐(1,4‐buta‐1,3‐diynyl)bis(2‐naphthoic acid) (BDNA) via bisacylperoxide formation on different Au substrates. By using this unprecedented dehydrogenative polymerization a biscarboxylic acid, linear poly‐BDNA with chain length over 100 nm was prepared. It is shown that monomer BDNA can be prepared in situ at surface Glaser coupling 6‐ethynyl‐2‐naphthoic acid (ENA). Under conditions, directly undergoes to give polymeric...

We describe a reliable fabrication procedure of silver tips for scanning tunneling microscope (STM) induced luminescence experiments. The tip was first etched electrochemically to yield sharp cone shape using selected electrolyte solutions and then sputter cleaned in ultrahigh vacuum remove surface oxidation. status, particular the plasmon mode its emission intensity, can be further tuned through field voltage pulse. quality thus fabricated not only offers atomically resolved STM imaging,...

Flächenwirkung: Die zweidimensionale (2D-)Synthese ist ein Ansatz für den Aufbau kovalent verknüpfter Nanostrukturen auf Oberflächen. Zahl von Reaktionen, die im 2D-Raum durchgeführt werden können, allerdings stark begrenzt. Nun wurde mit der 2D-Glaser-Kupplung eine neue Methode zur Verknüpfung Arylalkinen Metalloberflächen entwickelt (siehe Bild). Diese Reaktionen ermöglichen direkten konjugierter Materialien an Grenzflächen.

Silylation and desilylation are important functional group manipulations in solution-phase organic chemistry that heavily used to protect/deprotect different functionalities. Herein, we disclose the first examples of σ-bond metathesis silylated alkynes with aromatic carboxylic acids on Ag(111) Au(111) surfaces give corresponding terminal silyl esters, which is supported by density theory calculations further confirmed X-ray photoelectron spectroscopy analysis. Such a protecting strategy...

Intermolecular C-C coupling after cleavage of C-X (mostly, X = Br or I) bonds has been extensively studied for facilitating the synthesis polymeric nanostructures. However, accidental appearance C-H at terminal carbon atoms would limit successive extension covalent polymers. To our knowledge, selective dehalogenation not so far reported, which may illuminate another interesting field chemical on surfaces besides in situ fabrication polymers, i.e., novel organic molecules. By combining STM...

A molecular rotor based on N-heterocyclic carbenes (NHCs) has been rationally designed following theoretical predictions, experimentally realized, and characterized. Utilizing the structural tunability of NHCs, a computational screening protocol was first applied to identify NHCs with asymmetric rotational potentials surface as prerequisite for unidirectional rotors. Suitable candidates were then synthesized studied using scanning tunneling microscopy/spectroscopy (STM/STS), analytical...

Herein, we report the assembly behavior of triptycenes with aldehyde (Trip-1) and amino (Trip-2) groups on pristine iodine-passivated Au(111) surfaces by a combination scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, density functional theory (DFT) calculation. On surface, Trip-1 forms long trimer chains two-dimensional islands via aldehyde-aldehyde hydrogen bonding in one dimension π-π stacking adjacent benzene rings other dimension. In...

Crown ethers (CEs), macrocyclic polyethers, have attracted significant attention in supramolecular chemistry. It is known that they many isomers due to their flexibility. challenging select some exact conformation and tune the following self-assembly structure of CEs, it has rarely been reported date. Herein, by choosing 18-crown-6-ether dibenzo-18-crown-6-ether for study, we report an effective stereoisomeric selectivity CEs a strategy both chemical modification hosting Na/K ions. The...

The structure of bis(catecholato)silane has been subject to debate, as whether it is its tetrahedral or planar Si(IV). To tackle the discussion, here, molecules with visible molecular-level images on different metal surfaces are investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) simulations. It found that shows a Si(IV) both Au(111) Ag(111) surfaces, while can show nearly Cu(111) surface due strong interaction...