silicon and benzyne

Graphene has attracted great interest for its superior physical, chemical, mechanical, and electrical properties that enable a wide range of applications from electronics to nanoelectromechanical systems. Functionalization is among the significant vectors that drive graphene towards technological applications. While the physical properties of graphene have been at the center of attention, we still lack the knowledge framework for targeted graphene functionalization. In this critical review, we describe some of the important chemical and physical processes for graphene functionalization. We also identify six major challenges in graphene research and give perspectives and practical strategies for both fundamental studies and applications of graphene (315 references).

Topics: Benzene Derivatives; Electronics; Graphite; Halogenation; Hydrogenation; Nanoparticles; Nanotechnology; Polymers; Silicon

Colloidal silicon nanocrystals (SiNCs) have garnered significant interest in optoelectronics and biomedical applications. Direct arylation provides pathways to enhance the solution processability of particles and manipulate the photophysical and electronic properties of SiNCs. Unfortunately, existing methods employed to prepare aryl-functionalized SiNCs are based on organometallic coupling or transition-metal-catalyzed strategies, which require metal-based reagents for preactivation or the precursors and complicated post-treatment processes for product purification. Herein, we demonstrate a metal-free method that directly functionalizes SiNCs with aryl-based ligands. We design a series of benzyne derivatives formed from the thermal cyclization of predesigned alkynes, allowing efficient arylation on hydride-terminated silicon surfaces under mild conditions. These aryl-functionalized SiNCs exhibit strong blue emissions with nanosecond-scaled decay, suggesting the formation of a new radiative recombination channel on SiNC surfaces.

Topics: Alkynes; Benzene Derivatives; Cyclization; Silicon

Towards the goal of covalently bound molecular wires on silicon, the adsorption of benzyne on Si(001) was studied by means of scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional calculations (DFT). The benzyne molecule is found to adsorb preferentially via the strained triple bond on one dimer of the Si(001) surface which results in an intact π system covalently bound to the surface. With increasing coverage, the molecules primarily adsorb along the dimer rows; on stepped surfaces, these molecular wires are all oriented in the same direction.

Topics: Microscopy, Scanning Tunneling; Semiconductors; Silicon; Surface Properties

Topics: Amines; Aniline Compounds; Benzene Derivatives; Electrons; Silicon; Stereoisomerism