In this review, we describe the recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities, some of which have not been observed in or achieved by biological systems. In addition, a brief historical overview of the helical assemblies of small molecules and remarkable progress in the synthesis of single-stranded and multistranded helical foldamers and polymers, their properties, structures, and functions, mainly since 2009, will also be described.

Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions

This review is concerned with quantum confinement effects in low-dimensional semiconductor systems. The emphasis is on the optical properties, including luminescence, of nanometre-sized microcrysta...

Low-dimensional systems: quantum size effects and electronic properties of semiconductor microcrystallites (zero-dimensional systems) and some quasi-two-dimensional systems

Dialkylbiaryl phosphines are a valuable class of ligand for Pd-catalyzed amination reactions and have been applied in a range of contexts. This perspective attempts to aid the reader in the selection of the best choice of reaction conditions and ligand of this class for the most commonly encountered and practically important substrate combinations.

Dialkylbiaryl phosphines in Pd-catalyzed amination: a user's guide

Metal−Metal Interactions in Linked Metallocenes

Persistent and stable radicals of the heavier main group elements and related species.

Synthesis and Electronic Properties of 9,10-Disilylanthracenes

Octakis(1,1,2‐trimethylpropyl)octasilacubane: Synthesis, Molecular Structure, and Unusual Properties

We have studied and compared the optical properties of both porous Si and the chemically synthesized planar and cubic Si skeleton clusters. Broad photoluminescence with large Stokes shifts were observed at the visible region in both samples. Spectroscopic analysis suggests that the surface of porous Si is similar to a condensation of Si clusters. Small Si clusters play a key role in the strong room‐temperature photoluminescence in porous Si.

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Visible photoluminescence of silicon‐based nanostructures: Porous silicon and small silicon‐based clusters

Cyclopentasilane-fused hexasilabenzvalene 1 was synthesized by the reduction of tetrachlorocyclopentasilane 6 in 19% yield as a green powder. The molecular structure and properties of 1 were studied by spectroscopic and X-ray crystallographic analyses. Theoretical calculations of the model and real molecules of 1 and their structural isomers 12–16 suggest that the linkage of the central hexasilabenzvalene moiety with trisilane chains and the introduction of tert-butyl groups affect their relative energies.

Soichiro Kyushin

Papers

Synthesis and Electronic Properties of 9,10-Disilylanthracenes

Octakis(1,1,2‐trimethylpropyl)octasilacubane: Synthesis, Molecular Structure, and Unusual Properties

Visible photoluminescence of silicon‐based nanostructures: Porous silicon and small silicon‐based clusters

Cyclopentasilane-fused hexasilabenzvalene.

Oligocyclic Ladder Polysiloxanes: Alternative Synthesis by Oxidation