Weak Te,Te Interactions through the Looking Glass of NMR Spin-Spin Coupling

Tellurium-Modified Nucleosides, Nucleotides, and Nucleic Acids with Potential Applications

Tellurium was successfully incorporated into proteins and applied to protein structure determination through X-ray crystallography. However, studies on tellurium modification of DNA and RNA are limited. This review highlights the recent development of Te-modified nucleosides, nucleotides, and nucleic acids, and summarizes the main synthetic approaches for the preparation of 5-PhTe, 2'-MeTe, and 2'-PhTe modifications. Those modifications are compatible with solid-phase synthesis and stable during Te-oligonucleotide purification. Moreover, the ideal electronic and atomic properties of tellurium for generating clear isomorphous signals give Te-modified DNA and RNA great potential applications in 3D crystal structure determination through X-ray diffraction. STM study also shows that Te-modified DNA has strong topographic and current peaks, which immediately suggests potential applications in nucleic acid direct imaging, nanomaterials, molecular electronics, and diagnostics. Theoretical studies indicate the potential application of Te-modified nucleosides in cancer therapy.

Chalcogen Bonding: An Overview

In the last few decades, "unusual" noncovalent interactions like anion-π and halogen bonding have emerged as interesting alternatives to the ubiquitous hydrogen bonding in many research areas. This is also true, to a somewhat lesser extent, for chalcogen bonding, the noncovalent interaction involving Lewis acidic chalcogen centers. Herein, we aim to provide an overview on the use of chalcogen bonding in crystal engineering and in solution, with a focus on the recent developments concerning intermolecular chalcogen bonding in solution-phase applications. In the solid phase, chalcogen bonding has been used for the construction of nano-sized structures and the self-assembly of sophisticated self-complementary arrays. In solution, until very recently applications mostly focused on intramolecular interactions which stabilized the conformation of intermediates or reagents. In the last few years, intermolecular chalcogen bonding has increasingly also been exploited in solution, most notably in anion recognition and transport as well as in organic synthesis and organocatalysis.

Probing interactions through space using spin–spin coupling

A series of eight 5-(TeAr)-6-(SePh)acenaphthenes (Ar = aryl) were prepared and structurally characterised by X-ray crystallography, solution and solid-state NMR spectroscopy and DFT/B3LYP calculations.

Electrochemically informed synthesis: oxidation versus coordination of 5,6-bis(phenylchalcogeno)acenaphthenes

Chalcogen dications: Facile synthesis of E--E bonded dications can be readily achieved. Radical cations are identified as the intermediates.