23 Jul 03:23
by Pranay Ranjan,
Jang Mee Lee,
Prashant Kumar,
Ajayan Vinu
Borophene is considered as one of the most promising 2D nanomaterials, owing to its unique structural and electronic properties. The various synthetic approaches for the fabrication of borophene nanostructures with different phases and morphologies, including free‐standing borophene sheets, are described. The frontline applications of these nanostructures in flexible electronics, sensing, disease diagnosis, catalysis, and hybrid energy storage are also considered.
Abstract
Borophene, a 2D allotrope of boron and the lightest elemental Dirac material, is the latest very promising 2D material owing to its unique structural and electronic characteristics of the X3 and β12 phases. The high atomic density on ridgelines of the β12 phase of borophene provides a substantial orbital overlap, which leads to an excellent electron density in the conduction level and thus to a highly metallic behavior. These unique structural characteristics and electronic properties of borophene attract significant scientific interest. Herein, approaches for crystal growth/synthesis of these unique nanostructures and their potential technological applications are discussed. Various substrate‐supported ultrahigh‐vacuum growth techniques for borophene, such as molecular beam epitaxy, atomic layer deposition, and chemical vapor deposition, along with their challenges, are also summarized. The sonochemical exfoliation and modified Hummer's technique for the synthesis of free‐standing borophene are also discussed. Solution‐phase exfoliation seems to address the scalability issues and expands the applications of these unique materials to various fields, including renewable energy devices and ultrafast sensors. Furthermore, the electronic, optical, thermal, and elastic properties of borophene are thoroughly discussed and are compared with those of graphene and its “cousins.” Numerous frontline applications are envisaged and an outlook is presented.
17 Mar 21:20
by Pavel A. Abramov,
Anton A. Ivanov,
Tatiana N. Pozmogova,
Anastasiya O. Solovieva,
Tatiana S. Frolova,
Olga I. Sinitsyna,
Olga V. Lundovskaya,
Alphiya R. Tsygankova,
Mohamed Haouas,
David Landy,
Enrico Benassi,
Lidiya V. Shestopalova,
Clément Falaise,
Emmanuel Cadot,
Michael A. Shestopalov,
Maxim N. Sokolov
![From Specific γ‐CD/[Nb6Cl12(H2O)6]2+ Recognition to Biological Activity Tuning](https://chemistry-europe.onlinelibrary.wiley.com/cms/asset/5683abc5-3d19-4d1c-a9ab-e191b4902c6a/chem202000739-toc-0001-m.png)
Welcome ! Specific molecular recognition of γ‐cyclodextrin (γ‐CD) by the [Nb6Cl12(H2O)6]2+ niobium cluster complex in aqueous solutions results in a 1:1 supramolecular assembly {[Nb6Cl12(H2O)6]@γ‐CD}2+. Crystallization results in a 1:2 host–guest complex {[Nb6Cl12(H2O)6]@(γ‐CD)2}Cl2⋅20 H2O. The molecular association affects the biological activity of [Nb6Cl12(H2O)6]2+. Quantum chemical calculations were performed to model host–guest interaction.
Abstract
Specific molecular recognition of γ‐cyclodextrin (γ‐CD) by the cationic hexanuclear niobium [Nb6Cl12(H2O)6]2+ cluster complex in aqueous solutions results in a 1:1 supramolecular assembly {[Nb6Cl12(H2O)6]@γ‐CD}2+. NMR spectroscopy, isothermal titration calorimetry (ITC), and ESI‐MS were used to study the interaction between the inorganic cluster and the organic macrocycle. Such molecular association affects the biological activity of [Nb6Cl12(H2O)6]2+, decreasing its cytotoxicity despite enhanced cellular uptake. The 1:1 stoichiometry is maintained in solution over a large window of the reagents’ ratio, but crystallization by slow evaporation produces a 1:2 host–guest complex [Nb6Cl12(H2O)6@(γ‐CD)2]Cl2
⋅ 20 H2O featuring the cluster encapsulated between two molecules of γ‐CD. The 1:2 complex was characterized by XRD, elemental analysis, IR spectroscopy, and thermogravimetric analysis (TGA). Quantum chemical calculations were performed to model host–guest interaction.
08 Dec 02:06
by Li-Li Liao, Guang-Mei Cao, Jian-Heng Ye, Guo-Quan Sun, Wen-Jun Zhou, Yong-Yuan Gui, Si-Shun Yan, Guo Shen, Da-Gang Yu
Journal of the American Chemical Society
DOI: 10.1021/jacs.8b08792
