Theoretical investigation of various aspects of two dimensional holey boroxine, BO.

By means of first-principles calculations, we study the structural, electronic and mechanical properties of the newly synthesized boron-oxygen holey framework ( 2018, , 3971). It has a planar structure formed by BO hexagons, which are joined strong covalent boron-boron bonds. The six BO units are connected with six-fold symmetry exhibiting a large hole with a surface area of 23 Å, which is ideal for the adsorption of alkalis.

Hydrogenation and Fluorination of 2D Boron Phosphide and Boron Arsenide: A Density Functional Theory Investigation.

First-principles density functional theory calculations are performed to study the stability and electronic properties of hydrogenated and fluorinated two-dimensional sp boron phosphide (BP) and boron arsenide (BAs). As expected, the phonon dispersion spectrum and phonon density of states of hydrogenated and fluorinated BX (X = P, As) systems are found to be different, which can be attributed to the different masses of hydrogen and fluorine. Hydrogenated BX systems bear larger and indirect band gaps and are found to be different from fluorinated BX systems.

Unusual Enhancement of the Adsorption Energies of Sodium and Potassium in Sulfur-Nitrogen and Silicon-Boron Codoped Graphene.

Herein, we have employed first-principles calculations to investigate the interaction between XY dual-doped graphene (DDG) (X = AL, Si, P, S; Y = B, N, O) and sodium/potassium. The introduction of two dopants alters the adsorption energy (AE) of sodium and potassium with respect to perfect graphene by an average of 0.88 and 0.

Electronic properties and vibrational spectra of (NH)M″(SO)·6HO (M = Ni, Cu) Tutton's salt: DFT and experimental study.

The complex crystals of the family of the Tutton's salt have been investigated through the numerous experimental and theoretical studies to understand their physical properties and their potential technological applications. In spite of the more than 60 years of research, there are very few studies about the electronic properties of Tutton's salt. In our present work, we have calculated the stability, electronic properties and the first theoretical study of band structure of the three different crystals of the Tutton's salt, ammonium nickel sulfate hexahydrate ((NH)Ni(SO)·6HO), ammonium nickel-copper sulfate hexahydrate ((NH)NiCu(SO)·6HO) and ammonium copper sulfate hexahydrate ((NH)Ni(SO)·6HO) with the help of periodic ab-initio calculations based on density functional theory (DFT).

Triple-Doped Monolayer Graphene with Boron, Nitrogen, Aluminum, Silicon, Phosphorus, and Sulfur.

The structure, stability, electronic properties and chemical reactivity of X/B/N triple-doped graphene (TDG) systems (X=Al, Si, P, S) are investigated by means of periodic density functional calculations. In the studied TDGs the dopant atoms prefer to be bonded to one another instead of separated. In general, the XNB pattern is preferred, with the exception of sulfur, which favors the SBN motif.

Substituent effects on molecular properties of dicarba-closo-dodecarborane derivatives.

In this paper we study the role played by substituent effects on reactivity and NLO properties of ortho-, meta- and para- dicarba-closo-dodecarborane derivatives at B3LYP/6-31G(d,p) level of theory. In addition correlations with Hammett parameters of the substituents were established. In accordance with obtained results the reactivity properties of derivatives have not been significantly influenced by the isomer type, however the replaced para isomers were the most sensitive to NLO calculations.

Prediction of ordered phases of encapsulated C60, C70, and C78 inside carbon nanotubes.

We report the first detailed fully atomistic molecular dynamics study of the encapsulation of symmetric (C(60)) and asymmetric fullerenes (C(70) and C(78)) inside single-walled carbon nanotubes of different diameters. Different ordered phases have been found and shown to be tube diameter dependent. Rotational structural disorder significantly affecting the volume fraction of the packing was observed for the molecular arrangements of asymmetric fullerenes.

Lock-and-key effect in the surface diffusion of large organic molecules probed by STM.

A nanoscale understanding of the complex dynamics of large molecules at surfaces is essential for the bottom-up design of molecular nanostructures. Here we show that we can change the diffusion coefficient of the complex organic molecule known as Violet Lander (VL, C(108)H(104)) on Cu(110) by two orders of magnitude by using the STM at low temperatures to switch between two adsorption configurations that differ only in the molecular orientation with respect to the substrate lattice. From an interplay with molecular dynamics simulations, we interpret the results within a lock-and-key model similar to the one driving the recognition between biomolecules: the molecule (key) is immobilized only when its orientation is such that the molecular shape fits the atomic lattice of the surface (lock); otherwise the molecule is highly mobile.