Dynamic Conversion Between Se–N Covalent and Noncovalent Interactions

Abstract

Se-N dynamic covalent bond is a new dynamic covalent bond which has applications in the fabrication of stimuli responsive and self-healing functional materials. Although recent advances have been achieved in the experimental aspect, little is known about the formation mechanism of Se-N dynamic covalent bond. Here the structures and nature of Se-N dynamic covalent bond between three kinds of pyridine derivatives R-CHN, [pyridine (R = H), 4-methylpyridine (R = CH), 4-dimethylamino-pyridine (R = N(CH))] and phenylselenyl bromine (PhSeBr) have been analyzed using density functional theory. The interactions between Se atom in PhSeBr and N atom in pyridine or pyridine derivatives can be divided into three models: dissociation, nonbonding interaction and covalent bond interaction. Quantum chemical calculations on three series compounds show that these three models can convert mutually, which results in the generation of Se-N dynamic covalent bond. Solvent effects produced in polar solvents such as CHCl can make the conversion between Se-N covalent bond and Se···N nonbonding interactions easier. The kind of the substituents in pyridine ring can affect the conversion process: the stronger the electron-donating ability of the substituent, the easier the structure transformation.

Reversible Modification of Nitrogen-Doped Graphene Based on Se–N Dynamic Covalent Bonds for Field-Effect Transistors

“…Thus, after the formation of Se–N covalent bond, Br become the opposite ions of protonated pyridine. According to the literature, there is a remote distance between the Br and Se atom when the Se–N covalent bond formed. Besides, a hydrogen bond might form between Br and adjacent H atoms on the pyridine and benzene ring.…”

“…The modification of Se–N dynamic covalent bonds leads to a strong shift of the Dirac point from −7 to 29 V. Besides, Se–NG 1–30 shows p-type hole conduction behavior by donating lone pairs of electrons of N atoms to form Se–N bonds. Theoretical studies indicate that charge transfers from the lone pair in N to the σ* orbital of the Se–N bond in the forming processes of Se···N interaction. At the same time, there might be a very low amount of PhSeBr molecules adsorbed on NG during the modification.…”

Insight into the Effects of Electrostatic Potentials on the Conversion Mechanism of the Hydrogen-Bonded Complexes and Carbon-Bonded Complexes: An Ab Initio and Quantum Theory of “Atoms in Molecules” Investigation

“…In previous works, researchers have focused more attention on the characteristics and properties of different noncovalent interactions, such as X–C···π interactions, XH 3 F···HM (X = C, Si, Ge, and Sn; M = Li, Na, BeH, and MgH) tetrel–hydride interaction, XH 3 F···N 3 – /OCN – /SCN – (X = C, Si, Ge, and Sn) interactions, and so on. , However, studies on further mechanism and structural transformation are seldom. − …”