title: On the properties of Se⋯N interaction: the analysis of substituent effects by energy decomposition and orbital interaction.
abstract: The nature and strength of intermolecular Se⋯N interaction between selenium-containing compounds HSeX (X = CH3, NH2, CF3, OCH3, CN, OH, NO2, Cl, F), and NH3 have been investigated at the MP2/aug-cc-pVDZ level. The Se⋯N interaction is found to be dependent on the substituent groups, which greatly affect the positive electrostatic potential of Se atoms and the accepting electron ability of X-Se σ(∗) antibonding orbital. Energy decomposition of the Se ⋯N interaction reveals that electrostatic and induction forces are comparable in the weak-bonded complexes and induction becomes more significant in the complexes with strong electron-withdrawing substituents. Natural bond orbital (NBO) analysis indicates that the primary source of the induction is the electron transfer from the N lone pair to the X-Se σ(∗) antibonding orbital. The geometry of the complex and the interaction directionality of NH3 to X-Se bond can be regarded as a consequence of the exchange-repulsion. The topological analysis on the electron density reveals the nature of closed-shell interaction in these X-Se⋯N contacts. The Se⋯N interaction in the complexes with the strong electron-withdrawing substituent has a partly covalent character.
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
authors.forename: Ruirui
authors.initials: R
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
authors.forename: Yahui
authors.initials: Y
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun, 130012, People's Republic of China. houyuzhang@jlu.edu.cn.
authors.forename: Houyu
authors.initials: H
authors.lastname: Zhang
keywords: Charge transfer; Energy decomposition; Exchange-repulsion; Substituent effects; Topological analysis