Insights into the Factors Controlling the Origin of Activation Barriers in the [2 + 2] Cycloaddition Reactions of Heavy Imine-like Molecules Featuring a Ge=Group 15 Double Bond with Heterocumulenes

The [2 + 2] cycloaddition reactions of the heterocumulene (<b>N=C=N</b>) with the heavy imine-like molecule <b>Ge=G15-Rea</b> (G15 = Group 15 element) were examined using density functional theory (M06-2X-D3/def2-TZVP). The theoretical findings indicate that the doubly bonded...

Full description

Saved in:
Bibliographic Details
Main Authors: Zheng-Feng Zhang, Ming-Der Su
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/30/9/1905
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850030341837815808
author Zheng-Feng Zhang
Ming-Der Su
author_facet Zheng-Feng Zhang
Ming-Der Su
author_sort Zheng-Feng Zhang
collection DOAJ
description The [2 + 2] cycloaddition reactions of the heterocumulene (<b>N=C=N</b>) with the heavy imine-like molecule <b>Ge=G15-Rea</b> (G15 = Group 15 element) were examined using density functional theory (M06-2X-D3/def2-TZVP). The theoretical findings indicate that the doubly bonded Ge=G15 moiety in <b>Ge=G15-Rea</b> (L<sub>1</sub>L<sub>2</sub>Ge=G15L<sub>3</sub>) is characterized by electron-sharing bonding between the triplet L<sub>1</sub>L<sub>2</sub>Ge and triplet G15–L<sub>3</sub> fragments. All five Ge=G15-based heavy imine analogues readily undergo [2 + 2] cycloaddition reactions with <b>N=C=N</b>. Energy decomposition analysis (EDA–NOCV) suggests that the [2 + 2] cycloaddition reaction between <b>Ge=G15-Rea</b> and <b>N=C=N</b> involves a donor–acceptor (singlet–singlet) interaction instead of an electron-sharing (triplet–triplet) interaction. Frontier molecular orbital (FMO) theory and the energy decomposition analysis–natural orbitals for chemical valence (EDA–NOCV) findings emphasize that the key bonding interaction involves the occupied p-π orbital of <b>Ge=G15-Rea</b> and the vacant p-π* orbital of <b>C=N=C</b>. Based on the activation strain model results, the activation barrier of the [2 + 2] cycloaddition reaction is predominantly controlled by the deformation energies of <b>Ge=G15-Rea</b> and <b>N=C=N</b>.
format Article
id doaj-art-8fa3016e72db49cf998922b58374de83
institution DOAJ
issn 1420-3049
language English
publishDate 2025-04-01
publisher MDPI AG
record_format Article
series Molecules
spelling doaj-art-8fa3016e72db49cf998922b58374de832025-08-20T02:59:14ZengMDPI AGMolecules1420-30492025-04-01309190510.3390/molecules30091905Insights into the Factors Controlling the Origin of Activation Barriers in the [2 + 2] Cycloaddition Reactions of Heavy Imine-like Molecules Featuring a Ge=Group 15 Double Bond with HeterocumulenesZheng-Feng Zhang0Ming-Der Su1Department of Applied Chemistry, National Chiayi University, Chiayi 60004, TaiwanDepartment of Applied Chemistry, National Chiayi University, Chiayi 60004, TaiwanThe [2 + 2] cycloaddition reactions of the heterocumulene (<b>N=C=N</b>) with the heavy imine-like molecule <b>Ge=G15-Rea</b> (G15 = Group 15 element) were examined using density functional theory (M06-2X-D3/def2-TZVP). The theoretical findings indicate that the doubly bonded Ge=G15 moiety in <b>Ge=G15-Rea</b> (L<sub>1</sub>L<sub>2</sub>Ge=G15L<sub>3</sub>) is characterized by electron-sharing bonding between the triplet L<sub>1</sub>L<sub>2</sub>Ge and triplet G15–L<sub>3</sub> fragments. All five Ge=G15-based heavy imine analogues readily undergo [2 + 2] cycloaddition reactions with <b>N=C=N</b>. Energy decomposition analysis (EDA–NOCV) suggests that the [2 + 2] cycloaddition reaction between <b>Ge=G15-Rea</b> and <b>N=C=N</b> involves a donor–acceptor (singlet–singlet) interaction instead of an electron-sharing (triplet–triplet) interaction. Frontier molecular orbital (FMO) theory and the energy decomposition analysis–natural orbitals for chemical valence (EDA–NOCV) findings emphasize that the key bonding interaction involves the occupied p-π orbital of <b>Ge=G15-Rea</b> and the vacant p-π* orbital of <b>C=N=C</b>. Based on the activation strain model results, the activation barrier of the [2 + 2] cycloaddition reaction is predominantly controlled by the deformation energies of <b>Ge=G15-Rea</b> and <b>N=C=N</b>.https://www.mdpi.com/1420-3049/30/9/1905[2 + 2] cycloadditionheterocumuleneheavy iminedonor–acceptor interactionelectron-sharing
spellingShingle Zheng-Feng Zhang
Ming-Der Su
Insights into the Factors Controlling the Origin of Activation Barriers in the [2 + 2] Cycloaddition Reactions of Heavy Imine-like Molecules Featuring a Ge=Group 15 Double Bond with Heterocumulenes
Molecules
[2 + 2] cycloaddition
heterocumulene
heavy imine
donor–acceptor interaction
electron-sharing
title Insights into the Factors Controlling the Origin of Activation Barriers in the [2 + 2] Cycloaddition Reactions of Heavy Imine-like Molecules Featuring a Ge=Group 15 Double Bond with Heterocumulenes
title_full Insights into the Factors Controlling the Origin of Activation Barriers in the [2 + 2] Cycloaddition Reactions of Heavy Imine-like Molecules Featuring a Ge=Group 15 Double Bond with Heterocumulenes
title_fullStr Insights into the Factors Controlling the Origin of Activation Barriers in the [2 + 2] Cycloaddition Reactions of Heavy Imine-like Molecules Featuring a Ge=Group 15 Double Bond with Heterocumulenes
title_full_unstemmed Insights into the Factors Controlling the Origin of Activation Barriers in the [2 + 2] Cycloaddition Reactions of Heavy Imine-like Molecules Featuring a Ge=Group 15 Double Bond with Heterocumulenes
title_short Insights into the Factors Controlling the Origin of Activation Barriers in the [2 + 2] Cycloaddition Reactions of Heavy Imine-like Molecules Featuring a Ge=Group 15 Double Bond with Heterocumulenes
title_sort insights into the factors controlling the origin of activation barriers in the 2 2 cycloaddition reactions of heavy imine like molecules featuring a ge group 15 double bond with heterocumulenes
topic [2 + 2] cycloaddition
heterocumulene
heavy imine
donor–acceptor interaction
electron-sharing
url https://www.mdpi.com/1420-3049/30/9/1905
work_keys_str_mv AT zhengfengzhang insightsintothefactorscontrollingtheoriginofactivationbarriersinthe22cycloadditionreactionsofheavyiminelikemoleculesfeaturingagegroup15doublebondwithheterocumulenes
AT mingdersu insightsintothefactorscontrollingtheoriginofactivationbarriersinthe22cycloadditionreactionsofheavyiminelikemoleculesfeaturingagegroup15doublebondwithheterocumulenes