Exceptionally Strong Triply Dative Be-F Bonds in [CO3]BeF- and [C2O4]BeF- Complexes: Reducing Valence Shell Electron Repulsion to Achieve High Bond Dissociation Energies

Li-Juan Cui; Xin-Bo Liu; Zhong-Hua Cui

doi:10.1021/acs.inorgchem.4c03909

Exceptionally Strong Triply Dative Be-F Bonds in [CO₃]BeF^- and [C₂O₄]BeF^- Complexes: Reducing Valence Shell Electron Repulsion to Achieve High Bond Dissociation Energies

Inorg Chem. 2025 Jan 17. doi: 10.1021/acs.inorgchem.4c03909. Online ahead of print.

Authors

Li-Juan Cui¹, Xin-Bo Liu¹, Zhong-Hua Cui^{1

2}

Affiliations

¹ Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China.
² State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023, China.

PMID: 39823365
DOI: 10.1021/acs.inorgchem.4c03909

Abstract

Dative bonds are typically polar, weaker, and longer than electron-sharing covalent bonds. The intriguing diatomic BeF^- anion uniquely exhibits triple Be-F dative bonding with a considerable bond dissociation energy (BDE) of 88 kcal/mol. Here, we report exceptionally strong dative-bonded systems, [CO₃]BeF^- and [C₂O₄]BeF^-, with BDE values exceeding 155 kcal/mol by integrating [CO₃] and [C₂O₄] groups into the BeF^- framework. These designed C_2v-symmetric molecules represent the lowest-energy configurations and maintain similar triply bonded Be-F interactions with orbital characteristics and bond distances closely resembling those in BeF^-. Chemical bonding analysis reveals that [CO₃] and [C₂O₄] groups significantly withdraw s-type nonbonding electrons from Be, which minimizes valence shell electron repulsion from the F^- to Be interactions. This reduction in Pauli repulsion between the closed-shell fragments in [CO₃]BeF^- and [C₂O₄]BeF^-, compared to that of BeF^-, establishes a new record in dative bond strength and offers substantial insights into dative bonding mechanisms. The identified high thermodynamic and kinetic stability of these systems positions them as promising candidates for experimental detection in low-temperature matrices or the gas phase.