Structural Characterization and Bonding Analysis of [Hg{Fe(CO)5}2]2+ [SbF6]-2

10 March 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

The non-classical carbonyl complex [Hg{Fe(CO)5}2]2+ [SbF6]-2 is prepared by reaction of Hg(SbF6)2 and excess Fe(CO)5 in anhydrous HF. The single-crystal X-ray structure reveals a linear Fe-Hg-Fe moiety as well as an eclipsed conformation of the eight basal CO ligands. Interestingly, the Hg-Fe bond length of 2.5745(7) Angstrom is relatively similar to the corresponding Hg-Fe bonds in literature-known [Hg{Fe(CO)4}2]2- dianions (2.52-2.55 Angstrom) which intrigued us to analyze the bonding situation in both the dications and dianions with the EDA-NOCV method. Both species are best described as Hg(0) compounds which are also confirmed by the shape of the HOMO-4 and HOMO-5 of the dication and dianion, respectively, in which the electron pair is located mainly at the Hg. Furthermore, for the dication and the dianion the sigma-backdonation from Hg into the [Fe(CO)5]22+ or the [Fe(CO)4]22- fragment is the most dominant orbital interaction and surprisingly these interaction energies are also very similar even in absolute values. The fact that both iron-based fragments are missing two electrons explains their prominent sigma-acceptor properties.

Keywords

bonding analysis
mercury
iron
carbonyl

Supplementary materials

Title
Description
Actions
Title
Structural Characterization and Bonding Analysis of [Hg{Fe(CO)5}2]2+ [SbF6]-2
Description
experimental details, spectroscopic and computational data
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.