Issue 44, 2019

Ligand stabilization of manganocene dianions – in defiance of the 18-electron rule

Abstract

Manganocene [Mn(C5H5)2], a 17-electron system, is expected to have a high electron affinity, as addition of an extra electron would make it a closed-shell 18-electron system. Surprisingly, it has a very low electron affinity of only 0.28 eV. Combined with its high ionization potential of around 7.0 eV, manganocene, therefore, should not be eager to either donate or accept an electron. We show that this property can be fundamentally altered with the proper choice of ligands, even though the total electron count remains the same. For example, the electron affinities of manganocene-derivatives Mn[C5(CN)5]2 and Mn[C5(BO)5]2, created by replacing H with CN or BO, are found to be 4.78 eV and 4.85 eV, respectively, making these species superhalogens. The power of the ligands is further demonstrated by studying the stability of their di-anions. Note that [Mn(C5X5)2]2− (X = H, CN, BO) di-anions, with 19-electrons, have one electron more than necessary to satisfy the 18-electron rule for stability. This factor, combined with the unavoidable repulsion between the two extra electrons, should destabilize [Mn(C5X5)2]2−. While that is the case for [Mn(C5H5)2]2−, we show that both Mn[C5(CN)5]22− and Mn[C5(BO)5]22− are stable against auto-detachment of the second electron by 0.7 eV and 0.38 eV, respectively. These results, based on first-principles calculations, demonstrate that ligand-manipulation can be used as an effective strategy to design and synthesize new materials with novel and tailored properties.

Graphical abstract: Ligand stabilization of manganocene dianions – in defiance of the 18-electron rule

Supplementary files

Article information

Article type
Paper
Submitted
24 Apr 2019
Accepted
03 Sep 2019
First published
09 Sep 2019
This article is Open Access
Creative Commons BY-NC license

Phys. Chem. Chem. Phys., 2019,21, 24300-24307

Ligand stabilization of manganocene dianions – in defiance of the 18-electron rule

M. Yadav, H. Fang, S. Giri and P. Jena, Phys. Chem. Chem. Phys., 2019, 21, 24300 DOI: 10.1039/C9CP02331C

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements