Halcrow, MA (2016) The Effect of Ligand Design on Metal Ion Spin State - Lessons from Spin Crossover Complexes. Crystals, 6 (5). 58. ISSN 2073-4352
Abstract
The relationship between chemical structure and spin state in a transition metal complex has an important bearing on mechanistic bioinorganic chemistry, catalysis by base metals, and the design of spin crossover materials. The latter provide an ideal testbed for this question, since small changes in spin state energetics can be easily detected from shifts in the spin crossover equilibrium temperature. Published structure-function relationships relating ligand design and spin state from the spin crossover literature give varied results. A sterically crowded ligand sphere favors the expanded metal–ligand bonds associated with the high-spin state. However, steric clashes at the molecular periphery can stabilize either the high-spin or the low-spin state in a predictable way, depending on their effect on ligand conformation. In the absence of steric influences, the picture is less clear since electron-withdrawing ligand substituents are reported to favor the low-spin or the high-spin state in different series of compounds. A recent study has shed light on this conundrum, showing that the electronic influence of a substituent on a coordinated metal ion depends on its position on the ligand framework. Finally, hydrogen bonding to complexes containing peripheral N–H groups consistently stabilizes the low-spin state, where this has been quantified.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2016 by the author; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | transition metals; spin state; spin crossover; structure–function relationships; magnetostructural correlations; magnetic measurements |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Inorganic Chemistry (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 19 May 2016 12:55 |
Last Modified: | 11 Apr 2018 12:17 |
Published Version: | http://dx.doi.org/10.3390/cryst6050058 |
Status: | Published |
Publisher: | MDPI |
Identification Number: | 10.3390/cryst6050058 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:99860 |