Next Article in Journal / Special Issue
Pybox-Iron(II) Spin-Crossover Complexes with Substituent Effects from the 4-Position of the Pyridine Ring (Pybox = 2,6-Bis(oxazolin-2-yl)pyridine)
Previous Article in Journal / Special Issue
High-Temperature Wide Thermal Hysteresis of an Iron(II) Dinuclear Double Helicate
Article Menu
Issue 3 (September) cover image

Export Article

Open AccessArticle
Inorganics 2017, 5(3), 51; https://doi.org/10.3390/inorganics5030051

Heteroleptic and Homoleptic Iron(III) Spin-Crossover Complexes; Effects of Ligand Substituents and Intermolecular Interactions between Co-Cation/Anion and the Complex

School of Chemistry, Building 23, 17 Rainforest Walk, Monash University, Clayton, VIC 3800, Australia
*
Author to whom correspondence should be addressed.
Received: 19 June 2017 / Revised: 26 July 2017 / Accepted: 28 July 2017 / Published: 1 August 2017
(This article belongs to the Special Issue Spin-Crossover Complexes)
View Full-Text   |   Download PDF [3725 KB, uploaded 1 August 2017]   |  

Abstract

The structural and magnetic properties of a range of new iron(III) bis-tridentate Schiff base complexes are described with emphasis on how intermolecular structural interactions influence spin states and spin crossover (SCO) in these d5 materials. Three pairs of complexes were investigated. The first pair are the neutral, heteroleptic complexes [Fe(3-OMe-SalEen)(thsa)] 1 and [Fe(3-MeOSalEen)(3-EtOthsa)] 2, where 3-R-HSalEen = (E)-2-(((2-(ethylamino)ethyl)imino)methyl)-6-R-phenol and 3-R-H2thsa = thiosemicarbazone-3-R-salicylaldimine. They display spin transitions above room temperature. However, 2 shows incomplete and gradual change, while SCO in 1 is complete and more abrupt. Lower cooperativity in 2 is ascribed to the lack of π–π interactions, compared to 1. The second pair, cationic species [Fe(3-EtOSalEen)2]NO3 3 and [Fe(3-EtOSalEen)2]Cl 4 differ only in the counter-anion. They show partial SCO above room temperature with 3 displaying a sharp transition at 343 K. Weak hydrogen bonds from cation to Cl probably lead to weaker cooperativity in 4. The last pair, CsH2O[Fe(3-MeO-thsa)2] 5 and Cs(H2O)2[Fe(5-NO2-thsa)2] 6, are anionic homoleptic chelates that have different substituents on the salicylaldiminate rings of thsa2−. The Cs cations bond to O atoms of water and the ligands, in unusual ways thus forming attractive 1D and 3D networks in 5 and 6, respectively, and 5 remains HS (high spin) at all temperatures while 6 remains LS (low spin). Comparisons are made to other literature examples of Cs salts of [Fe(5-R-thsa)2] (R = H and Br). View Full-Text
Keywords: iron(III) complexes; spin crossover; heteroleptic; homoleptic; magnetism; structure; intermolecular interactions; cation–anion interactions iron(III) complexes; spin crossover; heteroleptic; homoleptic; magnetism; structure; intermolecular interactions; cation–anion interactions
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Phonsri, W.; Darveniza, L.C.; Batten, S.R.; Murray, K.S. Heteroleptic and Homoleptic Iron(III) Spin-Crossover Complexes; Effects of Ligand Substituents and Intermolecular Interactions between Co-Cation/Anion and the Complex. Inorganics 2017, 5, 51.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Inorganics EISSN 2304-6740 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top