Heteroleptic and homoleptic iron(III) spin-crossover complexes; Effects of ligand substituents and intermolecular interactions between co-cation/anion and the complex

Wasinee Phonsri, Luke Darveniza, Stuart R Batten, Keith S Murray

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)

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).

Original languageEnglish
Article number51
Number of pages13
JournalInorganics
Volume5
Issue number3
DOIs
Publication statusPublished - 1 Sep 2017

Keywords

  • Cation-anion interactions
  • Heteroleptic
  • Homoleptic
  • Intermolecular interactions
  • Iron(III) complexes
  • Magnetism
  • Spin crossover
  • Structure

Cite this

@article{700eca57b27a42299a39d1bbe35d1e59,
title = "Heteroleptic and homoleptic iron(III) spin-crossover complexes; Effects of ligand substituents and intermolecular interactions between co-cation/anion and the complex",
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).",
keywords = "Cation-anion interactions, Heteroleptic, Homoleptic, Intermolecular interactions, Iron(III) complexes, Magnetism, Spin crossover, Structure",
author = "Wasinee Phonsri and Luke Darveniza and Batten, {Stuart R} and Murray, {Keith S}",
year = "2017",
month = "9",
day = "1",
doi = "10.3390/inorganics5030051",
language = "English",
volume = "5",
journal = "Inorganics",
issn = "2304-6740",
publisher = "MDPI",
number = "3",

}

Heteroleptic and homoleptic iron(III) spin-crossover complexes; Effects of ligand substituents and intermolecular interactions between co-cation/anion and the complex. / Phonsri, Wasinee; Darveniza, Luke; Batten, Stuart R; Murray, Keith S.

In: Inorganics, Vol. 5, No. 3, 51, 01.09.2017.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Heteroleptic and homoleptic iron(III) spin-crossover complexes; Effects of ligand substituents and intermolecular interactions between co-cation/anion and the complex

AU - Phonsri, Wasinee

AU - Darveniza, Luke

AU - Batten, Stuart R

AU - Murray, Keith S

PY - 2017/9/1

Y1 - 2017/9/1

N2 - 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).

AB - 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).

KW - Cation-anion interactions

KW - Heteroleptic

KW - Homoleptic

KW - Intermolecular interactions

KW - Iron(III) complexes

KW - Magnetism

KW - Spin crossover

KW - Structure

UR - http://www.scopus.com/inward/record.url?scp=85045329805&partnerID=8YFLogxK

U2 - 10.3390/inorganics5030051

DO - 10.3390/inorganics5030051

M3 - Article

VL - 5

JO - Inorganics

JF - Inorganics

SN - 2304-6740

IS - 3

M1 - 51

ER -