The University of Southampton
University of Southampton Institutional Repository
Warning ePrints Soton is experiencing an issue with some file downloads not being available. We are working hard to fix this. Please bear with us.

Targeted structural modification of spin crossover complexes: pyridine vs pyrazine

Targeted structural modification of spin crossover complexes: pyridine vs pyrazine
Targeted structural modification of spin crossover complexes: pyridine vs pyrazine

2-(Aminomethyl)pyrazine has been prepared in five steps from 2-pyrazine carboxylic acid. From this key amine, two new bis-terdentate triazole-based ligands which feature pendant pyrazine groups, PZMAT and PZMPT (4-amino- and 4-pyrrolyl-3,5-bis{[(2-pyrazylmethyl)amino]methyl}-4H-1,2,4-triazole, respectively), and two dinuclear complexes of them, [FeII 2(PZMAT)2](BF4)4∙MeOH∙2H2O (1∙MeOH∙2H2O) and [FeII 2(PZMPT)2](BF4)4∙3H2O (2∙3H2O), have been prepared. A structure determination at 100 K on 2∙3.5MeCN confirmed that the ligands adopt the expected binding mode, providing all twelve donors to the two iron(II) centres and two N1,N2-triazole bridges between them. Both undergo gradual incomplete spin transitions: at room temperature 1∙MeOH∙2H2O and 2∙3H2O are approximately two-thirds to three-quarters [HS-HS], dropping to mostly ‘[HS-LS]’ at 50 K. The structure determination and Mössbauer spectroscopy of 2 qualitatively support this. These findings are consistent with the pendant pyrazines providing a somewhat higher field strength than the pendant pyridines do in the analogous PMRT complexes.

2-(aminomethyl)pyrazine; heterocycle, dinuclear, iron(II), pyrazine, Spin crossover, triazole
1061-0278
296-304
Feltham, Humphrey L.C.
343099f1-b760-408c-8ade-ef93e1a9a746
Cowan, Matthew G.
9637c7ba-b172-4655-a2f0-03b92d0d8101
Kitchen, Jonathan A.
3999f5cb-d53e-4c51-b750-627bd2a1b9b6
Jameson, Guy N.L.
6c485bbe-c1b1-4ea5-8cb5-973731cd24b9
Brooker, Sally
2ee9681a-3ff7-41be-88c5-681f66b953ef
Feltham, Humphrey L.C.
343099f1-b760-408c-8ade-ef93e1a9a746
Cowan, Matthew G.
9637c7ba-b172-4655-a2f0-03b92d0d8101
Kitchen, Jonathan A.
3999f5cb-d53e-4c51-b750-627bd2a1b9b6
Jameson, Guy N.L.
6c485bbe-c1b1-4ea5-8cb5-973731cd24b9
Brooker, Sally
2ee9681a-3ff7-41be-88c5-681f66b953ef

Feltham, Humphrey L.C., Cowan, Matthew G., Kitchen, Jonathan A., Jameson, Guy N.L. and Brooker, Sally (2018) Targeted structural modification of spin crossover complexes: pyridine vs pyrazine. Supramolecular Chemistry, 30 (4), 296-304. (doi:10.1080/10610278.2017.1358449).

Record type: Article

Abstract

2-(Aminomethyl)pyrazine has been prepared in five steps from 2-pyrazine carboxylic acid. From this key amine, two new bis-terdentate triazole-based ligands which feature pendant pyrazine groups, PZMAT and PZMPT (4-amino- and 4-pyrrolyl-3,5-bis{[(2-pyrazylmethyl)amino]methyl}-4H-1,2,4-triazole, respectively), and two dinuclear complexes of them, [FeII 2(PZMAT)2](BF4)4∙MeOH∙2H2O (1∙MeOH∙2H2O) and [FeII 2(PZMPT)2](BF4)4∙3H2O (2∙3H2O), have been prepared. A structure determination at 100 K on 2∙3.5MeCN confirmed that the ligands adopt the expected binding mode, providing all twelve donors to the two iron(II) centres and two N1,N2-triazole bridges between them. Both undergo gradual incomplete spin transitions: at room temperature 1∙MeOH∙2H2O and 2∙3H2O are approximately two-thirds to three-quarters [HS-HS], dropping to mostly ‘[HS-LS]’ at 50 K. The structure determination and Mössbauer spectroscopy of 2 qualitatively support this. These findings are consistent with the pendant pyrazines providing a somewhat higher field strength than the pendant pyridines do in the analogous PMRT complexes.

This record has no associated files available for download.

More information

Accepted/In Press date: 18 July 2017
e-pub ahead of print date: 18 August 2017
Published date: 3 April 2018
Keywords: 2-(aminomethyl)pyrazine; heterocycle, dinuclear, iron(II), pyrazine, Spin crossover, triazole

Identifiers

Local EPrints ID: 418091
URI: http://eprints.soton.ac.uk/id/eprint/418091
ISSN: 1061-0278
PURE UUID: 07003d9f-36a4-4119-8188-cf3b3c07b69c
ORCID for Jonathan A. Kitchen: ORCID iD orcid.org/0000-0002-7139-5666

Catalogue record

Date deposited: 22 Feb 2018 17:30
Last modified: 25 Nov 2021 17:56

Export record

Altmetrics

Contributors

Author: Humphrey L.C. Feltham
Author: Matthew G. Cowan
Author: Jonathan A. Kitchen ORCID iD
Author: Guy N.L. Jameson
Author: Sally Brooker

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×