Spin crossover complexes and [M3Ln] macrocyclic single-molecule magnets
Date: Monday 7 May 2012
Time: 11:00 a.m. to 12:00 p.m.
Location: Room 531, Chemistry
Contact: For further information regarding this event, please contact Sarah Mattsen by sending email to firstname.lastname@example.org or by calling 6100
Audience: University staff and students
The Department of Chemistry welcomes Professor Sally Brooker who will present a seminar entitled "Spin crossover complexes and [M3Ln] macrocyclic single-molecule magnets".
Professor Sally Brooker is from University of Otago.
Humphrey L.C. Feltham,1 Matthew G. Cowan,1 Jonathan A. Kitchen,1 Nicholas G. White,1 Juan Olguin,1 Guy N. L. Jameson,1 Jeffery L. Tallon,2 Claudio Gandolfi,3 Martin Albrecht,3 Rodolphe Clerac,4 Annie K. Powell5 and Sally Brooker1,*
1 Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
2 MacDiarmid Institute for Advanced Materials and Nanotechnology and Industrial Research Limited, Lower Hutt, New Zealand
3 School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
4 CNRS, UPR 8641, Centre de Recherche Paul Pascal (CRPP), Equipe "Matériaux Moléculaires Magnétiques", Pessac, France.
5 Institut für Anorganische Chemie, Karlsruher Institut für Technologie, Karlsruhe, Germany
Our interests in spin crossover (SCO) started when we identified that a dicobalt complex of a [2+2] Schiff-base macrocycle based on 3,6-diformylpyridazine, L, [CoII2L(NCS)2(SCN)2], had unique SCO behaviour. Our focus in the area of SCO then moved on to the formation of related triazole-based complexes of iron(II). The first iron complex we prepared, [FeII2(PMAT)2](BF4)4•DMF, utilised a bis-terdentate triazole ligand, PMAT, and led to the first structural characterization of a mixed spin state dimetallic complex.
Figure: left [Co2L(NCS)2(SCN)2]; middle [Fe2(PMAT)2](BF4)4•DMF; right [Zn3Dy(LPr)(NO3)3(MeOH)3].
More recently we have also started exploring the controlled preparation of Single-Molecule Magnets (SMMs). Inspired by the [3+3] macrocycles described by Nabeshima and MacLachlan, we have prepared M3Ln SMMs using Schiff-base macrocycles such as (LPr)6- with approximate 3-fold symmetry.
This lecture will describe our recent results in the SCO and SMM fields. It will focus on self-assembling systems featuring transition metal complexes of (a) related triazole-based ligands, (b) new pyrazine-based ligands for SCO and (c) a new class of macrocyclic 3d-4f SMMs.
We thank the Marsden Fund (RSNZ), MacDiarmid Institute for Advanced Materials and Nanotechnology, and the University of Otago for supporting this research. SB thanks the RSC (UK) for funding the Australasian Lectureship of which she is the 2011 recipient.