Inorganic Discussion Weekend
Department of Chemistry and Biochemistry
Inorganic Discussion Weekend 2010 Abstract Submission
Presentation Type:
Oral Presentation
Poster Presentation
Title of Presentation:
<p> Where Have All the Fluorines Gone? Investigation of the Magnetic Properties of Several Binuclear Coordination Complexes of Dithiadiazolyl and Diselenadiazolyl Radical Ligands.</p>
Author(s) Name(s) and Affiliation(s):
<p> <u>Dan MacDonald</u>, Kathryn Preuss*, Wu "Kyle" Jian, Michael Jennings. Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1. .</p>
Presenter's Email:
Abstract:
<p> The binuclear coordination complexes of the radical ligand 4-(2’-pyrimidyl)-1,2,3,5-dithiadiazolyl (pym-DTDA) with Co<sup>II</sup>(hfac)<sub>2</sub> (<strong>1</strong>) and Ni<sup>II</sup>(hfac)<sub>2</sub> (<strong>2</strong>) have shown ferromagnetic coupling between spin of the unpaired electron of the radical ligand and the spins of the unpaired electrons of the metal ions, while the binuclear Mn<sup>II</sup>(hfac)<sub>2</sub> (<strong>3</strong>) coordination complex exhibits antiferromagnetic coupling, giving a ground state S = 9/2.<sup>1</sup> The latter complex exhibited a sharp asymptotic increase in χT as the temperature was decreased to 2.5 K, indicative of a ferrimagnetic coupling scheme. This intermolecular coupling is mediated by close S...O contacts, analogous to those seen in the Mn<sup>II</sup>(hfac)<sub>2</sub> complex of the radical ligand 4-(2’-benzoxazolyl)-1,2,3,5-dithiadiazolyl (boa-DTDA) (<strong>4</strong>).<sup>2</sup> However, disorder in the radical ligand has resulted in the formation of discrete oligomeric chains of <strong>3</strong>, preventing an observation of the bulk response expected for a single-chain magnet. The selenium analogue of <strong>3</strong> has also been isolated and was shown to crystallize in the exact same unit cell, with almost identical magnetic properties<img align="right" alt="" height="109" src="http://web2.uwindsor.ca/chemistry/idw/files/1287497979.jpeg" width="120" />.</p> <p> 1) Wu, J; Preuss, K.E.; Jennings, M.C. Chem. Commun. 2006, 341.<br /> 2) Fatila, E.M.; Goodreid, J.; Clerac, R.; Jennings, M.; Assod, J.; Preuss, K.E. Chem. Commun. 2010, 46, 6569.<br /> </p>
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November 5, 2010
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Toldo Room 100
Toldo Room 102
Toldo Lobby
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