Synthesis and Characterization of Novel Multidentate 1,2,3,5- Dithiadiazolyl Radical Ligands with Potential Luminescent and Magnetic Applications

Mackenzie, Scott B
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University of Guelph

Novel, multidentate (denticity greater than two) 1,2,3,5-dithiadiazolyl radical ligands have been synthesized and characterized. The 4-(2',2''-bipyrid-6'-yl)-1,2,3,5- dithiadiazolyl (bipyDTDA) radical ligand has been characterized via X-ray crystallography and displays cis-cofacial dimerization in the solid state. BipyDTDA features a tridentate nitrogen coordination pocket and was successfully coordinated to Ln(III) metal centers including Ce(III), Pr(III) and Dy(III). The complexes above are structurally interesting in terms of Ln-Thiazyl compounds as they are isostructural throughout most of the lanthanide series. An additional undimerized complex SbCl3(bipyDTDA) has also been synthesized which contains contacts that imply a potential pathway for intermolecular magnetic coupling. A second DTDA ligand 6,6'-bis-1,2,3,5-dithiadiazolyl-2,2'-bipyridine (bisDTDAbipy) has been prepared and characterized via DART-MS. The EPR spectrum for this diradical species exhibits a five-line pattern consistent with two non-interacting radical centers each with coupling to two equivalent 14N nuclei. Coordination of bisDTDAbipy has yet to be achieved.

thiazyl, coordination, complexes, molecular materials, magnetism, luminescence, Ruthenium, Lanthanide, radical, spin bearing ligands