Synthesis and characterization of a new family of spin bearing TTF ligands.
The syntheses and characterization of two new tetrathiafulvalene (TTF) derivatives bearing pyridine-based substituents and 1,5'-dimethyl-6-oxoverdazyl radicals are described. The TTF-pyridine and bipyridine aldehydes were prepared via a palladium-catalyzed cross-coupling reaction between mono(tributylstannyl)tetrathiafulvalene (3) and the appropriate formylpyridyl halides (4). The radical precursors, the corresponding 1,2,4,5-tetrazanes, were prepared by condensation of the bis(1-methylhydrazide) of carbonic acid with the TTF bearing pyridyl aldehyde. Oxidation of tetrazanes 8 and 9 with 1,4-benzoquinone afforded the donor radicals 1 and 2 as 1:1 complexes with hydroquinone. Both complexes are stable in the solid state and their electronic properties have been characterized by EPR, cyclic voltammetry, and UV/vis spectroscopy. The TTF core of both compounds was oxidized both chemically and electrochemically to afford the corresponding cation diradical species. The electronic properties of both donor radicals have been probed by cyclic voltammetry, UV-vis spectroscopy, and preliminary EPR measurements.
Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario L2S 3A1, Canada.
M'hamed
M
Chahma
Xiaoshu
X
Wang
Art
A
van der Est
Melanie
M
Pilkington
D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005609:Free Radicals / Q000138:chemical synthesis / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011725:Pyridines / Q000737:chemistry; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
D005609:Free Radicals; D006571:Heterocyclic Compounds; D008024:Ligands; D011725:Pyridines; C063887:tetrathiafulvalene