Dithienopyrrole Derivatives with Nitronyl Nitroxide Radicals and Their Oxidation to Cationic High-Spin Molecules.

Three 1 N-phenyl nitronyl nitroxide (NN) 4-substituted dithieno[3,2-b:2',3'-d]pyrrole (DTP) derivatives with R1=4-phenyl-, 4H-, and 4-methylthiothiophenyl- (R1 2 DTP-Ph-NN, R1 =H, Ph and MeSTh) were designed, synthesized and characterized. The electrochemical properties were studied by cyclic voltammetry (CV). All the molecules exhibited two main oxidation peaks, first for radical cation and next for dication formation. The cation and dication formation were also confirmed by UV/Vis absorption spectroscopy for Ph2 DTP-Ph-NN and MeSTh2 DTP-Ph-NN titrated with tris(4-bromophenyl)aminiumhexachloroantimonate (magic blue). In addition, the cation and dication formation were verified by EPR spectroscopy. Finally, the exchange interactions (J/kB ) of NN and radical cation were calculated by DFT studies.