2,3,7,8-Tetramethoxythianthrene: A Novel Ground State Triplet Dication, The Neutral Photogenerated Triplet, and the Radical Cation.

摘要

The dication of 2,3,7,8-tetramethoxythianthrene was studied in solid nitromethane at 77K by computer controlled electron spin resonance. The Delta m=2 transition was observed, yielding a value of D* = 0.094/cm. For comparison the value of D* for thianthrene and 2,3,7,8-tetramethoxythianthrene photogenerated triplets determined. Lifetimes of these triplet states were also determined. Frozen solutions of the tetramethoxythianthrene dication exhibited a very broad Delta m=1 signal that could not be resolved into components D and E of the dipolar tensor. The free energy separation between the triplet and singlet states is between 90 and 190/cm. The esr spectrum of the cation was redetermined.