Bis-thallium(I) porphyrin complexes

Treatment of octaethylporphyrin ($\text{1}$) or tetraphenylporphyrin ($\text{2}$) with more than two equiv of thallium(I) ethoxide gives the corresponding stable bisthallium(I)] porphyrin complexes ($\text{5}$) and ($\text{6}$), respectively; these thallium(I) porphyrins are shown to have very different chemical and spectroscopic properties than do the corresponding thallium(III) porphyrin complexes.