Thallium(III) Trifluoroacetate-Trifluoroacetic Acid in the Chemistry of Polythiophenes. 2. Treatment of 3-Alkylthiophenes and Electron Paramagnetic Resonance Results was written by Tormo, Jordi;Moreno, F. Jesus;Ruiz, Jordi;Fajari, Lluis;Julia, Luis. And the article was included in Journal of Organic Chemistry in 1997.Safety of 3-Ethylthiophene This article mentions the following:
The treatment of thiophene and 3-alkylthiophenes with thallium(III) trifluoroacetate (TTFA) in trifluoroacetic acid (TFA) gives insoluble and dark powdery solids with oxygen content and elec. conductivities ranging from 10-4 to 10-6 Ω-1 cm-1. Polar and short fractions are negligible. All of them show semiconductivity (10-3-10-6 Ω-1 cm-1) when doped in iodine atm. ESR (EPR) spectra of either as-synthesized or I2-treated solids display characteristic single and broad lines (ΔHpp, 1.84-7.4 G) with Lorentzian shapes and g-values in the range 2.0028-2.0038. IR spectra show characteristic C-H out-of-plane deformations (780 cm-1 for polythiophene and 820-825 cm-1 for poly(3-alkylthiophenes)) in addition to a strong peak at 1650-1690 cm-1 which has not been conclusively assigned. EPR spectra of some disubstituted and tetrasubstituted 2,2′-bithiophene radical cations have been observed and their g-values and coupling constants assigned when the corresponding parent compounds are photolyzed with UV light in TFA. Photolysis of 3-alkylthiophenes in TFA in the EPR instrument gave the radical cations of 4,4′-dialkyl-2,2′-bithiophenes. In no case, were EPR signals of the isomeric 3,3′-dialkyl- or 3,4′-dialkyl-2,2′-bithiophene radical cations observed, indicating that dimerization of 3-alkylthiophenes occurs through the less sterically hindered 5-position. The presence of two doublet species corresponding to both conformers, syn and anti, in the radical cations is associated with a large barrier to rotation about the C(2)-C(2′) bond. In the experiment, the researchers used many compounds, for example, 3-Ethylthiophene (cas: 1795-01-3Safety of 3-Ethylthiophene).
3-Ethylthiophene (cas: 1795-01-3) belongs to benzothiophene derivatives. Functionalized benzothiophenes are important constructs found in molecules with wide ranging biological activity and in organic materials. Its aromaticity makes it relatively stable, although as a heterocycle, it has reactive sites which allow for functionalization.Safety of 3-Ethylthiophene
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem