19477-77-1Relevant academic research and scientific papers
Reaction of acetophenone hydrazones with TeCl4: Novel formation of 2,5-diaryltellurophenes and benzotellurophenes
Okuma, Kentaro,Yahata, Shuhei,Nagahora, Noriyoshi,Shioji, Kosei
supporting information, p. 405 - 407 (2017/12/26)
Reaction of acetophenone hydrazones with TeCl4 in the presence of DBU in CH2Cl2 at rt gave vinyl ditellurides and tellurides, whereas 2,5-diaryltellurophenes were obtained in refluxing DMF. Interestingly, when 1,2-diphenyl
A Mechanistic Study of Halogen Addition and Photoelimination from π-Conjugated Tellurophenes
Carrera, Elisa I.,Lanterna, Anabel E.,Lough, Alan J.,Scaiano, Juan C.,Seferos, Dwight S.
supporting information, p. 2678 - 2689 (2016/03/12)
The ability to drive reactivity using visible light is of importance for many disciplines of chemistry and has significant implications for sustainable chemistry. Identifying photochemically active compounds and understanding photochemical mechanisms is important for the development of useful materials for synthesis and catalysis. Here we report a series of photoactive diphenyltellurophene compounds bearing electron-withdrawing and electron-donating substituents synthesized by alkyne coupling/ring closing or palladium-catalyzed ipso-arylation chemistry. The redox chemistry of these compounds was studied with respect to oxidative addition and photoelimination of bromine, which is of importance for energy storage reactions involving X2. The oxidative addition reaction mechanism was studied using density functional theory, the results of which support a three-step mechanism involving the formation of an initial η1 association complex, a monobrominated intermediate, and finally the dibrominated product. All of the tellurophene derivatives undergo photoreduction using 430, 447, or 617 nm light depending on the absorption properties of the compound. Compounds bearing electron-withdrawing substituents have the highest photochemical quantum efficiencies in the presence of an alkene trap, with efficiencies of up to 42.4% for a pentafluorophenyl-functionalized tellurophene. The photoelimination reaction was studied in detail through bromine trapping experiments and laser flash photolysis, and a mechanism is proposed. The photoreaction, which occurs by release of bromine radicals, is competitive with intersystem crossing to the triplet state of the brominated species, as evidenced by the formation of singlet oxygen. These findings should be useful for the design of new photochemically active compounds supported by main-group elements.
Efficient halogen photoelimination from dibromo, dichloro and difluoro tellurophenes
Carrera, Elisa I.,Seferos, Dwight S.
supporting information, p. 2092 - 2096 (2015/02/05)
We present the reactivity and photochemistry of 2,5-diphenyltellurophene. A change in oxidation state from Te(II) to Te(IV) occurs by oxidative addition of bromine, chlorine, and fluorine from appropriate halogen sources. Photoreductive halogen eliminatio
Tellurophenes with delocalized π-systems and their extended valence adducts
McCormick, Theresa M.,Jahnke, Ashlee A.,Lough, Alan J.,Seferos, Dwight S.
, p. 3542 - 3548 (2012/04/10)
The π-conjugated 2,5-substituted tellurophene compounds 2,5-bis(2-(9,9-dihexylfluorene))tellurophene (1) and 2,5-diphenyltellurophene (3) were synthesized through ring closing reactions of 1,4-substituted butadiyne. The oxidative addition of Br2 to tellurophene compounds 1 and 3 was studied through absorption spectroscopy, NMR, electrochemistry, X-ray crystallography, and density functional theory (DFT) calculations. When Br 2 adds to the tellurium center the absorption spectrum shifts to a lower energy. From electrochemistry and DFT calculations we show that this is caused by lowering the lowest unoccupied orbital. The highest occupied orbital is also lowered, but to a lesser extent. This shift in absorption spectrum and lowering of the oxidation potential can provide a method to modify tellurophene containing materials. The two-electron oxidative addition is promising for catalyzing energy storage reactions.
Synthesis and stille cross-coupling reactions of 2-(tributylstannyl)-and 2,5-bis(trimethylstannyl)tellurophene
Sweat, Daniel P.,Stephens, Chad E.
experimental part, p. 3214 - 3218 (2010/03/03)
Herein, we describe the synthesis and Stille cross-coupling reactions of 2-(tributylstannyl)-and 2,5-bis(trimethylstannyl) tellurophene. The reactions were most optimal when using aryl iodides as coupling partners, and a mixed catalyst system consisting o
Iodocyclization of (Z)-1-(butyltelluro)-1,4-diorganylbut-1-en-3-ynes. Synthesis and reactions of 3-iodotellurophenes
Dabdoub, Miguel J.,Dabdoub, Va?nia B.,Pereira, Marco A.,Zukerman-Schpector, Julio
, p. 9503 - 9511 (2007/10/03)
The iodocyclization of (Z)-tellurobutenynes 5a-g by reaction with I2/petroleum ether was studied in detail. 3-Iodotellurophenes 7a-f were formed, and optimum conditions to obtain these compounds in high yields were established. The reaction inv
An electron spin resonance study of the 2,5-diphenylchalcophene radical ions
Davies, Alwyn G.,Schiesser, Carl H.
, p. 301 - 313 (2007/10/02)
The 2,5-diphenylchalcophene radical ions (chalcogen = O, S, Se, Te) have been prepared by the action of alkali metal in 1,2-dimethoxyethane (anions), or by the action of sulphuric acid or thallium(III) trifluoroacetate in trifluoroacetic acid (TFAH) (cati
