15497-91-3Relevant articles and documents
New water soluble terphenylene diethynylene fluorophores
Vongnam, Kunnigar,Vilaivan, Tirayut,Sukwattanasinitt, Mongkol,Rashatasakhon, Paitoon
, p. 197 - 202 (2014/03/21)
Inspired by our earlier works on sensors from dendritic phenyleneethynylenes, two new star-shaped water-soluble fluorophores containing terphenylene diethynylene units and anionic carboxylate peripheries are successfully synthesized. The convergent synthesis relies on Sonogashira cross-coupling reactions between tris-(4-ethynylphenyl)amine and the iodophenyleneethynylene branches. All of the compounds are characterized by 1H, 13C NMR, and mass spectrometry. In aqueous solution, the less polar fluorophore 1 shows lower quantum yield than 2 (18 vs 33 %) as a result of hydrophobic induced aggregation. One of these anionic water-soluble fluorophores exhibits a selective fluorescence quenching by Fe3+ ion in phosphate buffer pH 8.
Product and mechanistic studies of the anodic oxidation of methoxylated naphthalenes. The EECrCp mechanism
Dolson, Mark G.,Swenton, John S.
, p. 2361 - 2371 (2007/10/21)
The anodic oxidations of 1- and 2-methoxy- and 1,2-, 1,3-, 1,4-, 1,5-, 1,6-, 1,7-, 2,3-, 2,6-, and 2,7-dimethoxynaphthalenes have been studied in methanolic potassium hydroxide. At lower temperatures (0-20°C) the major process in 1-methoxynaphthalene and 1,5-, 1,6-, and 1,7-dimethoxynaphthalenes is two-electron oxidation resulting in addition of methoxy groups across the 1,4-positions followed by loss of methanol on workup to afford the methoxylated naphthalene. In contrast, 2-methoxynaphthalene and 1,3-, 2,3-, 2,6-, and 2,7-dimethoxynaphthalenes give major amounts of products derived from four-electron oxidation under these conditions. When the anodic oxidation of this first class of compounds was conducted in refluxing methanol, increased amounts of four-electron oxidation products were isolated. While 1-methylnaphthalene and naphthalene also undergo anodic oxidation under these conditions, these unactivated systems react less selectively and efficiently. Mechanistic studies are most consistent with the key step of the anodic oxidation under these conditions being the reaction of methoxy radical with the aromatic radical cation. This reaction sequence is termed the EECrCp mechanism, and the results of the oxidation of the methoxylated naphthalenes above are discussed in this format.
