72322-75-9Relevant academic research and scientific papers
Facile synthesis and characterization of indene-fused 4-methylcoumarins and an unexpected skeletal rearrangement via Pechmann condensation
Wu, Jie,Liu, Wei,Liang, Li,Gan, Ya,Xia, Shuang,Gou, Xiaojun,Sun, Xiaohua
supporting information, (2020/04/15)
The Pechmann condensation of phenolic fluorenes with ethyl acetoacetate afforded indene-fused 4-methylcoumarins. In addition to the expected indeno[1,2-g]coumarin, a skeletal rearranged compound was obtained as a concomitant product when 9,9-dimethyl-9H-fluorene-2,7-diol was utilized as the substrate. X-ray crystallography was used to identify the structures of the isomers. Photochemical and photophysical studies indicated that compared with the non-rearranged products, the skeletal rearranged isomers have red shifted absorption maxima and much higher fluorescence quantum yields. A mechanism involving two competitive pathways for the simultaneous production of isomers was proposed.
Efficient luminescence from fluorene- and spirobifluorene-based lanthanide complexes upon near-visible irradiation
Bottaro, Gregorio,Rizzo, Fabio,Cavazzini, Marco,Armelao, Lidia,Quici, Silvio
supporting information, p. 4598 - 4607 (2014/05/06)
We describe herein the synthesis and photophysical characterization of new lanthanide complexes that consist of a (9,9-dimethylfluoren-2-yl)-2-oxoethyl or a (9,9-spirobifluoren-2-yl)-2-oxoethyl unit as the antenna, covalently linked to a 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A) unit as the Ln3+ (Gd3+, Eu3+, Sm3+, Tb 3+, Dy3+) coordination site. We were able to translate the spectroscopic properties of the innovative bipartite ligands into the formation of highly luminescent europium complexes that exhibit efficient emission (φse>0.1) upon sensitization in the near-visible region, that is, with an excitation wavelength above 350 nm. The luminescence of the Eu 3+complexes is clearly detectable at concentrations as low as 10 pM. Furthermore, the structural organization of these bipartite ligands makes the complexes highly soluble in aqueous solutions and chemically stable over time. Lighting up: Innovative fluorene- and spirobifluorene-based lanthanide complexes show efficient luminescence upon sensitization in the near-visible region. Lanthanide emission is detectable at concentration as low as 10 pM in aqueous solution (see figure).
Synthesis and properties of alkynethiolate gold(i) complexes
Lardies, Nora,Romeo, Inocencio,Cerrada, Elena,Laguna, Mariano,Skabara, Peter J.
, p. 5329 - 5338 (2008/03/18)
A series of alkynethiolate gold(i) derivatives have been synthesised by the cleavage of 4-monosubstituted 1,2,3-thiadiazoles in the presence of strong bases. The syntheses of the 1,2,3-thiadiazoles with p-cyanophenyl, p-tolyl, 2-thienyl, 3-thienyl and 9,9-dimethylfluoren-2-yl fragments are also described. All the complexes have been characterised by spectroscopic techniques and the complexes [Au(p-CH3-C6H4-CC-S)PPh3], [Au(3-C4H3S-CC-S)PPh3] and PPN[Au(p-CH 3-C6H4-CC-S)(C6F5)] by X-ray analysis. The electrochemically polymerizable mononuclear bis(alkynethiolate) gold(i) complex PPN[Au(3-C4H3S-CC-S) 2] is also described, including its electropolymerization and electrochemical properties. This journal is The Royal Society of Chemistry.
