6-Formyl-7-hydroxy-5-methoxy-2-methylchromone on bromination yields the 8-bromo deriva­ tive or the 8-bromo-6-formyl-5,7-dihydroxy derivative depending on the reaction condition. Cyclization of both leads to the corresponding 3-acetyl-, 3-benzoyl-, 3-carboxamido-, 3-carbethoxybenzodipyran derivatives. The 3-acetylbenzodipyran derivative when treated with ethyl acetoacetate or ethyl cyanoacetate...

We present a series of efficient near-infrared (NIR) Cr3+-doped non-gallate long-persistence phosphors (Zn2SnO4: Cr and Zn(2-x) Al2xSn(1-x)O4: Cr) and highlight their special optical characteristics of broad emission band (650–1200 nm, peaking at 800 nm) and long afterglow duration (435 h). In the context of materials selection, these systems successfully avoid the existing ubiquitous reliance ...

The electron-donating ability of gallates, which are food and pharmaceutical antioxidants, is quantitatively assessed on the basis of their electrochemical characteristics. Gallic acid and the propyl, i-propyl, butyl, i-butyl, pentyl and i-pentyl gallate derivatives were electrochemically oxidized on the glassy carbon electrode by using differential pulse voltammetry, cyclic voltammetry and hyd...

Treatment of benzanthrone (1) with biphenyl-2-yl lithium leads to the surprisingly stable enol 4, which is converted by dehydrogenation into the benzanthrone derivative 7. Under acidic conditions 4 isomerises to the spiro compound 11 and the bicyclo[4.3.1]decane derivative 12. Furthermore, the formation of 7 and the hydrogenated compound 13 is observed. A mechanism for the formation of the reac...

The synthesis and structural characterization of a new liquid crystalline coordination complex based on pentacoordinated Zn(II) metal centre with the fulfilled by tridentate chelating N^N^N 2,2′;6′,2″-terpyridine ligand two monoanionic gallates decorated several long alkyl chains is described. mesomorphic properties were accurately investigated small- wide-angle X-ray scattering studies. Despit...