Topic
Xanthene
About: Xanthene is a research topic. Over the lifetime, 2132 publications have been published within this topic receiving 34803 citations. The topic is also known as: Xanthene & dibenzo[a,e]pyran.
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TL;DR: In this paper, Fe(HSO4)3 has been used as an efficient and recyclable catalyst for the one-pot synthesis of 14-aryl-or alkyl-14H-dibenzo[a, j] xanthene derivatives by the reaction of 2-naphtol and aldehydes.
25 citations
TL;DR: A novel cooperatively catalyzed C(sp3)–C(sp2) bond C–H activation cross-coupling reaction has been developed and a series of 9-aryl-9H-xanthenes were selectively synthesized in moderate to good yields by controlling the reaction time and temperature.
Abstract: A novel cooperatively catalyzed C(sp3)–C(sp2) bond C–H activation cross-coupling reaction has been developed. A series of 9-aryl-9H-xanthenes and 9,9-diaryl-xanthenes were selectively synthesized in moderate to good yields by controlling the reaction time and temperature.
25 citations
TL;DR: In this article, a new transformation of bisphenol A to polymethylated 9,9-dimethylxanthenes 2−5 in the presence of an exogenous phenol is described.
Abstract: A new transformation of bisphenol A (1) to polymethylated 9,9-dimethylxanthenes 2−5 in the presence of an exogenous phenol is described. The reaction proceeds with concurrent liberation of phenol, is catalyzed by strong acid, and takes place at synthetically useful rates at temperatures above 100 °C. Materials chemically related to bisphenol A, polycarbonate 10, chroman 11, and tars generated during the manufacture of 1, behave similarly. The product xanthenes are useful as precursors to novel xanthene polyesters such as 33 having high glass transition temperatures relative to analogous materials based on 12 or 13. Catalytic oxidation of xanthenes 2−4 affords highly insoluble diacids that are esterified to the esters 6−8. A mechanistic framework accounting for the appearance of chroman 23 and spiroketal 24 as intermediates is given. Overall, the reaction has the characteristics of a complex series of equilibria in which xanthenes such as 2 are strongly favored.
25 citations
25 citations
TL;DR: In this article, the surface interactions between xanthene (XN) dyes, including rhodamine B, Rhodamine 3B, rhodamines 3B and Rhodamines B, were investigated on the WO3 colloid surface.
Abstract: The surface interactions between xanthene (XN) dyes, including rhodamine B, rhodamine 3B, rhodamine 19, rhodamine 6G, rhodamine 110, and rhodamine 123, and tungsten(VI) oxide (WO3) colloid particles were investigated. These XN dyes were strongly adsorbed as a monolayer onto the WO3 surface via the electrostatic interaction between their peripheral cationic amino substituents and negatively surface-charged WO3 colloid particles, and most of the ones adsorbed eventually formed stable π-stacked dimers. The geometry of dimers formed on the WO3 colloid surface is discussed on the basis of the molecular exciton theory framework. Cationic XN dyes formed the approximately ideal face-to-face H-dimers on the WO3 colloid surface, whereas zwitterionic ones had a higher tendency to form the oblique J-dimers. Additionally, we have experimentally demonstrated the possibility of pH-induced switching between H- and J-aggregation modes of the XN dye’s dimers formed on the WO3 colloid surface. The findings lead to a better ...
25 citations