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.

Zirconium dodecylphosphonate promoted synthesis of xanthene derivatives by condensation reaction of aldehydes and β-naphthol or dimedone in green media

Abstract: A green and safe method for the synthesis of variety of xanthene derivatives by condensation reaction between aldehydes and β-naphthol or dimedone in an alcoholic solution is described. Cheap and environmentally benign reaction media, simple work-up, mild reaction conditions, recovery of catalyst, and excellent yields are the main advantages of this procedure. On the other hand, the acyclic producing intermediates are important ligands for the synthesis of organometallic compounds.

Effects of Electrostatic and π—π Interactions on the Stabilities of Xanthene Dye—4,4′-Bipyridinium Complexes: Structural Design of a Geared Supramolecular Machine

Abstract: Xanthene dyes and substituted 4,4′-bipyridinium salts form well defined 1:1 complexes in solution and in the crystalline state. Electrostatic, charge-transfer, and π-π interactions are the driving forces for the formation of these complexes. Electrostatic interactions contribute 1.1–1.3 kcal/mol per ion pair, and interring interactions, i.e., charge transfer and π-π interactions, contribute 6.2–6.3 kcal mol−1 to the complexes' stabilization. Application of a bis-bipyridinium host results in enhanced binding of eosin Y, 1, due to increased π-π and donor-acceptor interactions and complementary electrostatic attractions. The binding properties of the bipyridinium moiety to eosin Y is controlled by its functionalization with a photochromic azobenzene unit. The association constants of 8-trans and 8-cis to eosin Y, 1, are 3000 M−1 and 38000 M−1, respectively. This difference in the association constants of the diad isomers to 1 allows the photo-controlled reversibly-geared association and dissociation of the diad to and from eosin Y in the supramolecular assembly.

Studies on the toxicity of coal-tar dyes II. Examination of the biological reaction of coal-tar dyes to vital body.

Abstract: The toxicity of xanthene dyes were studied by various interaction between the dyes and the components in vital body. (1) An increase in the amount of Rose Bengale adsorbed on the gill of fish was followed by the increase in red corpuscle number, and it was assumed that the death of fish in xanthene dye solution was due to anoxemia. (2) Binding capacity of xanthene dyes with bovine serum albumin decreased in the following ; Rose Bengale, Phloxine, Erythrosine, Eosine and Uranine. This order was quite coincident with the toxicity compared by TLm values. (3) From the results of recassay test by use of Bacillus subtilis, it was confirmed that Phloxine and Rose Bengale had DNA-damaging capacity related to the mutagenecity.