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.

Synthesis of an Amide‐Linked Diporphyrin Xanthene as a Neutral Carrier for a Lead(II)‐Sensitive Electrode

Abstract: The synthesis of a new compound, amide‐linked diporphyrin xanthene(ADPX), and its application for preparation of lead(II) ion selective electrodes are described. The electrode was prepared with a PVC membrane combining ADPX as a neutral carrier, 2‐nitrophenyl octyl ether (o‐NPOE) as a plasticizer and sodium tetraphenylborate (NaTPB) as an additive in the percentage ratio of 3:3:65:32 (ADPX: NaTPB: o‐NPOE: PVC, w:w). The electrode exhibited linear response with a near Nernstian slope of 28.2 mV per decade within the concentration range of 2.6×10−6 to 1.0×10−1 M lead ions, with a working pH range from 4.5 to 7.5, and a fast response time of less than 30 s. Selectivity coefficients for Pb(II) relative to a number of interfering ions were investigated. The electrode is highly selective for Pb2+ ions over a large number of cations. Several electroactive materials and solvent mediators have been compared and the experimental conditions were optimized. The sensor was applied as indicator electrode in ti...

The solubilities of xanthone and xanthene in supercritical carbon dioxide: Structure effect

Abstract: The equilibrium solubility of the two pesticides – xanthone and xanthene – in supercritical carbon dioxide was determined with a flow-type method. Measurements were performed at pressures ranging from 80 to 300 bar and temperatures from 308.15 to 328.15 K. The results show that xanthene was much more soluble in supercritical carbon dioxide than xanthone with its solubility being over 10-fold higher than that of xanthone due to their different volatility related to their chemical structures. The determined solubility data were well correlated by the Peng–Robinson equation of state and the empirical density-based Chrastil model with the average absolute relative deviation (AARD) less than 11.5% for two solutes investigated.

Silica Supported Perchloric Acid: An Efficient Catalyst for the Synthesis of 14-Aryl-14H-dibenzo(a,i)xanthene-8,13-diones

Abstract: The condensation of β-naphthol with aromatic aldehydes and 2-hydroxynaphthalene-1,4-dione in presence of silica supported perchloric acid under solvent-free media to afford the corresponding 14-aryl-14H-dibenzo[a,i]xanthene-8,13-diones in excellent yields and short reaction times is described. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused several times in subsequent reactions.

An efficient ratiometric fluorescent excimer probe for hypochlorite based on a cofacial xanthene-bridged bispyrene

Abstract: In this paper, by employing a rigid xanthene scaffold as a bridge, we for the first time report a cofacial bispyrene derivative DPH as an efficient ratiometric fluorescent excimer probe for hypochlorite (OCl−). The probe is comprised of a rigid xanthene scaffold and two parallel pyrenes, which are linked by an OCl−-sensitive dicarboxylic acid hydrazide group. The introduction of OCl−, however, will induce oxidation of the dicarboxylic acid hydrazide moiety into a diimide group, and the subsequent hydrolysis of the diimide, to give 1-pyrenecarboxylic acid which exhibits a monomer emission at about 380 nm, with its intensity increasing with the addition of increased concentration of OCl−. Meanwhile, the excimer emission intensity gradually decreases. Such a ratiometric fluorescent response of the probe affords a high sensitivity to OCl−, with a linear response concentration range of 1 to 300 μM, and a detection limit of 0.35 μM for OCl−. It also shows a high selectivity for OCl− with no interference observed from other common anions and small molecules. Moreover, it can also act as a colorimetric probe for OCl− due to the cyan-to-blue fluorescence color change. It has been preliminarily used for practical detection of OCl− in river water samples with satisfying results.