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: A novel aromatic tetraamine, 2',7'-bis(3,4-diaminophenoxy)-spiro(fluorene-9,9'- xanthene), was synthesized, which was employed to react with various commercial available aromatic dianhydrides to yield a series of polypyrrolones (PPys) as discussed by the authors.
Abstract: A novel aromatic tetraamine, 2',7'-bis(3,4-diaminophenoxy)-spiro(fluorene-9,9'- xanthene), was synthesized, which was employed to react with various commercial available aromatic dianhydrides to yield a series of polypyrrolones (PPys). The intermediate poly(amide amino acid) had inherent viscosities of 0.28-0.35 g/dl and could be thermally converted into lightly yellow PPys films. All the resulting PPys exhibited good thermal stabilities. The glass-transition temperatures were in the range of 371-386 degrees C, and the temperatures of 5 and 10% weight loss were 472-549 degrees C and 552-612 degrees C in nitrogen, respectively; the residual weight was above 62% at 800 degrees C. In addition, the PPys films had tensile strengths in the range of 42.3-85.8 MPa, tensile moduli of 1.8-2.5 GPa, and elongations at break of 6.8-7.4%. The polymer films also exhibited excellent alkaline hydrolysis resistance, retaining their original shapes and toughness after boiling for 7 days in 10% sodium hydroxide solution.
2 citations
TL;DR: The crystal structure of o-sulfophenylfluorone (SPF) was determined by X-ray diffraction as mentioned in this paper, and the final R value is 0.046 for 5242 reflections (I > 2σ(I)).
Abstract: The crystal structure of o-sulfophenylfluorone (SPF) was determined by X-ray diffraction. This compound crystallizes in monoclinic, space P21/c with a = 10.5722(6), b = 15.6153(9), c = 17.216(1)A, β = 91.420(1)°, V = 2841.2(3)A3, Z = 4. The final R value is 0.046 for 5242 reflections (I > 2σ(I)). The structure takes a dihedral formation consisting of xanthene and benzene sulfonic rings and tautomers exist with a zwitterionic character.
2 citations
TL;DR: In this article, the design, synthesis and photophysical characterization of a fluorogenic derivatization reagent with exclusive selectivity for primary amines is described. But the derivatized amine is not chromogenic.
2 citations
TL;DR: In this article , a new class of anion exchange membranes (AEMs) with trimethylammonium, methylpiperidinium, and quinuclideinium cations was synthesized and studied.
Abstract: Poly(xanthene)s (PXs) carrying trimethylammonium, methylpiperidinium, and quinuclidinium cations were synthesized and studied as a new class of anion exchange membranes (AEMs). The polymers were prepared in a superacid-mediated polyhydroxyalkylation involving 4,4′-biphenol and 1-bromo-3-(trifluoroacetylphenyl)-propane, followed by quaternization reactions with the corresponding amines. The architecture with a rigid PX backbone decorated with cations via flexible alkyl spacer chains resulted in AEMs with high ionic conductivity, thermal stability and alkali-resistance. For example, hydroxide conductivities up to 129 mS cm–1 were reached at 80 °C, and all the AEMs showed excellent alkaline stability with less than 4% ionic loss after treatment in 2 M aq. NaOH at 90 °C during 720 h. Critically, the diaryl ether links of the PX backbone remained intact after the harsh alkaline treatment, as evidenced by both 1H NMR spectroscopy and thermogravimetry. Our combined findings suggest that PX AEMs are viable materials for application in alkaline fuel cells and electrolyzers.
2 citations
TL;DR: In this article, the potential of surface enhanced Raman spectroscopy (SERS) for the detection of water-soluble fullerene derivatives and their covalent conjugates with xanthene dyes was investigated in model biological liposome membranes and in the albumin protein structure.
Abstract: The potential of surface enhanced Raman spectroscopy (SERS) for the detection of water-soluble fullerene derivatives and their covalent conjugates with xanthene dyes was investigated in model biological liposome membranes and in the albumin protein structure. It was shown that in liposomes and in albumin, fullerene derivatives and their covalent conjugates with dyes show characteristic SERS spectra, which allows detection of water-soluble fullerene derivatives in phosphatidylcholine liposomes at the lipid/fullerene derivative ratio of 100 as well as fullerene–dye conjugates in liposomes and albumin.
2 citations