We report a reversible off/on fluorescent probe for monitoring concentration changes of sulfane sulfur by utilizing the unique ability of sulfane sulfur to bind reversibly to other sulfur atoms and the intramolecular spirocyclization reaction of xanthene dyes. It reversibly visualized sulfane sulfur in living A549 cells and primary-cultured hippocampal astrocytes.

The title compound, C(15)H(12)O(3), was obtained unintentionally as the by-product of an attempted recrystallization from methanol of propantheline bromide, an anti-muscarinic drug. The xanthone unit is folded, with a dihedral angle of 24.81 (9)° between the benzene rings. The ester substituent adopts a trans staggered conformation, with a C-C-O-C torsion angle of 178.4 (1)°. The mol-ecules pac...

Wide energy gap materials dispiro[fluorene-9,9?-anthracene-10?,9?-fluorene] (SAS) and dispiro[xanthene-9,9?-anthracene-10?,9?-xanthene] (XAX) containing double spiro–carbons, are introduced as hosts for blue phosphorescent organic light-emitting diodes (PHOLEDs). Both SAS XAX free of heteroatomic exocyclic bonds, which implicated in limiting the stability PHOLEDs. The synthesized gram-scale qua...

In the title compound, C(31)H(25)ClO(3), the central ring of the xanthene core shows a shallow boat conformation, while the outer six-membered rings display envelope conformations. The dihedral angle between the outer aromatic rings is 88.1 (3)° and the dihedral angles between the chloro-benzene ring and the two phenyl rings are 69.5 (2) and 69.6 (2)°.

In the title compound, C(27)H(26)O(4), each of the cyclo-hexenone rings adopts a half-chair conformation. The dihedral angle between the two phenyl rings is 89.53 (5)°. The hy-droxy and carbonyl O atoms face each other and are orientated to allow the formation of two intra-molecular O-H⋯O hydrogen bonds, which are typical of xanthene derivatives.

A xanthene-forming condensation reaction yields rhodol and rhodamine dyes carrying a zinc-binding ligand that includes the aniline-type nitrogen donor of the fluorophores. Upon zinc coordination in neutral aqueous solution, rhodol RF3 behaves as a ratiometric sensor, and rhodamine RA1 acts as a turn-off intensity-based indicator. Both fluorescent compounds bind the divalent zinc cation with mic...

An enhanced fluorescent emission of the dye Rhodamine 800 in the Near-IR is observed in the presence of other xanthene dye molecules (RhX) when they are hosted in different matrices due to the formation of a new type of fluorescent J-heteroaggregates. This enhanced emission of the acceptor occurs despite the low spectral overlapping and the low quantum yield of Rh800.

A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3'-indoline]-pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this pro...