The photophysics of two dyes from the xanthene family, eosin B (EB), and eosin Y (EY) has been investigated in various solvents by femtosecond transient absorption spectroscopy, first, to clarify the huge disparity of the EB fluorescence lifetimes reported in literature, and, second, to understand the mechanism responsible for the ultrafast excited-state deactivation of EB in water. The excited...

We baked low-calorie bread by mixing charred cellulose granules with wheat flour, using the charred cellulose granules to eliminate toxic xanthene food dyes contained in processed foods from the alimentary canal. The size of the charred cellulose granules played an important role in determining good breadmaking properties in respect of the bread height (mm) and specific volume (SV, cm3/g). Char...

The title compound, C(28)H(30)N(2)OS(2), was obtained by thio-nation of 3',6'-bis-(diethyl-amino)-3H-spiro-[isobenzofuran-1,9'-xan-thene]-3-one with 2,4-bis-(p-methoxy-phen-yl)-1,3-dithia-diphos-phetane disulfide (Lawesson's reagent). The planes of the two benzene rings of the xanthene system are inclined at a dihedral angle of 17.4 (1)°, and the plane of the dithio-phthalide group and the plan...

A readily accessible new class of near infrared (NIR) molecular probes has been synthesized and evaluated. Specific fluorophores in this unique xanthene based regioisomeric seminaphthofluorone dye series exhibit a combination of desirable characteristics including (i) low molecular weight (339 amu), (ii) aqueous solubility, and (iii) dual excitation and emission from their fluorescent neutral a...

In the title compound, C(39)H(25)NO(2)·0.5C(6)H(14), the β-lactam ring is nearly planar [maximum deviation of 0.012 (2) Å from the mean plane] and makes dihedral angles of 36.41 (13), 88.87 (13) and 54.16 (12)°, respectively, with the naphthalene, xanthene and anthracene ring systems. The mol-ecular conformation is stabilized by intra-molecular C-H⋯O and C-H⋯N contacts. The complete solvent mol...

This paper assesses the magnitude of change in the dipole potential (φd) of membranes caused by the adsorption of modifiers on lipid bilayers of various compositions. We tested flavonoids, muscle relaxants, thyroid hormones, and xanthene and styrylpyridinium dyes in order to assess their dipole-modifying properties. A quantitative description of the modifying action of flavonoids, muscle relaxa...

In the title compound, C(20)H(22)O(5), the tetra-hydro-pyran, cyclo-hexene and cyclo-hexane rings of the xanthene ring system adopt half-chair, half-boat and chair conformations, respectively. The mean plane of the four roughly planar atoms of the tetra-hydro-pyran ring (r.m.s. deviation = 0.111 Å) forms a dihedral angle of 82.91 (4)° with the meth-oxy-benzene group. In the crystal, mol-ecules ...

An environmentally friendly, facile and solvent-free synthetic route for aluminum sulfate octadecahydrate (Al2(SO4)3.18H2O) catalyzed one-pot multi-component synthesis of 12-aryltetrahydrobenzo[α]xanthene-11-ones, 1,8-dioxo-octahydroxanthenes and 14-aryl-14Hdibenzo[α,j]xanthenes has been developed. The readily, easy to handle, non-toxic, environmental friendly and low-cost catalyst, easily sepa...

Over the past two decades, polyoxometalates (POM) have received considerable attention as solid catalysts, due to their unique physicochemical characteristics, since, first, they very strong Bronsted acidity, approaching region of a superacid, and second, are efficient oxidizers that exhibit rapid redox transformations under fairly mild conditions. Their structural mobility is also highlighted,...