After oneand two-colour ps-excitation the transient absorption of rose bengal, erythrosin B and eosin Y in the spectral range from 450 to 670 nm was probed using picosecond continuum pulses generated in H2O—D 2 O mixture. Our experiments showed for all dyes a high T1—Tn absorption signal above 590 nm where no ground state absorption occurs. These excited triplet states can be effectively popula...

The title compound, C(31)H(20)N(2)O(5)·C(2)H(3)N, was synthesized by the reaction of fluorescein hydrazide and excess 2-hydr-oxy-1-naphthaldehyde in acetonitrile. The spirolactam ring is planar and is nearly at right angles to the two benzene rings of the xanthene system. The dihedral angle between the two benzene rings of the xanthene system is 9.92 (4)°. In the crystal structure, the mol-ecul...

We present a computational study on the electrical bistability behavior of four xanthene derivatives based on sodium fluorescein. Intra- and intermolecular charge transfer parameters are computed and employed to rationalize the efficiencies experimentally determined for resistive memory devices based on these organic materials. Charge injection at the electrode/organic interface in the presence...

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...

Erythrosine (ErB) is a xanthene and an US Food and Drug Administration approved dye used in foods, drugs and cosmetics. Although its utilization is permitted, ErB is described as inhibitor of enzymes and protein-protein interactions and is toxic to pituitary and spermatogenesis processes. However, the genotoxicity and mutagenicity of ErB is inconclusive in the literature. This study aimed to an...

The effect of xanthene dyes on the chemiluminescence from the aerobic indole-3-acetic acid (IAA) oxidation, catalyzed by horseradish peroxidase (HRP), was studied. The rate of IAA oxidation and dye destruction were controlled. It was found that the addition of dyes to the IAA/HRP/O2 system resulted in: (i) the appearance of emission in the region of dye fluorescence, (ii) an increase of the tot...

Phthalimide was reacted with chlorosulfonic acid to give sulfonic acid-functionalized phthalimide (SFP), which characterized by 1H NMR, 13C NMR, FT-IR, XRD (X-ray diffraction), SEM (scanning electron microscopy), EDX (energy-dispersive X-ray), mass, TG (thermogravimetry) and DTG (derivative thermal gravimetry) spectra. Afterward, its catalytic activity was examined for the condensation of aryla...

Besides having revealed transitions masked in the bulk, optical spectroscopy of single molecules has enabled the observation of elementary molecular quantum events, such as the absorption and emission of a photon. Single photon transitions are quantified by a cross section that can be regarded as the photon capture area of a molecule. Therefore, absolute optical cross sections can readily be me...