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.

Two rhodamine derivatives: 9-[2-(ethoxycarbonyl)phenyl]-3,6-bis-(ethylamino)-2,7-dimethylxanthylium chloride monohydrate and 3,6-diamino-9-[2-(methoxycarbonyl)-phenyl]xanthylium chloride trihydrate.

Abstract: The title compounds, C28H31N2O3+·Cl−·H2O (common name rhod­amine-6g), (I), and C21H17N2O3+·Cl−·3H2O (common name rhod­amine-123), (II), both have planar xanthene skeletons with a formal +1 charge on the amino N atoms delocalized through the π-electron system so that the N—Csp2 bond distances indicate significant double-bond character. The substituted planar phenyl groups make angles of 63.29 (8) and 87.96 (11)° with the xanthene planes in (I) and (II), respectively. In both mol­ecules, the carbonyl bond vectors point toward the xanthene rings. The ethyl­amine groups in (I) are oriented similarly with their CH2–CH3 bond vectors pointing nearly perpendicular to the xanthene plane. The chloride ions and water mol­ecules are disordered in both structures. In (I), the chloride ion and water mol­ecule are disordered between two sites. One water and chloride alternately occupy the same site with occupancy factors of 0.5. The other 0.5-chloride and 0.5-water occupy two distinct positions separated by 0.747 (8) A. In (II), the chloride ion is disordered between three sites and one of the waters is disordered about two other sites. Both crystal structures are stabilized by hydrogen bonds involving the chloride ions, amino groups and water mol­ecules, as well as by π–π stacking between xanthene planes.

Intermediates for selectively soluble magenta colorants

Abstract: Novel addition products of isocyanates with oxyalkylene-substituted aminophenol compounds as intermediates for the production of urethane-substituted xanthene colorants, particularly triphenylmethane derivatives such as rhodamines, are provided. The xanthene colorants exhibit improved wax and/or oil solubility and high purity. The urethane-substituted xanthene colorant features very good wax and/or oil solubility, and is believed to be relatively nontoxic. A method for producing this novel colorant is also provided.

Ruthenium anchored on multi-walled carbon nanotubes: an efficient and reusable catalyst for the synthesis of xanthenes

Abstract: A novel and highly efficient ruthenium-based catalyst was synthesized by immobilizing Ru(CO)4 onto functionalized multi-walled carbon nanotubes. The catalyst was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis, diffuse reflectance UV–Vis spectrophotometry, inductively coupled plasma and elemental analysis. This heterogeneous catalyst was successfully applied in the multi-component synthesis of various xanthene derivatives in good to excellent yields (28 samples, up to 96 % yield) under reflux condition and ultrasonic irradiation. The prepared catalyst was recovered four times without appreciable loss of activity.