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.

New Xanthene Dyes with NIR-II Emission Beyond 1200 nm for Efficient Tumor Angiography and Photothermal Therapy.

Abstract: Fluorescence (FL) bioimaging in the second near-infrared window (NIR-II, 1000-1700 nm) provides improved imaging quality and high resolution for diagnosis of deep-seated tumors. However, integrating FL bioimaging and photothermal therapy (PTT) in a single photoactive molecule exhibits a great challenge because a dramatic increase of PTT in the NIR-II window benefitting from the nonradiative decay will sacrifice the fluorescence brightness that is unfavorable for FL bioimaging. Therefore, balancing the radiative decay and nonradiative decay is an effective and rational design strategy. Herein, four NIR-II xanthene dyes (CL1-CL4) are synthesized with maximal emission beyond 1200 nm under 1064 nm excitation. CL4 exhibits the largest fluorescence quantum yield and a significant fluorescence enhancement after complexation with fetal bovine serum (FBS). As-prepared CL4/FBS has a maximal emission of 1235 nm and a high photothermal conversion efficiency of 36% under 1064 nm excitation. Bright and refined tumor vessels with a fine resolution of 0.23 mm can be clearly distinguished by CL4/FBS. In vivo studies show that a balanced utilization of fluorescence and photothermy in the NIR-II window is successfully achieved with superior biocompatibility. This efficient strategy provides promising avenue for precise theranostics of deep tumors.

Novel organic electroluminescent compound and preparation thereof

Abstract: The invention provides a novel organic electroluminescent compound and a preparation method thereof. The compound is synthesized by connecting heterogeneous functional groups to 2,7 positions of spirofluorene xanthene as a center unit, and has a structure represented by a general formula in the specification; and in the general formula, R1 and R2 are different, and respectively represent a secondary amino group, a pyrryl group, an indolyl group, a carbazyl group, a benzimidazolyl group, or derivative groups of the above groups. The compound is synthesized through a two-step method, the method is simple, the above prepared micro-molecular compound luminescence material has a good dissolvability, and the organic electroluminescent compound emits blue light. The compound can be used in luminescent layers of electroluminescent devices, and is hopeful to be used in hole injection layers, hole transport layers, electron transfer layers and electron injection layers, and can also be hopeful to be used as an organic solar battery and an organic electronic material.

An adapted route to efficient synthesis of 1,8-dioxooctahydro-xanthene derivatives using InCl3 and (HPO3)n as recyclable catalysts

Abstract: © 2015 Growing Science Ltd. All rights reserved.

Synthesis of xanthene and thioxanthene derivatives and study of their antimicrobial activity

Abstract: It has been reported that some of the thioxanthene derivatives are biologically active. For example, 1,4-aminoalkyl amino-9H-thioxanthen-9-ones showed antimicrobial, fungicide, and antitumor activity [1]. We have studied the antimicrobial activity of a series of the secondary aromatic amines, including N-arylmethyl-4(xanthen-9-yl)anilines (Ia Id) and N-arylmethyl-4-(thioxanthen-9-yl)anilines (IIa-IIc) , and a group of structurally related imines, N-arylmethylene-4-(xanthen-9-yl)anilines (IIIa-IIId) and N-arylmethylene-4-(thioxanthen-9-yl)anilines ( IVaIVe). Imines IIIa, IIIc and IVa, IVb can be obtained by dehydrogenation of the corresponding amines by Schiffbases [2, 3].