Photodegradation of Environmental Mutagens by Visible Irradiation in the Presence of Xanthene Dyes as Photosensitizers

Basic Investigations of Singlet Oxygen Detection Systems with ESR for the Measurement of Singlet Oxygen Quenching Activities

“…Nakamura et al reported a similar ESR spectrum derived from TEMP-OH in rose bengal solution after irradiation of laser light at 532 nm for 60 s. 12) The irradiation of xanthine dyes such as rose bengal generates both 1 O 2 and superoxide anion radicals by energy transfer and electron transfer processes. 16) In addition, generation of hydrogen peroxide by the irradiation of visible light to rose bengal, and generation of hydroxyl radical by the irradiation of laser light have been reported. 12,17) Next, we examined the possibility of generation of ROS other than 1 O 2 as the cause of the signal split observed from the reaction of TEMP-OH under photo-activation of rose bengal.…”

Efficient one-pot synthesis of 14-aryl-14H-dibenzo[a,j]xanthene derivatives promoted by niobium pentachloride

“…These compounds have also been employed as sensitisers in photodynamic therapy (Neckers, 1989;Gutiérrez & García, 1998;Chang et al, 2008), in the food industry as additives (Tanaka, 2001;Chequer et al, 2012;Odo et al, 2012;Qi et al, 2012), in laser technologies (Ahmad et al, 2002;De et al, 2005) and as fluorescent materials for the visualisation of biomolecules (Knight & Stephens, 1989;Liu et al, 2001;Hilderbrand & Weissleder, 2007). In addition, xanthenes and their derivatives can be used as sensitisers in dye-sensitised solar cells (DSSCs) (Hara et al, 2000;Pradhan et al, 2007;Guillén et al, 2008;Sharma et al, 2009) and as hole-transporting materials in organic light-emitting devices (OLEDs) (Chu et al, 2012).…”

Nano-Fe3O4 Encapsulated-Silica Particles Bearing Sulfonic Acid Groups as a Magnetically Separable Catalyst for Highly Efficient Knoevenagel Condensation and Michael Addition Reactions of Aromatic Aldehydes with 1,3-Cyclic Diketones

“…Classically, tetraketones and their enol forms have been synthesized through a combination of the Knoevenagel condensation and Michael addition reactions of aldehydes with 1,3-cyclic diketones. These compounds are themselves key intermediates in the preparation of a variety of different heterocyclic compounds, including acridine diones [13] and xanthenes, which have been used as dyes, fluorescent materials for the visualization of bio-molecules, and in laser technologies on account of their useful spectroscopic properties [14,15]. Recently, we reported the catalyst-free synthesis of tetraketones under mild conditions in PEG-400 [16].…”