The β-lactam (azetidin-2-one) ring of the title compound, C28H27N3O5, is nearly planar [maximum deviation = 0.010 (1) Å] and makes dihedral angles of 75.77 (5), 52.78 (9) and 88.72 (5)°, respectively, with the benzene ring, the least-squares plane formed by the four C atoms of the morpholine ring, which adopts a chair conformation, and the xanthene ring system. In the crystal, C-H⋯O hydrogen-bo...

In the xanthene ring system of the title compound, C(23)H(25)BrO(4), the 4H-pyran ring is almost planar [maximum deviation = 0.040 (3) Å] and the cyclo-hexene ring adopts a sofa conformation. The cyclo-hexene ring attached to the xanthene system is puckered [Q(T) = 0.427 (3) Å, θ = 55.0 (4) ° and ϕ = 164.4 (6) °]. In the crystal, mol-ecules are linked to each other by O-H⋯O and C-H⋯O hydrogen b...

In the title compound, C(23)H(26)O(3), the three six-membered rings of the xanthene system are non-planar, having total puckering amplitudes, Q(T), of 0.443 (2), 0.202 (2) and 0.449 (2) Å. The central ring adopts a boat conformation and the outer rings adopt sofa conformations. The crystal structure is stabilized by van der Waals inter-actions.

An efficient and greener protocol for the synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one using tetradecyltrimethylammonium bromide (TTAB) at room temperature in water is described.

This minireview describes the syntheses, structure-photophysical properties relationship, and bioimaging applications of fluorescent coumarins, xanthenes, BODIPYs, cyanines. Advantages disadvantages emissive units are also discussed, as general practical issues that need to be considered when using fluorophores in a biological setting.

Polyhalogenated dibenzo-p-dioxins are arguably among the most toxic molecules known to man. In addition to anthropogenic sources, marine invertebrates also harbor polybrominated dibenzo-p-dioxins of as yet unknown biogenic origin. Here, we report that the bmp gene locus in marine bacteria, a recently characterized source of polybrominated diphenyl ethers, can also synthesize dibenzo-p-dioxins b...

Several photosensitizing agents, which are activated by illumination with sunlight or artificial light sources, have been shown to be accumulated in significant amounts by a variety of insects when they are administered in association with suitable baits. The subsequent exposure of such insects to UV/visible light leads to a significant drop in survival. Of the photosensitizers tested so far, x...

The ability of the dibenzofuran- and dibenzo-p-dioxin-mineralizing bacterium Sphingomonas sp. strain RW1 (R.-M. Wittich, H. Wilkes, V. Sinnwell, W. Francke, and P. Fortnagel, Appl. Environ. Microbiol. 58:1005-1010, 1992) to oxidize chlorinated derivatives of dibenzofuran and dibenzo-p-dioxin was analyzed. Strain RW1 degraded several mono- and dichlorinated dibenzofurans and dibenzo-p-dioxins, b...