melamine trisulfonic acid (mtsa) is utilized as a highly efficient catalyst for the solvent-free condensation reaction of 2-naphthol (2 eq.) with arylaldehydes (1 eq.) under conventional thermal as well as microwave conditions to give the d

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A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3'-indoline]-pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this pro...

The first fully conjugated bis-cyclopropenone (photo-DIBOD), a derivative of dibenzo[a,e][8]annulene, has been synthesized. 350-420 nm irradiation of this robust compound results in the efficient formation of dibenzo [a,e] cyclooctadiyne, an unstable, but useful SPAAC cross-linking reagent. Since photo-DIBO doesn't react with organic azides, this method allows for the spatiotemporal control of ...

Fluorinated dibenzo[ a , c ]-phenazine-based green to red thermally activated delayed fluorescent OLED emitters are accessible through judicious choice of donor.

 Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (“dioxins”) is a term used to refer to a group of 210 compounds with similar chemical structures  Most of these compounds pose no health hazard at the levels commonly found but 17 of them are of more toxicological concern  The most toxic dioxin is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and most of the available data ...

In a three-component system containing dibenzo-24-crown-8 (1), diamino-dibenzo-24-crown-8 (2), and 1,2-bis(4,4(')-dipyridyl)ethane (3(2+)), axle 3(2+) can shuttle between wheels 1 and 2 by acid-base control, accompanying color changes from yellow to red. This system could not only be taken as a chromophoric supramolecular switch, but also exhibit a function as INHIBIT logic gate.

The title compound, C(30)H(26)O(4), is a dimer of 6,6'-dimethyl-dibenzo[d,f][1,3]dioxepine linked by formation of a C-C bond in the para position with respect to one O atom. The dimer is arranged around an inversion centre. As is usually observed in related compounds, the dibenzo group is twisted, the two benzene rings making a dihedral angle of 41.56 (9)°. The seven-membered ring exhibits a tw...

The title compound, C(33)H(34)N(4)O(2)S·CH(3)OH, was prepared as a spiro-lactam ring formation of rhodamine 6 G dye for comparison with a ring-opened form. The xanthene and spiro-lactam rings are approximately planar [r.m.s. deviations from planarity = 0.122 (3) and 0.072 (6) Å, respectively]. The dihedral angles formed by the spiro-lactam and thio-phene rings with the xanthene ring system are ...

In the title compound, C25H29FO4, each cyclo-hexenone ring has an envelope conformation with the dimethyl-substituted atom as the flap. The hy-droxy and carbonyl groups form two intra-molecular O-H⋯O hydrogen bonds, as is typical for xanthene derivatives. In the crystal, very weak C-H⋯O hydrogen bonds link mol-ecules into dimers.