two simple protocols for the synthesis of tetrahydrobenzo[a]xanthenes-11-ones using nano silica phosphoric acid are reported. short reaction times, high yields, reusability of catalyst and easy workup are some advantages of these protocols.

Foliar fungal endophytes of Pinus strobus (eastern white pine) were collected from different sites across south-eastern New Brunswick, Canada and screened for the production of bioactive metabolites. From one site, two fungal isolates representing a formerly unknown genus and species within the family Massarinaceae (Pleosporales, Dothideomycetes, Ascomycota) were resolved by phylogenetic analys...

The asymmetric unit of the title compound, C(20)H(24)O(6), contains two mol-ecules that are identical within standard deviations concerning bond lengths and angles as well as their conformations. In the crystal structure, weak C-H⋯O inter-actions help to consolidate the packing.

With 3,3'-bi[benzo[b]thiophenyl] as starting material, dibenzo[d,d']benzo[1,2-b:4,3-b']dithiophene, a [5]heterohelicene, was synthesized efficiently in 60% yield via formylation and McMurry reaction. Cyclopenta[1,2-b:4,3-b']bis(benzo[d]thiophen)-6-one, another interesting helical ketone, was also prepared in 79% yield via deprotonation and ketonization of 3,3'-bi[benzo[b]thiophenyl]. In additio...

The carcinogenicity of several groups of carcinogens is evoked with particular reference to Dibenzo(c,g)carbazole derivatives. The activity of these derivatives is discussed with respect to their species and organ specificity. The enzymatic equipment is decisive as to whether the compounds formed can react with DNA or are simply detoxified and eliminated. All these carcinogens are complete carc...

polycyclic aromatic hydrocarbons (pahs) which are toxic pollutants are released by various sources of urban combustion. ahvaz in iran with around a million population and the industrial and oil centers, has encountered air quality problems. samples of dibenzo (a,h) antheracen were collected from six stations in ahvaz particle and gas phase in summer 2010. dibenzo(a,h) antheracen were collected ...

Novel n-type host materials based on tricyclic aromatic compounds, dibenzo[b,d]furan and dibenzo[b,d]thiophene (2Trz6CNDBF 2Trz6CNDBT), have been successfully synthesized characterized for high-performance blue thermally activated delayed fluorescence (TADF) organic light-emitting devices (OLEDs). Dibenzo[b,d]furan were utilized as central molecular building blocks to achieve excellent thermal ...

The 1,4-bis(3-guaiazulenylmethylium)benzene and 1,4-bis[1-(4,6,8-trimethylazulenylmethylium)]benzene dication salts were synthesized via an acid-catalyzed condensation/dehydration protocol with guaiazulene-terephthalaldehyde (2 : 1 ratio), and 4,6,8-trimethylazulene-terephthalaldehyde (2 : 1 ratio) respectively in one-pot processes. A similar condensation reaction with the parent azulene led to...

The differences in the macrocyclic structures lead to different flexibilities, and yet effect of solvents on conformations is not clear so far. In this work, four representational molecules (pillar[5]arene, p-tert-butyl calix[6]arene, benzylic amide macrocycle dibenzo-18-crown-6) three with distinct polarity have been studied by all-atom molecular dynamics simulations. structural features macro...

This is the Final Statement of Reasons for specific regulatory levels posing no significant risk for eight chemicals listed as known to the State to cause cancer under the Safe Drinking Water and Toxic Enforcement Act of 1986 (hereinafter “the Act” or Proposition 65; Health and Safety Code 25249.5 et seq.). On June 13, 2003, the Office of Environmental Health Hazard Assessment (OEHHA) issued a ...