Novel Fluorescent Probe Based on Anthryl Dendron Having Oligo(ethyleneoxide) Groups at the Terminals

Amphiphilic anthryl dendrons 5 and 6, which have carboxylate groups or oligo(ethyleneoxide) groups at the terminals, show solvatochromic properties. Reaction efficiency of photodimerization and dynamic light scattering (DLS) experiment of 5 and 6 reveal that formation of the aggregate of dendrons 5 or 6 plays a crucial role in this solvatochromism. Interestingly, solvatochromic property of anthryl dendron 6 was useful for determination of the ratio of methanol/water in solution as a fluorescent probe

1,3-Dibromo-5,5-dimethylhydantoin, a useful reagent for ortho-monobromination of phenols and polyphenols

Ortho-monobromination of phenols and polyphenols by 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) is described. A simple addition of commercially available DBDMH to phenols and polyphenols in chloroform at room temperature resulted in a good to excellent yield of corresponding ortho-monobromo derivatives

Synthesis of ellagic acid and its 4,4'-di-Ο-alky derivatives from gallic acid

Synthesis of ellagic acid and its 4,4'-di-Ο-alkyl derivatives from gallic acid is described. Ellagic acid is prepared by oxidative coupling of gallic acid with ο-chloranil. Functionalized methyl bormogallate underwent Ullmann coupling to give the biphenyl that upon lactonization resulted in the ellagic acid and its alkoxy derivatives

Formation of Zwitterionic Fullerodendron Using a New DBN-Focal Dendron

A new poly(amidoamine) dendron having 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) at the focal point was synthesized. Interestingly, formation of zwitterionic fullerodendrons (λmax = 930 nm for C60 and 795 nm for C70) were observed by Vis-NIR spectroscopy upon the reaction of C60 or C70 with the DBN-focal dendron. In particular, the C70 anion was effectively stabilized by the site isolation effect of the dendritic wedge. The half-life of fullerodendron 12b having C70 anion at the focal point reaches 7,345 min, which is 20 times longer than that of complex between C60 and pristine DBN. Furthermore, in order to confirm the structure of the zwitterionic complex, fullerodendron 12a was reprecipitated from benzonitrile/1,2,4-trimethylbenzene, and was observed using IR spectroscopy and APPI-MS