Is meltwater from Alpine glaciers a secondary DDT source for lakes?

A sharp increase in 2005 of pp'DDT and its metabolites was observed in mussels and fish from lakes Como and Iseo, the main glacier-fed southern Alpine lakes. DDTs in zebra mussels (Dreissena polymorpha) were more than 150 times higher than levels in 2003, and concentrations in pelagic fish (0.12 mgkg(-1) w.

Tailoring the properties of boron-dipyrromethene dyes with acetylenic functions at the 2,6,8 and 4-B substitution positions.

Substitution of F-Bodipy with alkynylaryl residues at boron, at the pyrrolic core or at the meso position, provides unique tri-, tetra-, and pentasubstituted dyes. Substitution at the (pyrrolic) 2,6-positions provides substantial red shifts with quantum yields in the 40-90% range and excited-state lifetimes of 3-7 ns. ON/OFF fluorescence switching can be produced by protonation of dibutylamino subunits.

Boron dipyrromethene dyes: a rational avenue for sensing and light emitting devices.

Boron dipyrromethene dyes bearing nitro, amino, isocyanate and isothiocyanate functions were readily prepared under mild conditions. Various combinations allow to produce urea, diurea, thiourea, dithiourea in the 3, 4 and 5-substitution positions of the appended phenyl group. Condensation of the 3,4-substituted diamino derivative with 1,10-phenanthroline-5,6-dione and 6-formyl-2-methylpyridine allow to prepare dipyridophenazine and indole derivatives.

Isocyanate-, isothiocyanate-, urea-, and thiourea-substituted boron dipyrromethene dyes as fluorescent probes.

Boron dipyrromethene dyes (Bodipy) bearing a meso-phenyl substituent carrying a variety of functional groups can be prepared under mild conditions. A single-crystal X-ray structure determination for the 3,5-dinitrophenyl compound shows the phenyl ring to be almost orthogonal (dihedral angle 84 degrees) to the plane of the Bodipy core, with one nitro group almost coplanar with the ring and the other tilted by approximately 21 degrees. Nitro substituents at the 3-, 4-, and 5- positions of the phenyl group are readily reduced to the corresponding amino groups and then converted to isocyanato, isothiocyanato, urea, thiourea, and some polyimine derivatives, the last providing additional functionality (phenazine and pyridylindole units) suitable for chelation of metal ions.

Highly luminescent gels and mesogens based on elaborated borondipyrromethenes.

Supramolecular gels and liquid-crystalline materials containing borondipyrromethene (F-Bodipy) are a new class of highly luminescent materials built by attachment of long-chain alkoxydiacylamido scaffoldings to boradiazaindacene templates. Robust gels were formed in nonane, and luminescence spectroscopy was used to probe the aggregation processes of the flat indacene cores. Coincidently, columnar mesophase was obtained from the pure material over a wide temperature range, allowing textural observations by fluorescence microscopy.