A. De Mico

DODCI molecules incorporated in sol-gel glasses: The interaction with the silica matrix

Abstract The optical properties of the dye DODCI (3,3′-diethyloxadicarbocyanine iodide) incorporated in sol–gel silica-glass matrices have been investigated with regard to interaction with the surrounding silica cage. The absorption and emission spectra have been measured in silica-glass samples with different pore sizes and compared with the spectra obtained in liquid solutions that simulate different environments for the dye molecule. Measurements of a DODCI-derivative molecular structure have been performed by NMR spectroscopy in dimethyl sulfoxide. The results suggest that new electronic states are produced in the trapped molecule, for glass-pore sizes in the range of 2.5–3.5 nm, as a result of the attack of Si–O − groups on the conjugate chain and the protonation to the dicationic form.

A facile route to 5-alkyl-2(3H)-furanones by photoisomerisation of enedicarbonyl compounds

Abstract A new and useful synthesis of a title compounds is reported. They can be obtained easily by photocyclization of enedicarbonyl compounds 3 and 4. A different behaviour, ascribed to the geometry of a double bond, is observed; 3 are converted only to butenolides 5, while trans-isomers 4 are converted into alkyl-furyl-ketones 5 and 6. A possible mechanism is described.