Synthesis and Characterization of Novel Polythiophenes Containing Pyrene Chromophores: Thermal, Optical and Electrochemical Properties.

A novel series of pyrene containing thiophene monomers TPM1-5 were synthesized and fully characterized by FTIR, MS, ¹H- and (13)C-NMR spectroscopy; their thermal properties were determined by TGA and DSC. These monomers were chemically polymerized using FeCl3 as oxidizing agent to give the corresponding oligomers TPO1-5) and they were electrochemically polymerized to obtain the corresponding polymer films deposited onto ITO. All oligomers exhibited good thermal stability, with T10 values between 255 and 299 °C, and Tg values varying from 36 to 39 °C. The monomers showed an absorption band at 345 nm due to the S0 → S2 transition of the pyrene group, whereas the fluorescence spectra showed a broad emission band arising from the "monomer" emission at 375-420 nm. The obtained polymers exhibited two absorption bands at 244 and 354 nm, due to the polythiophene and the pyrene moieties, respectively. The fluorescence spectra of polymers showed a broad "monomer" emission at 380-420 nm followed by an intense excimer emission band at 570 nm, due to the presence of intramolecular pyrene-pyrene interactions in these compounds.

Synthesis of porphyrin-dendrimers with a pyrene in the periphery and their cubic nonlinear optical properties.

Dendrons of pyrene derivatives were attached to a porphyrin core. A marked effect in solution for the dendrimers was observed in the absorption spectra. All the compounds obtained were characterized by (1)H-, (13)C-NMR, FTIR, UV-vis, MALDI-TOF or FAB+ mass spectrometry and elemental analysis. The cubic nonlinear optical behavior of some the synthesized compounds was tested via Z-Scan measurements in spin-coated film samples.

Dendrimers containing ferrocene and porphyrin moieties: synthesis and cubic non-linear optical behavior.

Dendrons with ferrocenyl ended groups joined by styryl moieties were attached to a porphyrin core. All the dendrons used for dendrimer synthesis showed trans configuration. The chemical structure of the first generation dendron was confirmed by X-ray crystallographic studies. The structure of the synthesized dendrimers was confirmed by 1H- and 13C-NMR, electrospray mass spectrometry and elemental analysis. Cubic non-linear optical behavior of the ferrocene and porphyrin-containing dendrimers was studied in solid thin films by THG Maker-Fringe technique at 1,260 nm.

Crystal structure of 1-meth-oxy-pyrene.

The title compound, C17H12O, crystallized with three independent mol-ecules (A, B and C) in the asymmetric unit. In the crystal, the three independent mol-ecules are linked by π-π inter-actions [centroid-centroid distances = 3.551 (3)-3.977 (2) Å], which lead to the formation of trimers. Between the trimers there are a number of C-H⋯π inter-actions generating a laminar arrangement parallel to (010). The meth-oxy-methyl group in mol-ecule A is disordered over two sets of sites, with an occupancy ratio of 0.56 (9):0.44 (9).