C. Loewe, C. Weder
Jun 28, 2002
Citations
0
Influential Citations
31
Citations
Journal
ChemInform
Abstract
1,4-Bis-(α-cyano-4-methoxystyryl)benzene (1a) and 1,4-bis-(α-cyano-4-methoxystyryl)-2,5-dimethoxybenzene (1b) were synthesized by the Knoevenagel reaction of (4-methoxyphenyl)acetonitrile with terephthaldicarboxyaldehyde and 2,5-dimethoxy terephthaldicarhoxyaldehyde, respectively. Both phenylene vinylene oligomers are highly photoluminescent, and the comparison of the emission spectra of the crystalline solids with the ones of the corresponding low-viscosity molecular solutions reveals, particularly in case of 1b, an extremely large bathochromic shift. This effect is consistent with the formation of excimers that are characterized by low-bandgap emission With the objective to control the emission characteristics of these dyes beyond the limiting states of molecular solution and crystalline solid, the investigation of their photophysical characteristics was extended to the liquid crystalline state and the isotropic melt, as well as to blends with isotactic polypropylene.