Temperature Induced Optical Changes in Type II Metallopolymer based in Fluorene-Terpyridine Europium Complex

Thermochromic polymers are emerging as an important class of temperature sensors. The luminescent thermometry explores six parameters to analyze the luminescent emission of a given material: intensity, band shape, spectral position polarization, lifetime and bandwidth. In this contribution, the photophysical properties, with special emphasis on thermochromism of a -conjugated polymer-Eu3+ in the solid state, were studied. Absorption/emission spectra and lifetime measurements were carried out to explore the interaction of the europium complex with the polymer. For comparison purposes the same measurements were made with a model compound (representing the complexed sites in the metallopolymer) and with the corresponding conjugated polymer without complexation. The range of temperature studied was of 20 to 400 K. The most striking feature of this system is that the polymer emission, in the metallopolymer, becomes less sensitive to temperature variations. This effect was interpreted as a strong stiffening of the polymer chain that hindered electron-phonon interactions.