Pyridinium Complexes Supported on a Polymeric Biomaterial: Synthesis of NLO-Phores at Molecular Level

Pyridinium salts are very useful synthetic building blocks to obtain substituted pyridines, dihydropyridines or piperidines. Furthermore, pyridinium dyes present a multiple application fields including biological and optical responses due to their photophysical features, in particular, high fluorescence, charge transfer character and solvatochromic properties. Different methods are available for the synthesis of pyridinium salts depending on the symmetry around of the cation. One of them involves the use of pyrylium salts as precursor. Linear and non-linear optical behaviour are controlled by different parameters both macro- and microscopically level. At molecular level is necessary to know parameters such as dipole moment, polarizatility, first-order hyperpolarizability, among others.   Herein we report, a novel easy synthesis and characterization of new anchored pyridinium moiety into a polymeric backbone. Moreover, DFT calculations have been performed on suitable model to explore molecular parameters involved in lineal and non-lineal optical properties. We thank the AECID (Projects A/023577/09 and A/030422/10) and the 'Junta de Andalucía' (FQM 142 and Project P09-AGR-4597) for financial support.