Polyterthiophenes Cross‐Linked with Terpyridyl Metal Complexes for Molecular Architecture of Optically and Electrochemically Tunable Materials

Abstract

In memory of Professor Jingdong Zhang Novel conductive polymer-based metal complexes were electrochemically synthesized and characterized in relation to (spectro)electrochemical stimuli. Particularly, we focused our attention on terthiophenes functionalized with terpyridine groups, along with Fe 2 + cations present during electrochemical synthesis. The resultant electroactive films are coherent, robust, and exhibit mixed absorption profiles upon electrochemical doping, characteristic for both polyterthiophenes and metalligand transitions. At certain oxidation potentials, the formation of radical cation and also dication states were observed. The latter, influence the optical transitions related to metal centers, and can reversibly be everted by switching to lower potentials. Furthermore, the polymer "cross-linking metal" can be removed from the structure, which we obtained by partial exchange of Fe 2 + with Cu 2 + and Zn 2 + cations. The conducted cation exchange studies however elucidate the complexity and difficulty of such an approach. With future electropolymerization "strategies" we are expecting to extend film stability during application of relatively high potentials, as well as in the interim of cation exchange.

Resonance Raman Excitation Profiles of Fe(II)–Terpyridine Complexes: Electronic Effects of Ligand Modifications

“…All spectra show vibration bands characteristic for Fe(II) coordinated terpyridine. 9,50,55,65 All spectra show a shift in the breathing mode of pyridine units above 1000 cm −1 in comparison with free ligands. Overtones and combination bands are observable only at 445 and 532 nm excitations.…”