Application of room temperature ionic liquids for in situ ATR-FTIR spectroscopy of doped poly(para-phenylene) By Michal Wagner NGS-Nano meeting, Lammi Supervisors: Dr. Carita Kvarnström Prof. Ari Ivaska Laboratory of Analytical Chemistry, Piispankatu Turku

Presentation plan:  Introduction to conducting polymers and ionic liquids  Electrochemical reactions  Experimantal techniques  Results  Conclusions

Conducting Polymers What is conducting polymer?  The conducting polymers are materials with intrinsic conduction which is denoted to structural properties  Delocalization of π-electrons and overlapping makes these polymers conductive (usually doping is needed) polyanilinepolypyrrole polythiophenes

Ionic Liquids What is an ionic liquid?  A new class of solvents which are in liquid state at room temperature  Consists of only ionic parts  Large number of ILs are composed of organic cations and inorganic anions 1-butyl-3-methylimidazoliumhexafluorophosphate 1-butyl-1-methylpyrrolidiumbis(trifluoromethylsulfonyl)imide Properties  Low vapor pressure  High conductivity  Wide electrochemical window  Designable- unlimited combinations  Low combustibility  Good thermal stability  Wide liquid range

Electrochemical polymerization and doping of PPP Poly(para-phenylene) (PPP) Biphenyl Radical-radical coupling Anodic oxidation - 2e Doping Polaron Bipolaron

Cyclic voltammetry (CV)  Determines the kinetics of electrode processes  Current is monitored as the potential of the electrode is changed

In situ ATR-FTIR

Electropolymerization in ILs and ACN

Electrochemical doping in ILs and ACN

In situ ATR-FTIR spectroscopy of p-doped [BMIM][PF 6 ]

In situ ATR-FTIR spectroscopy of p-doped [BMP][Tf 2 N]

In situ ATR-FTIR spectroscopy of n-doped [BMIM][PF 6 ]

In situ ATR-FTIR spectroscopy of n-doped [BMP][Tf 2 N]

Conclusions  The best electrochemical polymerization performance was achieved in [BMIM][PF 6 ] ionic liquid  During both p- and n-doping the achieved spectra indicated formation of IRAV bands in the wavenumber region cm -1  It was found that n-doping is preferable in [BMP][Tf 2 N] and p-doping in [BMIM][PF 6 ]  Obtained results suggest that ionic liquids are able to become a new promising group of solvents in electrochemistry research area

Thanks for your kind attention!