Cation recognition properties of polypyrrole 3-substituted by azacrown ethers

Abstract

The synthesis of new functionalized conducting polypyrroles bearing azacrown ethers at C-3 is described; these show selective cation binding on voltammetric cycling in organic media.The functionalization of polypyrrole has been studied for many years through the covalent bonding of various active groups on the nitrogen atom of the pyrrole nucleus, owing to the easy chemical access to such a modified monomer. Thus, the N-substitution of pyrrole with organometallic complexes derived from porphyrins,l cyclam2 or polypyridine3 has led to polypyrroles with promising modified electrode behaviour .However, it has been also largely observed that poly(Nsubstituted pyrroles) possess extremely low conductivity, of the order of 10-4 S cm-1 or less, indicating an important loss of conjugation, which strongly limits the potential interest of these polymers. On the other hand, it has been clearly shown

Electrochemistry of Poly(3,4‐alkylenedioxythiophene) Derivatives

“…This technique has been applied primarily to polythiophene [133±139] and polypyrrole; [140,141] however, the Bäuerle group has used the corresponding alkylenedioxy [142] derivatives. Polymers 53, 54, and 55 were synthesized electrochemically from their respective mono-, bis-, and terthiophene Swager's group has taken a different approach to metal ion sensing.…”

Calixarenes in electroanalysis

“…Such schemes have been described recently for both poly(pyrro1e-cyclodextrin) [65] and poly(pyrro1e-crown ether) [66] modified electrodes. Both cyclodextrins and crown ethers are similar to calixarenes in terms of binding of molecular and ionic host species.…”

Potentiometric Ion Sensors Based on Conducting Polymers

“…A large amount of research work has also been devoted to covalent binding of recognition sites, like crown ethers [87 ± 98], benzo-crown ether [99], cyclam (tetraazamacrocycle) [100,101], glucose oxidase [102], cyclodextrin [103], aza crown ethers [104,105], calixarenes [106 ± 108], ferrocene crown ether [109], porphyrin [110], oligo(oxyethylene) [111,112], nucleobases [113], oligonucleotides [114], and antibodies [115] to conducting polymers like polypyrrole and polythiophene [116]. However, conducting polymers with covalently bound ion-recognition sites seems to be a rather unexplored research area in terms of potentiometric ion sensors.…”