Spectroscopic study of polytoluidines in the UV‐visible and IR regions

Abstract

SYNOPSISElectropolymerization of o-toluidine ( o-methylaniline ) and m-toluidine was carried out in acidic aqueous solution, and UV-visible and IR spectra of the resulting polymer films were obtained at various electric potentials and pHs. In Na2S04 aqueous solution, poly (o-toluidine ) gave considerably different UV-visible spectra from polyaniline, whereas, in HCl (pH -0 ) , the spectra of poly( o-toluidine) changed in the same way as polyaniline when the potential was varied. This spectral change depended also on counterion. This suggests that the intermediate state (radical cation) of poly (0-toluidine) is unstable in a neutral solution especially when a large counter ion exists, which is contrast to polyaniline. The dependency of the FT-IR spectra of poly( o-toluidine) on the potential and pH supported also the above result of UV-visible spectra. From both UV-visible and IR spectra under various conditions, it was found that o-toluidine and m-toluidine give the same polymer.

An efficient route towards the covalent functionalization of single walled carbon nanotubes

“…However, the voltammetric response in presence of HCl shows a reversible redox behavior at 0.727 V, indicating doping of HCl (shown in Fig. 8) to form a dynamic layer of polyaniline, which is in agreement with that present in literature [34,35]. The cathodic peak corresponding to the nanotubes has been shifted towards negative direction by 90 mV and it fluctuates with several cycling, perhaps due to the formation of a thin polymer layer with subsequent covering of nanotubes.…”

Comparative studies of solid‐state synthesized poly(o‐methoxyaniline) and poly (o‐toluidine)

“…Similar CVs have been observed with electrochemically and chemically synthesized POT. 35 It is evident that the potentials of the second redox peaks of POMA and POT salts are less positive than the one obtained for PANI. This actually suggests that the electronic effect of the methoxy and methyl substituent hinders the second electron transfer and shifts it to more negative potentials.…”

Towards enhanced electrochemical capacitance with self‐assembled synthesis of poly(pyrrole‐co‐o‐toluidine) nanoparticles

“…The band at 1372 cm −1 is due to the symmetric deformation of methyl group . The peaks at around 1317 and 1213 cm −1 can be assigned to the CN stretching mode, whereas the peaks at 1155, 1113, and 1007 cm −1 are the characteristic bands of CH vibration . The three bands centered at 940, 882, and 813 cm −1 can be characterized to an in‐plane CH vibration of quinoid rings, 1,2,4‐substitution in the benzenoid rings, and an out‐of‐plane CH vibration .…”

“…The peaks at around 1317 and 1213 cm −1 can be assigned to the CN stretching mode, whereas the peaks at 1155, 1113, and 1007 cm −1 are the characteristic bands of CH vibration . The three bands centered at 940, 882, and 813 cm −1 can be characterized to an in‐plane CH vibration of quinoid rings, 1,2,4‐substitution in the benzenoid rings, and an out‐of‐plane CH vibration . As for the PPY [spectrum C in Figure (a)], the two peaks at 1543 and 1453 cm −1 can be attributed to the asymmetric and symmetric stretching vibrations of PY rings, respectively .…”

“…25,27,28 The three bands centered at 940, 882, and 813 cm 21 can be characterized to an in-plane CAH vibration of quinoid rings, 1,2,4-substitution in the benzenoid rings, and an out-of-plane CAH vibration. 28 As for the PPY [spectrum C in Figure 3(a)], the two peaks at 1543 and 1453 cm 21 can be attributed to the asymmetric and symmetric stretching vibrations of PY rings, respectively. 29 The band at about 1305 cm 21 is ascribed to the CAN stretching in PY units.…”