The position of benzenoid
substituent at the 3-position is called isoflavonoids.
The peaks present at 1,454 and 1,556 [cm.sup.-1] can be assigned to the C=C stretching vibrations of the benzenoid
and quinoid rings of PANI, respectively.
Polymerization of the aniline can be conrmed by the presence of spectral peaks near 1473 and 1552 cm-1 for PANI doped samples, which are attributed to the stretching C=C and C=N modes for quinonoid and benzenoid
units of PANI, respectively, for the HCl doped PANI .
To the best of our knowledge, only one first and second derivative spectrophotometric method have been reported for simultaneous quantification of atorvastatin (ATV) and fenofibrate (FEN) in methanol as solvent, but methanol is environmentally toxic and more expensive than aqueous buffers and one wavelength is 245 nm, which is normally originated from the benzenoid
The absorption band in 365 only appears at high levels of doping, because it comes from a combination of 360 e 440 nm bands, assigned to [pi]-[[pi].sup.*] transition of benzenoid
segment and polaron-[pi] transition in quinoid rings, respectively.
For aromatic compounds, UV absorbance bands at 253 and 220 nm are related to the electron transfer (ET) and benzenoid
(Bz) bands respectively.
The absorption band appeared at 254 nm (L-1), may be attributed to the benzenoid
[pi]-[pi] (*) transition.
Kang, "M-Polynomials and Degree-Based Topological Indices of Triangular, Hourglass, and Jagged-Rectangle Benzenoid
Systems," Journal of Chemistry, vol.
The increased inhibition of PAni in the presence of metal cations like [Zn.sup.2+] ions would likely be attributed to the formation of compact clusters and enhanced by more amounts of electron rich benzenoid
groups that facilitates the greater adsorption on the iron surface and hereby prevents further corrosion .
Five strong absorption bands were observed, whereby those appearing at [[lambda].sub.max] 215 nm (log [epsilon] = 2.95) and [[lambda].sub.max] 240 nm (log [epsilon] = 4.56) may be attributed to [pi] [right arrow] [[pi].sup.*] transition of the benzenoid
moiety of the compounds and intraligand [pi] [right arrow] [[pi].sup.*] transition.
In the Raman spectrum of PANI hydrochloride films excited with the 514 nm laser line (Figure 1, green line), in contrast with the spectrum obtained with the 633 nm excitation line, the most intense peak in the ring stretching region is observed at 1620 [cm.sup.-1] and in the C-H deformation region at 1194 [cm.sup.-1]; these bands are connected with benzenoid
In , it also presents that there forms excellent correlation between heat of formation of benzenoid
hydrocarbons and the GA index (the correlation coefficient is 0.972).