Perinaphthenyl radical

Figure Bl.15.6. The EPR spectrum of tire perinaphthenyl radical in mineral oil taken at room temperature. (A) First derivative of the EPR absorption x with respect to the external magnetic field, Bq. (B) Integrated EPR spectrum.

Figure Bl.15.6. The EPR spectrum of the perinaphthenyl radical in mineral oil taken at room temperature. 

Radicals with 13 conjugated 7r-electrons 4.7.1 Phenalenyl (perinaphthenyl) radicals... 

Perinaphthenyl radical (I) pyrolysed petroleum products solution 300 9 Ch 7 ... 

The effect of the partial orientation is demonstrated in Fig. 9 for the perinaphthenyl radical in azoxyanisol. This spectrum has been taken at the isotropic-nematic transition temperature [72] of the solution. Due to a small temperature gradient in the resonator the sample contained both isotropic and nematic regions on recording the spectrum. Fig. 9b gives therefore a superposition of the spectra of both the randomly and the partially oriented radicals. 

The results obtained for the hfs interaction of free radicals in marine diesel and the discussion regarding the organic molecule models indicate that perinaphthenyl radicals (Fig. 18) are the probably responsible for the septet-quartet EPR spectrum of this oil byproduct (Di Mauro et al., 2007). 

Fig. 18. Structural representation to perinaphthenyl radical indicating, 1 to 9, hydrogen atoms responsible for the hyperfine splitting observed in marine diesel spectrum.

It was verified that EPR signal attributed to the perinaphthenyl radical in marine diesel decreases in intensity and finally disappears with time, depending on the time that samples were exposed to air this suggested that the radical undergoes a chemical reaction, probably with oxygen in air, since phenalenyl is sufficiently persistent in dilute deoxygenated... 

The First attempt in the simulation, with WINEPR SimFonia Version 1.25 software of Bruker , was to consider a septet-quartet RPE spectrum attributed to the perinaphthenyl radical (C13H9 ). However, this interpretation was not sufficient to reproduce the sp>ectrum presented in Fig. 22c, indicating the superposition with other groups of less intensive lines which could be due to phenalenyl radicals with different number of splitting protons (Zaitev et al., 2006). 

---