Assessment of the Oxidative Desulfurization of Middle Distillate Surrogate Fuels with Spectroscopic Techniques

Table 3

IR absorptions of the model sulfur compounds in their initial solutions and during their oxidation. Characteristic groups that contribute to the monitoring of the oxidative process. The absorptions of the solvent, n-hexadecane, were excluded.

Characteristic groups	1-dodecanethiol	N-butyl sulfide	Tert-butyl disulfide	Benzothiophene	Dibenzothiophene
IR absorptions of the sulfur compounds in their initial solutions (cm ^−1)
Tertiary group C-H bending	—	—	1363	—	—
=CH- skeletal vibrations	—	1273, 1220	—	—	—
C-C skeletal vibrations	—	—	1161	—	—
Aromatic C-H in-plane bending	—	—	—	1207, 1157, 1089, 1055, 1014	1227, 1197, 1160, 1075, 1068, 1026
Aromatic C-H out-of-plane bending	—	—	—	880, 866, 848, 798, 760, 734	740
IR absorptions used to monitor the oxidation of the solutions (cm ^−1)
SO2 symmetric stretching	1133	1136	—	—	—
S=O stretching vibrations	1060	—	1060	—	—
Aromatic C-H out-of-plane bending	—	—	—	—	740