Investigation on Aromaticity Index and Double-Bond Equivalent of Aromatic Compounds and Ionic Liquids for Fuel Desulphurization

Table 1

Calculated aromaticity index (AI) and double-bond equivalent (DBE) value for common cation and anion.

Cation (basic structure)		Anion
Chemical formula	AI	Chemical formula	DBE
Benzimidazole, C7H6N2	1	Acetate, C2H3O2	1.5
Benzyltriphenylphosphine,	0.6458	Benzoate, C7H5O2	5.5
C25H21P		Bis(tpM)phos., C16H34O2P	0.5
Guanidine, CH5N3	—	Butylsulfate,C4H9O4S	0.5
Imidazole, C3H4N2	2	Decanoate, C10H19O2	1.5
Oxazole, C3H3NO	1.5	DBP, C8H18O4P	0.5
Piperidine, C4H10N2	0	Dicyanamide, C2N3	4.5
Pyrazole, C3H4N2	2	DEP, C4H10O4P	0.5
Pyridine, C5H5N	0.875	DHP, H2O4P	0.5
Pyrrolidone, C5H11N	0.125	DMP, C2H6O4P	0.5
Quinoline, C9H7N	1.083	EESO4, C4H9O5S	0.5
Thiazole, C3H3NS	1.5	ESO4, C2H5O4S	0.5
		Hydrogensulfate,HSO4	0.5
		Methanesulfonate, CH3O3S	0.5
		MESO4, C3H7O5S	0.5
		MSO4, CH3O4S	0.5
		Nitrate, NO3	1.5
		OSO4, C8H17O4S	0.5
		Salicylate, C7H5O3	5.5
		Thiocyanate, CNS	2.5
		TOS, C7H7O3S	4.5
		TCM, C4N3	6.5
		(ME)ESO4, C5H11O6S	0.5
		Imidazolide or pyrazolide, C3H3N2	3.5
		Bis(PFE)phos., C4F10O2P	0.5
		Bis(PFES)ami., C4F10NO4S2	0.5
		Bis(TFM)imi., C2F6N	0.5
		Bis(TFMS)meth., C3HF6O4S2	0.5
		Perchlorate, ClO4	0.5
		HFB, C4F7O2	0.5
		IOPF, F4NO2P2	0.5
		pFBS, C4F9O3S	0.5
		NTf2, C2F6NO4S2	0.5
		TFA, C2F3O2	1.5
		OTf, CF3O3S	0.5
		Tris(tFMS)meth., C4F9O6S3	0.5