Leaving groups ordered in decreasing ability to leave
R–N2^+	dinitrogen
R–OR'2^+	dialkyl ether
R–OSO2R	perfluoroalkylsulfonates (e.g. triflate)
R–OTs, R–OMs, etc.	tosylates, mesylates and similar sulfonates
R–I	iodide
R–Br	bromide
R–OH2^+, R'–OHR^+	water, alcohols
R–Cl	chloride
R–ONO2, R–OPO(OR')2	nitrate, phosphate, and other inorganic esters
R–SR'2^+	thioether
R–NR'3^+, R–NH3^+	amines, ammonia
R–F	fluoride
R–OCOR	carboxylate
R–OAr	phenoxides
R–OH, R–OR	hydroxide
R–NR2	amides
R–H	hydride
R–R'	arenide, alkanide