The present invention provides compounds represented by the formula Y
+−
N(SO
2
R
f
)(CF
3
). Such a compound can be manufactured through a reaction between M
+−
N(SO
2
R
f
)(CF
3
) and Y
+−
B. The present invention also provides compounds represented by the formula Y
+−
N(SO
2
R
f
)(CN). Such a compound can be manufactured through a reaction between M
+−
N(SO
2
R
f
)(CN) and Y
+−
B. R
f
in the above formulae is a perfluoroalkyl group. Y
+
is an organic or inorganic cation.
−
B is an organic or inorganic anion. M
+
is an alkali metal cation or a silver cation.