abstract |
The present invention provides a salt comprising at least one anion selected from the group consisting of the anions represented by the formulas (I), (II), (III) and (IV), respectively, and having □ (xanthene) a cation of a skeleton; □ [In the formula (I), X1 and X2 are independently shown as a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms, or a bond of X1 and X2 to form a fluorination having a carbon number of 2 to 4; Alkanediyl], □ [In the formula (II), X3 to X5 are each independently shown as a fluorine atom or a fluorinated alkyl group having a carbon number of 1 to 4], □ [in the formula (III), Y1 is represented by a carbon number of 1~ 4 fluorinated alkanediyl], □ [in the formula (IV), Y2 is represented by a fluorinated alkyl group having 1 to 4 carbon atoms]. |