Patent ID: 7205441

Claim:
A method for producing a tetrakis (fluoroaryl) borate.magnesium halide compound represented by Formula (1): where each of R 1 , R 2 , R 3 , R 4 , and R 5 independently represents one of a hydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxy group, provided that at least one of R 1 –R 5 represents a fluorine atom, and X a represents one of a chlorine atom, a bromine atom, and an iodine atom, comprising the step of reacting fluoroaryl magnesium halide represented by Formula (3): where each of R 1 , R 2 , R 3 , R 4 , and R 5 independently represents one of a hydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxy group, provided that at least one of R 1 –R 5 represents a fluorine atom, and X b represents one of a chlorine atom, a bromine atom, and an iodine atom, with a boron compound represented by Formula (2) B(X c ) 3 (2) where X c represents either a chlorine atom or a bromine atom, so that a molar ratio of the fluoroaryl magnesium halide to the boron compound is not less than 3.0 and not more than 3.7.