| abstract |
Provided is a mononuclear metal complex, a tautomer or stereoisomer thereof, or a salt thereof, which has high catalytic activity and can be used as a hydrogenation reduction catalyst capable of efficiently subjecting a reduced substance to hydrogen reduction. A mononuclear metal complex represented by the following formula (1), a tautomer or stereoisomer thereof, or a salt thereof. [Chemical 1] In the formula (1), Ar 1 is an aromatic anionic ligand or an aromatic ligand, or does not exist, Ar 2 is an aromatic ligand and has a substituent. When it has a substituent, the substituent may be one or plural, M is a transition metal atom or ion, A 1 and A 2 are both carbon atoms, or one is a carbon atom and the other is a nitrogen atom, Y is an anionic group or a cationic group, or is not present, L is any ligand or absent, m is a positive integer, 0 or a negative integer. |