Patent ID: 8722912

Claim:
A hydration catalyst used for hydration reaction comprising a metal complex compound represented by the following general formula (I): wherein M is a metal ion selected from the group consisting of ruthenium, osmium, rhodium, iridium, nickel, palladium and platinum, L 1 is a cyclic or acyclic, neutral or minus 1-valent unsaturated hydrocarbon group of 1 to 30 carbon atoms which may have a substituent, L 2 and L 3 are each independently fluorine, chlorine, bromine, iodine, a hydroxyl group, an alkoxy group which may have a substituent or an aryloxy group which may have a substituent, and L 4 is a compound bonded to M through phosphorus or arsenic and represented by the following general formula (IIa) or (IIb): wherein E is phosphorus or arsenic, Y 1 is oxygen or sulfur, Y 2 , Y 3 and Y 4 are each independently a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group which may have a substituent and a hetero atom other than carbon, an alkoxy group which may have a substituent or an aryloxy group which may have a substituent, and H is a hydrogen atom.