pH-Dependent isotope exchange and hydrogenation catalysed by water-soluble NiRu complexes as functional models for [NiFe]hydrogenases.
The pH-dependent hydrogen isotope exchange reaction between gaseous isotopes and medium isotopes and hydrogenation of the carbonyl compounds have been investigated with water-soluble bis(mu-thiolate)(mu-hydride)NiRu complexes, Ni(II)(mu-SR)(2)(mu-H)Ru(II) {(mu-SR)(2) = N,N'-dimethyl-N,N'-bis(2-mercaptoethyl)-1,3-propanediamine}, as functional models for [NiFe]hydrogenases. In acidic media (at pH 4-6), the mu-H ligand of the Ni(II)(mu-SR)(2)(mu-H)Ru(II) complexes has H(+) properties, and the complexes catalyse the hydrogen isotope exchange reaction between gaseous isotopes and medium isotopes. A mechanism of the hydrogen isotope exchange reaction between gaseous isotopes and medium isotopes through a low-valent Ni(I)(mu-SR)(2)Ru(I) complex is proposed. In contrast, in neutral-basic media (at pH 7-10), the mu-H ligand of the Ni(II)(mu-SR)(2)(mu-H)Ru(II) complexes acts as H(-), and the complexes catalyse the hydrogenation of carbonyl compounds.
Kure
Bunsho
B
Center for Future Chemistry, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
Matsumoto
Takahiro
T
Ichikawa
Koji
K
Fukuzumi
Shunichi
S
Higuchi
Yoshiki
Y
Yagi
Tatsuhiko
T
Ogo
Seiji
S
D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D006864:Hydrogenase / Q000737:chemistry* / Q000378:metabolism*; D006865:Hydrogenation; D007554:Isotopes / Q000737:chemistry; D008954:Models, Biological; D008956:Models, Chemical; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011522:Protons; D012428:Ruthenium / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry*
D007554:Isotopes; D009942:Organometallic Compounds; D011522:Protons; D014867:Water; D009532:Nickel; D012428:Ruthenium; C043296:nickel-iron hydrogenase; D006864:Hydrogenase