American Chemical Society
ic7018692_si_004.cif (62.02 kB)

Coordination Chemistry of a Model for the GP Cofactor in the Hmd Hydrogenase:  Hydrogen-Bonding and Hydrogen-Transfer Catalysis

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posted on 2008-01-21, 00:00 authored by Aaron M. Royer, Thomas B. Rauchfuss, Scott R. Wilson
Cp*M2+ complexes (M = Rh, Ir; Cp* = C5Me5) are described for 6-(carboxymethyl)-4-methyl-2-hydroxypyridine (cmhpH2), an analogue of the guanylylpyridone cofactor in the hydrogenase Hmd. Three findings indicate that Cp*M(Hcmhp)+ stabilizes the binding of hydrogen-bond acceptors to the sixth coordination site:  (i) water binds in preference to Cl-, (ii) the adduct Cp*Rh(cmhp)(2-hydroxypyridine) exhibits a very short intramolecular hydrogen bond (rO-O = 2.38 Å; 1H NMR δH 17.2), and (iii) Cp*Ir(cmhpH)Cl efficiently catalyzes the dehydrogenation of PhCH(OH)Me to PhC(O)Me.