Alkoxo derivatives of platinum metals

O–H Activation and Addition to Unsaturated Systems

“…Early in the 1970s, Muetterties reported very briefly that a trialkylphosphine complex of platinum, [Pt(PEt 3 ) 3 ] (26a) reacted with water reversibly to form an unstable species, [PtH(PEt 3 ) 3 ]OH (27), which was not isolated (Scheme 6-2) [14]. The first hydroxoplatinum complex prepared by O-H bond activation was reported by Bennet in 1973.…”

“…Though many methods of preparation of transition metal hydroxides, alkoxides, etc. by a metathesis reaction have been reported [1], 3 ] with NaOH or KOH [5]. Depending on the reaction conditions, the reaction leads to hydroxobridged dimers, [{RuH(PPh 3 ) 2 (S)} 2 (µ-OH) 2 ] (S = Me 2 CO, H 2 O, or t BuOH) and a tetranuclear complex of stoichiometry [Ru 4 H 4 (OH) 2 (PPh 2 ) 2 (CO) 2 (PPh 3 ) 6 (Me 2 CO) 2 ] (Eq.…”

“…6.4) [7]. Several other iridium alkoxide analogs [Cp*IrH(OR) RuH(Cl)(PPh 3 ) 3 NaOH or KOH tetranuclear species (PPh 3 )] (5) (R = C 2 D 5 , n Pr, i Pr, Ph) were prepared by treatment of the ethoxide 4 with an excess of the corresponding alcohol (Eq. 6.5).…”

“…The hydroxo(isopropoxo) complex 5c was characterized by X-ray diffraction [8]. 3 ), have been prepared by the metathesis reaction of NaOPh with trans-[NiHClL 2 ] (Eq. 6.6).…”

“…Studies on the O-H bond activation by transition metal complexes are also much less developed compared to those on C-H bond activation by transition metal complexes [2], and review articles dealing with the activation of the O-H bond by transition metals are rare [1]. The chemistry of alkoxo complexes of late transition metals does not appear to have received much attention [3]. A widely accepted explanation for the scarcity of alkoxides or hydroxides of late transition metals was that such metal-oxygen bonds are characteristically weak because of a mismatch of these hard basic ligands with soft late transition metals, and they have propensity to easily decompose presumably by β-hydride elimination to metal hydrides [4].…”