The improved preparation and the new synthesis of the hydroxo complexes [Pt(Me)(OH)(PP)] (PPPh 2PCH 2CH 2PPh 2 ( 1), Ph 2PCHCHPPh 2 ( 2)), abbreviated as [Pt]OH, is reported. The chemical behavior of 1 towards bases, organic and organometallic halides has been tested. There was no NMR spectroscopic evidence for the formation of a reactive oxo intermediate [Pt]O − upon reaction with a strong base. In the presence of an electrophilic organic reagent such as an alkyl halide RX (R=Me, CH 2Ph, Et, t-Bu; X=Cl, Br, I), the OH for X exchange process takes place with the formation of the organometallic derivative [Pt(Me)(X)(PP)] and the corresponding alcohols ROH. Similar reactions carried out in the presence of an electrophilic organometallic species such as the neutral complexes [PtCl 2(CNC 6H 4 p-OMe)(PPh 3)] and [PtCl 2(COD)] or the cationic derivative trans-[PtCl(CNMe)(PPh 3) 2][BF 4] indicate primarily OH for Cl exchange with formation of the chloro species [Pt(Me)(Cl)(PP)] and unstable hydroxo complexes, which decompose under the experimental conditions. In the case of the cationic complex also OH for PPh 3 exchange is observed. A possible mechanism for the observed reactivity is described.