Simple pathway of formation and reactions of methyl complexes of platinum(IV) in aqueous solutions

Mechanistic Aspects of C−H Activation by Pt Complexes

“…The idea that Pt(IV) alkyl, aryl, and hydride complexes were involved in C−H activation evolved during the 1960s, , but it was not until the 1970s that experimental evidence for the existence of Pt(IV) alkyls and aryls was found, and attempts were made to synthesize Pt(IV) alkyl complexes from RHgBr . In 1982 Zamashchikov et al recorded the 1 H NMR spectrum of a species believed to be PtCl 4 Me(H 2 O) - , where a signal corresponding to Pt−CH 3 was observed at δ 3.38 relative to Me 3 SiOSiMe 3 with characteristic 195 Pt satellites ( 2 J H - Pt = 77 Hz) . In the following years more Pt(IV) alkyl species were observed , and eventually isolated. ,− The Pt(II) methyl complex MePtCl 3 2- , believed to be the first intermediate after C−H bond breaking and deprotonation, proved more elusive.…”

Catalysts for C–H functionalization: Platinum, gold and even nanodiamonds

“…model complex and complex isolated from the СН 4 -PtCl 4 2− -PtCl 6 2− reaction mixture were close [22,25]. Kinetic evidence of S N 2 mechanism of reductive elimination as a result of decomposition of K 2 Pt(CH 3 Cl 5 ) in aqueous solution is reported in [26].…”

“…The formation of phenyl-and methylplatinum (IV) in functionalization of hydrocarbons catalyzed by Pt (II) complexes in water solution was proved experimentally using NMR spectroscopy [21,22] and was supported by preparation of crystalline σ-aryl complexes of Pt IV in the direct reaction between arenes and H 2 PtCl 6 in trifluoroacetic acid [23,24]. A model methyl complex of Pt IV of the [MePt IV Cl 4 (H 2 O)] − general formula was obtained as a result of the reaction of СH 3 I with PtCl 4 2− in water [25]. NMR parameters (δ of protons of СН 3 -Pt = 3.04 ppm, J( 1 H) 3 …”

Mechanochemistry in heterogeneous catalysis

“…The mechanism of chain termination in the chain reaction of substitution of the halogen in RI at the surface of the activated salt KCl.In aqueous solutions the [PtCl 4 ] 2-anion, like chloride ions, is a metal-centered nucleophile and reacts with methyl iodide by an oxidative addition path with the formation of the methyl complex of platinum(IV) MePt(IV)[93,99,100]. The reaction can take place by an S N 2 mechanism [reaction (3), model of transition state A][93,100] and as concerted three-center addition, in which the coordination-unsaturated platinum(II) complex simultaneously plays the role of nucleophile attacking the carbon atom and electrophile combining with the leaving group[101] [reaction (4), model of transition state B]:…”