Genesis of electron deficient Pt1(0) in PDMS-PEG aggregates

While numerous single atoms stabilized by support surfaces have been reported, the synthesis of in-situ reduced discrete metal atoms weakly coordinated and stabilized in liquid media is a more challenging goal. We report the genesis of mononuclear electron deficient Pt 1 (0) by reducing H 2 PtCl 6 in liquid polydimethylsiloxane-polyethylene glycol (PDMS-PEG) (Pt 1 @PDMS-PEG). UV–Vis, far-IR, and X-ray photoelectron spectroscopies evidence the reduction of H 2 PtCl 6 . CO infrared, and 195 Pt and 13 C NMR spectroscopies provide strong evidence of Pt 1 (0), existing as a pseudo-octahedral structure of (R 1 OR 2 ) 2 Pt(0)Cl 2 H 2 (R 1 and R 2 are H, C, or Si groups accordingly). The weakly coordinated (R 1 OR 2 ) 2 Pt(0)Cl 2 H 2 structure and electron deficient Pt 1 (0) have been validated by comparing experimental and DFT calculated 195 Pt NMR spectra. The H + in protic state and the Cl − together resemble HCl as the weak coordination. Neutralization by a base causes the formation of Pt nanoparticles. The Pt 1 @PDMS-PEG shows ultrahigh activity in olefin hydrosilylation with excellent terminal adducts selectivity.