Formation and Ring Expansion of Germaplatinacycles via Dehydrogenative Ge−Ge and Ge−Pt Bond-Forming Reactions

Abstract

The bis(germyl)platinum complex [Pt(GeHPh2)2(dmpe)] (1) (dmpe = 1,2-bis(dimethylphosphino)ethane) reacts with a small excess of H2GePh2 at 90 °C to produce four-membered germaplatinacycle [Pt(GePh2GePh2 GePh2)(dmpe)] (2). Further reaction of 2 with excess H2GePh2 at 90 °C forms tetragermaplatinacyclopentane [Pt(GePh2GePh2GePh2 GePh2)(dmpe)] (3), while 3 is obtained also by the direct reaction of excess H2GePh2 with 1 for a prolonged period. Complexes 1−3 were characterized by X-ray crystallography and NMR spectroscopy. Germaplatinacycles 2 and 3 react with H3GePh to cause cleavage of the Pt−Ge bonds and formation of the oligogermanes H(GePh2)3H and H(GePh2)4H, respectively.

Organodiphosphines in PtP2X2 (X = As, Ge or Te) derivatives – Structural aspects

“…In monoclinic [Pt{η 2 -Me 2 P(CH 2 ) 2 PMe 2 }{η 2 -(GePh 2 ) 3 }] ( Figure 2) (Tanabe et al, 2009), two dissimilar chelating ligands build up a distorted square-planar environments (PtP 2 Ge 2 ). The P,P-donor ligand creates five-membered metallocycle (PC 2 P) with the P-Pt-P angle of 85.9°, and (GePh 2 ) 3 ligand form four-membered metallocycle (GeGeGe) with the value of Ge-Pt-Ge angle of 83.1°.…”

“…There are two complexes monoclinic [Pt {η 2 -Ph 2 P(CH 2 ) 2 PPh 2 }{η 2 -(Ge(η 2 -C 12 H 8 )) 4 }]. CH 2 Cl 2 (at 100 K) (Braddock-Wilking et al, 2009) and orthorhombic [Pt{η 2 -Me 2 P(CH 2 ) 2 PMe 2 }{η 2 -(Ge(Ph 2 ) 4 }]‧toluene (at 113 K) (Tanabe et al, 2009) each R 2 P(CH 2 ) 2 PR 2 creates fivemembered metallocycles with the mean value of P-Pt-P bite angle of 85.7° (PC 2 P). Each bidentate Ge,Ge'-donor ligand forms five-membered metallocyclic ring with the mean Ge-Pt-Ge bite angle of 89.7° (GeGe 2 Ge).…”

“…The aim of this review is to classified and analyzed structural parameters of cis-Pt(η 2 -P 2 L)(XL) 2 (X = Ge, Te), cis-Pt(η 2 -P 2 L)(η 2 -X 2 L) (X = As, Ge, Te) and trans-Pt(η 2 -P 2 TeL) 2 . Their structural data are compared (Tanabe et al, 2009). and discussed with Pt(η 2 -P 2 L)(XL) 2 (X = O, N, CN, B, Cl, S, Br, Se, Si, I), Pt(η 2 -P 2 L)(η 2 -X 2 L) (X = O, N, S, Se, Si) and Pt(η 2 -P,SiL) 2 complexes.…”

Carbon, silicon, germanium, tin and lead

“…For [GeAu 8 ] À , two isomers are predicted to be almost equal in energy and the spectroscopic results support this proposition. 109 Sila-110 and germaplatinacycles 110,111 are available from reactions analogous to those already reported for the equivalent palladium compounds, Scheme 5. Treatment of 24 with excess phenylgermane leads to the elimination of oligogermanes [(GePh 2 ) n H 2 ], and simple and expedient route to oligogermane dihydrides with excellent control of linearity.…”

Steric Effect of a Phosphane Ligand on the Equilibrium of Ge–Ge Bond Formation at a Platinum Center

“…Recently, platinum complexes have also been employed in the oligomerization of secondary germanes to form Pt–Ge cycles in which the tetragermyl group may be isolated as the corresponding tetragermane by treatment with a primary germane 4–6. We studied the kinetics for the conversion of the bis(germyl)platinum complex cis ‐[Pt(PPh 3 ) 2 (GeH 2 Mes) 2 ] (Mes = 2,4,6‐trimethyphenyl) into the digermylplatinum complex cis ‐[Pt(PPh 3 ) 2 (H)(GeHMesGeH 2 Mes)], which has been well characterized through spectroscopic measurements and X‐ray diffraction analysis 7.…”