Dialkylplatinum complexes

Dialkylplatinum complexes with the cod ligand undergo photolysis at Amax>320nm in GD2CI2 (Scheme 10). The dimethylplatinum complex releases 1,5-dimethylcyclooctane 78 and Pt metal, while the analogs with two isopropyl or benzyl groups produce chloro(alkyl)platinum complexes 79 under the same conditions. Both products are formed via photochemically induced homolytic dissociation of a Pt-C cr-bond. 

The alkynyl ligand of Pt-phosphine complexes serves as the metallaligand that binds Ag(i) or Cu(i), forming di- or trinuclear complexes. Cationic Ag(i) and Gu(i) centers are bonded with two m-dialkylplatinum complexes to yield the trinuclear complexes with 7r-coordination of the four alkynyl ligands to a alkynyl ligands of the complexes with a /r< / i -structure to GuCNOa) forms the PtCu2 complex 709. " ... 

According to this postulate, the difference between coupling with silver and disproportionation with iron rests on the decomposition of the alkylmetal intermediate in Equation 50. Indeed, it has been shown separately in Equation 42 that the decomposition of alkylsilver(I) proceeds by reductive coupling. Unfortunately, the highly unstable alkyliron intermediate in Scheme 6 is not yet accessible to independent study, but the somewhat analogous dialkylmanganese(ll) species in Equation 51 undergoes similar reductive disproportionation by a mechanism S) reminiscent of dialkylplatinum(ll) complexes described in Equation 7. 

Dialkylplatinum(II) complexes bearing P-hydrogens undergo exclusive P-hydrogen elimination on thermolysis [179,180,182]. On the other hand, the di-neopentyl complex, which has no P-hydrogens. undergoes y-C—H bond activation to provide a platinacyclobutane (eq (140)) [183]. 

Since the reductive elimination involves reduction in the formal oxidation state, the reactivity of an organometallic complex may be enhanced by oxidation of the metal center, most typically by two-electron oxidation. For example, dialkylplatinum(II) complexes are fairly stable but after the oxidative addition of alkyl halides the resulting trialkylplatinum(IV) halides readily undergo C-C reductive elimination (see Section 9.5.1). On the other hand, there have been several examples where one-electron oxidation also has a pronounced effect on the rate acceleration of reductive elimination. Early instances have been documented for the complexes bearing the first-row metals (e.g., trans-NiMe(aryl)(PEt3)2 [86], cw-EeR2(bipy)2 (R = Me, Et) [87], c x-[CoR2(bipy)2] ... 

The complex with a PGP pincer ligand and a heptafluoropropyl ligand 613 has been prepared by metallation of l,3-bis(diphenylphosphinomethyl)benzene by the dialkylplatinum(ii) complex of TMEDA (Equation (132))." ... 

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