Reactions of Pt PPh3 and Related Species

Pt(PPh3) (n = 3, 4) species [54] have been studied with profit for many years they undergo a wide range of addition reactions with attendant loss of phosphine, the kinetically active species probably being Pt(PPh3)2. (The palladium analogues generally behave similarly but are much less studied.) 

There is (a) cr-donation from a filled oxygen orbital to an empty platinum orbital and (b) 7r back-bonding from a filled metal d orbital into an empty oxygen 7r -anti-bonding orbital. 

Addition of radical inhibitors (e.g. duroquinone, galvinoxyl), which will slow up any pathway involving radicals. 

Adding a radical trap like BulNO to the reaction mixture this reacts with radicals (R ) forming nitroxide radicals Bul(R )NO that can be detected by ESR. 

Observation of CIDNP effects in the resonances of either reactant or product species in the NMR spectrum of the reaction mixture. 

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