Reactions of Complexes Containing Methylene Bridges

The -methylene complexes of the type L M( i-CH2) ML are quite stable. Photolytic and thermal stability of dimetallacyclopropane compounds is exceptional. 

For example, the complex (OC)cpRh(/i-CH2)Rhcp(CO) does not decompose at reflux in benzene solution for two days it also resists long-term UV irradiation. The 

Tebbe s complex [cp2Ti(/i-CH2)(/i-Cl) AlMcj] readily reacts with alkenes and alkynes to form metallacyclobutanes (unstable) and metallacyclobutenes. It was found that there is a CH2 exchange between metallacyclobutene and CH2=CMe2 [equation (5.155)]. The /r-methylene compounds of the first series of the transition 

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