Molybdenum complexes cyclopropenyl

Similarly, metathetical exchange of the labile acetonitrile ligands in the octahedral molybdenum complex (CO)2(MeCN)2BrMo( 3-C3Ph3) with a variety of bidentate amines led to the corresponding amino complexes (equation 267)311. These form crystalline acetonitrile solvates suitable for X-ray determination, which confirm the octahedral structure of these complexes and the occurrence of the cyclopropenyl and bromide groups in a tram-relationship. 

A closely related formation of z/ -cyclopropenyl molybdenum complex Cp P(OMe)3 2Mo(z/ -C3Ph2Me), possibly involving an interamolecular ligand cycloaddition within a carbyne-acetylene intermediate complex, has been accomplished by treating the acetylenic cation complex [Cp P(OMe)3 2Mo(z/ -PhC=CPh)]Bp4 with vinylmagne-sium bromide in THE (equation 253) ... 

Notably, early attempts to similarly prepare cyclopropenyl complexes of group 6 molybdenum and tungsten, using [CpM(CO),] anions (M = Mo, W) and [C,(Bu-/),]BF4, resulted in the electrophilic attack of the cyclopropenium cation on the peripheral cyclopentadienyl ligand, to give hydride complexes (equation 196)270. These air-sensitive hydride complexes readily react with CC14, to afford the corresponding air-stable chloro complexes. 

---