Synthesis, structure, and reactivity of eta(1)- and eta(3)-allyl rhenium carbonyls

In (eta (3)-C3H5)Re(CO)(4) one CO ligand can be substituted by PPh3, pyridi nc, isocyanide and benzonitrile. With 1,2-bis(diphenylphosphino)ethylene, 1 ,1'-bis(diphenylphosphino)ferrocene and 1,2-bis(4-pyridyl)ethane dinuclear ligand bridged complexes are obtained. The eta (3)-eta (1) conversion of th e allyl ligand occurs on reaction of (eta (3)-C3H5)Re(CO)(4) with the bidon date ligands 1,2-bis(disphenylphosphino)ethane and 1,3-bis(diphenylphosphin o)propane and with 2,2'-bipyridine (L-L) which gives the complexes (eta (1) -C3H5)Re-(CO)(3)(L-L). By reaction of (eta (3)-C3H5)Re(CO)(4) with bis(diph onylphosphino)methane the allyl group is protonated and under clemination o f propene the complex (OC)(3)Re(Ph2PCHPPh2)(eta (1) -Ph2PCH2PPh2) (19) with a diphosphinomethanide lignad is formed. On heating solutions of (eta (3)- C3H5)Re(CO)(4) and (eta (3)-C3H5)Re(CO)(3)(CN-2,5-Me2C6H3) (5) in methanol the methoxy bridged compounds Re-4(CO)(12)(OH)(OMe)(3) and Re-2(CO)(4)(CN-2 ,5-Me2C6H3)(4)-(mu -OMe)(2) (20) were isolated. The crystal structures of ( eta (3)-C3H5)Re(CO)(3)(CNCH2SiMe3) (4), [(eta (3)-C3H5)(OC)(3)Re](2)-(mu -b is-(diphenylphosphino)ferrocene) (8), (eta (1)-C3H5)Re(CO)(3)-(bby) (14), o f 19, 20 and of (OC)(3)Re-[Ph2P(CH2)(3)PPh2]Cl (16) were determined by X-ra y diffraction.