Synthesis and polymerisation of bis(η-styrene)molybdenum and related studies: crystal structures of Mo(η-C6H5CH2CHCH2)2 and [Mo(η-C6H5SiMe2H)2]BF4

Abstract The synthesis of the compounds Mo(η-C 6 H 5 R) 2 , where R  CHCH 2 , 4-C 5 H 4 CHCH 2 and CH 2 CHCH 2 is described. The crystal structure of Mo(η-C 6 H 5 CH 2 CHCH 2 ) 2 has been determined. These vinyl monomers are polymerised by free radical initiation using AIBN. Di-η-benzenemolybdenum is lithiated by Bu n Li/Me 2 NCH 2 CH 2 NMe 2 to give a bis(η-lithiobenzene)molybdenum derivative, which reacts with D 2 O, MeI, or SiMe 3 Cl to give Mo(η-C 6 H 5 R) 2 , where R = D, Me or SiMe 3 respectively. The dilithio system reacts with SiMe 2 Cl to give a polymeric mixture containing Cl{SiMe 2 -η-C 6 H 5 Mo-η-C 6 H 5 } n SiMe 2 Cl, and hydrolysis of this yields the disiloxane Mo(η-C 6 H 5 SiMe 2 OSiMe 2 -η-C 6 H 5 ), whose crystal structure has been determined. Co-condensation of molybdenum atoms with dimethylphenylsilane gives Mo(η-C 6 H 5 SiMe 2 H) 2 , which is oxidised by aqueous HBF 4 to give the compound [Mo(η-C 6 H 5 SiMe 2 H) 2 ]BF 4 , whose crystal structure has been determined.