SYNTHESIS AND INSERTION REACTIONS OF CP(2 )'HFCL(AS(SIME(3))(2)) (CP'=C(5)H(4)ME)

The reaction of Cp(2)'HfCl2 (Cp' = C(5)H(4)Me) with Li(HF)(2.5)As(SiMe (3))(2) (1:1) at room temperature gives the terminal hafnocene arsenid e complex Cp(2)'HfCl{As(SiMe(3))(2)} (1) in high yield. 1 inserts CS2 and PhNC into the Hf-As bond yielding Cp(2)'HfCl{eta(2)-S2CAs(SiMe(3)) (2)} (2) and Cp(2)'HfCl{eta-N(Ph)CAs(SiMe(3))(2)} (3). The thermally s ensitive complexes 1-3 were characterised spectroscopically and crysta l structure determinations were carried out on 1 and 3 which shows the eta(2) bonding mode of the N(Ph)CAs(SiMe(3))(2) ligand in the latter.