ETA(2)-ALKYNE COMPLEXES OF ETA(5)-CYCLOPE NTADIENYL-1-NORBORNYL

Cp,Ni reacts at -50 degrees C with 1-norLi (I-nor = 1-norbornyl = bicy clo[2.2.1]heptane-l-yl) in THF to give CpNi-1-norbornyl (3) which is s table up to -30 degrees C. 3 reacts with alkynes to complexes of the t ype CpNi(1-nor)(eta(2)-RC equivalent to CR) (R = Me (5a), SiMe(3) (5b) , Ph (5c), CH(2)OMe (5d), CH(2)NMe(2) (5e), CH(2)OSiMe(3) (5f)) which are stable at room temperature. 5f forms when chromatographing on Al2O 3 the complex CpNi(1-nor)(HOCH2C equivalent to CCH2OH) (5g). In some c ases the complexes (CpNi-1-nor)(2)(RC equivalent to CR) (R = SiMe(3) ( 6b), Ph (6c)) and (CpNi)(2)(RC equivalent to CR) (R = Me (7a), SiMe(3) (7b), Ph (7c), CH(2)NMe(2) (7e), CH(2)OSiMe(3) (7f), CH2OH (7g)) are observed in small concentrations as products of thermal decomposition. The compounds were characterized by analytical and spectroscopic data (MS, H-1 and C-13 NMR).