The synthesis, characterization and some reactions of cationic eta(2)-(alpha,omega-diene) complexes of iron

The cationic iron eta (2)-(alpha,omega -diene) complexes of the type, [(eta (5)-C5H5)Fe(CO)(2){eta (2)-(alpha,omega -diene)}]PF6, (diene = 1,3-butadie ne; 1,4-pentadiene; 1,5-hexadiene; and 1,7-octadiene) were prepared by the reaction of eta (1)-alkenyl compounds of the type [(eta (5)-C5H5)Fe(CO)(2)( eta (1)-alkenyl)] with the so-called trityl salt, (Ph3CPF6). The reactions of the eta (2)-diene complexes with a number of nucleophiles give a range o f products resulting from nucleophillic addition to the coordinated diene a nd/or displacement of the diene. The reaction with triethylamine results in deprotonation leading to the formation of [(eta (5)-C5H5)Fe(CO)(2)(eta (1) -allyl)] complexes. (C) 2001 Elsevier Science B.V. All rights reserved.