Aminozirconocenes: A new class of zirconocenes with a nitrogen atom directly bonded to an η5-cyclopentadienyl (indenyl) ligand

Article abstract of DOI:10.1016/S0022-328X(96)06254-7

The reactions of 2-indanone or 3,4-diphenylcyclopent-2-enone with pyrrolidine and N,N'-dimethylethylenediamine respectively lead to the corresponding 2-aminoindenes and 1-amino-3,4-diphenylcyclopentadienes, whose lithium salts can be reacted with ZrCl₄ to generate the corresponding moisture-sensitive aminozirconocene dichlorides. The X-ray crystal structure of di-(2-N-pyrrolidine-η⁵-indenyl)zirconium dichloride was determined, in which the zirconocene exists exclusively as a racemic-mixture, whereas the meso-rotamer is not present. The (indenyl) carbon-nitrogen bond lengths range from 132.5(7) to 134.9(8) pm, which is indicative of considerable multiple bond character.