Complex catalysis 57.: Simplified synthesis of Nd(π-C3H5)3.C4H8O2 using the Grignard method and synthesis of new allylneodymium (III) complexes [Nd(π-C5Me5)(π-C3H5)2.C4H8O2] and [Nd(π-C3h5)Cl(THF)5]B(C6H5)4.THF as precatalysts for stereospecific butadiene polymerization

For the tris(allyl)neodymium(III) compound [Nd(pi -C3H5)(3). Dioxan] (1a) an essentially more simple synthesis by the Grignard method is reported. Therewith also further allylneodymium compounds as potential complex catalysts for the stereospecific butadiene polymerization become accessible more easily. As a new bis(allyl)- and a new mono(allyl)neodymium(III) compound the neutral complex [Nd(pi -C5Me5)(pi -C3H5)(2). Dioxan] (2a) and the cationic complex [Nd(pi -C3H5)Cl(THF)(5)]B(C6H5)(4). THF (3a) are described, respectively; both were characterized by X-ray crystal structure analysis. Whereas from 2a highly active catalyst systems for butadiene polymerization can be obtained by combination with proper Lewis acids like methylaluminoxane (MAO), 3a proved to be unsuitable for catalyst generation. The conclusions concerning the catalytic structure-reactivity relationship are discussed briefly. (C) 2001 Elsevier Science B.V. All rights reserved.