An Unusual Monomeric Alkenyl-Substituted Pyrazolato Aluminum Dichloride and Its Derivatives with Both Terminal and η2-Pyrazolato Ligands†
journal contributionposted on 23.06.2001, 00:00 by Wenjun Zheng, Nadia C. Mösch-Zanetti, Torsten Blunck, Herbert W. Roesky, Mathias Noltemeyer, Hans-Georg Schmidt
The facile formation of the unusual monomeric alkenyl-substituted pyrazolato aluminum dichloride [(3,5-tBu2-N-CHC(SiMe3)-pz)AlCl2] (2; 3,5-tBu2pz = 3,5-di-tert-butylpyrazolato) was achieved in high yield by reacting dimeric pyrazolato aluminum dichloride [η1-η1-3,5-tBu2pz(μ-Al)Cl2]2 (1) with 2 equiv of trimethylsilylethine. The addition of 1 and 2 equiv of K[3,5-tBu2pz] to 2, respectively, resulted in the formation of two novel complexes, [(3,5-tBu2-N-CHC(SiMe3)-pz)AlCl(3,5-tBu2pz)] (3) and [(3,5-tBu2-N-CHC(SiMe3)-pz)Al(η1-3,5-tBu2pz)(η2-3,5-tBu2pz)] (4), for which crystallographic data are presented. The coordination of the pyrazolato ligand in 3 represents an extreme example of a “slipped” η2-coordination.