Tris(pyrazolyl)methane Ligands: Syntheses and Structures of Monometallic and Metallodendritic Complexes

✍ Scribed by Alberto Sánchez-Méndez; Gustavo F. Silvestri; Ernesto de Jesús; F. Javier de la Mata; Juan C. Flores; Rafael Gómez; Pilar Gómez-Sal

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 197 KB
• Volume: 2004
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200400162

✦ Synopsis

Abstract

The substituted ligands Me~3~SiC(pz)~3~ (1) and Me~3~SiOCH~2~C(pz)~3~ (2) have been prepared starting from HC(pz)~3~ and HOCH~2~C(pz)~3~. The molecular structure of compound 1 has been determined by X‐ray diffraction studies, which show a propeller‐like conformation of the pyrazolyl rings. Compound 2 has been found to be useful for the synthesis of [Mo(CO)~3~{Me~3~SiOCH~2~C(pz)~3~}] (3), [TiCl~2~(N__t__Bu){Me~3~SiOCH~2~C(pz)~3~}] (4), and [PdCl~2~{Me~3~SiOCH~2~C(pz)~3~}] (5), through ligand exchange reactions. The characterization of the new complexes is compatible with a tridentate coordination of the ligands in complexes 3 and 4, and a bidentate coordination in 5 as confirmed by an X‐ray analysis carried out with the palladium complex. The procedure has been extended for the synthesis of the carbosilane G1−[OCH~2~C(pz)~3~]~4~ (6) and the tetrametallic compound G1−[OCH~2~C(pz)~3~Mo(CO)~3~]~4~ (7) (G1 = Si(CH~2~CH~2~CH~2~Me~2~Si)~4~−). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)