Rhenium complexes of tris(pyrazolyl)methanes and sulfonate derivative

• Autor(a) principal: Alegria, Elisabete
• Data de Publicação: 2006
• Outros Autores: Martins, Luisa, Haukka, Matti, Pombeiro, Armando
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.21/12078
• topic: Rhenium complexes; Tris(pyrazolyl)methanes; Sulfonate derivative

The trioxo [ReO3{SO3C(pz)3}] (1) (pz = pyrazolyl) and oxo [ReOCl{SO3C(pz)3}(PPh3)]Cl (2) compounds with tris(pyrazolyl)methanesulfonate were obtained by treatment of Re2O7 or [ReOCl3(PPh3)2], respectively, with Li[SO3C(pz)3], whereas [ReCl3{HC(pz)3}] (3), [ReCl3{HC(3,5-Me2pz)3}] (4) and [ReCl4{η2-HC(pz)3}] (5) were prepared by reaction of [ReOCl3(PPh3)2] (3,4) or [ReCl4(NCMe)2] (5) with hydrotris(pyrazolyl)methane HC(pz)3 (3,5) or hydrotris(3,5-dimethyl-1-pyrazolyl)methane HC(3,5-Me2pz)3 (4). [ReO{SO3C(pz)3}{OC(CH3)2pz}][ReO4] 6, with a chelated pyrazolyl-alkoxide, was derived from an unprecedented ketone-pyrazolyl coupling on reaction of crude 1 with acetone. The compounds have been characterized by elemental analyses, IR and NMR spectroscopies, FAB-MS spectrometry and cyclic voltammetry and, in the case of 5 and 6, also by single-crystal X-ray diffraction. The electrochemical EL Lever parameter has been estimated, for the first time, for the SO3C(pz)3− and oxo ligands allowing the measurement of their electron-donor character and comparison with other ligands. Compounds 1, 2 and 6 appear to be the first tris(pyrazolyl)methanesulfonate complexes of rhenium to be reported.