title: Rhenium complexes of tris(pyrazolyl)methanes and sulfonate derivative.
abstract: The trioxo [ReO(3){SO(3)C(pz)(3)}] (1) (pz = pyrazolyl) and oxo [ReOCl{SO(3)C(pz)(3)}(PPh(3))]Cl (2) compounds with tris(pyrazolyl)methanesulfonate were obtained by treatment of Re(2)O(7) or [ReOCl(3)(PPh(3))(2)], respectively, with Li[SO(3)C(pz)(3)], whereas [ReCl(3){HC(pz)(3)}] (3), [ReCl(3){HC(3,5-Me(2)pz)(3)}] (4) and [ReCl(4){eta(2)-HC(pz)(3)}] (5) were prepared by reaction of [ReOCl(3)(PPh(3))(2)] (3,4) or [ReCl(4)(NCMe)(2)] (5) with hydrotris(pyrazolyl)methane HC(pz)(3) (3,5) or hydrotris(3,5-dimethyl-1-pyrazolyl)methane HC(3,5-Me(2)pz)(3) (4). [ReO{SO(3)C(pz)(3)}{OC(CH(3))(2)pz}][ReO(4)] 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 E(L) Lever parameter has been estimated, for the first time, for the SO(3)C(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.
authors.affiliation: Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisboa, Portugal.
authors.forename: Elisabete C B
authors.initials: EC
authors.lastname: Alegria
authors.forename: Luísa M D R S
authors.initials: LM
authors.lastname: Martins
authors.forename: Matti
authors.initials: M
authors.lastname: Haukka
authors.forename: Armando J L
authors.initials: AJ
authors.lastname: Pombeiro
mesh_terms: D018360:Crystallography, X-Ray; D004563:Electrochemistry; D008024:Ligands; D009942:Organometallic Compounds / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D012211:Rhenium / Q000737:chemistry*; D013057:Spectrum Analysis; D013451:Sulfonic Acids / Q000737:chemistry*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D011720:Pyrazoles; D013451:Sulfonic Acids; D012211:Rhenium