title: Bis(acetylacetonato)bis(pyrazolato)ruthenate(iii) as a redox-active scorpionate ligand.
abstract: The potential of a new anionic octahedral metal complex [Ru(III)(acac)2(pz)2](-) ((-)) (pzH = pyrazole) as a ligand with a scorpionate coordination behaviour like tris(pyrazolyl)borate (tp) and reversible redox activity is presented. Trinuclear metal complexes, [Ru(III)2Zn(II)(acac)4(pz)4] () and [Ru(II)Ru(III)2(acac)4(pz)4] (), were each synthesized by the reaction of ZnCl2 or Ru3(CO)12 with [Ru(III)(acac)2(pz)(pzH)] (H) that is in situ deprotonated and acts as a precursor of (-). Single-crystal X-ray diffraction studies clarified that (-) acts as a scorpionate ligand; two (-) units in and one unit in function as bidentate ligands with two pyrazolates as pincers, while another (-) unit in functions as a tridentate ligand with one oxygen atom as a tail in addition to the two pyrazolate pincers. Moreover, and showed reversible multi-stage redox behaviours based on the Ru(II)/Ru(III) and Ru(III)/Ru(IV) couples of the (-) units in the cyclic voltammetry (CV) measurements. Based on the X-ray, IR, and CV measurements and the comparison with other Ru(ii) complexes with tp derivatives, the (-) unit was found to act as a redox-active scorpionate with electron withdrawing properties compared to the tp.
authors.affiliation: Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0329, Japan. yoshidaj@kitasato-u.ac.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Yoshida
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sugawara
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Yuge
authors.forename: Jun
authors.initials: J
authors.lastname: Okabayashi
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry*; D008024:Ligands; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D011720:Pyrazoles / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D008024:Ligands; D009942:Organometallic Compounds; D011720:Pyrazoles; D012428:Ruthenium