title: Synthesis, structure, and catecholase activity of bispyrazolylacetate copper(II) complexes.
abstract: A series of six-coordination copper(ii) complexes containing bis(3,5-di-t-butylpyrazol-1-yl)acetate (bdtbpza) and N-heterocycles or chelating aliphatic ligands have been synthesized. The steric bulkiness of bis(pyrazol-1-yl)acetate anchors two bdtbpza to situate a trans position and to adopt an O-bound monodentate coordination mode with other nitrogen bases occupying the basal plane. Five mononuclear mixed ligand complexes, [Cu(bdtbpza)2(py)4] , [Cu(bdtbpza)2(t-Bupy)4] , [Cu(bdtbpza)2(pym)2(MeOH)2] , [Cu(bdtbpza)2(eda)2] , [Cu(bdtbpza)2(tmeda)(H2O)2] , where py = pyridine, t-Bupy = tert-butylpyridine, pym = pyrimidine, eda = ethylenediamine, and tmeda = tetramethylethylenediamine, were isolated and thoroughly characterized. Intriguingly, the heteroleptic complex , which has two aquo-ligands oriented in the cis positions, demonstrates higher catecholase-like activity in performing aerial oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ) than other bis(pyrazolyl)acetate-embedded copper complexes reported herein, which suggests the essential role of labile cis-aquo ligands to promote the catalytic reaction.
authors.affiliation: Institute of Chemistry, Academia Sinica, Nankang, Taipei 105, Taiwan. chhung@gate.sinica.edu.tw.
authors.forename: Małgorzata J
authors.initials: MJ
authors.lastname: Gajewska
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Ching
authors.forename: Yuh-Sheng
authors.initials: YS
authors.lastname: Wen
authors.forename: Chen-Hsiung
authors.initials: CH
authors.lastname: Hung
mesh_terms: D002384:Catalysis / Q000187:drug effects; D004156:Catechol Oxidase / Q000737:chemistry* / Q000494:pharmacology; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D003300:Copper / Q000737:chemistry*; D008958:Models, Molecular; D010084:Oxidation-Reduction / Q000187:drug effects; D011720:Pyrazoles / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D011720:Pyrazoles; D003300:Copper; D004156:Catechol Oxidase