title: Divalent metal complexes (Ca, Sr, Ba, Yb) of the unsymmetrical 3-(2'-thienyl)-5-(trifluoromethyl)pyrazolate ligand.
abstract: The divalent complexes [M(ttfpz)(2)(thf)(4)] (ttfpz = 3-(2'-thienyl)-5-(trifluoromethyl)pyrazolate; M = Yb, 1, Ca, 2, Sr, 3, Ba, 4; thf = tetrahydrofuran) and [M(ttfpz)(2)(dme)(n)] (M = Ca, 5, Sr, 6, Yb, 7, n = 2; M = Ba, 8, n = 3; dme = 1,2-dimethoxyethane) have been prepared by redox transmetallation/protolysis reactions employing the free metals, Hg(C(6)F(5))(2) and ttfpzH in donor solvents and their structures determined. The monomeric structures exhibit η(2)-bound pyrazolate ligands with eight-coordinate metal atoms for complexes 1-7 and a ten-coordinate metal for 8. The pyrazolate ligands in the thf-complexes 1-4 as well as dme-derivatives 5 and 6 are in a transoid configuration, whilst in complex 7 the ttfpz ligands exhibit a cisoid relationship. In 8 the ligands have an intermediate role in between cisoid and transoid.
authors.affiliation: Monash University, Clayton, Victoria, Australia. glen.deacon@monash.edu
authors.forename: Glen B
authors.initials: GB
authors.lastname: Deacon
authors.forename: Peter C
authors.initials: PC
authors.lastname: Junk
authors.forename: Aron
authors.initials: A
authors.lastname: Urbatsch
mesh_terms: D018360:Crystallography, X-Ray; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D008024:Ligands; D008673:Metals, Alkaline Earth / Q000737:chemistry*; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D015018:Ytterbium / Q000737:chemistry*
chemical_list: C558273:3-(2'-thienyl)-5-(trifluoromethyl)pyrazolate; D006845:Hydrocarbons, Fluorinated; D008024:Ligands; D008673:Metals, Alkaline Earth; D009942:Organometallic Compounds; D011720:Pyrazoles; D015018:Ytterbium