Structural trends in alkaline earth and rare earth metal 3,5-diisopropylpyrazolates

Julia Hitzbleck, Glen B. Deacon, Karin Ruhlandt-Senge

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


A series of 3,5-diisopropylpyrazolates of magnesium, calcium, and strontium in addition to a divalent europium analog continues our investigation on the differences and similarities between the alkaline earth and divalent rare earth metal elements. The alkane elimination reaction between dibutylmagnesium and excess 3,5-diisopropylpyrazole (iPr2pzH) in toluene afforded the dinuclear magnesium pyrazolate [{Mg(iPr2pz)2(iPr 2pzH)}2] (1). [{Ca(iPr2pz)2(iPr 2pzH)2}2] (2) and [{Eu(iPr2pz) 2(iPr2pzH)2}2] (3) were obtained as the product of redox-transmetallation/ligand-exchange reactions between an excess of the corresponding metal, 2 equiv. of iPr2pzH, and Hg(C 6F5)2 in toluene. This reaction with Sr metal led to the isolation of a unique byproduct, [Hg3(iPr 2pz)4-(C6F5)2] (4). High-temperature direct metallation of barium with iPr2pzH afforded [{Ba(iPr 2pz)2(py)3)2] (5) upon treatment of the hydrocarbon-insoluble homoleptic [{Ba(iPr2pz)2}n] with pyridine (py). X-ray crystal structure analyses revealed dinuclear structures for compounds 1-3 and 5 with μ-ηnm bridging pyrazolato ligands, including the new μ-η15 linkage, and further stabilization of 1-3 by intramolecular hydrogen bonding between the terminal pyrazole donor and terminal 1 or bridging pyrazolato ligands in 2 and 3. The trinuclear 4 displays the first example of a complex with an open, triangular Hg3 unit. It has μ-η1: η1 bridging pyrazolato ligands and terminal pentafluorophenyl groups.

Original languageEnglish (US)
Pages (from-to)592-601
Number of pages10
JournalEuropean Journal of Inorganic Chemistry
Issue number4
StatePublished - 2007


  • Alkaline earth metals
  • Coordination modes
  • Lanthanoids
  • N ligands

ASJC Scopus subject areas

  • Inorganic Chemistry


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