Can Bismuth Replace Mercury in Redox Transmetallation/Protolysis Syntheses from Free Lanthanoid Metals?

Zhifang Guo, Victoria Blair, Glen B. Deacon, Peter C. Junk

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8 Citations (Scopus)


Tris(pentafluorophenyl)bismuth has been examined as a potential replacement for diarylmercurials in redox transmetallation/protolysis (RTP) syntheses of reactive rare earth compounds from free rare earth metals, HgAr2, and a proligand HL. Thus, the lanthanoid pyrazolates, [Ln(Ph2pz)3(thf)3] (Ph2pz=3,5-diphenylpyrazolate; Ln=La, 1, Ce, 2, Nd, 3, Tb, 4; thf=tetrahydrofuran), [Ln2(Ph2pz)4(OMe)2(dme)2]⋅2 dme (Ln=Ho, 5, Er, 6, Tm, 7, Lu, 8; dme=1,2-dimethoxyethane), [Ln(Ph2pz)3(dme)2] (Ln=Dy, 9, Sm, 10), [Ln(tBu2pz)3(thf)2] (tBu2pz=3,5-di-tert-butylpyrazolate; Ln=La, 11, Ce, 12, Sm, 13, Gd, 14, Dy, 15, Ho, 16, Tm, 17, Yb, 18, Lu, 19), [Ln(ttfpz)3(thf)3] (ttfpz=3-(2′-thienyl)-5-(trifluoromethyl)pyrazolate; Ln=La, 20, Sm, 21), and [Er(PhMepz)3(thf)2] 22 (PhMepz=3-phenyl-5-methylpyrazolate) have been prepared in good yields by redox transmetallation/protolysis reactions employing lanthanoid metals and trispentafluorophenylbismuth [Bi(C6F5)3]⋅0.5 diox (diox=1, 4-dioxane) in donor solvents. This is a new and efficient synthetic route in which Bi(C6F5)3 replaces the commonly used Hg(C6F5)2 or HgPh2, and provides proof of concept for the method. [Ln2(Ph2pz)4(OMe)2(dme)2]⋅2 dme (5–8) complexes are derived from C−O bond activation of dme on crystallization of the initial products from this solvent, and are dimeric methoxide-bridged species. Other structures are monomeric with η2-bound pyrazolate ligands and nine-coordinate metal atoms for complexes 1–4, 9–10 and 20–21, and eight-coordinate metal atoms for complexes 11–19 and 22.

Original languageEnglish
Pages (from-to)17464-17474
Number of pages11
JournalChemistry - A European Journal
Issue number66
Publication statusPublished - 27 Nov 2018


  • crystal structures
  • lanthanoid metals
  • lanthanoid pyrazolates.
  • new synthetic method
  • redox transmetallation/protolysis (RTP) reactions
  • trispentafluorophenylbismuth (Bi(CF))

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