Reversible sulfur dioxide reactions with cyclopentadienylnickel(II) organochalcogenide complexes

James Darkwa, Richard M. Moutloali, Tebello Nyokong

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


A series of cyclopentadienylnickel(II) organochalcogenides containing different phosphines have been prepared by either reacting [CpNi(μ-SC6H4X-4)]2 (Cp#5-C5H5,(Cp), η5-C5H5Me, (Cp′); X=Cl, Br) with phosphines or Cp#Ni(PR3)Br with HSC6H4X-4 and Et3N or NaSeC6H4Cl-4. The complexes that were isolated have the general formula CpNi(PR3)(EC6H4X-4) {E=S, X=Cl, R=Ph (1a), Bu (2a), OPh (3a), OEt (4a), OMe (5a); X=Br, R=Bu (6a), Ph (7a)}. In addition to spectroscopic characterisation, the complexes CpNi(PBu3)(SC6H4Cl-4) (2a) and Cp'Ni(PPh3)(SeC6H4Cl-4) (9a) were subjected to single-crystal X-ray diffraction studies. While the solution and solid state structures of CpNi(PBu3)(SC6H4Cl-4) were found to be the same, that of Cp'Ni(PPh3)(SeC6H4Cl-4) were different. The orientation of the methyl group of 9a in the solid state is almost trans to the phosphine, but solution NMR data indicate that the methyl substituent on the cyclopentadienyl ligand is cis to the phosphorus. All the complexes, 1a-9a, were found to react reversibly with SO2 to form SO2 adducts and the reversibility could be monitored by visible and 1H-NMR spectroscopy. Electrochemical studies show that 2a and 6a have reversible couples whereas 1a and 7a are only quasi-reversible. The PBu3 complexes are easier to oxidise as compared with the PPh3 analogues.

Original languageEnglish
Pages (from-to)37-45
Number of pages9
JournalJournal of Organometallic Chemistry
Issue number1-2
Publication statusPublished - 14 Aug 1998
Externally publishedYes


  • Cyclopentadienylnickel(II)
  • Organochalcogenide
  • Reversible
  • Sulfur dioxide

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Materials Chemistry


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