Synthesis, structural, thermal, and magnetic investigations of Co(II), Ni(II), and Mn(II) pyrophosphate chains

Amanda E. Hoffman, Nadia Marino, Francesc Lloret, Miguel Julve, Robert P. Doyle

Research output: Contribution to journalArticle

8 Scopus citations


The reaction in water of cobalt(II), nickel(II) or manganese(II) chloride with 1,10-phenanthroline (phen) and sodium pyrophosphate (Na 4P 2O 7) at low pH (∼2) afforded three isostructural pyrophosphate complexes of an unprecedented one-dimensional typology, namely, {[M(phen)(H 2O)(H 2P 2O 7)] ·H 2O} n with M = Co(1), Ni(2) and Mn(3). The di-hydrogen-pyrophosphate anion featured in these complexes adopts a rare bidentate/monodentate bridging mode leading to chain propagation. This unusual bridging pathway produces a metal-metal intra-chain separation of about 6.6-6.7 Å for 1-3, values much larger than the metal-metal distance across the classic bis-bidentate PPi in the parent homodinuclear complexes {[Co(phen) 2] 2(μ-P 2O 7)}·6MeOH (1a), {[Ni(phen) 2] 2(H 2O)(μ-P 2O 7)}·27H 2O (2a) and {[Mn(phen) 2] 2(H 2O)(μ-P 2O 7)}·13H 2O (3a), corresponding to ca. 4.9, 5.0 and 4.7 Å, respectively. Variable-temperature magnetic susceptibility measurements on polycrystalline samples of 1-3 revealed weak intrachain antiferromagnetic couplings [J = -0.93 (1), -1.88 (2) and -0.26 cm -1 (3)], consistent with previous data on the dinuclear complexes 1a-3a.

Original languageEnglish (US)
Pages (from-to)151-158
Number of pages8
JournalInorganica Chimica Acta
StatePublished - Jul 1 2012



  • Chain compounds
  • Magnetic susceptibility
  • Pyrophosphate
  • X-ray crystal structures

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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