A Mn-4(II) cubane and a novel (Mn10Mn4III)-Mn-II cluster from the use of di-2-pyridyl ketone in manganese acetate chemistry

Constantinos C. Stoumpos, Ian A. Gass, Constantinos J. Milios, Nikolia Lalioti, Aris Terzis, Guillem Aromi, Simon J. Teat, Euan K. Brechin, Spyros P. Perlepes

Research output: Contribution to journalLiterature reviewpeer-review

Abstract

The employment of di-2-pyridyl ketone, (py)(2)CO, in manganese(II) acetate chemistry is reported. The syntheses, crystal structures and magnetochemical characterisation are described for [Mn-4(II)(O2CMe)(4){(py)(2)C(OH)O}(4)] (1) and [(Mn10Mn4O4)-Mn-II-O-III(O2CMe)(20){(py)(2)C(OH) O}(4)] (2), where (py)(2)C(OH)O- is the monoanion of the gem-diol form of the ligand. The reaction of Mn(O2CMe)(2)center dot 4H(2)O with one equivalent of (py)(2)CO in Me2CO gives 1. Complex 2 was obtained from the 1 : 1 reaction, in EtOH, between Mn(O2CMe)(2)center dot 4H(2)O and (py)(2)CO in the presence of NEt3. The tetranuclear molecule 1 has a cubane topology with the Mn-II and the deprotonated oxygen atoms from the eta(1):eta(3):eta(1):mu(3) ligands occupying alternate vertices of the cube. The core of 2 consists of two mixed valence cubane {(Mn2Mn2III)-Mn-II(mu(3)-O)(2)(mu(3)-OR '')(2)}(4+) subunits that are linked through an unusual {Mn-6(II)(eta(1):eta(2):mu-O2CMe)(6)(eta(2):eta(2):mu(3)-O2CMe)(2)}(4+) moiety via twelve eta(1):eta(1):mu MeCO2- groups. Some suggestions have been made concerning the possible assembly of 2 from 1. The magnetic properties of 1 in the 300-5 K range have been modelled with two J values, which reveal weak antiferromagnetic interactions within the molecule. Complex 2 has a low spin ground state. This work demonstrates the flexibility, versatility and synthetic potential of combining (py)(2)CO with carboxylate ligands.

Original languageEnglish
Pages (from-to)307-317
Number of pages11
JournalDalton Transactions
Issue number2
DOIs
Publication statusPublished - 2009

Keywords

  • SINGLE-MOLECULE MAGNETS
  • GEM-DIOL FORM
  • HIGH-SPIN MOLECULES
  • TRANSITION-METAL-COMPLEXES
  • NEUTRON-SCATTERING SPECTRA
  • DEFECTIVE DOUBLE-CUBANE
  • MU-O BRIDGES
  • CRYSTAL-STRUCTURES
  • TETRANUCLEAR MANGANESE(II)
  • CARBOXYLATE CHEMISTRY

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