Synthesis, crystal structure and magnetic studies of tetranuclear hydroxo and ligand bridged [Co4(μ3-OH)2(μ2-dea)2(L-L)4]4Cl·8H2O [L-L = 2,2'-bipyridine or 1,10-phenanthroline] complexes with mixed valence defect dicubane core

Dalton Trans. 2013 Jul 14;42(26):9513-22. doi: 10.1039/c3dt50854d. Epub 2013 May 14.

Abstract

X-ray crystallography of the title complexes indicates a discrete mixed valence (Co2(II)-Co2(III)) defect dicubane molecular unit where each cobalt nucleus attains a distorted octahedral geometry. The α-diimine (L-L) chelator coordinated to each cobalt ion stops further polymerization or nuclearization. The water molecules in the lattice play a crucial role in the formation of the supramolecular architectures. Magnetic data were analyzed using the effective spin-1/2 Hamiltonian approach and the parameters are, J = 115(6) K, ΔJ = -57.0(1.2) K, g(xy) = 3.001(25), and g(z) = 7.214(7) for 1 and J = 115(12) K, ΔJ = -58.5(2.5) K, g(xy) = 3.34(5), and g(z) = 6.599(12) for 2 suggesting that only the g matrices are prone to the change of α-diimine chelator.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2,2'-Dipyridyl / chemistry*
  • Cobalt / chemistry*
  • Crystallography, X-Ray
  • Ligands
  • Magnetic Phenomena
  • Models, Molecular
  • Molecular Structure
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Phenanthrolines / chemistry*

Substances

  • Ligands
  • Organometallic Compounds
  • Phenanthrolines
  • Cobalt
  • 2,2'-Dipyridyl
  • 1,10-phenanthroline