Trinuclear Cu(II) complexes containing peripheral ketonic oxygen bridges and a μ3-OH core: Steric influence on their structures and existence

Biswarup Sarkar, Mau Sinha Ray, Michael G.B. Drew, Albert Figuerola, Carmen Diaz*, Ashutosh Ghosh

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

61 Scopus citations

Abstract

Two tridentate Schiff bases, HL1(6-amino-3-methyl-1-phenyl-4-azahex-2-en-1-one), and HL2 (6-amino-3,6-dimethyl-1-phenyl-4-azahex-2-en-1-one) on reaction with Cu(II) perchlorate in the presence of triethyl amine yielded two new trinuclear copper(II) complexes, [(CuL1)33-OH)](ClO4) 2 (1) and [(CuL2)33-OH)](ClO4) 2 · 0.75H2O (2), whereas another tridentate ligand HL3 (7-amino-3-methyl-1-phenyl-4-azahept-2-en-1-one) underwent hydrolysis under the same reaction conditions to result in the formation of a mononuclear complex, [Cu(bn)(pn)ClO4] (3) [where bn = 1-benzoylacetonate and pn = 1,3-propanediamine]. All three complexes have been characterized by X-ray crystallography. For both 1 and 2 the cationic part is trinuclear with a [Cu3OH] core held by three carbonyl oxygen bridges between each pair of copper(II) atoms. The structure of 3 is a monomer with a chelating 1,3-propanediamine and a benzoyl acetone moiety. Magnetic measurements of 1 and 2 have been performed in the 2-300 K temperature range. The experimental data could be satisfactorily reproduced by using an isotropic exchange model, H = -J(S1S2 + S2S3 + S1S3), yielding as best fit parameters: J = -25.6 cm-1, g = 2.21 for 1 and J = -11.2 cm-1, g = 2.10 for 2. The EPR spectra at low temperature could be indicative of spin frustration in complex 1.

Original languageEnglish (US)
Pages (from-to)3084-3094
Number of pages11
JournalPolyhedron
Volume25
Issue number16
DOIs
StatePublished - Nov 13 2006

Keywords

  • Copper trimers
  • Magnetic properties
  • Schiff base
  • X-ray structure

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Trinuclear Cu(II) complexes containing peripheral ketonic oxygen bridges and a μ<sub>3</sub>-OH core: Steric influence on their structures and existence'. Together they form a unique fingerprint.

Cite this