Synthesis and characterisation of heterometallic [Cr7M] dimer rings

Abstract

Complexes of the general formulae {[Cr7MF3(Etglu)(O2CtBu)15]2(L)} and {[Cr7MF3(Me- glu)(O2CtBu)15]2(L)} [Etglu =N-ethyl-D-glucamine; N-methyl-D-glucamine; M = Zn and Mn; L is bridging ligand = dipyridyl (Py-Py); trans-1,2-dipyridylethene, (Py-CH=CH-Py) and py- razine (Pzn)] were synthesised and characterised using different techniques. Electron paramag- netic resonance (EPR) spectroscopy was the primary focusing technique that was used, and the results indicate that the distance between the spin centres partially determined the magnetic coupling between the rings. Additionally, the divalent metal Zn(II) or Mn(II) within the heter- ometallic ring has affected the EPR spectra of the dimers. The EPR spectra of Mn-based dimer compounds show more magnetic interaction between the two ring systems than the Zn-based dimers.