73012-36-9Relevant academic research and scientific papers
Mechanism of Spin Transfer to Near Neighbors in Copper(II) Complexes
Krishnamoorthy, G.,Prabhananda, B. S.
, p. 637 - 640 (2007/10/02)
Ligand exchange reactions have been used to prepare mixed ligand complexes of copper with acetylacetonate, thiopicolineanilide, and N-benzoyl-N',N'-diethylthiocarbamide as ligands.The ESR parameters associated with these complexes have been determined in chloroform solutions at 25 deg C.These parameters and the parameters obtained for other mixed ligand complexes in our earlier studies have been discussed on the basis of the hypothesis that covalent transfer of electrons with the stronger bonding ligand increases at the expense of the weaker bonding ligand in a mixed complex.We observed that (i) the averaging of g0 and the averaging of A - A, which indicated the averaging of unpaired d-electron density on the metal, were consistent with this hypothesis, (ii) the behavior of next neighbors (configuration interaction) in Cu(II) complexes was taken into consideration, (iii) near neighbor hyperfine splittings did not show the expected trend, (iv) metal hyperfine splittings showed deviations from the average value, suggesting that the 4s-mixing component of the unpaired electron density in mixed ligand complexes is not consistent with the hypothesis, and (v) corrections needed to make the near neighbor hyperfine splittings show the behavior required by the hypothesis were correlated with the change in the 4s-mixing component.These observations suggest the following: (a) the behavior of electrons with d character on the metal is consistent with the hypothesis, (b) the 4s component (on the metal) of the unpaired electron orbital also contributes to the spin transfer to near neighbors by covalent bonding to ligands, and (c) the deviation from the expected trend observed in near neighbor hyperfine splittings was due to change in the amount of 4s mixing when the mixed ligand complex is formed.
