Theoretical Studies Of The Defect Structures For Cu(En)(3)(2+) And Ru(En)(3)(3)(+) Clusters In Tris(Ethylenediamine) Complexes

The local structures and spin Hamiltonian parameters (SHPs, g factors, and hyperfine structure constants) for the Cu(en)(3)(2+) and Ru(en)(3)(3+) clusters in ethylenediamine complexes are theoretically studied from perturbation formulae for tetragonally and trigonally elongated octahedral 3d(9) and 4d(5) clusters, respectively. Cu2+ centres I and II may experience the slight relative elongations Delta Z by about 0.005 and 0.007 angstrom in Zn(en)(3)(NO3)(2) polycrystalline powder at 4.2 K and room temperature, respectively, along the C-4 axis arising from the Jahn-Teller effect. For Ru(en)(3)(3+) cluster in the uniaxial [Rh(en)(3)Cl-3](2)NaCl center dot 6H(2)O single crystal doped with the single-crystal chloride salt [Ru(en)(3)]Cl-3 center dot 4H(2)O, the local impurity-ligand bonding angle related to the C-3 axis suffers a negative variation Delta beta (approximate to-1.85 degrees) with respect to the host beta(H) in [Ru(en)(3)]Cl-3 center dot 4H(2)O at 4 K. The features of SHPs and defect structures for the Cu(en)(3)(2+) and Ru(en)(3)(3+) clusters are also discussed in view of the different experimental temperatures.