Identification of doped paramagnetic vanadyl impurity in dipotassium diaquabis(malonato-κ2O,O′) zincate dihydrate single crystal using EPR and optical techniques

Abstract

Single crystal electron paramagnetic resonance (EPR) spectroscopic investigation of VO(II) doped dipotassium diaquabis(malonato-κ2O,O′) zincate dihydrate has been carried out at X-band frequencies at 300 K. Single crystal, rotated along the three orthogonal crystallographic axes, has yielded spin Hamiltonian parameters g and A as g xx =1.978, g yy =1.972, g zz =1.936 and A xx =7.12, A yy =6.73, A zz =18.24 mT, respectively. These spin Hamiltonian parameters reflect a slight deviation from axial symmetry to rhombic, which is explained by the interstitial occupation of vanadyl ions. The isofrequency plots and powder EPR spectrum have been simulated using the calculated spin Hamiltonian parameters. The percentage of metal–oxygen bond has been estimated to be 20%. The admixture coefficients and bonding parameters have also been calculated by combining the EPR data with optical data.