Variable temperature EPR studies of Cu2+ and VO2+ doped potassium dihydrogen citrate (C6H7KO7)

Electron paramagnetic resonance (EPR) studies of single crystals and powder samples of Cu2+ and VO2+ doped potassium dihydrogen citrate (PDHC) have been carried out at different temperatures. The temperature-dependant g and A values have been obtained for powder spectra of both Cu2+ and VO2+ ions in PDHC and the ground state of Cu2+ ion has been determined. The powder spectra recorded for Cu2+ ion in the temperature range 70–298 K are discussed with Jahn–Teller distortion. It is concluded that the g and A values of Cu2+: PDHC show the static property at low temperatures. For all temperatures, the result g// < g⊥ < ge of VO2+: PDHC indicates that the unpaired electron exists in the dxy orbital.

Variation of EPR linewidth with temperature for Cu2+ in PDHC single crystal. The linewidths for mI = 3/2 hyperfine line of three complexes.Figure optionsDownload as PowerPoint slideHighlights
► Cu2+ and VO2+ in PDHC have been studied between 70 and 298 K by EPR technique.
► The Jahn–Teller distortion has been discussed for Cu2+: PDHC.
► At low temperatures, well-resolved spectra have been observed for two complexes.