W-band EPR studies of Mn-cluster in the S₀ and S₂ states of Cyanobacterial single crystals.

Abstract

EPR of the Mn multiline in the S₂-state of single crystals Synechococcus vulcanus has been observed at 6 K by W-band EPR spectrometer. The multiline composed of 21 lines, showing that four manganese contribute to the multiline. The hyperfine constant does not depend on crystal orientation but the positions of hyperfine lines are changing with orientation. No multiline EPR was observed in a frozen solution of the same sample. Similar spectra were observed in the S₀-state reduced by NH₂OH. These results are now under simulation assuming g-anisotropy.