Local structure of molten NaClO3 and KClO3 analyzed by pulsed neutron diffraction, Raman spectroscopy, and molecular orbital calculation

Abstract The short range structure of NaClO 3 and KClO 3 melts was investigated by time-of-flight neutron diffraction, Raman spectroscopy, and molecular orbital calculation. The structural parameters for each atomic pair were optimized in the Q -space, and the near neighbor Cl&O and OO distances in the discrete ClO 3 − ion were evaluated at 0.147 nm and 0.235 nm for NaClO 3 melt, respectively, the corresponding values for KClO 3 melt being 0.149 nm and 0.239 nm. The coordination number of O around Cl was almost equal to 3. Four peaks were observed in Raman spectra of these melts, being identified as the vibrational modes typical of a ClO 3 trigonal pyramid. The arrangements of Na + and K + ions relative to the ClO 3 − ion were discussed and the optimized structure of NaClO 3 and KClO 3 melts was determined.